WO2016074054A1

WO2016074054A1 - An on-ramp-start assistance system for automotive vehicles

Info

Publication number: WO2016074054A1
Application number: PCT/BR2015/050208
Authority: WO
Inventors: Carlos Abílio PASSOS TRAVAGLIA; Antônio Carlos DE OLIVEIRA; Luís Fernando NUSS DE SOUZA; Paula Mychelle BARROS MARINHO FERREIRA; Carlos Eduardo DE OLIVEIRA NOGUEIRA
Original assignee: Man Latin America Indústria E Comércio De Veículos Ltda.
Priority date: 2014-11-10
Filing date: 2015-11-09
Publication date: 2016-05-19
Also published as: UY36397A; AR102600A1; BR102014028097A2

Abstract

The invention relates to an on-ramp-start assistance system for rigid vehicles and towing vehicles with at least one drive shaft, one front axle and any number of tow axles, which makes use of a traction control system (ATC/ASR) derived from the ABS to feed and keep the braking pressure on all the brakes of the vehicle and of the tow through the valves of the traditional brake system, the ABS valves and the ATC/ASR system, the system being commanded by an electronic central and by sensor velocity, and enabling that, after the actuation of the service brake has ceased and by confirmation of the actuation of the on-ramp-start assistance function, the electronic central acts on the traction control valve and pressure control valves so as to keep the braking condition for a predetermined time period.

Description

Specification of the Patent of Invention for: "AM ON-RAMP-START ASSISTANCE SYSTEM FOR AUTOMOTIVE VEHICLES"

The present invention relates to an on-ramp-start assistance system for automotive vehicles, more specifically to a system for tows and/or large-size vehicles that promote actuation of brakes independently of direct command by the driver by means of electropneumatic logics.

DESCRIPTION OF THE PR!QR ART

Large-size vehicles, such as tows and buses, have certain inherent difficulty in moving in slope regions due to the fact that they are heavy and have an elongate geometry that is unfavorable to locomotion on uneven ground. The start and departure on a ramp are especially problematic, since in these conditions it is necessary to have torque sufficient to overcome the force composition that tends to cause the vehicle to go down from a null-acceleration point, which requires a relatively great effort on the part of the whole starting mechanism.

This difficulty in starting the vehicle on a ramp is well known, and a number of solutions have been developed and applied over the years. The most common solution known from the prior art is the use of brakes to facilitate the departure by controlling them by means of various pneumatic and mechanical systems. An example thereof is the system shown in patent BR 9301594, which relates to a device to be applied to a vehicle-brake system to aid in starting on a ramp.

The device of said patent comprises deformation sensors installed at the brakes to be controlled, which sends data to the control unit and then modifies the actuation of the brake system, so as to release the vehicle when the torque required for the start has been reached. Although this device achieves its objective, it makes use of a large number of solenoid valves and sensors to control each of the brakes, which becomes especially expensive and complex to operate when the objective is to adapt vehicles with a large number of axles, such as trucks and buses.

There are also on-ramp-start assistance systems that act only on the drive shaft of the vehicle, which enables the use of a smaller number of components to achieve the objective of the system. Patent BR 9705535 describes a start assistance system for use in parking lots which employs a traction control system (ABS + ATC/ASR) to modify the braking force on the drive shaft of the vehicle. For large-size vehicles, the braking control on only one of the shafts may prove to be insufficient to prevent movement of the vehicle in the direction opposite the desired displacement, since the braking torque from only one shaft is relatively small as compared to the strains generated by the weight of large-size vehicles.

There is still the possibility of controlling each shaft separately, in an independent manner, without using the ABS traction control system, as shown in patent BR 0801 158. This system is expensive and complex, since it is necessary to employ a set of sensors, valves and electric components for each brake to be operated.

OBJECTIVES OF THE INVENTION

In view of these negative aspects of the systems comprised by the prior art, the present invention aims at an on-ramp start assistance system that can control ail the brakes of an automotive vehicle assemble and further vehicles coupled to it, which can be applied in a practical and cost- saving manner and without addition of a large number of components that are not included in the original construction of the vehicle, by using only the wheel anti-blocking system and the traction-control system (ATC/ASR) coupled to appropriate pneumatic logics.

BRIEF DESCRIPTION OF THE INVENTION

The present invention has the objective of providing an on-ramp start assistance system for haul trucks and rigid vehicles, embracing an engine having at least one drive shaft, a front axle either without any shaft coupled to it or with one or more coupled axles, each having at each of its ends a wheel associated to a brake. The system is also composed by a traction-control system ATC/ASR derived from the ABS system, which comprises a traction-control valve, an ABS pressure-control valve associated to each brake of the drive shaft and an electronic control central, said central being connected to a service-brake sensor, to a rotation-velocity sensor attached to each wheel, to said traction-control valve and to said ABS pressure-control valves.

The electronic control central is further associated electronically to a control panel provided with a switch operable by the driver, which enables the function of aiding the start on a ramp. The system of the present invention is further provided with a brake valve operable by the driver by means of a brake pedal such that, upon actuation, enables passage of compressed air, the brake valve being pneumatically connected to the brakes of ail the vehicle shafts.

The on-ramp start assistance system functions upon actuation of the brake pedal. If the brakes are acting on command of the driver, when the actuation of the brake pedal ceases, the electronic central receives a signal from the service brake sensor indicating that it is inoperative and, if the function on~ramp aid function is actuated by means of the switch of the control panel the electronic centra! actuates the traction control valve so as to continue feeding air to the brakes for a predetermined time, the electronic central also actuating the ABS pressure control valves of the drive shaft, enabling one to keep the pressure intensity applied directly to the brakes of the drive shaft and indirectly to the brakes of the front and towed axles, the electronic central stopping actuation of the traction control valve after the predetermined time, or if the vehicle develops torque sufficient for on~ramp start.

The system further has a dual pilot control valve associated to the brakes of the front axle and a lower-pressure control valve associated to the brakes of the drive shaft to prevent the on-ramp start assistance system from interfering with the traction-control system ATC/ASR of the vehicle, while controlling directly the brakes of the front axle and of the towed axle. The predetermined time of feeding and keeping the pressure on the brakes is defined and controlled through the electronic control central.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described in greater detail with reference to an embodiment represented in the drawings. The figures show: - Figure 1 is a representation of the pneumatic circuit of the vehicle in which the system of the present invention is applied;

- Figure 2 is a representation of the pneumatic circuit of the towed axle, in which the system of the present invention is applied; and

- Figure 3 is a representation of the electronic circuit integrated to the electronic control central.

DETAILED DESCRIPTION OF THE FIGURES

As already evidenced, the prior art corresponding to systems for aiding in stationary start on a ramp has a number of solutions that exhibit great complexity in their electronic circuit, requiring extra control components such as relays, or else an ABS control unit with a larger number of control channels in order to control ail the vehicle wheels, including the towed one. Further, the prior art presents control systems that enable control of traction only on the drive shaft, that is, only on two wheels, which impairs the performance of the system on marked unleveied ground.

The present invention provides the control of all the wheels of the vehicle, including the wheels of any tow vehicle by interaction between the traction control system (ATC/ASR) and specific pneumatic logics for this function. Thus, there is no need to use any additional electronic component, or to modify the nature of the traction control system, thus configuring a more efficient and simple system than those comprised by the prior art, as will be explained.

Figure 1 shows the pneumatic circuit of the system proposed by the present invention applied to a vehicle 200, and Figure 2 shows a represents the application of the present invention in case the vehicle 200 has a one-axle tow. It should be noted that the invention is applicable to automotive vehicles that have an ABS, in addition to a traction control system ATC/ASR and make use of a pneumatic braking system, such as trucks, buses, tows, among others, such a vehicle either having a tow or not. It should be further noted that, for a better understanding of the pneumatic circuit presented in figures 1 and 2, the junction of the air lines is shown by a circle involving the lines that are joined, and the air-flowing direction is represented by an arrow at one of the ends of the line.

The vehicle 200, as shown in figure 1 , has a drive shaft 10 and a front axle 20, while figure 2 shows the tow associated to the vehicle having a coupled axle 30. Each axle 10, 20, 30 has at each of its two ends a wheel 1 1 , 12, 21 , 22, 31 , 32 associated to a pneumatic actuation brake 13, 14, 23, 24, 33, 34.

The vehicle 200 is further provided with a braking system having a brake valve 40 operated by the driver by means of a brake pedal (not shown). Said brake valve 40 has two inlets 41 , 42 and two outlets 43, 44, and when actuated it enables passage of compressed air through the two outlets. The braking system further has a control valve 130 that has two inlets 131 , 132 and two outlets 133, 134, the passage of air being only released to the outlets 133, 134 when both inlets 131 , 132 are fed.

The braking system of the present invention further includes a lower-pressure control valve 1 10 and a dual-pilot control valve 70. The dual- pilot control valve 70 has three inlets 71 , 72, 73 and two outlets 74, 75, wherein passage of air is allowed when two or more inlets are fed, and the air coming out is that among the inlets 71 and 73 that has higher pressure. On the other hand, the lower-pressure control valve 1 10 has two inlets 1 1 1 , 1 12 and one outlet 1 13, wherein the passage of air is allowed when the two inlets are fed, and the air that comes out is that from the inlet with lower pressure. Moreover, the system presents a pair of higher-pressure selective valves 170, which enable higher-pressure passage between two inlets.

If should be further noted that in this preferred embodiment of the system, the inlet 73 of the dual-pilot control valve 70 is constantly fed by the reservoir 410, and the inlet 132 of the control valve 130 is constantly fed by the reservoir 400.

As can be seen in figure 3, the vehicle 200, when applied to its braking system, relies upon a traction control system 50, 60, 100 formed by a traction control valve 50, which controls two pressure control valves 60 of the ABS of the drive shaft by means of an electronic control central 100. This set of components, coupled to others not cited, constitutes the ABS (Anti-lock braking system) composed by the ATC/ASR system (wheel drive control). Originally, this system was developed for monitoring and acting on the braking and acceleration of the vehicle wheels and improving their performance in cases of loss of torque. In the scope of this invention, the system has been adapted electronically and pneumatically to aid in starting the vehicle on a ramp, as will be explained latter.

Further in the scope of the traction control system 50, 60, 100, the electronic central 100 has connection with velocity sensors 500 positioned on the wheels 1 1 , 12, 21 and 22 of the vehicle 200, with the traction control valve 50, with the pressure control valves 60 and with the brake sensor 210 associated to the brake pedal operated by the drive. It further has connection with a control panel 120 positioned in the driver's cabin, on which there is a operable switch 121 that turn on or off the on-ramp start aid function.

It should be noted that the pneumatic connections between the components of the system may be made by any connection elements applicable to the particularity of the path to be traveled. For instance, one may use cables, tubing elbows, "T's", among others, and one observes that the arrangement of these connections varies immensely according to the vehicle, the components, the project particularities and still according to the preferences of the designer. Bearing this in mind, such connection elements will not be discriminated in this description, only the interaction between the circuit components.

The initial braking of the system of the present invention is similar to that used traditionally on haul trucks and rigid vehicles with pneumatic brakes. The brake valve 40 receives compressed air from the reservoirs 400, 41 Ό in its two inlets 41 , 42, respectively, and when actuated it feeds the brakes 13, 14, 23, 24, 34 of all the axles 10, 20, 30 of the vehicle. In the system proposed by this invention, the compressed air from the outlet 44 of the brake valve 40 is led to the inlet 72 of the dual-pilot control valve 70, thus enabling passage of air to the brakes 23, 24. For the drive shaft 10, the compressed air passes through the control valve 130. After the initial braking, and at the moment when the driver withdraws his feet from the brake pedal, the brake sensor 210 sends a signal to the electronic central 100 and the latter verifies the state of the switch 121 on the control panel 120. If it is actuated, this means that the on-ramp aid function is active, and the electronic central 100 actuates the traction control valve 50 and the pressure control valves 60 of the ABS of the drive shaft, and initiates the count of a predetermined time for operation of the assistance system. The time used in this preferred embodiment is 3-second operation.

The traction control valve 50 is fed by the reservoir 400, and upon actuation it releases compressed air to the inlet 131 of the control valve 130, thus allowing passage of air to the brakes 13, 14 of the drive shaft 10. The pressure control valves 60 of the ABS of the drive shaft actuated by the electronic central 100 keep the braking pressure used before in the initial braking, and so the braking of the drive shaft 10 is provided directly. After feeding the brakes 13, 14 of the drive shaft 10, the compressed air flows to the inlets 1 1 1 , 1 12 of the lower-pressure control valve 1 10, passing through its outlet 1 13 and actuating the brakes 23 and 24 of the front axle 20 indirectly by means of the inlet 71 of the dual-pilot control valve 70.

As shown in figure 2, if the vehicle has a tow connected to it, the air from the outlet 1 13 of the lower-pressure control valve 1 10 is also led to the brakes 33, 34 of the connected axle 30 by means of a feeding line B and a control line A, passing through three other pressure control valves 140, 150, 160 connected to the reservoirs 420 and 430. The valve 140 controls both the feeding pressure of the trailer (line B) and the control pressure (line A), while the valve 150 controls the pressure in the pneumatic line of ail the trailer axles. On the other hand, the valve 160 has the function of releasing the pressure of the outlet of the relay valve of the trailer to the frailer brakes. Thus, one keeps the braking condition for the tow and for the front axle directly.

The electronic central 100 keeps the count of three seconds while the braking process discriminated above is kept. The braking is interrupted if the count reaches three seconds or if the electronica central 100 feels that there is sufficient traction on the wheels to enable the vehicle to start on a ramp. When one says that the braking is interrupted, this means that the electronic central interrupts the actuation of the traction control valve 50, consequently interrupting the feed of air of the control valve 130, thus stopping the feed of air to the brakes 13, 14, 23, 24, 33, 34. Further, when the count reaches two seconds, the electronic central 100 sends a signal to the control panel 120, which emits a sound signal to the driver, indicating that the on-ramp start system is about to be deactivated.

A preferred example of embodiment having been described, one should understand that the scope of the present invention embraces other possible variations, being limited only by the contents of the accompanying claims, which includes the possible equivalents.

Claims

1 . An on-ramp-starl assistance system for automotive vehicles comprising:

- an automotive vehicle (200) having a drive shaft (10), a front axle (20) either without coupled axles (30) or with one or more coupled axle

(30), each axle (10, 20, 30) having at each of its two ends a wheel (1 1 , 12, 21 , 22, 32) associated to a brake (13, 14, 23, 24, 33, 34);

- a traction control system (50, 60, 100) comprises a traction control valve (50), pressure control valves (60) associated to the brakes (13, 14) of the drive shaft (10) and an electronic control central (100), the electronic control central (100) being connected to a service brake sensor (80), to rotation velocity sensors (90), attached to the drive- shaft wheels (1 1 , 12), to said traction control valve (50) and to said pressure control valves (60);

- the electronic control central (100) being electronically associated to a control panel (120) of the vehicle, the control panel (120) having a switch (121 ) operable by the vehicle driver, which enables actuation of the on-ranip-start aid function;

- a brake valve (40) operable by the driver by means of a brake pedal in such a manner that, when actuated, it enables passage of compressed air, the brake valve (40) being pneumatically connected to the brakes (13, 14, 23, 24, 33, 34) of ail the axles of the vehicle (200) and of the tow (300);

the system being characterized in that, after release of the brake pedal by the driver, when the air feed of the brake valve (40) is stopped, the electronic central (100) receives a signal from the service brake sensor (80) indicating that the service brake is inoperative;

if the on-ramp-aid function is actuated, the electronic central (100) actuates the traction control valve (50) so as to continue to feed air to the brakes (13, 14, 23, 24, 33, 34) for a predetermined time;

the electronic central (100) also actuating the pressure control valves (60), enabling one to keep the pressure intensity applied to the brakes (13, 14, 23, 24, 33, 34) of the drive shaft (10), front axle (20) and of the tow (30);

the electronic central (100) stopping the actuation of the traction control valve (50) by counting a predetermined time or if the vehicle develops torque sufficient for the start.

2. The system according to claim 1 , characterized by having a dual-pilot control valve (70) associated to the brakes (23, 24) of the front axle (20),

3. The system according to claim 1 , characterized by having a lower- pressure control valve (1 10) associated to the brakes (13, 14) of the drive shaft (10), to the brakes (23, 24) of the front axle (20) and (33, 34) of the towed axle (30).

4. The system according to claim 1 , characterized in that the predetermined time of feeding and keeping the pressure on the brakes (13, 14, 23, 24, 33, 34) is defined and by the electronic control central (100).

5. The system according to claim 1 , characterized in that the on-ramp- start assistance system provided by the switch (121 ) on the control panel (120) is automatically deactivated when the vehicle reaches a velocity higher than 40 km/h.

8. The system according to claim 1 , characterized in that the predetermined time for keeping the actuation of the on-ramp-start assistance system is of 3 seconds.

7. The system according to claim 6, characterized in that, after actuation of the on-ramp-start assistance system, a sound warning is emitted from the control panel (100) 2 seconds later.