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
  • B60T8/26—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force characterised by producing differential braking between front and rear wheels
• • 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
  • B60T8/26—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force characterised by producing differential braking between front and rear wheels
  • B60T8/261—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force characterised by producing differential braking between front and rear wheels specially adapted for use in motorcycles

Definitions

• This invention relates to a system and method for the distribution of the braking action between the front axle and rear axle of a three-wheeled vehicle (tricycle) having one front wheel and two rear wheels.
• the purpose of this invention is to identify a method and a system for optimally allocating the braking action between the front axle and rear axle of a three-wheeled vehicle, also on the basis of the adhesion conditions between the vehicle and the road.
• Figures 1 to 8 illustrate the theory developed by the inventor, on which the system and the method according to the invention are based.
• Figure 9 illustrates a realisation scheme of a braking system according to this invention.
• This invention is the result of an original theory developed by the inventor based on the hypothesis that, from the point of view of its behaviour during braking, a three-wheeled vehicle has a behaviour that is mid-way between that of a four-wheeled vehicle (automobile) and a two-wheeled vehicle (motorcycle) .
• the optimum braking conditions depend on the conditions of adhesion between tyre and road.
• FA braking force to the front wheel developed by the front brake
• Pcuti pressure threshold with the vehicle “loaded”
• ⁇ coefficient of adhesion available between tyre and road
• ⁇ y coefficient of adhesion committed by the vehicle in the transverse direction
• iR minimum friction coefficient from which is the condition necessary for the rollover of the vehicle is satisfied
• the inventor has also set a necessary " condition for the rollover of the vehicle.
• the vertical component of the forces acting on the vehicle can be reduced to the sole weight force:
• Figure 2 graphically represents the system of equations 8) and highlights how, for coefficients of friction less than ⁇ , there are no intersections between the straight line defined by equation 5) and the circumference associated to equation 4) .
• braking distribution After a braking system of the vehicle is dimensioned, the relationship between the braking force to the rear wheels FP and the braking force to the front wheel FA is defined "braking distribution":
• K0 may be greater or smaller than Kl .
• the braking system is dimensioned so ⁇ as to achieve a cautionary braking distribution K* between K0 and Kl, without any correction device ( Figure 5) .
• the braking system is dimensioned so as to achieve a cautionary braking distribution K* between K0 and Kl, and provides a correction device 114 ( Figures 6 and 9).
• Said correction device comprises a limitation valve 114b suitable for to limit the pressure P ou t output as a function of the ' load of the vehicle, for example detected on the basis of the state of the suspensions, for example rear, or as a function of the deceleration developed in braking or by fixing a pre-set threshold value.
• the limitation of pressure P out is performed so as to obtain a braking distribution trend that approximates in a manner deemed adequate the limit adhesion curve, generally by a broken line.
• the pressure P out is limited by maintaining a constant pressure P out /' according to a further .
• the pressure P out is limited by imposing a constant of proportionality coefficient q with respect to the input pressure Pi n , defined characteristic coefficient of the braking corrector.
• the braking system is dimensioned so as to achieve maximum braking distribution (K0 or Kl, depending of the greater value between the two) , for example Kl, and provides for the introduction of a correction device 114 comprising a modulation valve 114a that modulates the distribution K between K0 and Kl as a function of the load ( Figures 7 and 9) , through variation of P out -
• the braking system is dimensioned so as to achieve the maximum braking distribution (K0 or Kl, depending on the greater value between the two) , for example Kl, and providing a correction device 114 comprising a modulation valve 114a that modulates the distribution K between K0 and Kl as a function of the load and a limitation valve 114b to impose a pressure limitation as a function of the load of the vehicle, for example detected based on the state of the suspensions, for example rear, or as a function of the deceleration developed in braking, or by setting a predefined threshold value (Figures 8 and 9).
• the limitation of the pressure P out is performed so as to obtain a braking distribution trend that approximates in a manner deemed adequate the limit adhesion curve, generally by a broken line.
• the pressure P ou t is limited by maintaining a constant pressure Pout; according to a further example, the pressure P out is limited by imposing a constant of proportionality coefficient q with respect to the input pressure Pj. n .
• a system 100 for the distribution of braking between front axle and rear axle of a three-wheeled vehicle comprises :
• an actuating element 102 for braking control for example a lever or a pedal
• a front brake group 106 suitable to operate in braking on the front wheel of the vehicle
• a correction device 114 hydraulically associated to the actuating element and to the rear brake group 104a, 104b (or, in a variant not represented, to the front brake group 106) .
• the system 100 comprises
• system 100 includes a front circuit 108'' operatively engaged with the actuation element 102 and with the front brake group 106.
• the correction device 114 comprises only . a pressure limitation valve 114b; according to a further embodiment, the correction device 114 comprises only a modulation valve 114b; according to a yet further embodiment, the correction device comprises both a pressure limitation valve 114b and a modulation valve 114a, wherein the limitation valve 114b is placed in series with the modulation valve 114a, downstream of it.
• the correction device 114 is realised as two structurally separate groups that function as limitation valve and the modulation valve respectively; according to a further variant, it is realised as a single structural group that operates as limitation valve and modulation valve.
• the correction device 114 is constituted by a single valve that operates simultaneously for modulation and for limitation.
• the system 100 comprises detection means 120.
• the detection means 120 are suitable to detect the load configuration of the vehicle; for example, said detection means are operatively connected with the suspensions, for example the rear, of the vehicle and determine a load signal as a function of the state of the suspensions. For example, said signal is determined as a function of the distance between the wheel hub and the casing.
• said detection means 120 are suitable to .detect the deceleration of the vehicle; for example, said detection means comprise a deceleration sensor.
• said detection means 120 are suitable to determine a threshold pressure value; for example, said detection means comprise storage means containing a predefined pressure threshold value.
• said detection means comprise electronic management means, for example an electronic control unit.
• the system 100 includes a power group 130 operatively associated to the actuation element 102 and suitable for pressurising the fluid contained in the hydraulic circuit at a pressure dependent on the entity of the actuation element 102.
• the power group 130 is for example hydraulic or electro-hydraulic (BBW, brake by wire type systems).
• the inventor has established how the application of the distribution method described above, for example by means of the braking system described above, produces a remarkable stability of the three-wheeled vehicle during braking, especially at low adhesions.
• system and method described above are also applicable to a three-wheeled vehicle having one rear wheel and two front wheels, tilting or not.

Landscapes

• Engineering & Computer Science (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Regulating Braking Force (AREA)
• Hydraulic Control Valves For Brake Systems (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=53385758

Family Applications (1)

Country Status (3)

Families Citing this family (2)

Family Cites Families (11)

• 2016
  • 2016-03-24 EP EP16723515.9A patent/EP3274224A1/de not_active Withdrawn
  • 2016-03-24 CN CN201680026775.3A patent/CN107864646A/zh active Pending
  • 2016-03-24 WO PCT/IB2016/051694 patent/WO2016157049A1/en active Application Filing

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events