(19)
(11)EP 3 418 138 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
27.07.2022 Bulletin 2022/30

(21)Application number: 18177884.6

(22)Date of filing:  14.06.2018
(51)International Patent Classification (IPC): 
B60T 8/26(2006.01)
(52)Cooperative Patent Classification (CPC):
B60T 8/26; B60T 8/4809

(54)

HYDRAULIC SYSTEM FOR BRAKES

HYDRAULIKSYSTEM FÜR BREMSEN

SYSTÈME HYDRAULIQUE POUR FREINS


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 23.06.2017 GB 201710072

(43)Date of publication of application:
26.12.2018 Bulletin 2018/52

(73)Proprietor: Caterpillar SARL
1208 Geneva (CH)

(72)Inventors:
  • JOHNSON, Steven Edward
    Washington, IL Illinois 61571 (US)
  • ADEEB, Adam
    Seaham, SR7 0DB (GB)

(74)Representative: Finch, Steven Caffall 
Novagraaf UK 3rd Floor 77 Gracechurch Street
London EC3V 0AS
London EC3V 0AS (GB)


(56)References cited: : 
GB-A- 2 008 216
US-A- 5 236 252
US-A- 5 171 071
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    Technical Field



    [0001] The present disclosure relates to a hydraulic system for brakes, and in particular to a hydraulic system for a vehicle having first and second brakes.

    Background



    [0002] Vehicle brakes are often controlled by hydraulic systems, in which a pedal-actuated valve is used to control supply of hydraulic fluid to the brakes. Some vehicles have more than one brake system, for instance front and rear brakes. Hydraulic systems for such vehicles use two valve sections, one for the front brakes and the other for the rear brakes, which allow flow of hydraulic fluid to the front and rear brakes when a brake pedal is pressed by an operator. Known hydraulic systems often have the two valve sections configured in series which may result in brake pressure bias and/or overshoot. Bias occurs when the brake pressure provided to the two brake systems is not equal; overshoot occurs when the brake pressure exceeds the nominal pressure setting of the pedal valve. Bias and overshoot may have a negative effect on brake and axle component durability.

    [0003] Many vehicles have a second actuation system for the brakes, which may be used for retarding, anti-skid braking or dynamic brake control. Typically the hydraulic system includes a solenoid-controlled valve for each brake system to provide the second actuation system and additional valves to resolve and determine whether pedal-actuation or solenoid-actuation will control the supply of hydraulic fluid to the brake systems. Inclusion of additional valves may increase bias and overshoot between brake systems, and may increase overall cost of the hydraulic system.

    [0004] US 5 236 252 A discloses a control method for a vehicle ABS brake system which uses control valves which affect the state of first and second brake valves in order to permit hydraulic fluid to flow to apply the brakes.

    Summary of the Disclosure



    [0005] In an aspect of the present disclosure, a hydraulic system for a vehicle having first and second brakes is provided. The hydraulic system comprises a source of hydraulic fluid, a first brake valve and a second brake valve. The first and second brake valves have a pressure inlet, an exhaust outlet and a control inlet. The hydraulic system is characterized by the first and second brake valves being arranged in a parallel configuration, wherein the pressure inlet of the first and second brake valves are connected to the source of hydraulic fluid, and the exhaust outlet of the first and second brake valves being connected to the first and second brakes, respectively. The control inlets of the first and second brake valves are directly responsive to a braking signal from an operator of the vehicle. The hydraulic system further comprises a first control valve and a second control valve, each connected to the source of hydraulic fluid, wherein the first and second control valves are configured to selectively provide hydraulic fluid to the control inlet of the first and second brake valves, respectively.

    [0006] In another aspect of the present disclosure, a method for controlling hydraulic fluid in a vehicle having first and second brakes is provided. The method is characterised by providing a source of hydraulic fluid, and arranging a first brake valve and a second brake valve in a parallel configuration, wherein a pressure inlet of the first and second brake valves are connected to a source of hydraulic fluid, and an exhaust outlet of the first and second brake valves are connected to the first and second brakes, respectively. The method is further characterised by controlling operation of the first and second brake valves such that the first and second brake valves provide hydraulic fluid to the first and second brakes, respectively, in response to a braking signal from an operator of the vehicle. The method is further characterised by controlling operation of the first and second brake valves such that the first brake valve provides hydraulic fluid to the first brake in response to a first control signal, and the second brake valve provides hydraulic fluid to the second brake in response to a second control signal.

    [0007] Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawing.

    Brief Description of the Drawings



    [0008] 

    FIG. 1 is a schematic diagram of a hydraulic system according to embodiments of the present disclosure; and

    FIG. 2 is a flowchart of a method for controlling hydraulic fluid in a vehicle according to embodiments of the present disclosure.


    Detailed Description



    [0009] Reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Wherever possible, corresponding or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts.

    [0010] FIG. 1 shows a hydraulic system 10 for a vehicle having first brakes 12 and second brakes 14. In the illustrated embodiment shown in FIG. 1, the first brakes 12 comprise a front-right brake 12a and a front-left brake 12b, and the second brakes 14 comprise a rear-right brake 14a and a rear-left brake 14b. In other embodiments of the present disclosure, other combinations of brakes may form the first and second brakes.

    [0011] The hydraulic system 10 comprises a source of hydraulic fluid 16. The source of hydraulic fluid 16 may comprise a first accumulator 16a and a second accumulator 16b. In some embodiments of the present disclosure, a single accumulator may be used. Alternative sources of hydraulic fluid known to those skilled in the art may also be used with other embodiments of the present disclosure.

    [0012] The hydraulic system 10 further comprises a first brake valve 18a and a second brake valve 18b. The first brake valve 18a has a pressure inlet 20a, an exhaust outlet 22a and a control inlet 24a. Similarly, the second brake valve 18b has a pressure inlet 20b, an exhaust outlet 22b and a control inlet 24b.

    [0013] The pressure inlets 20a, 20b of the first and second brake valves 18a, 18b are connected to the source of hydraulic fluid 16. In some embodiments of the present disclosure, the pressure inlet 20a of the first brake valve 18a may be connected to the first accumulator 16a and the pressure inlet 20b of the second brake valve 18b may be connected to the second accumulator 16b. In other embodiments of the present disclosure, the pressure inlets 20a, 20b may be connected to a common accumulator.

    [0014] The exhaust outlets 22a, 22b of the first and second brake valves 18a, 18b are connected to the first and second brakes 12, 14 via hydraulic lines 26a, 26b, respectively.

    [0015] The first and second brake valves are arranged in a parallel configuration whereby the control inlets 24a, 24b of the first and second brake valves 18a, 18b are directly responsive to a braking signal from an operator of the vehicle. In the illustrated embodiment shown in FIG. 1, the first and second brake valves 18a, 18b are each responsive to a braking signal in the form of actuation of a foot pedal 30 by an operator of the vehicle. Actuation of the foot pedal 30 compresses springs 32a, 32b. In other embodiments of the present disclosure, the control inlets 24a, 24b may be responsive to a braking signal by other suitable mechanisms, such as a solenoid actuated by an engine control unit in response to an operator pressing a brake pedal.

    [0016] The first and second brake valves 18a, 18b may each comprise a 3-way 3-position valve. In the embodiment of the present disclosure illustrated in FIG. 1, the first and second brake valves 18a, 18b are the same; for brevity only the first brake valve 18a will be described, however it should be understood that the second brake valve 18b is of the same form. Like reference numerals are used in FIG. 1, with a suffix 'a' appearing on parts of first brake valve 18a and a suffix 'b' appearing on parts of second brake valve 18b.

    [0017] The first brake valve 18a may have a valve slide 34a movable between a first valve slide position 36a and a second valve slide position 38a with a transition position 40a provided between valve slide positions 36a and 38a.

    [0018] The valve slide 34a may be biased towards the first valve slide position 36a by a spring 42a provided at a secondary control inlet 44a. When the valve slide 34a is in the first valve slide position 36a, hydraulic fluid flows may be prevented from flowing between the pressure inlet 20a and the exhaust outlet 22a, while the exhaust outlet 22a may be in fluid communication with a drain outlet 46a. In the illustrated embodiment, the first valve slide position 36a may correspond with no braking applied to the first brakes 12.

    [0019] When the valve slide 34a is in the second valve slide position 38a, the pressure inlet 20a may be in fluid communication with the exhaust outlet 22a to permit hydraulic fluid to flow to the exhaust outlet 22a and hence to the first brakes 12 via the hydraulic line 26a. In the illustrated embodiment, the second valve slide position 38a may correspond with braking being applied to the first brakes 12.

    [0020] The first brake valve 18a may be a load-sensing valve whereby an orifice 48a is provided between the exhaust outlet 22a and the secondary control inlet 44a. The orifice 48a may be provided internally to the first brake valve 18a. In some embodiments of the present disclosure, it may be preferred that the first and second brake valves 18a, 18b are load-sensing valves, which may provide a smoother operator experience of the brakes 12, 14.

    [0021] The hydraulic system 10 further comprises a first control valve 50a and a second control valve 50b. The first and second control valves 50a, 50b are each connected to the source of hydraulic fluid 16. The first control valve 50a may be connected to the first accumulator 16a and the second control valve 50b may be connected to the second accumulator 16b. The first and second control valves 50a, 50b are configured to selectively provide hydraulic fluid to the control inlets 24a, 24b of the first and second brake valves 18a, 18b, respectively.

    [0022] In some embodiments of the present disclosure, the first and second control valves 50a, 50b may each comprise a 3-way 2-position solenoid valve. The first and second control valves 50a, 50b may be responsive to a corresponding first and second control signal 52a, 52b, respectively. The first control valve 50a may selectively provide hydraulic fluid to the control inlet 24a of the first brake valve 18a in response to the first control signal 52a. Similarly second control valve 50b may selectively provide hydraulic fluid to the control inlet 24b of the second brake valve 18b in response to the second control signal 52b.

    [0023] The valve slides 34a, 34b may be biased towards the second valve slide position 36a, 36b by the springs 42a, 42b. The valve slides 34a, 34b of both brake valves 18a, 18b will be biased towards the second valve slide positions 36a, 36b with no input from foot pedal 30. With no input from foot pedal 30, both springs 32a and 32b maintain foot pedal 30 in the fully retracted position. The valve slides 34a, 34b of both brake valves 18a, 18b will be biased towards the first valve slide positions 38a, 38b when the operator presses the foot pedal 30. The valve slides 34a and 34b may be independently biased towards the first valve slide positions 38a and 38b, respectively, by hydraulic fluid from the corresponding control valve 50a, 50b since the control valves 50a, 50b may be separately controlled via control signals 52a, 52b, respectively. The control signals 52a, 52b may be received from an engine control unit (not shown) and may be permit the first and/or second brakes 12, 14 to be used for braking independently of the operator.

    [0024] Referring now to FIG. 2 of the drawings, a method 100 for controlling hydraulic fluid in a vehicle having first and second brakes 12, 14 is shown.

    [0025] At step 102 a source of hydraulic fluid 16 is provided. Optionally, the source of hydraulic fluid 16 may comprise a first accumulator 16a and a second accumulator 16b, the first brake valve 18a being connected to the first accumulator 16a and the second brake valve 18b being connected to the second accumulator 16b.

    [0026] At step 104, a first brake valve 18a and a second brake valve 18b are arranged in a parallel configuration, wherein a pressure inlet 20a, 20b of the first and second brake valves 18a, 18b are connected to the source of hydraulic fluid 16, and an exhaust outlet 22a, 22b of the first and second brake valves 18a, 18b are connected to the first and second brakes 12, 14, respectively.

    [0027] At step 106, operation of the first and second brake valves 18a, 18b is controlled such that the first and second brake valves 18a, 18b provide hydraulic fluid to the first and second brakes 12, 14, respectively, in response to a braking signal from an operator of the vehicle.

    [0028] At step 108, operation of the first and second brake valves 18a, 18b is controlled such that the first brake valve 18a provides hydraulic fluid to the first brake 12 in response to a first control signal 52a, and the second brake valve 18b provides hydraulic fluid to the second brake 14 in response to a second control signal 52b. The method may comprise providing first and second control valves 50a, 50b responsive to first and second control signals 52a, 52b, respectively, and configuring the first and second control valves 50a, 50b to control operation of the first and second brake valves 18a, 18b to selectively provide hydraulic fluid to the first and second brakes 12, 14, respectively.

    [0029] In some embodiments of the method of the present disclosure, the first brakes 12 of the vehicle comprise a front-right brake 12a and a front-left brake 12b, and the second brakes 14 of the vehicle comprise a rear-right brake 14a and a rear-left brake 14b.

    Industrial Application



    [0030] The present disclosure provides a hydraulic system for controlling brakes in a vehicle. The hydraulic system 10 may be applicable to vehicles where braking is required to be controlled independently of the operator. The hydraulic system 10 may reduce the number of valves required, and may thereby reduce manufacturing costs and may increase reliability due to requiring fewer components.


    Claims

    1. A hydraulic system (10) for a vehicle having first and second brakes (12, 14), comprising a source of hydraulic fluid (16a, 16b), a first brake valve (18a) and a second brake valve (18b), each of the first and second brake valves (18a, 18b) having a pressure inlet (20a, 20b), an exhaust outlet (22a, 22b) and a control inlet (24a, 24b);

    the first and second brake valves (18a, 18b) being arranged in a parallel configuration, wherein the pressure inlet (20a, 20b) of each of the first and second brake valves is connected to the source of hydraulic fluid (16a, 16b), and the exhaust outlet (22a, 22b) of each of the first and second brake valves is connected to a respective one of the first and second brakes (12, 14);

    wherein either:

    (a) each of the first and second brake valves (18a, 18b) is responsive to a braking signal in the form of actuation of a foot pedal (30) by an operator of the vehicle to permit hydraulic fluid to flow from said source of hydraulic fluid (16a, 16b) to apply the respective one of the first and second brakes (12, 14), or

    (b) the control inlet (24a, 24b) of each respective one of the first and second brake valves is directly responsive to a braking signal from an operator of the vehicle to control the respective one of the first and second brake valves (18a, 18b) to permit hydraulic fluid to flow from said source of hydraulic fluid (16a, 16b) to apply the respective one of the first and second brakes (12, 14); and further including

    a first control valve (50a) and a second control valve (50b), each connected to the source of hydraulic fluid (16a, 16b);

    characterised in that the first and second control valves (50a, 50b) are responsive to control signals (52a, 52b) to selectively provide hydraulic fluid from said source of hydraulic fluid (16a, 16b) to the control inlet (24a, 24b) of the first and second brake valves (18a, 18b), respectively, to control the first and second brake valves (18a, 18b) to permit hydraulic fluid to flow from said source of hydraulic fluid (16a, 16b) to apply the first and second brakes (12, 14) independently of the operator of the vehicle.


     
    2. The hydraulic system of claim 1, wherein the source of hydraulic fluid comprises a first accumulator (16a) and a second accumulator (16b), wherein the first brake valve (18a) and the first control valve (50a) are connected to the first accumulator (16a) and the second brake valve (18b) and the second control valve (50b) are connected to the second accumulator (16b).
     
    3. The hydraulic system of claim 1 or 2, wherein the first brakes (12) of the vehicle comprise a front-left brake (12b) and a front-right brake (12a), and the second brakes (14) of the vehicle comprise a rear-left brake (14b) and a rear-right brake (14a).
     
    4. The hydraulic system of any preceding claim, wherein the first and second control valves (50a, 50b) each comprise a single valve.
     
    5. The hydraulic system of any preceding claim, wherein the first and second control valves (50a, 50b) are responsive to first and second control signals (52a, 52b), respectively.
     
    6. The hydraulic system of any preceding claim, wherein the control inlet (24a, 24b) of the first and second brake valves (18a, 18b) is directly responsive to a foot-actuated braking signal from an operator of the vehicle.
     
    7. The hydraulic system of any preceding claim, wherein the first and second brake valves (18a, 18b) each comprise a single valve.
     
    8. The hydraulic system of claim 7, wherein the first and second brake valves (18a, 18b) each comprise a load-sensing valve.
     
    9. A vehicle comprising the hydraulic system (10) of any preceding claim.
     
    10. A method for controlling hydraulic fluid in a vehicle (10) having first and second brakes (12, 14), characterised by:

    providing a source of hydraulic fluid (16a, 16b);

    arranging a first brake valve (18a) and a second brake valve (18b) in a parallel configuration, wherein a pressure inlet (20a, 20b) of each respective one of the first and second brake valves (18a, 18b) is connected to the source of hydraulic fluid (16a, 16b), and an exhaust outlet (22a, 22b) of each respective one of the first and second brake valves (18a, 18b) is connected to a respective one of the first and second brakes (12, 14);

    controlling operation of the first and second brake valves (18a, 18b) such that the first and second brake valves (18a, 18b) permit hydraulic fluid to flow from said source of hydraulic fluid (16a, 16b) to the first and second brakes (12, 14), respectively, to apply the first and second brakes (12, 14), respectively, in response to a braking signal from an operator of the vehicle; and

    controlling operation of the first and second brake valves (18a, 18b) independently of the operator of the vehicle such that the first brake valve (18a) permits hydraulic fluid to flow from said source of hydraulic fluid (16a) to the first brake (12) to apply the first brake (12) in response to a first control signal (52a), and the second brake valve (18b) permits hydraulic fluid to flow from said source of hydraulic fluid (16b) to the second brake (14) to apply the second brake (14) in response to a second control signal (52b).


     
    11. The method of claim 10, wherein the source of hydraulic fluid comprises a first accumulator (16a) and a second accumulator (16b), the first brake valve (18a) being connected to the first accumulator (16a) and the second brake valve (18b) being connected to the second accumulator (16b).
     
    12. The method of claim 10 or 11, wherein the first brakes (12) of the vehicle comprise a front-left brake (12b) and a front-right brake (12a), and the second brakes of the vehicle comprise a rear-left brake (14b) and a rear-right brake (14a).
     
    13. The method of claim 10, claim 11, or claim 12, further comprising providing first and second control valves (50a, 50b) responsive to first and second control signals (52a, 52b), respectively, the first and second control valves (50a, 50b) configured to controlling operation of the first and second brake valves (18a, 18b) to selectively provide hydraulic fluid to the first and second brakes (12, 14), respectively.
     


    Ansprüche

    1. Hydrauliksystem (10) für ein Fahrzeug mit ersten und zweiten Bremsen (12, 14), umfassend eine Quelle von Hydraulikflüssigkeit (16a, 16b), ein erstes Bremsventil (18a) und ein zweites Bremsventil (18b), wobei jedes des ersten und des zweiten Bremsventils (18a, 18b) einen Druckeinlass (20a, 20b), einen Ablassausgang (22a, 22b) und einen Steuereingang (24a, 24b) aufweist;

    wobei das erste und das zweite Bremsventil (18a, 18b) in einer parallelen Konfiguration angeordnet sind, wobei der Druckeinlass (20a, 20b) jedes des ersten und des zweiten Bremsventils mit der Quelle von Hydraulikflüssigkeit (16a, 16b) verbunden ist und der Ablassausgang (22a, 22b) jedes des ersten und des zweiten Bremsventils mit einer jeweiligen der ersten und der zweiten Bremsen (12, 14) verbunden ist;

    wobei entweder:

    (a) jedes des ersten und des zweiten Bremsventils (18a, 18b) auf ein Bremssignal in der Form einer Betätigung eines Fußpedals (30) durch einen Bediener des Fahrzeugs reagiert, um zu ermöglichen, dass Hydraulikflüssigkeit aus der Quelle von Hydraulikflüssigkeit (16a, 16b) strömt, um die jeweilige der ersten und zweiten Bremsen (12, 14) zu betätigen, oder

    (b) der Steuereingang (24a, 24b) jedes jeweiligen des ersten und des zweiten Bremsventils direkt auf ein Bremssignal von einem Bediener des Fahrzeugs reagiert, um das jeweilige des ersten und des zweiten Bremsventils (18a, 18b) zu steuern, um zu ermöglichen, dass Hydraulikflüssigkeit aus der Quelle von Hydraulikflüssigkeit (16a, 16b) strömt, um die jeweilige der ersten und zweiten Bremsen (12, 14) zu betätigen; und ferner einschließlich

    ein erstes Steuerventil (50a) und ein zweites Steuerventil (50b), die jeweils mit der Quelle von Hydraulikflüssigkeit (16a, 16b) verbunden sind;

    dadurch gekennzeichnet, dass das erste und das zweite Steuerventil (50a, 50b) auf Steuersignale (52a, 52b) reagieren, um wahlweise Hydraulikflüssigkeit aus der Quelle von Hydraulikflüssigkeit (16a, 16b) zu dem Steuereingang (24a, 24b) des ersten bzw. des zweiten Bremsventils (18a, 18b) bereitzustellen, um das erste und das zweite Bremsventil (18a, 18b) zu steuern, um zu ermöglichen, dass Hydraulikflüssigkeit aus der Quelle von Hydraulikflüssigkeit (16a, 16b) strömt, um die ersten und zweiten Bremsen (12, 14) unabhängig vom Bediener des Fahrzeugs zu betätigen.


     
    2. Hydrauliksystem nach Anspruch 1, wobei die Quelle von Hydraulikflüssigkeit einen ersten Akkumulator (16a) und einen zweiten Akkumulator (16b) umfasst, wobei das erste Bremsventil (18a) und das erste Steuerventil (50a) mit dem ersten Akkumulator (16a) verbunden sind und das zweite Bremsventil (18b) und das zweite Steuerventil (50b) mit dem zweiten Akkumulator (16b) verbunden sind.
     
    3. Hydrauliksystem nach Anspruch 1 oder 2, wobei die ersten Bremsen (12) des Fahrzeugs eine vordere linke Bremse (12b) und eine vordere rechte Bremse (12a) umfassen und die zweiten Bremsen (14) des Fahrzeugs eine hintere linke Bremse (14b) und eine hintere rechte Bremse (14a) umfassen.
     
    4. Hydrauliksystem nach einem der vorstehenden Ansprüche, wobei das erste und das zweite Steuerventil (50a, 50b) jeweils ein einziges Ventil umfassen.
     
    5. Hydrauliksystem nach einem der vorstehenden Ansprüche, wobei das erste und das zweite Steuerventil (50a, 50b) auf erste bzw. zweite Steuersignale (52a, 52b) reagieren.
     
    6. Hydrauliksystem nach einem der vorstehenden Ansprüche, wobei der Steuereingang (24a, 24b) des ersten und des zweiten Bremsventils (18a, 18b) direkt auf ein fußbetätigtes Bremssignal von einem Bediener des Fahrzeugs reagiert.
     
    7. Hydrauliksystem nach einem der vorstehenden Ansprüche, wobei das erste und das zweite Bremsventil (18a, 18b) jeweils ein einziges Ventil umfassen.
     
    8. Hydrauliksystem nach Anspruch 7, wobei das erste und das zweite Bremsventil (18a, 18b) jeweils ein Lasterfassungsventil umfassen.
     
    9. Fahrzeug, umfassend das Hydrauliksystem (10) nach einem der vorstehenden Ansprüche.
     
    10. Verfahren zum Steuern von Hydraulikflüssigkeit in einem Fahrzeug (10) mit ersten und zweiten Bremsen (12, 14), gekennzeichnet durch:

    Bereitstellen einer Quelle von Hydraulikflüssigkeit (16a, 16b);

    Anordnen eines ersten Bremsventils (18a) und eines zweiten Bremsventils (18b) in einer parallelen Konfiguration, wobei ein Druckeinlass (20a, 20b) jedes jeweiligen des ersten und zweiten Bremsventils (18a, 18b) mit der Quelle von Hydraulikflüssigkeit (16a, 16b) verbunden ist und ein Ablassausgang (22a, 22b) jedes jeweiligen des ersten und des zweiten Bremsventils (18a, 18b) mit einer jeweiligen der ersten und zweiten Bremsen (12, 14) verbunden ist;

    Steuern des Betriebs des ersten und des zweiten Bremsventils (18a, 18b) derart, dass das erste und das zweite Bremsventil (18a, 18b) ermöglichen, dass Hydraulikflüssigkeit aus der Quelle von Hydraulikflüssigkeit (16a, 16b) zu den ersten bzw. zweiten Bremsen (12, 14) strömt, um die ersten bzw. zweiten Bremsen (12, 14) als Reaktion auf ein Bremssignal von einem Bediener des Fahrzeugs zu betätigen; und

    Steuern des Betriebs des ersten und des zweiten Bremsventils (18a, 18b) unabhängig vom Bediener des Fahrzeugs derart, dass das erste Bremsventil (18a) ermöglicht, dass Hydraulikflüssigkeit aus der Quelle von Hydraulikflüssigkeit (16a) zu der ersten Bremse (12) strömt, um die erste Bremse (12) als Reaktion auf ein erstes Steuersignal (52a) zu betätigen, und das zweite Bremsventil (18b) ermöglicht, dass Hydraulikflüssigkeit aus der Quelle von Hydraulikflüssigkeit (16b) zu der zweiten Bremse (14) strömt, um die zweite Bremse (14) als Reaktion auf ein zweites Steuersignal (52b) zu betätigen.


     
    11. Verfahren nach Anspruch 10, wobei die Quelle von Hydraulikflüssigkeit einen ersten Akkumulator (16a) und einen zweiten Akkumulator (16b) umfasst, wobei das erste Bremsventil (18a) mit dem ersten Akkumulator (16a) verbunden ist und das zweite Bremsventil (18b) mit dem zweiten Akkumulator (16b) verbunden ist.
     
    12. Verfahren nach Anspruch 10 oder 11, wobei die ersten Bremsen (12) des Fahrzeugs eine vordere linke Bremse (12b) und eine vordere rechte Bremse (12a) umfassen und die zweiten Bremsen des Fahrzeugs eine hintere linke Bremse (14b) und eine hintere rechte Bremse (14a) umfassen.
     
    13. Verfahren nach Anspruch 10, Anspruch 11 oder Anspruch 12, ferner umfassend das Bereitstellen von ersten und zweiten Steuerventilen (50a, 50b) als Reaktion auf erste bzw. zweite Steuersignale (52a, 52b), wobei das erste und das zweite Steuerventil (50a, 50b) konfiguriert sind, um den Betrieb des ersten und des zweiten Bremsventils (18a, 18b) zu steuern, um selektiv Hydraulikflüssigkeit an die ersten bzw. zweiten Bremsen (12, 14) bereitzustellen.
     


    Revendications

    1. Système hydraulique (10) pour un véhicule ayant des premier et second freins (12, 14), comprenant une source de fluide hydraulique (16a, 16b), une première soupape de frein (18a) et une seconde soupape de frein (18b), chacune des première et seconde soupapes de frein (18a, 18b) ayant une entrée de pression (20a, 20b), une sortie d'échappement (22a, 22b) et une entrée de contrôle (24a, 24b) ;

    les première et seconde soupapes de frein (18a, 18b) étant agencées dans une configuration parallèle, dans lequel l'entrée de pression (20a, 20b) de chacune des première et seconde soupapes de frein est connectée à la source de fluide hydraulique (16a, 16b), et la sortie d'échappement (22a, 22b) de chacune des première et seconde soupapes de frein est connectée à l'un respectif des premier et second freins (12, 14) ;

    dans lequel soit :

    (a) chacune des première et seconde soupapes de frein (18a, 18b) est réactive à un signal de freinage dans la forme d'un actionnement d'une pédale de pied (30) par un opérateur du véhicule pour permettre à du fluide hydraulique de s'écouler en provenance de ladite source de fluide hydraulique (16a, 16b) pour appliquer l'un respectif des premier et second freins (12, 14), ou

    (b) l'entrée de contrôle (24a, 24b) de chacune respective des première et seconde soupapes de frein est directement réactive à un signal de freinage en provenance d'un opérateur du véhicule pour contrôler l'une respective des première et seconde soupapes de frein (18a, 18b) pour permettre à un fluide hydraulique de s'écouler en provenance de ladite source de fluide hydraulique (16a, 16b) pour appliquer l'un respectif des premier et second freins (12, 14) ; et incluant en outre

    une première soupape de contrôle (50a) et une seconde soupape de contrôle (50b), chacune connectée à la source de fluide hydraulique (16a, 16b) ;

    caractérisé en ce que les première et seconde soupapes de contrôle (50a, 50b) sont réactives à des signaux de contrôle (52a, 52b) pour fournir sélectivement du fluide hydraulique en provenance de ladite source de fluide hydraulique (16a, 16b) à l'entrée de contrôle (24a, 24b) des première et seconde soupapes de frein (18a, 18b), respectivement, pour contrôler les première et seconde soupapes de frein (18a, 18b) pour permettre à un fluide hydraulique de s'écouler en provenance de ladite source de fluide hydraulique (16a, 16b) pour appliquer les premier et second freins (12, 14) indépendamment de l'opérateur du véhicule.


     
    2. Système hydraulique selon la revendication 1, dans lequel la source de fluide hydraulique comprend un premier accumulateur (16a) et un second accumulateur (16b), dans lequel la première soupape de frein (18a) et la première soupape de contrôle (50a) sont connectées au premier accumulateur (16a) et la seconde soupape de frein (18b) et la seconde soupape de contrôle (50b) sont connectées au second accumulateur (16b).
     
    3. Système hydraulique selon la revendication 1 ou 2, dans lequel les premiers freins (12) du véhicule comprennent un frein avant gauche (12b) et un frein avant droit (12a), et les seconds freins (14) du véhicule comprennent un frein arrière gauche (14b) et un frein arrière droit (14a).
     
    4. Système hydraulique selon l'une quelconque revendication précédente, dans lequel les première et seconde soupapes de contrôle (50a, 50b) comprennent chacune une soupape unique.
     
    5. Système hydraulique selon l'une quelconque revendication précédente, dans lequel les première et seconde soupapes de contrôle (50a, 50b) sont réactives à des premier et second signaux de contrôle (52a, 52b), respectivement.
     
    6. Système hydraulique selon l'une quelconque revendication précédente, dans lequel l'entrée de contrôle (24a, 24b) des première et seconde soupapes de frein (18a, 18b) est directement réactive à un signal de freinage actionné au pied en provenance d'un opérateur du véhicule.
     
    7. Système hydraulique selon l'une quelconque revendication précédente, dans lequel les première et seconde soupapes de frein (18a, 18b) comprennent chacune une soupape unique.
     
    8. Système hydraulique selon la revendication 7, dans lequel les première et seconde soupapes de frein (18a, 18b) comprennent chacune une soupape de détection de charge.
     
    9. Véhicule comprenant le système hydraulique (10) selon l'une quelconque revendication précédente.
     
    10. Procédé pour le contrôle de fluide hydraulique dans un véhicule (10) ayant des premier et second freins (12, 14), caractérisé par :

    la fourniture d'une source de fluide hydraulique (16a, 16b) ;

    l'agencement d'une première soupape de frein (18a) et d'une seconde soupape de frein (18b) dans une configuration parallèle, dans lequel une entrée de pression (20a, 20b) de chacune respective des première et seconde soupapes de frein (18a, 18b) est connectée à la source de fluide hydraulique (16a, 16b), et une sortie d'échappement (22a, 22b) de chacune respective des première et seconde soupapes de frein (18a, 18b) est connectée à l'un respectif des premier et second freins (12, 14) ;

    le contrôle de l'opération des première et seconde soupapes de frein (18a, 18b) de telle sorte que les première et seconde soupapes de frein (18a, 18b) permettent à un fluide hydraulique de s'écouler en provenance de ladite source de fluide hydraulique (16a, 16b) vers les premier et second freins (12, 14), respectivement, pour appliquer les premier et second freins (12, 14), respectivement, en réaction à un signal de freinage en provenance d'un opérateur du véhicule ; et

    le contrôle de l'opération des première et seconde soupapes de frein (18a, 18b) indépendamment de l'opérateur du véhicule de telle sorte que la première soupape de frein (18a) permet à un fluide hydraulique de s'écouler en provenance de ladite source de fluide hydraulique (16a) vers le premier frein (12) pour appliquer le premier frein (12) en réaction à un premier signal de contrôle (52a), et la seconde soupape de frein (18b) permet à du fluide hydraulique de s'écouler en provenance de ladite source de fluide hydraulique (16b) vers le second frein (14) pour appliquer le second frein (14) en réaction à un second signal de contrôle (52b).


     
    11. Procédé selon la revendication 10, dans lequel la source de fluide hydraulique comprend un premier accumulateur (16a) et un second accumulateur (16b), la première soupape de frein (18a) étant connectée au premier accumulateur (16a) et la seconde soupape de frein (18b) étant connectée au second accumulateur (16b).
     
    12. Procédé selon la revendication 10 ou 11, dans lequel les premiers freins (12) du véhicule comprennent un frein avant gauche (12b) et un frein avant droit (12a), et les seconds freins du véhicule comprennent un frein arrière gauche (14b) et un frein arrière droit (14a).
     
    13. Procédé selon la revendication 10, la revendication 11, ou la revendication 12, comprenant en outre la fourniture de première et seconde soupapes de contrôle (50a, 50b) en réaction à des premier et second signaux de contrôle (52a, 52b), respectivement, les première et seconde soupapes de contrôle (50a, 50b) configurées pour contrôler l'opération des première et seconde soupapes de frein (18a, 18b) pour fournir sélectivement du fluide hydraulique aux premier et second freins (12, 14), respectivement.
     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description