GB2032553A - Creation of Inventions and Patents with Artificial Intelligence

GB2032553A – Deceleration responsive brake control valves
– Google Patents

GB2032553A – Deceleration responsive brake control valves
– Google Patents
Deceleration responsive brake control valves

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Publication number
GB2032553A

GB2032553A
GB7934354A
GB7934354A
GB2032553A
GB 2032553 A
GB2032553 A
GB 2032553A
GB 7934354 A
GB7934354 A
GB 7934354A
GB 7934354 A
GB7934354 A
GB 7934354A
GB 2032553 A
GB2032553 A
GB 2032553A
Authority
GB
United Kingdom
Prior art keywords
piston
chamber
braking
bore
pilot
Prior art date
1978-10-05
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.)

Granted

Application number
GB7934354A
Other versions

GB2032553B
(en

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.)

DBA SA

Original Assignee
DBA SA
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.)
1978-10-05
Filing date
1979-10-03
Publication date
1980-05-08

1979-10-03
Application filed by DBA SA
filed
Critical
DBA SA

1980-05-08
Publication of GB2032553A
publication
Critical
patent/GB2032553A/en

1982-11-03
Application granted
granted
Critical

1982-11-03
Publication of GB2032553B
publication
Critical
patent/GB2032553B/en

Status
Expired
legal-status
Critical
Current

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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

B60T8/28—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 responsive to deceleration

B60T8/285—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 responsive to deceleration using horizontal moving mass

Description

1 GB 2 032 553 A 1
SPECIFICATION
Braking compensator dependent on the 65 deceleration The invention relates to braking compensators and more particularly to a compensator dependent on the deceleration of the vehicle.
The compensator in accordance with the invention is of the type in which the cut-off point is defined by measurement of the pressure of the brake liquid trapped in a pilot chamber when the latter is isolated by closure of a valve associated 75 with a mass which is responsive to the deceleration of the vehicle and which is urged by resilient means toward a position corresponding to the opening of said valve.
It is characterized in that it comprises means responsive to the braking pressure, which modify the calibration of said resilient means as a function of said pressure.
It will be understood that, with such a characteristic, the higher the pressure in the braking circuit upstream (or downstream) the compensator the more strongly being the deceleration-responsive mass of the compensator urged towards the position corresponding to the opening of the valve, the point of cut-off of the compensator will be reached for deceleration which is variable as a function of the braking pressure and consequently of the load on the vehicle without there being any need to provide a 95 coupling member between the compensator and the suspension of the vehicle in a known manner.
The invention will now be described with reference to the accompanying drawings wherein:
Figure 1 is a longitudinal section of a braking compensator according. to the invention; 100 Figure 2 represents the relationships between the pressures at the input and at the output of the compensator of Figure 1 in various cases of operation as well as the relationships between the deceleration and these same pressures; and 105 Figure 3 is a longitudinal section of a braking compensator according to the invention for a double braking circuit.
Referring to Figure 1, the braking compensator dependent on the deceleration and the load designated by the general reference 10 comprises a housing 12 in which are arranged in parallek-a compensator 14 and a pilot system 16 on the one hand, and on the other hand a decelerometer 18 and a manometer 20.
The compensator 14 and the pilot system 16 are arranged in a common blind stepped bore consisting of two coaxial portions 21 and 22. A stepped piston 24 is slidably mounted in the portion 21 of the bore and passes through an aperture 26 arranged in a ring 28 which is mounted in the bottom of the portion 22 of the bore and equipped with a seal 30 which ensures oil-tightness both between the piston and the ring and between the ring and the bore. The right hand end of the portion 22 of the bore (looking at figure 1) receives a stopper 32 screwed into a thread provided for this purpose. The right hand end of the piston 24 has a flange 34. Between the flange 34 and the end of the stopper 32 is interposed a spring 36. The left hand end of the piston 24 cooperates with the portioA 21 of the borely means of a bearing surface 38. A seal 40 is arranged between the piston 24 and the bore. An axial aperture 42 and a radial aperture 44 arranged in the piston 24 put into communication two chambers 46 and 48. The chamber 46 bounded by the piston 24, the bore and the two seals 30 and 40 will be called the inlet chamber, the chamber 48 bounded by the piston 24, the bore, the seal 40 and a pilot piston 50 will be called the outlet chamber. In the axial aperture 42 are mounted from left to right an annular seat 52 and a ball 54 which cooperate with one another to 80 form a valve, and a spring 56 which urges the ball 54 towards its seat 52. The pilot piston 50 is mounted with a sliding seal in the end of the bore at the left of the piston 24. It includes a pushrod 58 which nasses through the seat 52 in order to push the ball 54 away from the latter when, at rest, the spring 36 pushes back the piston 24 into abutment against the pilot piston 50 and the latter into abutment against the end 60 of the bore. The piston 50, the bores 21-22 and the end 60 of 90 the latter define a pilot chamber 62.
The decelerometer 18 and the manometer 20 are arranged in a commen bore consisting of two coaxial portions 64 and 66. The decelerometer 18 consists of a cylindrical mass 68 which slides in the portion 64 of the bore by means of roller bearings 70 arranged at 1201 along three generatrices. The left-hand face of the mass 68 includes a valve member 72 capable of closing an orifice 74 arranged in the end of the bore. The orifice 74 communicates with the pilot chamber 62 by means of a passage 76. The bore 64-66 communicates with the inlet chamber 46 by means of a passage 78. The mass 68 is recessed at 80 and a passage 82 puts into communications with the recess 80 the annular space lying between the mass 68 and the bore 64.
The manometer 20 comprises a stopper 84 seaUngly mounted in the bore 66. In the stopper 84 are drilled two coaxial bores 86 and 88. A piston 90 is mounted with a sliding seal in the bore 86; it includes an the one hand an extension 92 which extends inside the recess 80 and ends in a flange 94, and on the other hand a threaded extension 96 screwed into a disc 98 located in the bore 88. The bore 88 is closed of by a screwed plug 100 equipped with an orifice for connectioin to the atmosphere. A spring 102 is interposed between the plug 100 and the disc 98. The mass 68 includes an annular shoulder 104 directed towards the interior of the recess 80. A spring 106 of conical shape is interposed between the flange 94 and the shoulder 104. This spring returns the mass 68 into abutment against the stopper 84, separating the valve member 72 from the orifice 74.
An inlet orifice 108 puts the bore 64 into communication with a master cylinder (not shown) and an orifice 100 puts the outlet 2 chamber 48 into communication with the rear brakes.
The corrector which has just been described is fastened onto the vehicle so that the axis of movement of the mass 68 is substantially horizontal, with the valve member 72 located towards the front of the vehicle. It operates in the following manner:
If the vehicle is assumed to be stationary and no braking pressure is applied, the components of the 75 corrector occupy the positions in which they are represented in Figure 1: the piston 24 in abutment against the pilot piston 50, which in turn abuts against the end of the bore 60, under the action of the spring 36; the mass 68 in abutment against the stopper 84 and the piston 90 pushed back towards the left by the spring 102 as far as the position in which the disc 98 comes into abutment against the end of the bore 66.
The vehicle being still stationary, a brake application is effected. The pressure created in the 85 master cylinder is transmitted to the braking circuit through the orifice 108. This pressure is transmitted through the passage 82 towards the recess 80, through the passage 78 towards the inlet chamber 46 and through the passage 76 towards the pilot chamber 62. The ball 54 being separated from its seat 52, this inlet pressure PE is likewise transmitted to the outlet chamber 48 through the passages 44 and 42 and then to the brakes through the orifice 110. Up to a predetermined pressure PO the piston 24 remains stationary, the force caused by the pressure acting upon the area of the piston arranged in the aperture 26, of area S2, remaining less than the force F, from the spring 36; the inlet pressure PE and outlet pressure PS are hence equal (see Figure 2, segment OA). If this pressure PO is exceeded, the piston 24 moves towards the right against the spring 36 and the ball 54 comes to be applied against the seat 52.
The closure of the communication between the inlet chamber 46 and the outlet chamber 48 prevents increase of pressure in the outlet chamber 48. Consequently, the pilot piston 50 being from now on no longer subjected to identical pressure, moves towards the right, the push rod 58 separating the ball from its seat 52, which reestablishes communication between the inlet chamber 46 and the outlet chamber 48. The result is that the outlet pressure P. and the ihiet pressure ‘-‘E are always equ-til (Figure 2, straight line AB).
If when the pressure P E has reached a value P,, the mass 68 is moved against the spring 106, the valve member 72 comes to shut off the orifice 74. The volume bounded by the passage 76 and the pilot chamber 62 can no longer vary and the pilot piston 50 consequently remains stationary. If the inlet pressure PE is increased, the piston 24 is displaced against the spring 36 and the seat 52 is displaced, coming close to the ball 54. There ensues a control of the fluid flow between the ball 54 and its seat 52 which is typical of the operation of a compensator. The development of the outlet GB 2 032 553 A 2 pressure P. may be calculated as follows: if the internal area of the seat 52 is called S3 and the arga of the portion of bore 21 reduced by the area S. above is called S,, the ball is subjected to a forcePE’S3 directed towards the left and to a force Ps,S3 directed towards the right and hence it transmits overall to its seat 52 and hence to the piston 24 a force (PE–pg)S3 directed towards the left. The piston 24 is further-more subjected on the other hand to two other forces directed towards the left, namely: the force F, from the spring 36 and a force PE.Si resulting from the action of the inlet pressure on the area S, above, and on the other hand to two forces directed towards the right, namely: a force PE’S2 resulting from the action of the inlet pressure against the area S2 and a force Ps.S, resulting from the action from the outlet pressure on the area S, above. – Hence the equilibrim of the piston is written:
F, + PES1 + WE – PS)S3 PES2 + PSS1 or else PS PE SI+S3-S2 F, Sl+S3 SI+S3 Hence the outlet pressure P. increases less quickly than PE under the action of the braking corrector 14. 90 The relationships between PS and PE is illustrated in Figure 2 by the line OCD. The pressure P, above which PS becomes less than PE is called the cut-off pressure. The role of the decelerometer 18 and of the manometer 20 is to effect the closure of the orifice 74 and as has just been seen, to initiate the operation of the corrector 14 by fixing of the pilot piston 50, beyond a variable cut-off pressure as explained below:
The vehicle is now assumed to move in the direction of the arrow 112 (Figure 1). Depending upon its load, the deceleration y which would be 1 obtained by applying the input pressure PE to the brakes is practically proportional to this pressure and this relationships is illustrated diagramatically in Figure 2 by the straight lines OF (vehicle empty), OG (vehicle loaded to the maximum) or OH (vehicle moderately loaded).
Upon application of a braking pressure PE, the decelerometer and the manometer are urged as follows: the piston 90 (if one neglects the force of the spring 106) is urged towards the left by the force F2 of the spring 102 and towards the right by the force PES4 produced from the pressure PE by the area S4 of the section 86. When this product PES4 becomes greater than F2 the piston 90 is moved toward the right with an amplitude X = PES4 – F2 k2 k2 being the stiffness of the spring 102. This movement x of the piston 90 has the effect of compressing the spring 106. If the stiffness of the latter is k3 the restoring force which it then exerts 3 GB 2 032 553 A 3 on the mass 68 becomes k3 F = F3 + k3X or else F = – (p ES4 – F2) k2 where F. is the calibration force of the spring 106. Further-more under the effect of the deceleration y the mass 68, of mass M, is subjected to a force due to inertia equal to My. Hence one observes that as long as My is less than F the mass 68 remains stationary and the ouflet pressure Ps is equal to P, For each value of PE there exists a deceleration called the cut-off deceleration above which My becomes greater than F, the mass 68 then moving in order to close the orifice 74 and initiate the operation of the corrector. For PE less than or equal to F,/S4, yc is equal to F3/M and for PE greater than or equal to FS4 F3 k3 Pc – + – (PES4-f2)’ M k2.
These relationships between p. and PE are represented in Figure 2 by the segment X and the straight line KI—. Consequently for each state of loading of the vehicle there exists a cut-off pressure P F (or P G or P H) defined by the point of intersection F’ or (G’ or W) between the straight line OF (or OG or OH) and the curve XL and it may be observed that the more loaded the vehicle the greater the deceleration of the vehicle corresponding with this cut off point which is the most important feature of the operation of such a corrector; the adhesion of the rear wheels being better when the vehicle is loaded it is therefore possible to brake a vehicle efficiently by taking its load into account.
Figure 3 represents a second embodiment of the corrector in accordance with the invention, intended more precisely for braking systems in which two brakes are fed from two different sources of pressure as, for example, in the braking 100 systems known as “X-.
In this embodiment is found besides the corrector 14, the pilot system 16, the decelerometer 18 and the manometer 20, a second corrector 114 the components of which are identical with those of the corrector 14 and carry the same reference numbers increased by 100, a second pilot system 116 identical with the pilot system 16 and a buffer piston 250.
The buffer piston 250 is mounted with a sliding 110 seal in the end of the bore 121 between the left hand end of the piston 150 and the end 160 of the bore. The passage 76 communicating with the pilot chamber 62 is extended by a passage 176 communicating with a second pilot chamber 162 115 located at the left of the buffer piston 250.
The system receives two inlet pressures PEG and PED, the one through the orifice 108 and the other through the orifice 178, and transmits two outlet pressures PSG and PSD (the one through the 120 orifice 110 and the other through the orifice 210) to the left and rignt rear brake motors respectively.
The examination of the relationships between the inlet pressures and outlet pressures as a function of the deceleration, carried out above in relation to the corrector of Figure 1, applies in an identical way to this second corrector, the assembly formed by the pistons 150 and 250 moving as a whole.
It, may be observed that this embodiment enables the two correctors to be controlled from the same manometer 20- decelerometer 18 assembly.
The special feature connected with the presence of the buffer piston 250 is to separate the two braking circuits by a chamber 252 connected to atmosphere through an orifice 254.
That is, in the event of deterioration of one of the two seals associated with the pistons 150 and 250, the independence of the two braking circuits is maintained on the one hand, and on the other hand. this deterioration may be detected thanks to a leakage of brake liquid through the orifice 254.

Claims (7)

1. A braking compensator for a motor vehicle, dependent on the deceleration, the point of cut-off of which is defined by measurement of the pressure of the brake liquid trapped in a pilot chamber when the latter is isolated by closure of a valve associated with a mass which is responsive to the deceleration of the vehicle and which is urged by resilient means towards a position corresonding to the opening of said valve, characterized in that it comprises means responsive to the braking pressure, which modify the calibration of said resilient means as a function of said pressdre.

. A compensator according to claim 1, characterized in that the aforesaid means responsive to pressure consist of a plunger extending into a chamber in which said mass is slidably received and subjected on one of its faces to the braking pressure prevailing in said chamber and which tends to displace it against an opposing spring, preferably of adjustable strength, the aforesaid resilient means being connected between the said plunger and the said mass.

3. A braking compensator according to claim 2, characterized in that said resilient means consist of a spiral compression spring bearing against abutment surfaces provided respectively on the mass and on the plunger.

4. A braking compensator according to claim 3, characterized in that means are provided between the opposing spring and the plunger for adjusting the penetration of said plunger into said chamber and consequently the unloaded calibration of said spiral spring.

5. A braking compensator according to any one of claims 1 to 4, characterized in that said chamber surrounding the mass is connected to the two ends of a bore by two ducts, one of which being capable of being closed by the valve associated with said mass opens into said pilot chamber formed at one end of said bore, said bore 4 GB 2 032 553 A 4 slidingly receiving a pilot piston, one face of which being subjected to the pressure prevailing in said pilot chamber and a compensator piston which is urged by resilient means towards said pilot piston, the latter controlling by a pushrod carried by its other face a compensation valve mounted in said compensator piston and controlling the flow of brake liquid between the duct connected directly to said chamber, and an outlet duct connected to brake motors, said pilot piston being subjected on its other face to the pressure prevailing in said outlet duct.

6. A braking compensator according to claim 5, characterized in that it comprises a second bore in which are mounted a second pilot piston and – a second compensator piston similar to the afore mentioned ones, a second pilot chamber defined between said second pilot piston and said second bore being connected to the pilot chamber in the first bore, a second compensation valve controlling the flow of fluid between a second duct receiving a second braking pressure and a second outlet duct connected to other brake motors.

7. A braking compensator for a motor vehicle substantially as described and as shown in the accompanying drawings.
Printed for Her Majesty’s Stationery Office by the Courier Press, Leamington Spa, 1980. Published by the Patent Offici, 25 Southampton Buildings, London, WC2A 1 AY, from which copies may be obtained.
4 1 2 J

GB7934354A
1978-10-05
1979-10-03
Deceleration responsive brake control valves

Expired

GB2032553B
(en)

Applications Claiming Priority (1)

Application Number
Priority Date
Filing Date
Title

FR7828550A

FR2437962A1
(en)

1978-10-05
1978-10-05

BRAKE COMPENSATOR SERVED ON DECELERATION

Publications (2)

Publication Number
Publication Date

GB2032553A
true

GB2032553A
(en)

1980-05-08

GB2032553B

GB2032553B
(en)

1982-11-03

Family
ID=9213405
Family Applications (1)

Application Number
Title
Priority Date
Filing Date

GB7934354A
Expired

GB2032553B
(en)

1978-10-05
1979-10-03
Deceleration responsive brake control valves

Country Status (3)

Country
Link

US
(1)

US4334712A
(en)

FR
(1)

FR2437962A1
(en)

GB
(1)

GB2032553B
(en)

Cited By (2)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

US4431235A
(en)

1981-03-18
1984-02-14
Societe Anonyme Dba
Deceleration-controlled braking compensator for a motor vehicle

GB2184802A
(en)

1985-10-29
1987-07-01
Aisin Seiki
Fluid pressure control valve for vehicle braking system

Families Citing this family (4)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

ES8206309A1
(en)

1980-08-29
1982-08-16
Lucas Industries Ltd
Control valve assembly

FR2513954B1
(en)

1981-10-06
1987-06-26
Dba

BRAKING CORRECTOR SERVO FOR DECELERATION

FR2536355A1
(en)

1982-11-23
1984-05-25
Dba

DOUBLE CIRCUIT BREAKER CORRECTIVE SERVING DECELERATION

EP0184955B1
(en)

1984-11-21
1989-01-18
BENDIX France
Deceleration responsive braking corrector

Family Cites Families (9)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

US3480336A
(en)

1967-11-27
1969-11-25
Trw Inc
Hydraulic actuated skid control device

US3476443A
(en)

1968-08-02
1969-11-04
Gen Motors Corp
Inertia sensing proportioner

FR2130048B1
(en)

1971-03-15
1975-09-26
Kelsey Hayes Co

US3881786A
(en)

1971-03-15
1975-05-06
Kelsey Hayes Co
Inertia responsive proportioning valve

JPS5221661B2
(en)

1972-08-12
1977-06-11

FR2340229A1
(en)

1976-02-09
1977-09-02
Tokico Ltd
Pressure control for hydraulic brake – has valve with inertia device cutting off pressure when given braking rate is exceeded

JPS534167A
(en)

1976-06-29
1978-01-14
Sumitomo Electric Ind Ltd
Load response type regulating valve

JPS5362067A
(en)

1976-11-16
1978-06-03
Toyota Motor Corp
Deceleration detection type braking hydraulic control system

JPS5370276A
(en)

1976-12-02
1978-06-22
Toyota Motor Corp
Brake oil controller for vehicle

1978

1978-10-05
FR
FR7828550A
patent/FR2437962A1/en
active
Granted

1979

1979-10-01
US
US06/080,810
patent/US4334712A/en
not_active
Expired – Lifetime

1979-10-03
GB
GB7934354A
patent/GB2032553B/en
not_active
Expired

Cited By (3)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

US4431235A
(en)

1981-03-18
1984-02-14
Societe Anonyme Dba
Deceleration-controlled braking compensator for a motor vehicle

GB2184802A
(en)

1985-10-29
1987-07-01
Aisin Seiki
Fluid pressure control valve for vehicle braking system

US4761041A
(en)

1985-10-29
1988-08-02
Aisin Seiki Kabushiki Kaisha
Fluid pressure control valve for vehicle braking system

Also Published As

Publication number
Publication date

US4334712A
(en)

1982-06-15

FR2437962B1
(en)

1982-04-16

GB2032553B
(en)

1982-11-03

FR2437962A1
(en)

1980-04-30

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