GB2132721A - Improvements in or relating to anti-skid brake pressure regulating systems for vehicles - Google Patents
Improvements in or relating to anti-skid brake pressure regulating systems for vehicles Download PDFInfo
- Publication number
- GB2132721A GB2132721A GB08332744A GB8332744A GB2132721A GB 2132721 A GB2132721 A GB 2132721A GB 08332744 A GB08332744 A GB 08332744A GB 8332744 A GB8332744 A GB 8332744A GB 2132721 A GB2132721 A GB 2132721A
- Authority
- GB
- United Kingdom
- Prior art keywords
- brake pressure
- brake
- wheel
- pressure regulating
- skid
- 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.)
- Granted
Links
- 230000001105 regulatory effect Effects 0.000 title claims abstract description 34
- 230000009467 reduction Effects 0.000 claims description 3
- 230000001360 synchronised effect Effects 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 4
- 230000033228 biological regulation Effects 0.000 description 14
- 238000010276 construction Methods 0.000 description 5
- 230000009471 action Effects 0.000 description 2
- 230000000875 corresponding effect Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
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
- B60T8/32—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
- B60T8/343—Systems characterised by their lay-out
-
- 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
- B60T13/58—Combined or convertible systems
- B60T13/581—Combined or convertible systems both hydraulic and pneumatic
Landscapes
- Engineering & Computer Science (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Regulating Braking Force (AREA)
Abstract
To reduce yaw effects in a vehicle having an anti-skid brake pressure regulating system (2, 7-10), a simple short-circuit or by- pass line (15) is provided between the two passage outlets of a brake pressure-regulating valve (2), or between the outlets of two single valves (Fig. 2 not shown) so that any differences in pressure in the two brake circuits can be equalized e.g. when one brake is released to prevent locking. The system can be used both in compressed air-brake systems and in hydraulic brake systems of vehicles. <IMAGE>
Description
SPECIFICATION
Improvements in or relating to anti-skid brake pressure regulating systems for vehicles
The present invention relates to anti-skid brake pressure regulating systems for vehicles.
In one form of anti-skid brake pressure regulating system for motor vehicles each wheel of an axle has an associated signal generator for generating a signal characterising the rotational behaviour of the wheel, and these signals are fed to an electronic switching device which on the basis of these signals produces brake pressure regulating signals which are fed to brake pressure regulating valves which have two outlet passages for separately influencing the brake pressure at the two wheels; the electronic switching device contains control means which prevent a substantial build-up of brake pressure at one wheel upon a reduction of brake pressure at the other wheel and which, upon a pulsed build-up of pressure thereafter at one wheel only permits a synchronous pulsed build-up of pressure at the other wheel.By these means it is possible to avoid large yawing moments at the commencement of braking when the brakes are fully applied and the wheels of an axle are running on a roadway having greatly differing coefficients of friction. However, considerable differences in brake pressure, and consequently larger yawing moments occur after a long braking time.
One anti-skid brake pressure regulating system is disclosed in German Offenlegungsschrift No.2,830,809 in which such yawing moments can be kept small by limitation. The ratio of the brake pressures is limited to approximately 2:1. However, such a difference between brake pressures at opposite sides of a vehicle is still too high in many travelling conditions and dangerous braking conditions can arise.
According to the present invention there is provided an anti-skid brake pressure regulating system for motor vehicles in which each wheel of an axle has an associated signal generator for generating a signal characterising the rotational behaviour of the wheel, an electronic switching device which is responsive to the characterising signals and which, on the basis of these signals, produces brake pressure regulating signals, and brake pressure-regulating valves which have two outlet passages for separately influencing the brake pressure at the two wheels and to which these brake pressures regulating signals are fed, the electronic switching device containing control means which prevent a substantial build-up of brake pressure at one wheel upon a reduction of brake pressure at the other wheel and, upon a pulsed build-up of pressure thereafter at one wheel also only permits a synchronous pulsed build-up of pressure at the other wheel, and in which the two outlet passages of the brake pressure regulating valves are interconnected by way of a short-circuit or bypass line.
An anti-skid brake pressure regulating system embodying the present invention can have the advantage that yawing moments are largely suppressed, thereby avoiding the above-mentioned dangerous braking conditions.
Furthermore, it is advantageous that this simple mode of operation can be achieved with a minimum of expense and without additional valves.
It would, in itself, be possible to obtain an equivalent device electronically by incorporating a select-low circuit in the electronic switching device instead of mechanically with a short-circuit or by-pass line. However, a switching device of this kind would require the use of additional components which is incompatible with the mass production customary at the present time.
Two standard types of brake pressure regulation are realised in the electronic switching device in commercial vehicles:
1. Individual regulation or, alternatively, regulation of individual wheels in which an individual regulating channel and a brakepressure regulating device (pressure-control valve) are associated with each sensed wheel, and
2. Modified individual regulation which, with the same components and regulating channels as those for individual regulation, includes a special regulating logic at least on one axle, usually the steering axle. The effect of the regulating logic is to prevent the pressure difference in the brake cylinders of this axle from exceeding a predetermined value, thereby keeping the yawing moment within limits during braking operations on roadways having differing skid-resisting properties.
While the action of the modified individual regulation to limit yawing moments has the effect of relieving the stress on drivers of motor vehicles on such critical roadways, pure individual regulation is more advantageous in the case of trailer vehicles. The improved braking action then keeps the coupling between the tractor and the trailer in a tractor vehicle and trailer combination generally tensioned.
To avoid confusion between the two regulating variants on the one hand and, on the other hand, to ensure that they do not make it necessary to provide special control devices, the two systems are provided together in conventional standard electronics. According to the type of vehicle, the correct regulating variant (motor vehicles with modified individual regulation, trailers with modified individual regulation) is established by the wiring, for example by an additional earth pin on the trailer. This means that the electronics are brought into the correct switching state by the wiring and thereby electronics of the same construction can be used selectively in motor vehicles and trailers.
The requirements for a third regulating variant, the select-low regulation (generally of an axle), arises from the fact that disc brakes are also partially used in commercial vehicles and are commonly actuated axle-wise by way of a braking unit (an actuating cylinder and a master cylinder). The realisation of the individual or, alternatively, modified individual regulation would, in this case, lead to duplication of the brake units.
However, by virtue of the construction of the short-circuit or by-pass line in a system embodying the present invention, it is possible to provide select-low regulation in a simple manner with standard components, and thus to commonly regulate the wheels of one axle by way of one brake unit. The procedure can be the same in the case of axles having only one brake cylinder.
The invention will be further described by way of example with reference to the accompanying drawings, in which:
Figure 1 is a diagrammatic illustration of a first embodiment of the invention having a two-channel brake pressure-regulating valve,
Figure 2 is a diagrammatic illustration of a second embodiment of the invention having two combined, single-channel brake pressureregulating valves, and
Figure 3 is a diagrammatic illustration of an embodiment having a two-channel brake pressure-regulating valve as in the embodiment of
Fig. 1, but with a single brake unit for both wheels of one axle.
Fig. 1 shows a brake pressure generator 1 which, by way of a brake pressure-regulating valve 2 having two outlet passages 1 6 and 17, supplies two wheel brake cylinders 3 and 4 associated with the wheels on a common vehicle axle.
A sensor 5 or 6 is provided on each vehicle wheel and the two sensors 5 and 6 are connected to an electronic switching device 7 which is equipped with standard electronics having an individual and a modified regulating action. The solenoids 8, 9, 10 of three solenoid valves 11, 12, 13, disposed in the brake pressure-regulating valve 2, are connected to the switching device 7.
The three solenoid valves 11, 12, 1 3 are located adjacent to one another in the brake pressure-regulating valve 2. The two outer solenoid valves 11 and 1 3 are two-port, twoposition solenoid valves and serve as brake pressure holding valves. The central solenoid valve 1 2 is a three-port, two-position solenoid valve which either opens or closes a passage leading from the brake pressure generator 1 to the brake cylinder 3 and 4 and, when the
said passage is closed, connects the brake
cylinders 3 and 4 to a pressure relief point
14.
The pressure levels in the two brake cylin
ders 3 and 4 can be equalized by way of a
short-circuit or by-pass line 1 5 provided
downstream of the brake pressure-regulating
valve 2 and upstream of the two brake cylin
ders 3 and 4.
The embodiment illustrated in Fig. 1 oper
ates as follows:
The brake pressure generator 1 is activated
when the brakes are to be applied. The brake
pressure introduced is applied to the brake 'cylinders 3 and 4 by way of the pressure
regulating valve 2. The brakes are applied.
When a wheel locking limit pressure is
reached, that is to say upon incipient wheel
lock, the wheel sensors 5 and 6 apply corre
sponding signals to the electronic switching
device 7. After these signals have been evalu
ated, the solenoids 8, 9, 10 are energized
and the two-port, two-position or three-port,
two-position solenoid valves 11, 12, 1 3 cut
off a further rise in the brake pressure, relieve
the brake pressure and subsequently increase
it again in a pulsed manner to the vicinity of
the wheel locking limit pressure.
During these actuating operations, the elec
tronic switching device 7 operates with modi
fied individual regulation. This individual regu
lation is then converted in a simple manner to
a regulating action in accordance with a se
lect-low by way of the short-circuit line 15, since the short-circuit line always allows the
pressure to flow from the side of the vehicle
subjected to lower brake pressure. The flow
ing-off of pressure then effects almost com
plete pressure equalization. Yawing moment
then no longer occurs. This also applies in the
case of pressure changes effected by the
regulating logic.
Fig. 2 shows that it is also possible to
embody the invention in a type of construction having two single-channel brake pressure
regulating valves 1 8 and 1 9 each having an
outlet passage 20. Otherwise, this type of
construction largely corresponds to that of
Fig. 1, even in its mode of operation.
Fig. 3 shows a type of construction in
which a two-channel brake pressure-regulating
valve 22, corresponding to the valve 2 of Fig.
1, is used. In this instance, in order to obtain
boosting with an individual characteristic of
the pressure controlled by the two passages
26, 27, a brake unit comprising an actuating
cylinder and a master cylinder would, in itself,
be required in each passage 26 and 27.
However, only a single brake unit 24 is
needed when a short-circuit line 23 is used as
a connection line. A hydraulic brake line 28
leads downstream of the brake unit 24 to two
hydraulic wheel brake cylinders 29 and 30.
A select-low characteristic can then also be
obtained in a simple manner with a device of this kind with standard electronics.
A system embodying the present invention can be used equally well in compressed-air brake systems and in hydraulic brake systems.
Claims (5)
1. An anti-skid brake pressure regulating system for motor vehicles, in which each wheel of an axle has an associated signal generator for generating a signal characterising the rotational behaviour of the wheel, an electronic switching device which is responsive to the characterising signals and which, on the basis of these signals, produces brake pressure regulating signals, and brake pressure-regulating valves which have two outlet passages for separately influencing the brake pressure at the two wheels and to which these brake pressure regulating signals are fed, the electronic switching device containing control means which prevent a substantial build-up of brake pressure at one wheel upon a reduction of brake pressure at the other wheel and, upon a pulsed build-up of pressure thereafter at one wheel also only permits a synchronous pulsed build-up of pressure at the other wheel, and in which the two outlet passages of the brake pressure regulating valves are interconnected by way of a short-circuit or bypass line.
2. An anti-skid brake pressure regulating system as claimed in claim 1, having two single-channel brake pressure-regulating valves, with the short-circuit or by-pass line provided between the two outlets of the two brake pressure-regulating valves.
3. An anti-skid brake pressure regulating system as claimed in claim 1 or 2, in which the short-circuit or by-pass line is a connection line leading to a common brake line for the two wheels of one axle.
4. An anti-skid brake pressure regulating system as claimed in clajm 3, in which a single brake unit for hydraulic brake cylinders of the two wheels on an axle is disposed in the short-circuit or by-pass line.
5. An anti-skid brake pressure regulating system constructed and arranged and adapted to operate substantially as hereinbefore particularly described with reference to and as illustrated in Fig. 1 or Fig. 2 or Fig. 3 of the accompanying drawings
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19823245763 DE3245763A1 (en) | 1982-12-10 | 1982-12-10 | ANTI-BLOCK PROTECTION CONTROL DEVICE |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8332744D0 GB8332744D0 (en) | 1984-01-18 |
| GB2132721A true GB2132721A (en) | 1984-07-11 |
| GB2132721B GB2132721B (en) | 1986-03-19 |
Family
ID=6180342
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08332744A Expired GB2132721B (en) | 1982-12-10 | 1983-12-08 | Improvements in or relating to anti-skid brake pressure regulating systems for vehicles |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS59114149A (en) |
| DE (1) | DE3245763A1 (en) |
| FR (1) | FR2537520B1 (en) |
| GB (1) | GB2132721B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61218463A (en) * | 1985-03-23 | 1986-09-27 | Toyota Motor Corp | Antiskid type hydraulic braking device |
| DE3526559A1 (en) * | 1985-07-25 | 1987-01-29 | Wabco Westinghouse Fahrzeug | ANTI-BLOCKING SYSTEM |
| DE4003122A1 (en) * | 1990-02-02 | 1991-08-08 | Knorr Bremse Ag | DEVICE FOR SECURING THE SIDEWAY PRESSURE EQUALITY IN ELECTRONICALLY CONTROLLED AIR BRAKE SYSTEMS OF VEHICLES, IN PARTICULAR COMMERCIAL VEHICLES |
| WO1995011823A2 (en) * | 1993-10-29 | 1995-05-04 | Grau Limited | Vehicle brake system |
| DE4340210C1 (en) * | 1993-11-25 | 1995-06-22 | Grau Gmbh | Anti-lock braking system for vehicles |
| DE19536356B4 (en) * | 1995-09-29 | 2004-10-28 | Knorr-Bremse Systeme für Nutzfahrzeuge GmbH | Compressed air braking system for vehicles, especially commercial vehicles |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0043896A1 (en) * | 1980-07-11 | 1982-01-20 | WABCO Westinghouse Fahrzeugbremsen GmbH | Antilock system |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2226304B1 (en) * | 1973-04-19 | 1977-03-04 | Wabco Westinghouse Gmbh | |
| DE2320559C2 (en) * | 1973-04-21 | 1987-05-07 | Wabco Fahrzeugbremsen Gmbh, 3000 Hannover | Anti-lock system |
| DE2625502C2 (en) * | 1976-06-05 | 1984-11-15 | Robert Bosch Gmbh, 7000 Stuttgart | Anti-lock device |
| DE2810219A1 (en) * | 1978-03-09 | 1979-09-20 | Bosch Gmbh Robert | PRESSURE CONTROL VALVE AGGREGATE II |
| DE2830809A1 (en) * | 1978-07-13 | 1980-01-31 | Bosch Gmbh Robert | ANTI-BLOCKING CONTROL SYSTEM |
| JPS56128251A (en) * | 1980-03-14 | 1981-10-07 | Nippon Air Brake Co Ltd | Hydraulic pressure control unit for brake system with skid control |
| DE3101731A1 (en) * | 1981-01-21 | 1982-08-26 | Wabco Fahrzeugbremsen Gmbh, 3000 Hannover | ANTI-BLOCKING SYSTEM, ESPECIALLY FOR A MULTI-AXIS VEHICLE |
| JPS58450A (en) * | 1981-06-25 | 1983-01-05 | Honda Motor Co Ltd | anti-lock braking system |
-
1982
- 1982-12-10 DE DE19823245763 patent/DE3245763A1/en active Granted
-
1983
- 1983-12-08 GB GB08332744A patent/GB2132721B/en not_active Expired
- 1983-12-09 JP JP23160083A patent/JPS59114149A/en active Pending
- 1983-12-09 FR FR8319792A patent/FR2537520B1/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0043896A1 (en) * | 1980-07-11 | 1982-01-20 | WABCO Westinghouse Fahrzeugbremsen GmbH | Antilock system |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2537520A1 (en) | 1984-06-15 |
| GB2132721B (en) | 1986-03-19 |
| DE3245763A1 (en) | 1984-06-14 |
| JPS59114149A (en) | 1984-07-02 |
| GB8332744D0 (en) | 1984-01-18 |
| FR2537520B1 (en) | 1991-10-25 |
| DE3245763C2 (en) | 1991-09-19 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19921208 |