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
  • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
  • B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
  • B60T13/12—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid
  • B60T13/14—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid using accumulators or reservoirs fed by pumps
• • 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
  • B60T8/4081—Systems with stroke simulating devices for driver input
  • B60T8/409—Systems with stroke simulating devices for driver input characterised by details of the stroke simulating device
• • 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
  • B60T8/4068—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 the additional fluid circuit comprising means for attenuating pressure pulsations
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
  • F16L55/04—Devices damping pulsations or vibrations in fluids
  • F16L55/045—Devices damping pulsations or vibrations in fluids specially adapted to prevent or minimise the effects of water hammer
  • F16L55/05—Buffers therefor
  • F16L55/052—Pneumatic reservoirs

Definitions

• the present invention relates to a hydraulic capacity, for example usable as a variable pressure accumulator in a braking circuit.
• the present invention relates to a hydraulic capacity, comprising a hollow body elongated along an axis, and a rigid envelope, the hollow body being made of a material supporting elastic expansion, from a state of rest, at least according to a radial direction relative to the axis, the hollow body being defined at rest by a wall of thickness comprised between a minimum thickness and a maximum thickness, this wall being bordered by an orifice fixed relative to the rigid envelope, l rigid envelope surrounding the hollow body to limit expansion, and this capacity being intended to contain at any instant an instantaneous volume of fluid capable of evolving between a minimum volume and a maximum volume, this capacity applying to the instantaneous volume of fluid an instantaneous pressure depending on the instantaneous volume.
• the invention is situated in a very different context, and aims to achieve a capacity which can be used as a hydraulic accumulator capable of applying to the fluid it contains a pressure linked, by a predetermined law, to the volume of fluid accumulated, such an accumulator being able to serve as a brake actuation simulator, of the type described for example in patent documents FR - 2 753 949 and FR - 2 756 797.
• the hydraulic capacity of the invention is essentially characterized in that the wall of the hollow body, at least for a first instantaneous volume of fluid, is simultaneously in contact with the envelope at least by a first and a second zone of this wall, distant from the orifice, having first and second respective thicknesses, and separated from each other by a third zone distant from the envelope and having a third thickness different from the first and second thicknesses.
• the hollow body has an essentially cylindrical internal surface at rest.
• the wall can also reach its minimum thickness at one end of the hollow body, opposite the orifice, and present at this end an external surface inscribed, at rest, in a cylinder of first diameter.
• the envelope facing the end of the hollow body, to form a cylinder of second diameter, greater than the first diameter.
• the wall can reach its maximum thickness in a plurality of intermediate zones located axially between the orifice and the end of the hollow body, and in which the wall has an external surface inscribed, at rest, in a cylinder of third diameter, greater than the second diameter
• FIG. 1 is a sectional view of a capacity according to the invention.
• FIG. 2 is a diagram illustrating a law of evolution of the pressure of a fluid stored in the capacity of Figure 1 as a function of the volume of this fluid.
• the invention relates to a hydraulic capacity, essentially comprising a hollow body 2, of elongated shape along an axis 1, and a rigid envelope 3 surrounding the hollow body 2.
• the wall 21 of the hollow body is, in the vicinity of the inlet-outlet orifice 22 of the latter, provided with a groove 221 which is mounted on a rib 41 formed at the internal periphery of a retaining ring 4.
• the ring 4 is itself interposed between the rigid casing 3 and a hydraulic connection 5 which opens into the orifice 22 of the hollow body, this connection being fixed to the rigid casing 3 by means of screws 6, and the ring 4 being immobilized along axis 1 by pressing on respective shoulders 31, 51 of the casing and of the connector.
• a cover 7 may possibly be provided on the rigid envelope 3 to protect it from ambient pollution.
• the hollow body 2 is made of an elastomeric material, for example rubber, in order to be able to undergo elastic expansion without damage in a radial direction R, and possibly also in the direction of the axis 1, from a state of rest which is that illustrated in FIG. 1, the expansion of the hollow body 2 being blocked when the wall 21 is fully in contact with the rigid envelope 3.
• an elastomeric material for example rubber
• the wall 21 of the hollow body 2 has, at rest, a thickness between a minimum thickness Ea and a maximum thickness Ez.
• the capacity thus constituted is intended to contain at any instant an instant volume V of fluid capable of evolving between a minimum volume Va and a maximum volume Vz (FIG. 2), the elastic wall 21 allowing, according to the present invention, to apply to the instantaneous volume V of fluid an instantaneous pressure P which depends on the instantaneous volume V according to a predetermined law, such as that illustrates figure 2.
• the wall 21 is simultaneously in contact with the casing 3 by at least first and second zones Z1, Z2 of this wall, and this at least for a given instantaneous volume of fluid, FIG. 1 representing in l 'occurrence the case where this volume is equal to Va and where the hollow body is in its state of rest.
• first and second zones Z1, Z2, which are distant from the orifice 22, have respective first and second thicknesses E1, E2, and are separated from each other by a third zone Z3, this third zone being it - Even distant from the envelope 3 and having a third thickness E3 different from the first and second thicknesses E1, E2.
• the hollow body 2 has an internal surface 23 which is essentially cylindrical at rest, the wall 21 reaching its minimum thickness Ea at one end 24 of the hollow body 2, opposite the orifice 22, and having at this end 24 an external surface 25 inscribed, at rest, in a cylinder of first diameter D1.
• the wall 21, in the example illustrated, reaches its maximum thickness Ez in a plurality of intermediate zones 26 situated axially between the orifice 22 and the end 24 of the hollow body 2, and in which the wall 21 has a surface external inscribed, at rest, in a cylinder of third diameter D3, greater than the second diameter D2.
• openings 32 can be made in the rigid envelope 3 to allow the trapped air to escape between the hollow body 2 and this envelope 3.
• the principle of operation of the illustrated capacity is as follows. Generally, when a certain volume of hydraulic fluid is injected into the hollow body 2, the expansion of the latter occurs primarily in the areas of the wall 21 which, at the same time, are not in contact with the rigid envelope 3, and have the smallest thickness.
• the resistance which the hollow body opposes to its expansion is an increasing function of the thickness of the wall 21 in the zone where this hollow body undergoes expansion, and a decreasing function of the surface of the zone which undergoes expansion.
• any increase in this volume therefore causes expansion radial and axial of the end 24 of the hollow body 2, the thickness of which is minimal, and the resistance which the hollow body opposes to its expansion is relatively low.
• the pressure P varies more rapidly for the same increase in volume than for the volumes less than Vy, this variation depending on the distribution of the zones of thicknesses such as E2, E3, Ez, in accordance with the principles previously stated.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• Transportation (AREA)
• General Engineering & Computer Science (AREA)
• Supply Devices, Intensifiers, Converters, And Telemotors (AREA)
• Braking Systems And Boosters (AREA)
• Valves And Accessory Devices For Braking Systems (AREA)
• Regulating Braking Force (AREA)
• Actuator (AREA)
• Pipe Accessories (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9527882

Family Applications (1)

Country Status (8)

Cited By (2)

Families Citing this family (23)

Citations (2)

Family Cites Families (8)

• 1998
  • 1998-06-26 FR FR9808101A patent/FR2780369B1/fr not_active Expired - Fee Related
• 1999
  • 1999-06-08 DE DE69903033T patent/DE69903033T2/de not_active Expired - Lifetime
  • 1999-06-08 JP JP2000556945A patent/JP4597372B2/ja not_active Expired - Fee Related
  • 1999-06-08 KR KR1020007013997A patent/KR100585611B1/ko not_active Expired - Fee Related
  • 1999-06-08 EP EP99923689A patent/EP1089903B1/fr not_active Expired - Lifetime
  • 1999-06-08 US US09/331,944 patent/US6164336A/en not_active Expired - Lifetime
  • 1999-06-08 ES ES99923689T patent/ES2182525T3/es not_active Expired - Lifetime
  • 1999-06-08 WO PCT/FR1999/001344 patent/WO2000000373A1/fr not_active Ceased

Patent Citations (2)

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