EP1429946A1 - Tandem master cylinder for electrohydraulic braking system - Google Patents

Tandem master cylinder for electrohydraulic braking system

Info

Publication number
EP1429946A1
EP1429946A1 EP02774918A EP02774918A EP1429946A1 EP 1429946 A1 EP1429946 A1 EP 1429946A1 EP 02774918 A EP02774918 A EP 02774918A EP 02774918 A EP02774918 A EP 02774918A EP 1429946 A1 EP1429946 A1 EP 1429946A1
Authority
EP
European Patent Office
Prior art keywords
pin
fixed
secondary piston
piston
master cylinder
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP02774918A
Other languages
German (de)
French (fr)
Inventor
Nathalie Beccafico
Jean-Pierre Delage
Stéphane MANFREDINI
Yannick Nen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of EP1429946A1 publication Critical patent/EP1429946A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
    • B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
    • B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
    • B60T8/38—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition including valve means of the relay or driver controlled type
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T11/00—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant
    • B60T11/10—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant transmitting by fluid means, e.g. hydraulic
    • B60T11/16—Master control, e.g. master cylinders
    • B60T11/232—Recuperation valves
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
    • B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
    • B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
    • B60T8/40—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition comprising an additional fluid circuit including fluid pressurising means for modifying the pressure of the braking fluid, e.g. including wheel driven pumps for detecting a speed condition, or pumps which are controlled by means independent of the braking system
    • B60T8/4072—Systems in which a driver input signal is used as a control signal for the additional fluid circuit which is normally used for braking

Definitions

  • the present invention relates to a method of adjusting a tandem master cylinder for an electro-hydraulic braking system, a pin intended for implementing this method and a tandem master cylinder for an electro-hydraulic braking system.
  • a tandem master cylinder for an electro-hydraulic braking system of the type comprising:
  • Complementary mobile and fixed stops cooperating with each other to define the rest position of the secondary piston, carried respectively by the secondary piston and the body.
  • the driver controls the braking of the vehicle by actuating a brake pedal connected to a primary piston delimiting the primary pressure chamber.
  • the action of the brake pedal is transmitted to a hydraulic braking circuit by various means.
  • a braking system comprising a master cylinder of the aforementioned type can operate in normal and emergency configurations.
  • the hydraulic braking circuit When the braking system is in normal operating configuration, the hydraulic braking circuit is isolated from the master cylinder. The action of the brake pedal is transmitted to the hydraulic braking circuit by means of electrical means. When the braking system is in emergency operation configuration, the hydraulic braking circuit is connected to the master cylinder. The action of the brake pedal is transmitted to the hydraulic brake circuit via the brake fluid contained in this master cylinder.
  • the fixed closure means comprise an annular support seat formed in the body and the mobile closure means comprise an O-ring, carried by the secondary piston, intended to cooperate with this support seat.
  • the action of the driver on the brake pedal causes the secondary piston to move in a short stroke allowing the movable and fixed shutter means to remain spaced apart from one another and therefore to the means hydraulic connection to remain open.
  • the simulation means make it possible to restore to the driver, actuating the brake pedal, a braking sensation such as that which he would feel in the emergency operating configuration in which the master cylinder is connected to the circuit. hydraulic braking.
  • the action of the driver on the brake pedal causes the displacement of the secondary piston in a long stroke at the end of which the movable and fixed shutter means cooperate with one another to close the means for hydraulic connection of the primary pressure chamber with means for simulating braking force.
  • the hydraulic connection means not yet being closed, a certain quantity of brake fluid is transferred from the primary pressure chamber to the simulation means.
  • the object of the invention is to limit the stroke of the secondary piston as much as possible when the driver actuates the brake pedal in emergency operation configuration, in order to limit the amount of brake fluid transferred from the primary pressure chamber to the means. braking force simulation.
  • the subject of the invention is a method for adjusting a tandem master cylinder for an electro-hydraulic braking system, of the type comprising:
  • - means for hydraulic connection of the primary pressure chamber to means for simulating braking force - mobile and fixed complementary means for closing the hydraulic connection means, carried respectively by the secondary piston and the body, the secondary piston being axially displaceable between a rest position, in which the movable and fixed shutter means are spaced from each other, and a position of cooperation of these movable and fixed shutter means, and - mobile and fixed complementary stops cooperating with one another to define the rest position of the secondary piston, carried respectively by the secondary piston and the body, characterized in that the relative axial position of the mobile and fixed closure means is adjusted when the secondary piston is in its rest position by adjusting the axial position of the fixed stop in the body.
  • the master cylinder being of the type comprising a fixed pin extending substantially transversely to the direction of movement of the secondary piston in an oblong housing formed in this piston, the fixed and movable stops being defined respectively by complementary contact zones of the pin fixed and oblong housing, the pin being housed in a cylindrical bore, formed in the body, with an axis substantially transverse to the direction of movement of the secondary piston called the reference axis, the axial position of the fixed stop in the body is adjusted by adjusting the distance, relative to the reference axis, from the pin contact area;
  • the distance, relative to the reference axis, of the pin contact area is adjusted by means of a set of at least two pins each having a general shape of revolution having a part of contact with the stop movable extended by at least one centering end in the fixing hole, the diameters of the contact parts being different from one pin to the other while the diameters of the centering ends are identical from one pin to the other; o the master cylinder is fitted with a pin from the batch, called the reference pin; o the stroke of the secondary piston is measured between its rest and cooperation positions of the mobile and fixed shutter means, called dead travel; o comparing the value of the measured dead travel with a desired predetermined value; o the reference pin is replaced by another pin minimizing the difference between the measured and desired dead travel values.
  • the diameter of the contact part of the reference pin is the smallest of the batch so as to ensure maximum dead travel.
  • the distance relative to the reference axis of the pin contact area is adjusted by rotation around this reference axis of a part of this pin which has a contact contour with the mobile stop which evolves around this reference axis as an eccentric or a cam; o the stroke of the secondary piston is measured between its rest and cooperation positions of the mobile and fixed shutter means, called dead travel; o comparing the value of the measured dead travel with a desired predetermined value; o the pin is moved around the reference axis to an angular position for canceling the difference between the measured and desired values of the dead travel, known as the adjusted position; before measuring the dead stroke of the secondary piston, the pin is placed in a predetermined angular position around the reference axis, called the pre-adjustment position, in which the dead stroke is maximum;
  • this pin After displacement of the pin in its adjusted position, this pin is immobilized in the fixing hole, in particular by embedding one end of this pin in the fixing hole;
  • the subject of the invention is also a pin characterized in that it is intended for the implementation of the method defined above or in that it belongs to a set of pins for the implementation of the method defined above above.
  • the invention also relates to a tandem master cylinder for an electro-hydraulic braking system, of the type comprising:
  • the pin is provided with means for embedding in the fixing hole
  • the fixed closure means comprise an annular support seat formed in the body and the mobile closure means comprise an O-ring, carried by the secondary piston, intended to cooperate with this support seat;
  • the oblong housing is in communication with a brake fluid supply chamber, known as the secondary supply chamber, the secondary piston being provided with a channel for bringing the supply and secondary pressure chambers into communication, which can be closed by a valve;
  • FIG. 2 is a view of a batch of pins, each shown in elevation, for the implementation of the master cylinder adjustment method shown in Figure 1;
  • FIG. 3 is a view similar to Figure 1 of a tandem master cylinder for braking system intended to be adjusted according to a method according to a second embodiment of the invention;
  • - Figure 4 is an elevational view of an alternative embodiment of the master cylinder pin illustrated in Figure 3;
  • Figure 5 is a sectional view along line 5-5 of Figure 4.
  • FIG. 1 shows a tandem master cylinder for an electro-hydraulic braking system designated by the general reference 10.
  • the tandem master cylinder 10 is of the valve type.
  • the master cylinder 10 comprises a body 12 delimiting two chambers for pressurizing brake fluid, usually called primary pressure chambers 14 and secondary pressure chambers 16.
  • the body 12 also delimits a chamber 18 for supplying the secondary pressure chamber 16.
  • This chamber 18, usually called secondary supply chamber, is connected to a brake fluid reservoir (not shown) by means classics 19.
  • the master cylinder 10 also includes two primary and secondary pistons.
  • the primary piston (not shown) is connected, in a manner known per se, to a brake pedal intended to be actuated by the driver.
  • the secondary piston 20 separates the primary 14 and secondary 16 pressure chambers.
  • the two pistons respectively carry conventional primary and secondary valves. Only the secondary valve 22 is shown in FIG. 1.
  • the master cylinder 10 also comprises conventional means 24 for hydraulic connection of the primary pressure chamber to conventional means 26 for simulating braking force.
  • the hydraulic connection means 24 can be closed off using an O-ring 28, carried by the secondary piston 20, intended to cooperate with an annular support seat 30 formed in the body 12.
  • the O-ring 28 and the seat of support 30 respectively form mobile and fixed complementary means for closing the connection means 24.
  • the secondary piston 20 is axially displaceable, parallel to the axis X shown in FIG. 1, between a rest position, in which the O-ring 28 and support seat 30 are spaced from one another, and a cooperation position of these O-rings 28 and support seat 30 in which the connection means 24 are closed.
  • the secondary piston 20 is intended to cooperate with a pin 32, integral with the body 12.
  • the latter is housed in a cylindrical bore 33, formed in the body 12, extending transversely on either side of the chamber. secondary supply 18.
  • the bore 33 has an axis substantially transverse to the direction of movement of the secondary piston 20, called the reference axis Y.
  • the pin 32 extends substantially transversely to the direction of movement of the secondary piston 20 in an oblong housing
  • the fixed pin 32 and the contour of the secondary piston 20 delimiting the oblong housing 34 comprise complementary contact zones forming complementary fixed and mobile stops cooperating with each other to define the rest position of the secondary piston 20.
  • the oblong housing 34 is in communication with the secondary supply chamber 18.
  • the latter can be placed in communication with the secondary pressure chamber 16 via a channel 36 which can be closed off by means of the secondary valve 22.
  • the secondary valve 22 is provided with a control tail 38, extending through the channel 36, intended to cooperate with the pin 32 so as to maintain the valve 22 in the open position, when the secondary piston 20 is in its position rest, as illustrated in Figure 1.
  • the secondary piston 20 is biased elastically to its rest position by a spring 40, said secondary spring.
  • each pin 32 R] 32 p comprises two centering ends 44.
  • the diameters D n , D p of the contact parts 42 are different from one pin to another whereas the diameters D of the centering ends 44 are identical pin to another.
  • the invention proposes to adjust the distance, relative to the reference axis Y, of the contact area of the pin 32.
  • the invention proposes using a set of pins such as that shown in FIG. 2.
  • the master cylinder is fitted with a pin 32 n from the batch, called the reference pin.
  • This pin 32 n is for example identical to the pin 32 shown in FIG. 1.
  • the diameter D n of the contact part of the reference pin 32 n is the smallest of the batch so as to ensure a dead stroke Max.
  • the dead stroke of the secondary piston 20 is measured between its rest and cooperation positions of the O-ring 28 with the support seat 30, for example in accordance with the following sequence. Initially the secondary piston 20 is placed in its rest position, as shown in FIG. 1, the primary piston not yet being mounted in the body 12 of the master cylinder.
  • the primary pressure chamber 14 is supplied with a pressurized gas, in particular air, and the secondary piston 20 is displaced, meeting the elastic return force of the spring 40, towards the cooperation position of the O-ring. 28 with the support seat 30.
  • a pressurized gas in particular air
  • connection means 24 being open, the pressurized air contained in the primary pressure chamber 14 flows into the force simulation means 26.
  • the pressure in the braking force simulation means 26 is measured using an appropriate sensor.
  • a displacement sensor makes it possible to measure the displacements of the secondary piston 20.
  • connection means 24 are closed by cooperation of the O-ring 28 with the support seat 30.
  • This closure is detected by the pressure sensor which detects a pressure variation in the means 26 of effort simulation.
  • the dead travel C is determined by the secondary piston displacement detector 20.
  • the value of this measured dead travel is compared with a desired predetermined value. If there is an offset between these two values, we replace the reference pin 32 n with a another pin 32 p having a contact part 42 of diameter D p greater than that of the contact part 42 of the reference pin, so as to minimize or even cancel the difference between the measured and desired values of the dead travel vs.
  • FIG. 3 shows a tandem master cylinder 10 for an electro-hydraulic braking system according to the invention.
  • elements similar to those of the previous figures are designated by identical references.
  • the contact zone of the fixed pin 32 (forming the fixed stop for defining the rest position) is delimited by an outline of the contact part 42 of this fixed pin 32 moving around the reference axis.
  • Y as an eccentric (pin 32 as shown in Figure 3) or a cam (variant of pin 32 shown in Figures 4 and 5).
  • One of the centering ends 44 of the pin 32 is provided with a mounting collar 46 in the fixing hole 33.
  • This collar 46 is provided for example with a peripheral mounting teeth as for the pin 32 shown in the figure 3.
  • the invention proposes to adjust the distance relative to the reference axis Y of the contact area of the pin 32 (forming the stop fixed definition of the rest position) by rotation about this reference axis Y of the part 42 of this pin 32 which has an evolving contour.
  • the dead travel C of the secondary piston 20 is measured between its rest and cooperation positions of the O-ring 28 with the support seat 30, for example as described above, by means of a gas. under pressure.
  • the pin 32 is placed in a predetermined angular position around the reference axis Y, called the preset position, in which the dead stroke C is maximum.
  • This pre-adjustment position is for example materialized by marks, such as the mark R formed on one end of the pin 32, as illustrated in FIG. 4.
  • the value of the measured dead travel is compared with a desired predetermined value. If there is an offset between these two values, the pin 32 is moved around the reference axis Y to an angular position for canceling the difference between the measured and desired values of the dead travel, called set position.
  • this pin 32 After displacement of the pin 32 in its adjusted position, this pin 32 is immobilized in the fixing hole 33, in particular by embedding the flange 46 of this pin in the hole 33.
  • the invention therefore makes it possible to adjust the relative axial position of the movable and fixed shutter means 28 when the secondary piston 20 is in its rest position by adjusting the axial position of the fixed stop (contact zone of the fixed pin 32 ) in the body 12.
  • this makes it possible to easily adjust the dead stroke of the secondary piston 20 and thus to limit the amount of brake fluid transferred from the primary pressure chamber 14 to the braking force simulation means 26 when the driver actuates the brake pedal and the braking system (comprising the master cylinder 10 according to the invention) is in emergency operation configuration.

Abstract

The invention concerns a master cylinder comprising a body (12) delimiting primary (14) and secondary (16) pressure chambers separated by a secondary piston (20), means (24) for hydraulic connection between the primary pressure chamber (14) and simulation means (26), mobile (28) and fixed (30) means for closing the hydraulic connection means (24),borne by the secondary piston (20) and the body (12). The piston (20) is axially mobile between a neutral position, wherein the mobile (28) and fixed (30) closure means are spaced apart from one another, and a position wherein said closure means (28, 30) co-operate. Mobile (34) and fixed (32) stop elements, borne by the secondary piston (20) and the body (12) mutually co-operate to define the neutral position of the secondary piston (20). The relative axial position of the mobile (28) and fixed (30) closure means is adjusted when the secondary piston (20) is in its neutral position by adjusting the axial position of the contact zone of the fixed pin (32) in the body (12).

Description

La présente invention concerne un procédé de réglage d'un maître cylindre tandem pour système de freinage électrohydraulique, une goupille destinée à la mise en œuvre de ce procédé et un maître cylindre tandem pour système de freinage électrohydraulique. On connaît déjà dans l'état de la technique un maître cylindre tandem pour système de freinage électrohydraulique, du type comprenant : The present invention relates to a method of adjusting a tandem master cylinder for an electro-hydraulic braking system, a pin intended for implementing this method and a tandem master cylinder for an electro-hydraulic braking system. There is already known in the prior art a tandem master cylinder for an electro-hydraulic braking system, of the type comprising:
- un corps délimitant des chambres de pression primaire et secondaire séparées par un piston déplaçable axialement, dit piston secondaire,a body delimiting primary and secondary pressure chambers separated by an axially displaceable piston, known as a secondary piston,
- des moyens de raccordement hydraulique de la chambre de pression primaire à des moyens de simulation d'effort de freinage,means of hydraulic connection of the primary pressure chamber to means of braking force simulation,
- des moyens complémentaires mobiles et fixes d'obturation des moyens de raccordement hydraulique, portés respectivement par le piston secondaire et le corps, le piston secondaire étant déplaçable axialement entre une position de repos, dans laquelle les moyens d'obturation mobiles et fixes sont espacés les uns des autres, et une position de coopération de ces moyens d'obturation mobiles et fixes, et- additional movable and fixed means for closing the hydraulic connection means, carried respectively by the secondary piston and the body, the secondary piston being axially movable between a rest position, in which the mobile and fixed closure means are spaced from each other, and a position of cooperation of these mobile and fixed sealing means, and
- des butées complémentaires mobile et fixe coopérant entre elles pour définir la position de repos du piston secondaire, portées respectivement par le piston secondaire et le corps. Habituellement, le conducteur commande le freinage du véhicule en actionnant une pédale de frein reliée à un piston primaire délimitant la chambre de pression primaire. L'action de la pédale de frein est transmise à un circuit hydraulique de freinage par divers moyens.- Complementary mobile and fixed stops cooperating with each other to define the rest position of the secondary piston, carried respectively by the secondary piston and the body. Usually, the driver controls the braking of the vehicle by actuating a brake pedal connected to a primary piston delimiting the primary pressure chamber. The action of the brake pedal is transmitted to a hydraulic braking circuit by various means.
Un système de freinage comportant un maître cylindre du type précité peut fonctionner dans des configurations normale et de secours.A braking system comprising a master cylinder of the aforementioned type can operate in normal and emergency configurations.
Lorsque le système de freinage est en configuration de fonctionnement normal, le circuit hydraulique de freinage est isolé du maître cylindre. L'action de la pédale de frein est transmise au circuit hydraulique de freinage par l'intermédiaire de moyens électriques. Lorsque le système de freinage est en configuration de fonctionnement de secours, le circuit hydraulique de freinage est raccordé au maître cylindre. L'action de la pédale de frein est transmise au circuit hydraulique de freinage par l'intermédiaire du liquide de frein contenu dans ce maître cylindre.When the braking system is in normal operating configuration, the hydraulic braking circuit is isolated from the master cylinder. The action of the brake pedal is transmitted to the hydraulic braking circuit by means of electrical means. When the braking system is in emergency operation configuration, the hydraulic braking circuit is connected to the master cylinder. The action of the brake pedal is transmitted to the hydraulic brake circuit via the brake fluid contained in this master cylinder.
Habituellement, les moyens fixes d'obturation comprennent un siège annulaire d'appui ménagé dans le corps et les moyens mobiles d'obturation comprennent un joint torique, porté par le piston secondaire, destiné à coopérer avec ce siège d'appui. En configuration de fonctionnement normal du système de freinage, l'action du conducteur sur la pédale de frein provoque un déplacement du piston secondaire suivant une course courte permettant aux moyens d'obturation mobiles et fixes de demeurer espacés les uns des autres et donc aux moyens de raccordement hydraulique de rester ouverts.Usually, the fixed closure means comprise an annular support seat formed in the body and the mobile closure means comprise an O-ring, carried by the secondary piston, intended to cooperate with this support seat. In the normal operating configuration of the braking system, the action of the driver on the brake pedal causes the secondary piston to move in a short stroke allowing the movable and fixed shutter means to remain spaced apart from one another and therefore to the means hydraulic connection to remain open.
Dans cette configuration de fonctionnement normal, les moyens de simulation permettent de restituer au conducteur, actionnant la pédale de frein, une sensation de freinage telle que celle qu'il ressentirait dans la configuration de fonctionnement de secours dans laquelle le maître cylindre est raccordé au circuit hydraulique de freinage. En configuration de fonctionnement de secours du système de freinage, l'action du conducteur sur la pédale de frein provoque le déplacement du piston secondaire suivant une course longue à la fin de laquelle les moyens d'obturation mobiles et fixes coopèrent entre eux pour fermer les moyens de raccordement hydraulique de la chambre de pression primaire avec les moyens de simulation d'effort de freinage. Pendant la course longue du piston, les moyens de raccordement hydraulique n'étant pas encore obturés, une certaine quantité de liquide de frein est transférée depuis la chambre de pression primaire vers les moyens de simulation. Or, plus la quantité de liquide de frein transférée vers les moyens de simulation est faible, plus la montée en pression de cette chambre de pression primaire est rapide et le freinage efficace. L'invention a pour but de limiter autant que possible la course du piston secondaire lorsque le conducteur actionne la pédale de frein en configuration de fonctionnement de secours, afin de limiter la quantité de liquide de frein transférée depuis la chambre de pression primaire vers les moyens de simulation d'effort de freinage.In this normal operating configuration, the simulation means make it possible to restore to the driver, actuating the brake pedal, a braking sensation such as that which he would feel in the emergency operating configuration in which the master cylinder is connected to the circuit. hydraulic braking. In the emergency operating configuration of the braking system, the action of the driver on the brake pedal causes the displacement of the secondary piston in a long stroke at the end of which the movable and fixed shutter means cooperate with one another to close the means for hydraulic connection of the primary pressure chamber with means for simulating braking force. During the long stroke of the piston, the hydraulic connection means not yet being closed, a certain quantity of brake fluid is transferred from the primary pressure chamber to the simulation means. However, the lower the amount of brake fluid transferred to the simulation means, the faster the pressure build-up of this primary pressure chamber and the effective braking. The object of the invention is to limit the stroke of the secondary piston as much as possible when the driver actuates the brake pedal in emergency operation configuration, in order to limit the amount of brake fluid transferred from the primary pressure chamber to the means. braking force simulation.
A cet effet, l'invention a pour objet un procédé de réglage d'un maître cylindre tandem pour système de freinage électrohydraulique, du type comprenant :To this end, the subject of the invention is a method for adjusting a tandem master cylinder for an electro-hydraulic braking system, of the type comprising:
- un corps délimitant des chambres de pression primaire et secondaire séparées par un piston déplaçable axialement, dit piston secondaire,a body delimiting primary and secondary pressure chambers separated by an axially displaceable piston, known as a secondary piston,
- des moyens de raccordement hydraulique de la chambre de pression primaire à des moyens de simulation d'effort de freinage, - des moyens complémentaires mobiles et fixes d'obturation des moyens de raccordement hydraulique, portés respectivement par le piston secondaire et le corps, le piston secondaire étant déplaçable axialement entre une position de repos, dans laquelle les moyens d'obturation mobiles et fixes sont espacés les uns des autres, et une position de coopération de ces moyens d'obturatipn mobiles et fixes, et - des butées complémentaires mobile et fixe coopérant entre elles pour définir la position de repos du piston secondaire, portées respectivement par le piston secondaire et le corps, caractérisé en ce que l'on règle la position axiale relative des moyens d'obturation mobiles et fixes lorsque le piston secondaire est dans sa position de repos en réglant la position axiale de la butée fixe dans le corps.- means for hydraulic connection of the primary pressure chamber to means for simulating braking force, - mobile and fixed complementary means for closing the hydraulic connection means, carried respectively by the secondary piston and the body, the secondary piston being axially displaceable between a rest position, in which the movable and fixed shutter means are spaced from each other, and a position of cooperation of these movable and fixed shutter means, and - mobile and fixed complementary stops cooperating with one another to define the rest position of the secondary piston, carried respectively by the secondary piston and the body, characterized in that the relative axial position of the mobile and fixed closure means is adjusted when the secondary piston is in its rest position by adjusting the axial position of the fixed stop in the body.
Suivant des caractéristiques de différents modes de réalisation de ce procédé :According to the characteristics of different embodiments of this process:
- le maître cylindre étant du type comprenant une goupille fixe s'étendant sensiblement transversalement à la direction de déplacement du piston secondaire dans un logement oblong ménagé dans ce piston, les butées fixe et mobile étant délimitées respectivement par des zones de contact complémentaires de la goupille fixe et du logement oblong, la goupille étant logée dans un perçage cylindrique, ménagé dans le corps, d'axe sensiblement transversal à la direction de déplacement du piston secondaire appelé axe de référence, on règle la position axiale de la butée fixe dans le corps en réglant la distance, par rapport à l'axe de référence, de la zone de contact de la goupille ;the master cylinder being of the type comprising a fixed pin extending substantially transversely to the direction of movement of the secondary piston in an oblong housing formed in this piston, the fixed and movable stops being defined respectively by complementary contact zones of the pin fixed and oblong housing, the pin being housed in a cylindrical bore, formed in the body, with an axis substantially transverse to the direction of movement of the secondary piston called the reference axis, the axial position of the fixed stop in the body is adjusted by adjusting the distance, relative to the reference axis, from the pin contact area;
- on règle la distance, par rapport à l'axe de référence, de la zone de contact de la goupille au moyen d'un lot d'au moins deux goupilles ayant chacune une forme générale de révolution présentant une partie de contact avec la butée mobile prolongée par au moins une extrémité de centrage dans le perçage de fixation, les diamètres des parties de contact étant différents d'une goupille à l'autre alors que les diamètres des extrémités de centrage sont identiques d'une goupille à l'autre ; o on équipe le maître cylindre d'une goupille du lot, dite goupille de référence ; o on mesure la course du piston secondaire entre ses positions de repos et de coopération des moyens d'obturation mobiles et fixes, dite course morte ; o on compare la valeur de la course morte mesurée avec une valeur prédéterminée souhaitée ; o on remplace la goupille de référence par une autre goupille minimisant l'écart entre les valeurs mesurée et souhaitée de la course morte. - le diamètre de la partie de contact de la goupille de référence est le plus faible du lot de façon à assurer une course morte maximale. - on règle la distance par rapport à l'axe de référence de la zone de contact de la goupille par rotation autour de cet axe de référence d'une partie de cette goupille qui présente un contour de contact avec la butée mobil qui évolue autour de cet axe de référence comme un excentrique ou une came ; o on mesure la course du piston secondaire entre ses positions de repos et de coopération des moyens d'obturation mobiles et fixes, dite course morte ; o on compare la valeur de la course morte mesurée avec une valeur prédéterminée souhaitée ; o on déplace la goupille autour de l'axe de référence jusqu'à une position angulaire d'annulation de l'écart entre les valeurs mesurée et souhaitée de la course morte, dite position réglée ; avant de mesurer la course morte du piston secondaire, on place la goupille dans une position angulaire prédéterminée autour de l'axe de référence, dite position de pré-réglage, dans laquelle la course morte est maximale ;- the distance, relative to the reference axis, of the pin contact area is adjusted by means of a set of at least two pins each having a general shape of revolution having a part of contact with the stop movable extended by at least one centering end in the fixing hole, the diameters of the contact parts being different from one pin to the other while the diameters of the centering ends are identical from one pin to the other; o the master cylinder is fitted with a pin from the batch, called the reference pin; o the stroke of the secondary piston is measured between its rest and cooperation positions of the mobile and fixed shutter means, called dead travel; o comparing the value of the measured dead travel with a desired predetermined value; o the reference pin is replaced by another pin minimizing the difference between the measured and desired dead travel values. - the diameter of the contact part of the reference pin is the smallest of the batch so as to ensure maximum dead travel. - the distance relative to the reference axis of the pin contact area is adjusted by rotation around this reference axis of a part of this pin which has a contact contour with the mobile stop which evolves around this reference axis as an eccentric or a cam; o the stroke of the secondary piston is measured between its rest and cooperation positions of the mobile and fixed shutter means, called dead travel; o comparing the value of the measured dead travel with a desired predetermined value; o the pin is moved around the reference axis to an angular position for canceling the difference between the measured and desired values of the dead travel, known as the adjusted position; before measuring the dead stroke of the secondary piston, the pin is placed in a predetermined angular position around the reference axis, called the pre-adjustment position, in which the dead stroke is maximum;
- après déplacement de la goupille dans sa position réglée, on immobilise cette goupille dans le perçage de fixation, notamment par encastrement d'une extrémité de cette goupille dans le perçage de fixation ;- After displacement of the pin in its adjusted position, this pin is immobilized in the fixing hole, in particular by embedding one end of this pin in the fixing hole;
- pour mesurer la course morte du piston : o on place le piston secondaire dans sa position de repos ; o on alimente la chambre de pression primaire avec un gaz sous pression, notamment de l'air, o on déplace le piston secondaire vers la position de coopération des moyens d'obturation mobiles et fixes ; o on détecte l'obturation des moyens de raccordement par détection d'une variation de pression dans les moyen de simulation d'effort de freinage. L'invention a également pour objet une goupille caractérisée en ce qu'elle est destinée à la mise en œuvre du procédé défini ci-dessus ou en ce qu'elle appartient à un lot de goupilles pour la mise en œuvre du procédé défini ci-dessus.- to measure the dead stroke of the piston: o the secondary piston is placed in its rest position; o the primary pressure chamber is supplied with a pressurized gas, in particular air, o the secondary piston is moved to the position of cooperation of the movable and fixed closure means; o the closure of the connection means is detected by detection of a pressure variation in the braking force simulation means. The subject of the invention is also a pin characterized in that it is intended for the implementation of the method defined above or in that it belongs to a set of pins for the implementation of the method defined above above.
L'invention a encore pour objet un maître cylindre tandem pour système de freinage électrohydraulique, du type comprenant :The invention also relates to a tandem master cylinder for an electro-hydraulic braking system, of the type comprising:
- un corps délimitant des chambres de pression primaire et secondaire séparées par un piston déplaçable axialement, dit piston secondaire, - des moyens de raccordement hydraulique de la chambre de pression primaire à des moyens de simulation d'effort de freinage,a body delimiting primary and secondary pressure chambers separated by an axially displaceable piston, known as a secondary piston, means of hydraulic connection of the primary pressure chamber to means of braking force simulation,
- des moyens complémentaires mobiles et fixes d'obturation des moyens de raccordement hydraulique, portés respectivement par le piston secondaire et le corps, le piston secondaire étant déplaçable axialement entre une position de repos, dans laquelle les moyens d'obturation mobiles et fixes sont espacés les uns des autres, et une position de coopération de ces moyens d'obturation mobiles et fixes, et- additional movable and fixed means for closing the hydraulic connection means, carried respectively by the secondary piston and the body, the secondary piston being axially movable between a rest position, in which the mobile and fixed closure means are spaced from each other, and a position of cooperation of these mobile and fixed sealing means, and
- une goupille o fixée dans un perçage cylindrique, ménagé dans le corps, d'axe sensiblement transversal à la direction de déplacement du piston secondaire appelé axe de référence, et o s'étendant dans un logement oblong ménagé dans le piston secondaire, la goupille fixe et le logement oblong comportant des zones de contact complémentaires délimitant des butées complémentaires fixe et mobile coopérant entre elles pour définir la position de repos du piston secondaire, caractérisé en ce que la zone de contact de la goupille fixe est délimitée par un contour de cette goupille fixe évoluant autour de l'axe de référence comme un excentrique ou une came. Suivant d'autres caractéristiques de ce maître cylindre :- a pin o fixed in a cylindrical bore, formed in the body, with an axis substantially transverse to the direction of movement of the secondary piston called the reference axis, and o extending in an oblong housing formed in the secondary piston, the pin fixed and the oblong housing comprising complementary contact zones delimiting complementary fixed and mobile stops cooperating with one another to define the rest position of the secondary piston, characterized in that the contact zone of the fixed pin is delimited by a contour of this fixed pin moving around the reference axis like an eccentric or a cam. According to other characteristics of this master cylinder:
- la goupille est munie de moyens d'encastrement dans le perçage de fixation ;- The pin is provided with means for embedding in the fixing hole;
- les moyens fixes d'obturation comprennent un siège annulaire d'appui ménagé dans le corps et les moyens mobiles d'obturation comprennent un joint torique, porté par le piston secondaire, destiné à coopérer avec ce siège d'appui ;- The fixed closure means comprise an annular support seat formed in the body and the mobile closure means comprise an O-ring, carried by the secondary piston, intended to cooperate with this support seat;
- le logement oblong est en communication avec une chambre d'alimentation de liquide de frein, dite chambre d'alimentation secondaire, le piston secondaire étant muni d'un canal de mise en communication des chambres d'alimentation et de pression secondaires obturable par un clapet ;the oblong housing is in communication with a brake fluid supply chamber, known as the secondary supply chamber, the secondary piston being provided with a channel for bringing the supply and secondary pressure chambers into communication, which can be closed by a valve;
- le clapet est muni d'une queue de commande, s'étendant à travers le canal du piston secondaire, destinée à coopérer avec la goupille de façon à maintenir le clapet en position ouverte. L'invention sera mieux comprise à la lecture de la description qui va suivre, donnée uniquement à titre d'exemple et faite en se référant aux dessins dans lesquels : - la figure 1 est une vue partielle, en coupe axiale, d'un maître cylindre tandem pour système de freinage destiné à être réglé selon un procédé suivant un premier mode de réalisation de l'invention ;- The valve is provided with a control tail, extending through the channel of the secondary piston, intended to cooperate with the pin so as to maintain the valve in the open position. The invention will be better understood on reading the description which follows, given solely by way of example and made with reference to the drawings in which: - Figure 1 is a partial view, in axial section, of a tandem master cylinder for braking system intended to be adjusted according to a method according to a first embodiment of the invention;
- la figure 2 est une vue d'un lot de goupilles, représentée chacune en élévation, pour la mise en œuvre du procédé de réglage du maître cylindre représenté sur la figure 1 ;- Figure 2 is a view of a batch of pins, each shown in elevation, for the implementation of the master cylinder adjustment method shown in Figure 1;
- la figure 3 est une vue similaire à la figure 1 d'un maître cylindre tandem pour système de freinage destiné à être réglé selon un procédé suivant un second mode de réalisation de l'invention ; - la figure 4 est une vue en élévation d'une variante de réalisation de la goupille du maître cylindre illustré sur la figure 3 ;- Figure 3 is a view similar to Figure 1 of a tandem master cylinder for braking system intended to be adjusted according to a method according to a second embodiment of the invention; - Figure 4 is an elevational view of an alternative embodiment of the master cylinder pin illustrated in Figure 3;
- la figure 5 est une vue en coupe suivant la ligne 5-5 de la figure 4.- Figure 5 is a sectional view along line 5-5 of Figure 4.
On a représenté sur la figure 1 un maître cylindre tandem pour système de freinage électrohydraulique désigné par la référence générale 10. Dans l'exemple décrit, le maître cylindre tandem 10 est du type à clapets.FIG. 1 shows a tandem master cylinder for an electro-hydraulic braking system designated by the general reference 10. In the example described, the tandem master cylinder 10 is of the valve type.
Le maître cylindre 10 comprend un corps 12 délimitant deux chambres de mise sous pression de liquide de frein, appelées habituellement chambres de pression primaire 14 et secondaire 16.The master cylinder 10 comprises a body 12 delimiting two chambers for pressurizing brake fluid, usually called primary pressure chambers 14 and secondary pressure chambers 16.
Le corps 12 délimite également une chambre 18 d'alimentation de la chambre de pression secondaire 16. Cette chambre 18, appelée habituellement chambre d'alimentation secondaire, est raccordée à un réservoir de liquide de frein (non représenté) à l'aide de moyens classiques 19.The body 12 also delimits a chamber 18 for supplying the secondary pressure chamber 16. This chamber 18, usually called secondary supply chamber, is connected to a brake fluid reservoir (not shown) by means classics 19.
Le maître cylindre 10 comprend également deux pistons primaire et secondaire. Le piston primaire (non représenté) est relié, de façon connue en soi, à une pédale de frein destinée à être actionnée par le conducteur. Le piston secondaire 20 sépare les chambres de pression primaire 14 et secondaire 16.The master cylinder 10 also includes two primary and secondary pistons. The primary piston (not shown) is connected, in a manner known per se, to a brake pedal intended to be actuated by the driver. The secondary piston 20 separates the primary 14 and secondary 16 pressure chambers.
Les deux pistons portent respectivement des clapets primaire et secondaire classiques. Seul, le clapet secondaire 22 est représenté sur la figure 1.The two pistons respectively carry conventional primary and secondary valves. Only the secondary valve 22 is shown in FIG. 1.
Le maître cylindre 10 comprend encore des moyens classiques 24 de raccordement hydraulique de la chambre de pression primaire à des moyens classiques 26 de simulation d'effort de freinage.The master cylinder 10 also comprises conventional means 24 for hydraulic connection of the primary pressure chamber to conventional means 26 for simulating braking force.
Les moyens de raccordement hydraulique 24 sont obturables à l'aide d'un joint torique 28, porté par le piston secondaire 20, destiné à coopérer avec un siège annulaire d'appui 30 ménagé dans le corps 12. Le joint torique 28 et le siège d'appui 30 forment respectivement des moyens complémentaires mobiles et fixes d'obturation des moyens de raccordement 24. Le piston secondaire 20 est déplaçable axialement, parallèlement à l'axe X représenté sur la figure 1 , entre une position de repos, dans laquelle les joint torique 28 et siège d'appui 30 sont espacés l'un de l'autre, et une position de coopération de ces joints torique 28 et siège d'appui 30 dans laquelle les moyens de raccordement 24 sont obturés. Le piston secondaire 20 est destiné à coopérer avec une goupille 32, solidaire du corps 12. Celle-ci est logée dans un perçage cylindrique 33, ménagé dans le corps 12, s'étendant transversalement de part et d'autre de la chambre d'alimentation secondaire 18. Le perçage 33 a un axe sensiblement transversal à la direction de déplacement du piston secondaire 20, appelé axe de référence Y. La goupille 32 s'étend sensiblement transversalement à la direction de déplacement du piston secondaire 20 dans un logement oblong 34 ménagé dans ce piston 20.The hydraulic connection means 24 can be closed off using an O-ring 28, carried by the secondary piston 20, intended to cooperate with an annular support seat 30 formed in the body 12. The O-ring 28 and the seat of support 30 respectively form mobile and fixed complementary means for closing the connection means 24. The secondary piston 20 is axially displaceable, parallel to the axis X shown in FIG. 1, between a rest position, in which the O-ring 28 and support seat 30 are spaced from one another, and a cooperation position of these O-rings 28 and support seat 30 in which the connection means 24 are closed. The secondary piston 20 is intended to cooperate with a pin 32, integral with the body 12. The latter is housed in a cylindrical bore 33, formed in the body 12, extending transversely on either side of the chamber. secondary supply 18. The bore 33 has an axis substantially transverse to the direction of movement of the secondary piston 20, called the reference axis Y. The pin 32 extends substantially transversely to the direction of movement of the secondary piston 20 in an oblong housing 34 formed in this piston 20.
La goupille fixe 32 et le contour du piston secondaire 20 délimitant le logement oblong 34 comportent des zones de contact complémentaires formant des butées complémentaires fixe et mobile coopérant entre elles pour définir la position de repos du piston secondaire 20.The fixed pin 32 and the contour of the secondary piston 20 delimiting the oblong housing 34 comprise complementary contact zones forming complementary fixed and mobile stops cooperating with each other to define the rest position of the secondary piston 20.
Le logement oblong 34 est en communication avec la chambre d'alimentation secondaire 18. Cette dernière est susceptible d'être mise en communication avec la chambre de pression secondaire 16 par l'intermédiaire d'un canal 36 obturable au moyen du clapet secondaire 22.The oblong housing 34 is in communication with the secondary supply chamber 18. The latter can be placed in communication with the secondary pressure chamber 16 via a channel 36 which can be closed off by means of the secondary valve 22.
Le clapet secondaire 22 est muni d'une queue de commande 38, s'étendant à travers le canal 36, destinée à coopérer avec la goupille 32 de façon à maintenir le clapet 22 en position ouverte, lorsque le piston secondaire 20 est dans sa position de repos, comme cela est illustré sur la figure 1. De façon classique, le piston secondaire 20 est rappelé élastiquement vers sa position de repos par un ressort 40, dit ressort secondaire.The secondary valve 22 is provided with a control tail 38, extending through the channel 36, intended to cooperate with the pin 32 so as to maintain the valve 22 in the open position, when the secondary piston 20 is in its position rest, as illustrated in Figure 1. Conventionally, the secondary piston 20 is biased elastically to its rest position by a spring 40, said secondary spring.
Sur la figure 2 on a représenté un lot L comprenant au moins deux goupillesIn Figure 2 there is shown a lot L comprising at least two pins
32n, 32p ayant chacune une forme générale de révolution présentant une partie 42 de contact avec la zone de contact du trou oblong 34 prolongée par au moins une extrémité 44 de centrage dans le perçage de fixation 33. Dans l'exemple illustré, chaque goupille 32R] 32p comprend deux extrémités de centrage 44. Les diamètres Dn, Dp des parties de contact 42 sont différents d'une goupille à l'autre alors que les diamètres D des extrémités de centrage 44 sont identiques d'une goupille à l'autre.32 n , 32 p each having a general shape of revolution having a part 42 of contact with the contact zone of the oblong hole 34 extended by at least one centering end 44 in the fixing bore 33. In the example illustrated, each pin 32 R] 32 p comprises two centering ends 44. The diameters D n , D p of the contact parts 42 are different from one pin to another whereas the diameters D of the centering ends 44 are identical pin to another.
Pour régler la course du piston secondaire 20 entre sa position de repos, telle que représentée sur la figure 1 , et la position d'obturation des moyens de raccordement 24 (coopération du joint torique 28 avec le siège d'appui 30), appelée course morte C, l'invention propose de régler la distance, par rapport à l'axe de référence Y, de la zone de contact de la goupille 32.To adjust the stroke of the secondary piston 20 between its rest position, as shown in Figure 1, and the closed position of the connection means 24 (cooperation of the O-ring 28 with the support seat 30), called dead travel C, the invention proposes to adjust the distance, relative to the reference axis Y, of the contact area of the pin 32.
À cet effet, selon un premier mode de réalisation du procédé de réglage du maître cylindre, l'invention propose d'utiliser un lot de goupilles tel que celui représenté sur la figure 2.To this end, according to a first embodiment of the method for adjusting the master cylinder, the invention proposes using a set of pins such as that shown in FIG. 2.
Tout d'abord, on équipe le maître cylindre d'une goupille 32n du lot, dite goupille de référence. Cette goupille 32n est par exemple identique à la goupille 32 représentée sur la figure 1. De préférence, le diamètre Dn de la partie de contact de la goupille de référence 32n est le plus faible du lot de façon à assurer une course morte maximale.First of all, the master cylinder is fitted with a pin 32 n from the batch, called the reference pin. This pin 32 n is for example identical to the pin 32 shown in FIG. 1. Preferably, the diameter D n of the contact part of the reference pin 32 n is the smallest of the batch so as to ensure a dead stroke Max.
Puis, on mesure la course morte du piston secondaire 20 entre ses positions de repos et de coopération du joint torique 28 avec le siège d'appui 30, par exemple conformément à la séquence suivante. Initialement le piston secondaire 20 est placé dans sa position de repos, telle que représentée sur la figure 1 , le piston primaire n'étant pas encore monté dans le corps 12 du maître cylindre.Then, the dead stroke of the secondary piston 20 is measured between its rest and cooperation positions of the O-ring 28 with the support seat 30, for example in accordance with the following sequence. Initially the secondary piston 20 is placed in its rest position, as shown in FIG. 1, the primary piston not yet being mounted in the body 12 of the master cylinder.
Ensuite, on alimente la chambre de pression primaire 14 avec un gaz sous pression, notamment de l'air, et on déplace le piston secondaire 20, à rencontre de la force élastique de rappel du ressort 40, vers la position de coopération du joint torique 28 avec le siège d'appui 30.Then, the primary pressure chamber 14 is supplied with a pressurized gas, in particular air, and the secondary piston 20 is displaced, meeting the elastic return force of the spring 40, towards the cooperation position of the O-ring. 28 with the support seat 30.
Les moyens de raccordement 24 étant ouverts, l'air sous pression contenu dans la chambre de pression primaire 14 s'écoule dans les moyens 26 de simulation d'effort. La pression dans les moyens 26 de simulation d'effort de freinage est mesurée à l'aide d'un capteur approprié. Un capteur de déplacement permet de mesurer les déplacements du piston secondaire 20.The connection means 24 being open, the pressurized air contained in the primary pressure chamber 14 flows into the force simulation means 26. The pressure in the braking force simulation means 26 is measured using an appropriate sensor. A displacement sensor makes it possible to measure the displacements of the secondary piston 20.
Le déplacement du piston secondaire 20 est poursuivi jusqu'à obturer les moyens de raccordement 24 par coopération du joint torique 28 avec le siège d'appui 30. Cette obturation est décelée par le capteur de pression qui détecte une variation de pression dans les moyens 26 de simulation d'effort.The displacement of the secondary piston 20 is continued until the connection means 24 are closed by cooperation of the O-ring 28 with the support seat 30. This closure is detected by the pressure sensor which detects a pressure variation in the means 26 of effort simulation.
La course morte C est déterminée grâce au détecteur de déplacement du piston secondaire 20.The dead travel C is determined by the secondary piston displacement detector 20.
Après la mesure de la course morte C du piston secondaire 20, on compare la valeur de cette course morte mesurée avec une valeur prédéterminée souhaitée. S'il y a un décalage entre ces deux valeurs, on remplace la goupille de référence 32n par une autre goupille 32p ayant une partie de contact 42 de diamètre Dp supérieur à celui de la partie de contact 42 de la goupille de référence, de façon à minimiser, voire annuler, l'écart entre les valeurs mesurée et souhaitée de la course morte C.After measuring the dead travel C of the secondary piston 20, the value of this measured dead travel is compared with a desired predetermined value. If there is an offset between these two values, we replace the reference pin 32 n with a another pin 32 p having a contact part 42 of diameter D p greater than that of the contact part 42 of the reference pin, so as to minimize or even cancel the difference between the measured and desired values of the dead travel vs.
On a représenté sur la figure 3 un maître cylindre tandem 10 pour système de freinage électrohydraulique selon l'invention. Sur cette figure 3, les éléments analogues à ceux des figures précédentes sont désignés par des références identiques.FIG. 3 shows a tandem master cylinder 10 for an electro-hydraulic braking system according to the invention. In this figure 3, elements similar to those of the previous figures are designated by identical references.
Dans ce cas, la zone de contact de la goupille fixe 32 (formant la butée fixe de définition de la position de repos) est délimitée par un contour de la partie de contact 42 de cette goupille fixe 32 évoluant autour de l'axe de référence Y comme un excentrique (goupille 32 telle que représentée sur la figure 3) ou une came (variante de la goupille 32 représentée sur les figures 4 et 5).In this case, the contact zone of the fixed pin 32 (forming the fixed stop for defining the rest position) is delimited by an outline of the contact part 42 of this fixed pin 32 moving around the reference axis. Y as an eccentric (pin 32 as shown in Figure 3) or a cam (variant of pin 32 shown in Figures 4 and 5).
Une des extrémités de centrage 44 de la goupille 32 est munie d'une collerette d'encastrement 46 dans le perçage de fixation 33. Cette collerette 46 est munie par exemple d'une denture périphérique d'encastrement comme pour la goupille 32 représentée sur la figure 3.One of the centering ends 44 of the pin 32 is provided with a mounting collar 46 in the fixing hole 33. This collar 46 is provided for example with a peripheral mounting teeth as for the pin 32 shown in the figure 3.
Selon un second mode de réalisation du procédé de réglage adapté au maître cylindre représenté sur la figure 3, l'invention propose de régler la distance par rapport à l'axe de référence Y de la zone de contact de la goupille 32 (formant la butée fixe de définition de la position de repos) par rotation autour de cet axe de référence Y de la partie 42 de cette goupille 32 qui présente un contour évolutif.According to a second embodiment of the adjustment method adapted to the master cylinder shown in FIG. 3, the invention proposes to adjust the distance relative to the reference axis Y of the contact area of the pin 32 (forming the stop fixed definition of the rest position) by rotation about this reference axis Y of the part 42 of this pin 32 which has an evolving contour.
Ainsi, tout d'abord, on mesure la course morte C du piston secondaire 20 entre ses positions de repos et de coopération du joint torique 28 avec le siège d'appui 30, par exemple comme décrit plus haut, au moyen d'un gaz sous pression.Thus, first of all, the dead travel C of the secondary piston 20 is measured between its rest and cooperation positions of the O-ring 28 with the support seat 30, for example as described above, by means of a gas. under pressure.
De préférence, avant de mesurer la course morte du piston secondaire 20, on place la goupille 32 dans une position angulaire prédéterminée autour de l'axe de référence Y, dite position de pré-réglage, dans laquelle la course morte C est maximale.Preferably, before measuring the dead stroke of the secondary piston 20, the pin 32 is placed in a predetermined angular position around the reference axis Y, called the preset position, in which the dead stroke C is maximum.
Cette position de pré-réglage est par exemple matérialisée par des repères, tels que le repère R ménagé sur une extrémité de la goupille 32, comme illustré sur la figure 4.This pre-adjustment position is for example materialized by marks, such as the mark R formed on one end of the pin 32, as illustrated in FIG. 4.
Ensuite, on compare la valeur de la course morte mesurée avec une valeur prédéterminée souhaitée. S'il y a un décalage entre ces deux valeurs, on déplace la goupille 32 autour de l'axe de référence Y jusqu'à une position angulaire d'annulation de l'écart entre les valeurs mesurée et souhaitée de la course morte, dite position réglée.Then, the value of the measured dead travel is compared with a desired predetermined value. If there is an offset between these two values, the pin 32 is moved around the reference axis Y to an angular position for canceling the difference between the measured and desired values of the dead travel, called set position.
Après déplacement de la goupille 32 dans sa position réglée, on immobilise cette goupille 32 dans le perçage de fixation 33, notamment par encastrement de la collerette 46 de cette goupille dans le perçage 33. L'invention permet donc de régler la position axiale relative des moyens d'obturation mobiles 28 et fixes 30 lorsque le piston secondaire 20 est dans sa position de repos en réglant la position axiale de la butée fixe (zone de contact de la goupille fixe 32) dans le corps 12. Parmi les avantages de l'invention, on notera que celle-ci permet de régler facilement la course morte du piston secondaire 20 et ainsi de limiter la quantité de liquide de frein transférée depuis la chambre de pression primaire 14 vers les moyens de simulation d'effort de freinage 26 lorsque le conducteur actionne la pédale de frein et que le système de freinage (comportant le maître cylindre 10 selon l'invention) est en configuration de fonctionnement de secours. After displacement of the pin 32 in its adjusted position, this pin 32 is immobilized in the fixing hole 33, in particular by embedding the flange 46 of this pin in the hole 33. The invention therefore makes it possible to adjust the relative axial position of the movable and fixed shutter means 28 when the secondary piston 20 is in its rest position by adjusting the axial position of the fixed stop (contact zone of the fixed pin 32 ) in the body 12. Among the advantages of the invention, it will be noted that this makes it possible to easily adjust the dead stroke of the secondary piston 20 and thus to limit the amount of brake fluid transferred from the primary pressure chamber 14 to the braking force simulation means 26 when the driver actuates the brake pedal and the braking system (comprising the master cylinder 10 according to the invention) is in emergency operation configuration.

Claims

REVENDICATIONS
1. Procédé de réglage d'un maître cylindre tandem pour système de freinage électrohydraulique, du type comprenant : - un corps (12) délimitant des chambres de pression primaire (14) et secondaire (16) séparées par un piston (20) déplaçable axialement, dit piston secondaire,1. Method for adjusting a tandem master cylinder for an electro-hydraulic braking system, of the type comprising: - a body (12) delimiting primary (14) and secondary (16) pressure chambers separated by an axially displaceable piston (20) , says secondary piston,
- des moyens (24) de raccordement hydraulique de la chambre de pression primaire (14) à des moyens (26) de simulation d'effort de freinage, - des moyens complémentaires mobiles (28) et fixes (30) d'obturation des moyens de raccordement hydraulique (24), portés respectivement par le piston secondaire (20) et le corps (12), le piston secondaire (20) étant déplaçable axialement entre une position de repos, dans laquelle les moyens d'obturation mobiles (28) et fixes (30) sont espacés les uns des autres, et une position de coopération de ces moyens d'obturation mobiles- means (24) for hydraulic connection of the primary pressure chamber (14) to means (26) for simulating braking force, - additional mobile (28) and fixed (30) means for closing the means hydraulic connection (24), carried respectively by the secondary piston (20) and the body (12), the secondary piston (20) being axially displaceable between a rest position, in which the movable closure means (28) and fixed (30) are spaced from each other, and a position of cooperation of these movable closure means
(28) et fixes (30), et(28) and fixed (30), and
- des butées complémentaires mobile (34) et fixe (32) coopérant entre elles pour définir la position de repos du piston secondaire (20), portées respectivement par le piston secondaire (20) et le corps (12), caractérisé en ce que l'on règle la position axiale relative des moyens d'obturation mobiles (28) et fixes (30) lorsque le piston secondaire (20) est dans sa position de repos en réglant la position axiale de la butée fixe (32) dans le corps (12).- mobile (34) and fixed (32) complementary stops cooperating with each other to define the rest position of the secondary piston (20), carried respectively by the secondary piston (20) and the body (12), characterized in that l 'the relative axial position of the movable (28) and fixed (30) closure means is adjusted when the secondary piston (20) is in its rest position by adjusting the axial position of the fixed stop (32) in the body ( 12).
2. Procédé selon la revendication 1 pour le réglage d'un maître cylindre du type comprenant une goupille fixe (32, 32n, 32p) s'étendant sensiblement transversalement à la direction de déplacement du piston secondaire (20) dans un logement oblong (34) ménagé dans ce piston (20), les butées fixe et mobile étant délimitées respectivement par des zones de contact complémentaires de la goupille fixe2. Method according to claim 1 for the adjustment of a master cylinder of the type comprising a fixed pin (32, 32 n , 32 p ) extending substantially transversely to the direction of movement of the secondary piston (20) in an oblong housing (34) formed in this piston (20), the fixed and movable stops being delimited respectively by complementary contact zones of the fixed pin
(32) et du logement oblong (34), la goupille (32, 32π, 32p) étant logée dans un perçage cylindrique, ménagé dans le corps (12), d'axe sensiblement transversal à la direction de déplacement du piston secondaire (20) appelé axe de référence (Y), caractérisé en ce que l'on règle la position axiale de la butée fixe dans le corps (12) en réglant la distance, par rapport à l'axe de référence (Y), de la zone de contact de la goupille (32, 32n, 32p).(32) and the oblong housing (34), the pin (32, 32 π , 32 p ) being housed in a cylindrical bore, formed in the body (12), of axis substantially transverse to the direction of movement of the secondary piston (20) called reference axis (Y), characterized in that the axial position of the fixed stop in the body (12) is adjusted by adjusting the distance, relative to the reference axis (Y), of the pin contact area (32, 32 n , 32 p ).
3. Procédé selon la revendication 2, caractérisé en ce que l'on règle la distance, par rapport à l'axe de référence (Y), de la zone de contact de la goupille (32) au moyen d'un lot (L) d'au moins deux goupilles (32n, 32p) ayant chacune une forme générale de révolution présentant une partie (42) de contact avec la butée mobile (34) prolongée par au moins une extrémité (44) de centrage dans le perçage de fixation, les diamètres (Dnι Dp) des parties de contact (42) étant différents d'une goupille à l'autre alors que les diamètres (D) des extrémités de centrage (44) sont identiques d'une goupille à l'autre.3. Method according to claim 2, characterized in that one adjusts the distance, relative to the reference axis (Y), of the contact area of the pin (32) by means of a batch (L ) at least two pins (32 n , 32 p ) each having a shape general revolution having a part (42) of contact with the movable stop (34) extended by at least one end (44) for centering in the fixing bore, the diameters (D nι D p ) of the contact parts (42) being different from one pin to another while the diameters (D) of the centering ends (44) are identical from one pin to another.
4. Procédé selon la revendication 3, caractérisé en ce que :4. Method according to claim 3, characterized in that:
- on équipe le maître cylindre d'une goupille (32n) du lot, dite goupille de référence,- the master cylinder is fitted with a pin (32 n ) from the batch, called the reference pin,
- on mesure la course du piston secondaire (20) entre ses positions de repos et de coopération des moyens d'obturation mobiles (28) et fixes (30), dite course morte (C),the stroke of the secondary piston (20) is measured between its rest and cooperation positions of the movable (28) and fixed (30) shutter means, called dead travel (C),
- on compare la valeur de la course morte mesurée avec une valeur prédéterminée souhaitée,- the value of the measured dead travel is compared with a desired predetermined value,
- on remplace la goupille de référence (32n) par une autre goupille (32p) minimisant l'écart entre les valeurs mesurée et souhaitée de la course morte.- the reference pin (32 n ) is replaced by another pin (32 p ) minimizing the difference between the measured and desired values of the dead travel.
5. Procédé selon la revendication 4, caractérisé en ce que le diamètre de la partie de contact de la goupille de référence (32n) est le plus faible du lot (L) de façon à assurer une course morte maximale. 5. Method according to claim 4, characterized in that the diameter of the contact part of the reference pin (32 n ) is the smallest of the batch (L) so as to ensure a maximum dead travel.
6. Procédé selon la revendication 2, caractérisé en ce que l'on règle la distance par rapport à l'axe de référence (Y) de la zone de contact de la goupille (32) par rotation autour de cet axe de référence (Y) d'une partie (42) de cette goupille (32) qui présente un contour de contact avec la butée mobile (34) qui évolue autour de cet axe de référence (Y) comme un excentrique ou une came. 6. Method according to claim 2, characterized in that the distance relative to the reference axis (Y) of the contact area of the pin (32) is adjusted by rotation about this reference axis (Y ) of a part (42) of this pin (32) which has a contact contour with the movable stop (34) which evolves around this reference axis (Y) like an eccentric or a cam.
7. Procédé selon la revendication 6, caractérisé en ce que :7. Method according to claim 6, characterized in that:
- on mesure la course du piston secondaire (20) entre ses positions de repos et de coopération des moyens d'obturation mobiles (28) et fixes (30), dite course morte (C),the stroke of the secondary piston (20) is measured between its rest and cooperation positions of the movable (28) and fixed (30) shutter means, called dead travel (C),
- on compare la valeur de la course morte mesurée avec une valeur prédéterminée souhaitée,- the value of the measured dead travel is compared with a desired predetermined value,
- on déplace la goupille (32) autour de l'axe de référence (Y) jusqu'à une position angulaire d'annulation de l'écart entre les valeurs mesurée et souhaitée de la course morte, dite position réglée.- The pin (32) is moved around the reference axis (Y) to an angular position for canceling the difference between the measured and desired values of the dead travel, known as the adjusted position.
8. Procédé selon la revendication 7, caractérisé en ce que, avant de mesurer la course morte du piston secondaire (20), on place la goupille (32) dans une position angulaire prédéterminée autour de l'axe de référence (Y), dite position de pré-réglage, dans laquelle la course morte est maximale.8. Method according to claim 7, characterized in that, before measuring the dead stroke of the secondary piston (20), the pin (32) is placed in a position predetermined angle around the reference axis (Y), called the preset position, in which the dead travel is maximum.
9. Procédé selon la revendication 5 ou 8, caractérisé en ce que, après déplacement de la goupille (32) dans sa position réglée, on immobilise cette goupille (32) dans le perçage de fixation, notamment par encastrement d'une extrémité de cette goupille dans le perçage de fixation.9. Method according to claim 5 or 8, characterized in that, after displacement of the pin (32) in its adjusted position, this pin (32) is immobilized in the fixing hole, in particular by fitting one end of this pin in the fixing hole.
10. Procédé selon l'une quelconque des revendications 4 à 9, caractérisé en ce que pour mesurer la course morte du piston :10. Method according to any one of claims 4 to 9, characterized in that to measure the dead stroke of the piston:
- on place le piston secondaire (20) dans sa position de repos, - on alimente la chambre de pression primaire (14) avec un gaz sous pression, notamment de l'air,- the secondary piston (20) is placed in its rest position, - the primary pressure chamber (14) is supplied with a pressurized gas, in particular air,
- on déplace le piston secondaire (20) vers la position de coopération des moyens d'obturation mobiles (28) et fixes (30),the secondary piston (20) is moved to the position of cooperation of the movable (28) and fixed (30) closure means,
- on détecte l'obturation des moyens de raccordement (24) par détection d'une variation de pression dans les moyens (26) de simulation d'effort de freinage.- Closing of the connection means (24) is detected by detection of a pressure variation in the means (26) for simulating braking force.
11. Goupille caractérisée en ce qu'elle appartient à un lot (L) de goupilles11. Pin characterized in that it belongs to a lot (L) of pins
(32n, 32p) pour la mise en œuvre du procédé selon l'une quelconque des revendications 3 à 5 combinée éventuellement avec la revendication 10. (32 n , 32 p ) for implementing the method according to any one of claims 3 to 5, optionally combined with claim 10.
12. Goupille caractérisée en ce qu'elle est destinée à la mise en œuvre du procédé selon l'une quelconque des revendications 6 à 9 combinée éventuellement avec la revendication 10.12. Pin characterized in that it is intended for the implementation of the method according to any one of claims 6 to 9 possibly combined with claim 10.
13. Maître cylindre tandem pour système de freinage électrohydraulique, du type comprenant : - un corps (12) délimitant des chambres de pression primaire (14) et secondaire (16) séparées par un piston (20) déplaçable axialement, dit piston secondaire,13. Tandem master cylinder for electrohydraulic braking system, of the type comprising: - a body (12) delimiting primary (14) and secondary (16) pressure chambers separated by a piston (20) axially displaceable, called secondary piston,
- des moyens (24) de raccordement hydraulique de la chambre de pression primaire (14) à des moyens (26) de simulation d'effort de freinage, - des moyens complémentaires mobiles (28) et fixes (30) d'obturation des moyens de raccordement hydraulique (24), portés respectivement par le piston secondaire (20) et le corps (12), le piston secondaire (20) étant déplaçable axialement entre une position de repos, dans laquelle les moyens d'obturation mobiles (28) et fixes (30) sont espacés les uns des autres, et une position de coopération de ces moyens d'obturation mobiles- means (24) for hydraulic connection of the primary pressure chamber (14) to means (26) for simulating braking force, - additional mobile (28) and fixed (30) means for closing the means hydraulic connection (24), carried respectively by the secondary piston (20) and the body (12), the secondary piston (20) being axially displaceable between a rest position, in which the movable closure means (28) and fixed (30) are spaced from each other, and a position of cooperation of these movable closure means
(28) et fixes (30), et - une goupille (32) o fixée dans un perçage cylindrique (33), ménagé dans le corps (12), d'axe sensiblement transversal à la direction de déplacement du piston secondaire (20) appelé axe de référence (Y), et o s'étendant dans un logement oblong (34) ménagé dans le piston secondaire (20), la goupille fixe (32) et le logement oblong (34) comportant des zones de contact complémentaires délimitant des butées complémentaires fixe et mobile coopérant entre elles pour définir la position de repos du piston secondaire (20), caractérisé en ce que la zone de contact de la goupille fixe (32) est délimitée par un contour de cette goupille fixe (32) évoluant autour de l'axe de référence (Y) comme un excentrique ou une came.(28) and fixed (30), and - A pin (32) o fixed in a cylindrical bore (33), formed in the body (12), with an axis substantially transverse to the direction of movement of the secondary piston (20) called the reference axis (Y), and o extending in an oblong housing (34) formed in the secondary piston (20), the fixed pin (32) and the oblong housing (34) comprising complementary contact zones delimiting complementary fixed and movable stops cooperating with one another to define the rest position of the secondary piston (20), characterized in that the contact zone of the fixed pin (32) is delimited by an outline of this fixed pin (32) moving around the reference axis (Y) as an eccentric or a cam.
14. Maître cylindre selon la revendication 7, caractérisé en ce que la goupille (32) est munie de moyens (46) d'encastrement dans le perçage de fixation (33). 14. Master cylinder according to claim 7, characterized in that the pin (32) is provided with means (46) embedded in the fixing bore (33).
15. Maître cylindre selon la revendication 13 ou 14, caractérisé en ce que les moyens fixes d'obturation comprennent un siège annulaire d'appui (30) ménagé dans le corps et les moyens mobiles d'obturation comprennent un joint torique (28), porté par le piston secondaire (20), destiné à coopérer avec ce siège d'appui (30).15. Master cylinder according to claim 13 or 14, characterized in that the fixed closure means comprise an annular support seat (30) formed in the body and the movable closure means comprise an O-ring (28), carried by the secondary piston (20), intended to cooperate with this support seat (30).
16. Maître cylindre selon l'une quelconque des revendications 13 à 15, caractérisé en ce que le logement oblong (34) est en communication avec une chambre16. Master cylinder according to any one of claims 13 to 15, characterized in that the oblong housing (34) is in communication with a chamber
(18) d'alimentation de liquide de frein, dite chambre d'alimentation secondaire, le piston secondaire (20) étant muni d'un canal (36) de mise en communication des chambres d'alimentation (18) et de pression (16) secondaires obturable par un clapet (22).(18) for supplying brake fluid, known as the secondary supply chamber, the secondary piston (20) being provided with a channel (36) for connecting the supply (18) and pressure (16) chambers ) secondary closable by a valve (22).
17. Maître cylindre selon la revendication 16, caractérisé en ce que le clapet (22) est muni d'une queue (38) de commande, s'étendant à travers le canal (36) du piston secondaire, destinée à coopérer avec la goupille (32) de façon à maintenir le clapet (22) en position ouverte. 17. Master cylinder according to claim 16, characterized in that the valve (22) is provided with a control shank (38), extending through the channel (36) of the secondary piston, intended to cooperate with the pin (32) so as to keep the valve (22) in the open position.
EP02774918A 2001-09-20 2002-09-10 Tandem master cylinder for electrohydraulic braking system Withdrawn EP1429946A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR0112163A FR2829736B1 (en) 2001-09-20 2001-09-20 METHOD FOR ADJUSTING A TANDEM MASTER CYLINDER FOR AN ELECTROHYDRAULIC BRAKING SYSTEM, A PIN FOR IMPLEMENTING THE METHOD AND TANDEM MASTER CYLINDER FOR AN ELECTROHYDRAULIC BRAKING SYSTEM
FR0112163 2001-09-20
PCT/FR2002/003063 WO2003024759A1 (en) 2001-09-20 2002-09-10 Tandem master cylinder for electrohydraulic braking system

Publications (1)

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EP1429946A1 true EP1429946A1 (en) 2004-06-23

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US (1) US20040239176A1 (en)
EP (1) EP1429946A1 (en)
JP (1) JP2005502536A (en)
FR (1) FR2829736B1 (en)
WO (1) WO2003024759A1 (en)

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DE602005001260T2 (en) * 2005-02-07 2008-01-24 Delphi Technologies, Inc., Troy Master cylinder arrangement
JP2008018816A (en) * 2006-07-12 2008-01-31 Toyota Motor Corp Braking device, stroke simulator cutting mechanism and stroke simulator cutting method
US20120124991A1 (en) * 2010-11-24 2012-05-24 Hb Performance Systems, Inc. Method and apparatus for lever stroke adjustment
EP2692601B1 (en) * 2011-03-31 2016-06-08 Honda Motor Co., Ltd. Electric brake device

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FR2134082B1 (en) * 1971-04-19 1974-03-08 Stop Sa
DE4108899A1 (en) * 1990-04-12 1991-10-17 Teves Gmbh Alfred Method of setting closure travel in master cylinder valve
GB9225768D0 (en) * 1992-12-10 1993-02-03 Lucas Ind Plc Hydraulic master cylinder
FR2772706B1 (en) * 1997-12-22 2000-02-11 Bosch Syst Freinage MASTER CYLINDER FOR ELECTRO-HYDRAULIC BRAKE INSTALLATION OF MOTOR VEHICLE
DE19920849A1 (en) * 1999-05-06 2000-11-09 Continental Teves Ag & Co Ohg Procedure to adjust backlash with tandem brake cylinders for dual-circuit brake systems of motor vehicles entails fixing end stops in casing to achieve balanced closing strokes of pressure rod piston and floating piston
FR2804397B1 (en) * 2000-02-02 2002-05-03 Bosch Gmbh Robert METHOD FOR MANUFACTURING A MASTER CYLINDER COMPRISING AN ADJUSTMENT STEP AND MASTER CYLINDER OBTAINED BY SAID METHOD

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JP2005502536A (en) 2005-01-27
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FR2829736A1 (en) 2003-03-21
US20040239176A1 (en) 2004-12-02

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