GB2213544A - Braking corrector device for motor vehicle with hydraulic braking system and automatic levelling system with air springs - Google Patents
Braking corrector device for motor vehicle with hydraulic braking system and automatic levelling system with air springs Download PDFInfo
- Publication number
- GB2213544A GB2213544A GB8828642A GB8828642A GB2213544A GB 2213544 A GB2213544 A GB 2213544A GB 8828642 A GB8828642 A GB 8828642A GB 8828642 A GB8828642 A GB 8828642A GB 2213544 A GB2213544 A GB 2213544A
- Authority
- GB
- United Kingdom
- Prior art keywords
- motor vehicle
- braking
- air
- air springs
- diaphragms
- 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- Withdrawn
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
- B60T8/18—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 vehicle weight or load, e.g. load distribution
- B60T8/1881—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 vehicle weight or load, e.g. load distribution characterised by failure-responsive means
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60G—VEHICLE SUSPENSION ARRANGEMENTS
- B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
- B60G17/02—Spring characteristics, e.g. mechanical springs and mechanical adjusting means
- B60G17/04—Spring characteristics, e.g. mechanical springs and mechanical adjusting means fluid spring characteristics
- B60G17/0408—Spring characteristics, e.g. mechanical springs and mechanical adjusting means fluid spring characteristics details, e.g. antifreeze for suspension fluid, pumps, retarding means per se
-
- 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
- B60T11/28—Valves specially adapted therefor
- B60T11/34—Pressure reducing or limiting 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
- B60T8/18—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 vehicle weight or load, e.g. load distribution
- B60T8/1837—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 vehicle weight or load, e.g. load distribution characterised by the load-detecting arrangements
- B60T8/1843—Arrangements for detecting air spring pressure
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60G—VEHICLE SUSPENSION ARRANGEMENTS
- B60G2800/00—Indexing codes relating to the type of movement or to the condition of the vehicle and to the end result to be achieved by the control action
- B60G2800/90—System Controller type
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60G—VEHICLE SUSPENSION ARRANGEMENTS
- B60G2800/00—Indexing codes relating to the type of movement or to the condition of the vehicle and to the end result to be achieved by the control action
- B60G2800/90—System Controller type
- B60G2800/92—ABS - Brake Control
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Transportation (AREA)
- Braking Arrangements (AREA)
- Braking Systems And Boosters (AREA)
- Valves And Accessory Devices For Braking Systems (AREA)
- Regulating Braking Force (AREA)
- Hydraulic Control Valves For Brake Systems (AREA)
- Vehicle Body Suspensions (AREA)
Abstract
A braking corrector device for a motor vehicle provided with a hydraulic braking system and an automatic levelling system with air springs includes an operating device 22 defining two chambers 28, 29 which are both divided into first 28a, 29a and second 28b, 29b spaces by respective diaphragms 26, 27. The first spaces of the chambers communicate with respective air springs via pipes 19 and the second spaces communicate with the atmosphere through narrow passages 40, 41 whose dimensions are calibrated so as to limit the loss of air to atmosphere in the event of the rupture of one of the diaphragms. The loss of air causes a variation in the attitude of the vehicle and this results in the activation of the compressor of the leveling system, so as to compensate for the loss. <IMAGE>
Description
"A BRAKING CORRECTOR DEVICES FOR A MOTOR VEHICLE PROVIDED WITH A
HYDRAULIC BRAKING SYSTEM AND AN AUItMATIC LEVEL;LLNG SYSTEM WITH
AIR SPRINGS"
The present invention relates to a braking corrector device for a motor vehicle provided with a hydraulic braking system and an automatic levelling system with air springs.More particularly, the invention concerns a braking corrector device comprising:
a first rigid hollow body with an inlet and at least one outlet for connection to a master cylinder and to braking actuators for the wheels of one axle of the motor vehicle,
an operating member which is movable in the first body and can disconnect the outlet from the inlet when the pressure supplied to the inlet is equal to a calibration value dependent on the position of the member relative to the body, and
an operating device comprising a second hollow body which is connected to the first body and in which two adjacent chambers are formed, each of which is divided into a first space communicating with the air spring associated with one of the wheels and a second space communicating with the atmosphere; the diaphragms being associated with respective transmission members which can move relative to the second body and cause a corresponding movement of the operating member relative to the first body due to the deformation of at least one of the diaphragms, as a result of a variation in the pressure in the first space of at least one of the chambers.
A braking corrector device of the type indicated above is described, for example, in Italian patent application 68110-A/85.
The device according the present invention is characterised in that the second spaces of the chambers communicate with the atmosphere through respective narrow passages whose dimensions are calibrated so that, in the event of the rupture of one of the diaphragms, the flow of air from the corresponding air spring back to the atmosphere is limited.
By virtue of this characteristic, in the event of the rupture of one of the diaphragms, the corresponding air spring of the automatic levelling system of the motor vehicle is discharged extremely slowly, without seriously impairing the stability and controllability of the motor vehicle, at least for some time.
Automatic air-spring levelling systems usually include a compressor and a control and operating unit for activating the compressor so as to supply compressed air to the air springs in a predetermined manner when certain variations occur in the attitude of the motor vehicle. In the event of the rupture of one of the diaphragms of the device according to the invention, the loss of air to the atmosphere through the corresponding narrow passage of calibrated dimensions causes a variation in the attitude of the motor vehicle which can be detected by the control and operating unit of the levelling system. This unit can therefore be arranged to activate the compressor in these circumstances, so as to supply a flow of air to the air spring associated with the ruptured diaphragm to compensate for the loss. The stability of the motor vehicle can thus be ensured.The control and operating unit of the system is conveniently arranged to cause the emission of a signal for indicating to the driver that damage has occurred.
Further characteristics and advantages of the present invention will become clear from the detailed description which follows with reference to the appended drawings, provided by way of non-limiting example, in which:
Figure 1 shows the layout of a motor vehicle braking system including a braking corrector device according to the invention; Figure 1 also shows the layout of an automatic levelling system of the motor vehicle, and
Figure 2 is a partially-sectioned view of a braking corrector device according to the invention.
With reference to Figure 1, a braking system includes a master cylinder 1 operable by means of brake-operating pedal 2. The cylinders 3 for operating the brakes associated with the front wheels of the vehicle are connected hydraulically to the master cylinder 1.
A device for regulating the braking force applied to the rear wheels of the vehicle, produced according to the present invention, is generally indicated 4. This regulator device is connected to the master cylinder 1 through a line 5. The operating actuator cylinders 6 associated with the rear wheels of the motor vehicle are also connected to this regulator device.
The air springs associated with the rear wheels are indicated 7 and form part of the automatic levelling system of the motor vehicle, which will be described further below. These air springs are connected to a compressor 8 through pipes 9 and 10. Solenoid valves 11 are interposed in the pipes 9 and are operated by a control unit 12 which also controls the operation of the compressor 8. Sensors of the attitude of the motor vehicle, generally indicated 13, are also connected to the unit.
The control unit 12 causes the charging or discharging of the springs 7 as the attitude of the motor vehicle varies, so as to compensate for or eliminate the variations in attitude.
Pipes, indicated 19, connect the air springs 7 to two connectors of the braking connector 4.
One embodiment of the corrector 4 will now be described with reference to Figure 2. The embodiment illustrated corresponds for the most part to the embodiment described in the prior Italian patent application 68110-A/85.
With reference to Figure 2, then, the braking connector according to the invention comprises a pressure limiter of known type, generally indicated 20, whose intervention pressure is variable. The latter has an inlet 20a connected to the master cylinder 1 and an outlet 20b connected to the braking actuators 6 of the rear wheels. The movable operating member of the limiter is indicated 20c and is mounted for movement in an aperture 20d provided in the body of the limiter.
The intervention pressure of the pressure limiter 20 varies in known manner as the position of the operating member 20c varies. Resilient means (not illustrated) are associated with the operating member 20c, also in known manner, for opposing its movement towards the inside of the limiter device (that is, downwards as seen in Figure 2).
The attachment appendage 24a of the operating device, generally indicated 22, is fixed to the body of the limiter 20 by means of screws 21. The device 22 comprises two substantially cup-shaped end bodies 23 and 24 with respective apertures 23a and 24a in their base walls. The upper body 23 has its concavity facing downwards, whilst the concavity of the body 24 faces upward.
A substantially tubular intermediate body 25 with a lateral aperture 25a is mounted between the end bodies 23 and 24. The pipes 19 described above are connected to the aperture 23a of the upper body 23 and to the aperture 25a of the intermediate body 25, respectively.
A first diaphragm 26 is gripped between the upper body 23 and the intermediate body 25. A second diaphragm 27 is gripped between the intermediate body 25 and the upper edge of the lower body 24.
The intermediate body 25 has a transverse wall 25b with a central guide aperture 25c. A chamber is defined between the wall 25b and the upper body 23, and is divided into two separate spaces 28a and 28b by the diaphragm 26.
A second chamber is defined between the wall 25b and the lower body 24, and is divided into two spaces 29a and 29b by the diaphragm 27.
The spaces 28a and 29a communicate with the air springs 7 through the pipes 19.
The spaces 28b and 29b, however, communicate with the atmosphere through narrow passages, indicated 40 and 41. These passages have calibrated dimensions, for the reasons which will better be described below.
A body, indicated 30, comprises a rod 30b movable axially through the aperture 25c in the wall 25b, and a disc-shaped end head 30a disposed against the diaphragm 26 in the space 28b.
Another body, indicated 31, comprises a rod 31b movable axially in a central head aperture formed in the end of the rod of the body 30, and a head portion 31a disposed against the diaphragm 27 in the space 29a.
A helical spring arranged in the space 29b is indicated 33 and acts at one end against the base wall of the body 24 and at the other end against an annular body 34 which presses against the lower face of the diaphragm 27.
An operating rod, indicated 35, is movable in the aperture 24a of the cup-shaped body 24 and has one end force-fitted in the central aperture of the annular body 34.
The operating device 22 is connected to the body of the limiter 20 so that the operating rod 35 faces the operating member 20c of the limiter. In the rest condition, the spring 33 keeps the rod 35 at a predetermined distance from the operation member 20c of the limiter.
In operation, the pressure existing in the spaces 28a and 29a of the operating device 22 is univocally correlated with the pressure existing in the air springs 7 of the automatic levelling system.
The control unit 12 compensates for static or dynamic variations in the load bearing on the rear axle of the motor vehicle by means of corresponding variations in the air pressure in the air springs 7.
If a pressure increase in one or both of the air springs 7 exceeds a threshold value, then, there is a corresponding downward movement (as seen in Figure 2) of one or both of the bodies 30 and 31 and a corresponding movement of the rod 35 towards the member 20c of the limiter 20. The threshold value of the pressure increase in the air springs is determined by the characteristics of the spring 33.
When the threshold value is exceeded, therefore, the pressure increase in the air springs 7 causes the application of a correspondingly variable force on the operating member 20c of the limiter 20. The intervention of the latter is thus "modulated" in dependence on the pressure variations in the air springs 7 and therefore in dependence on the variations in the static or dynamic loads bearing on the rear wheels.
The operating device 22 described above enables the limiter 20 (which corresponds to the standard braking corrector device of conventional type) also to be used on motor vehicles provided with an automatic levelling system.
As stated above, the passages 40 and 41 which put the spaces 28b and 29b into communication with the atmosphere have calibrated dimensions so that, in the event of the rupture of a diaphragm 26 or 27, the flow of air lost back to the atmosphere from the corresponding air spring 7 is limited.
By virtue of this characteristic, the air spring associated with the damaged diaphragm is discharged slowly and the control unit 12 can compensate for the loss of air in the manner described in the introduction to the present description.
Naturally, the scope of the present invention extends to models which achieve equal utility by means of the same innovative concept.
Claims (2)
1. A braking corrector device for a motor vehicle provided with a hydraulic braking system and an automatic levelling system with air springs , comprising: - a first rigid hollow body with an inlet and at least one outlet for connection to a master cylinder and to braking actuators for the wheels of one axle of the motor vehicle, respectively,
an operating member which is movable in the first body and can disconnect the outlet from the inlet when the pressure supplied to the inlet is equal to a calibration value dependent on the position of the member relative to the body , and
an operating device comprising a second hollow body which is connected to the first body
and in which two adjacent chambers
are formed, each of which is divided into a first space communicating with the air spring associated with one of the wheels and a second space
communicating with the atmosphere; the diaphragms being associated with respective transmission members which can move and cause a corresponding movement of the operating member relative to the first body due to the deformation of at least one of the diaphragms as a result of a variation in the pressure in the first space
of at least one of the chambers,
characterised in that the second spaces of the chambers communicate with the atmopshere through respective narrow passages whose dimensions are calibrated so that, in the event of the rupture of one of the diaphragms the flow of air from the corresponding air spring back to the atmosphere is limited.
2. A braking corrector device for a motor vehicle provided with a hydraulic braking system and an automatic levelling system with air springs, substantially as described and illustrated and for the purposes specified.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IT5388287U IT212351Z2 (en) | 1987-12-14 | 1987-12-14 | BRAKING CORRECTOR DEVICE FOR A VEHICLE EQUIPPED WITH A HYDRAULIC BRAKING SYSTEM AND AN AUTOMATIC LEVELING SYSTEM WITH PNEUMATIC SPRINGS |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8828642D0 GB8828642D0 (en) | 1989-01-11 |
| GB2213544A true GB2213544A (en) | 1989-08-16 |
Family
ID=11285760
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8828642A Withdrawn GB2213544A (en) | 1987-12-14 | 1988-12-08 | Braking corrector device for motor vehicle with hydraulic braking system and automatic levelling system with air springs |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPH01257649A (en) |
| DE (1) | DE3841803A1 (en) |
| ES (1) | ES2012897A6 (en) |
| FR (1) | FR2624461A1 (en) |
| GB (1) | GB2213544A (en) |
| IT (1) | IT212351Z2 (en) |
| SE (1) | SE8804420L (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6224044B1 (en) * | 1999-01-20 | 2001-05-01 | Continental Aktiengesellschaft | Level control system for a motor vehicle |
| US6524611B2 (en) | 1996-05-31 | 2003-02-25 | The Howard Foundation | Compositions containing creatine and creatinine |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0863066A1 (en) * | 1997-03-07 | 1998-09-09 | Same Deutz-Fahr S.P.A. | An agricultural tractor with self-levelling pneumatic suspension for the driver's cab |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1080876B (en) * | 1957-10-30 | 1960-04-28 | Westinghouse Bremsen Gmbh | Brake force regulator for the compressed air braking device on vehicles, especially motor vehicles, with air suspension |
| FR1284012A (en) * | 1960-12-30 | 1962-02-09 | Dba Sa | Improvements to braking correctors |
| FR89778E (en) * | 1966-03-17 | 1967-08-18 | Westinghouse Freins & Signaux | Braking correcting device depending on the load of a vehicle with pneumatic suspension and braking installation using this device |
| NL141626B (en) * | 1965-12-03 | 1974-03-15 | Bilstein August Fa | SHOCK ABSORBER. |
| US4302058A (en) * | 1980-02-25 | 1981-11-24 | Nippon Air Brake Co., Ltd. | Variable load valve device |
| IT1184048B (en) * | 1985-12-27 | 1987-10-22 | Magneti Marelli Spa | BRAKING SYSTEM FOR MOTOR VEHICLES EQUIPPED WITH SELF-LEVELING SUSPENSIONS WITH AIR SPRINGS |
-
1987
- 1987-12-14 IT IT5388287U patent/IT212351Z2/en active
-
1988
- 1988-12-07 SE SE8804420A patent/SE8804420L/en not_active Application Discontinuation
- 1988-12-08 GB GB8828642A patent/GB2213544A/en not_active Withdrawn
- 1988-12-09 JP JP31278488A patent/JPH01257649A/en active Pending
- 1988-12-12 DE DE19883841803 patent/DE3841803A1/en not_active Withdrawn
- 1988-12-13 FR FR8816388A patent/FR2624461A1/en not_active Withdrawn
- 1988-12-13 ES ES8803783A patent/ES2012897A6/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6524611B2 (en) | 1996-05-31 | 2003-02-25 | The Howard Foundation | Compositions containing creatine and creatinine |
| US6224044B1 (en) * | 1999-01-20 | 2001-05-01 | Continental Aktiengesellschaft | Level control system for a motor vehicle |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01257649A (en) | 1989-10-13 |
| GB8828642D0 (en) | 1989-01-11 |
| ES2012897A6 (en) | 1990-04-16 |
| IT212351Z2 (en) | 1989-07-04 |
| FR2624461A1 (en) | 1989-06-16 |
| DE3841803A1 (en) | 1989-06-22 |
| SE8804420L (en) | 1989-06-15 |
| IT8753882V0 (en) | 1987-12-14 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |