Brake System for a Motor Vehicle and Trailer Control Module

Abstract

A trailer air supply and control module for a electronic brake system of a motor vehicle with a trailer interface, and a brake system of a motor vehicle with a trailer interface comprising the trailer air supply and control module, includes at least two electrical terminals configured to receive two independent but redundant electrical control input signals which comprise a signal for a preset brake control outlet pressure. At least one valve is configured to adjust a constant air pressure from an air pressure source to the preset brake outlet pressure. One pneumatic outlet terminal is configured to provide the preset brake supply outlet pressure to the pneumatic brake system of the trailer, and one pneumatic outlet terminal is configured to provide the preset brake control outlet pressure to the pneumatic brake system of the trailer.

Claims

1-11. (canceled)

12. A trailer control module for a brake system of a motor vehicle with a trailer having a pneumatic brake system, the trailer control module comprising: at least two electrical terminals configured to receive two independent but redundant electrical control input signals corresponding to a signal for a preset brake control outlet pressure; at least one pneumatic inlet terminal configured to receive compressed air from an air pressure source; at least one valve configured to adjust a constant air pressure from the air pressure source to the preset brake outlet pressure; a first one pneumatic outlet terminal configured to provide a brake supply outlet pressure to the pneumatic brake system of the trailer; and a second pneumatic outlet terminal configured to provide the preset brake control outlet pressure to the pneumatic brake system of the trailer.

13. The trailer control module according to claim 12, wherein the trailer control module includes at least two control solenoid groups, each the at least two solenoid groups forming part of a control channel including at least one load valve and at least one exhaust valve.

14. The trailer control module according to claim 13, wherein the at least one exhaust valve of a first one of the at least two solenoid control groups is a normally opened exhaust valve configured to provide normally not parked trailer control for each control channel.

15. The trailer control module according to claim 13, wherein the at least one exhaust valve of a second one of the at least two solenoid groups is a normally closed exhaust valve, and the normally closed exhaust valve and a feedback orifice are configured to provide for normally parked trailer control for each control channel.

16. The trailer control module according to claim 13, wherein the at least one exhaust valve of a second one of the at least two solenoid groups is a normally closed exhaust valve, the normally closed exhaust valve and a feedback orifice are configured to provide for normally parked trailer control for a first control channel, and the at least one exhaust valve of a first one of the at least two solenoid control groups is a normally opened exhaust valve configured to provide normally not parked trailer control for a second control channel.

17. The trailer control module according to claim 13, wherein each of the at least one exhaust valve of the at least two solenoid groups is a normally closed exhaust valve, and the normally closed exhaust valves and a feedback orifice are configured to provide for normally parked trailer control for both control channels.

18. The trailer control module according to claim 13, wherein each of the at least one exhaust valve of the at least two solenoid control groups is a normally opened exhaust valve configured to provide normally not parked trailer control for both control channels.

19. The trailer air supply and control module according to claim 12, further comprising: at least two independent pressure sensors configured to measure the brake control outlet pressure of the trailer.

20. The trailer air supply and control module according to claim 12, further comprising: a hold back valve configured to trigger automatic trailer emergency braking when a trailer brake pressure supply line is disconnected when a trailer is connected to a motor vehicle.

21. A motor vehicle brake system comprising: at least two independent brake control units; and a trailer control module having at least two electrical terminals configured to receive two independent but redundant electrical control input signals corresponding to a signal for a preset brake control outlet pressure, at least one pneumatic inlet terminal configured to receive compressed air from an air pressure source; at least one valve configured to adjust a constant air pressure from the air pressure source to the preset brake outlet pressure, a first one pneumatic outlet terminal configured to provide a brake supply outlet pressure to the pneumatic brake system of the trailer, and a second pneumatic outlet terminal configured to provide the preset brake control outlet pressure to the pneumatic brake system of the trailer; an air pressure source configured to supply a constant pneumatic pressure to the brakes of a trailer, wherein each brake control unit is configured to provide an independent but redundant electric control signal to the trailer control module.

22. The motor vehicle brake system according to claim 21, further comprising: a communication line between a trailer and the brake control units, and a multiplexer configured to permit only one of the at least two brake control units to be connected with the trailer at a time.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 a schematic layout of the motor vehicle brake system according to an embodiment of the invention.

[0018] FIG. 2 a schematic layout of the architecture of a TCM according to and embodiment of the invention.

DETAILED DESCRIPTION

[0019] FIG. 1 shows a schematic layout of the motor vehicle brake system according to an embodiment of the invention. The brake system according to the invention is powered by at least two independent electric energy sources 40a, 40b and controlled by at least two independent electronic control units 10a, 10b (ECU). The foot brake sensor 30 is operated by the operator of the motor vehicle in case that braking is necessary. The signal is provided at both, the first ECU 10a and the second ECU 10b. Further, a parking brake control 31 is connected with at least one of the ECUs 10a, or 10b. Both the parking brake control 31 and the foot brake sensor 30 are connected with the ECUs 10a, 10b via analog or digital electrical lines 90. The first ECU 10a is further connected with the second ECU 10b via a digital electric signal line 80. Both ECUs 10a, 10b are capable of controlling at least four wheel brake units 50a, 50b, 50c, 50d via a digital electrical line 80, so that both ECUs 10a, 10b are capable of commanding the wheel brake units 50a-50d through at least two independent communication lines.

[0020] The wheel brake units 50a, 50b as well as the first ECU 10a are powered by the first electric energy source 40a, while the wheel brake units 50c, 50d and the second ECU 10b are powered by the second electric energy source 40b.

[0021] In order to achieve braking performance of the trailer, both ECUs 10a, 10b send redundant electric signals via analog or digital electric lines 90 to a trailer control module (TCM) 20, which provides a braking outlet pressure to the trailer brake system. The TCM 20 is further connected to an air pressure source 60, which provides the TCM 20 with a constant pneumatic pressure. Thus, apart from the air pressure source 60, the TCM 20 is only provided with electric signals to adjust the brake pressure for the trailer.

[0022] A multiplexer 70 is connected with the trailer via a standardized CAN-bus according to ISO 11992 known from the state of the art and either passes the signals from the first ECU 10a or of the second ECU 10b to the trailer. It can be either physical (by an active switch) or functional (by e.g. an interconnected bus to both brake control units and a master is commanding and a slave is listening).

[0023] In operation, the operator (driver) of the motor vehicle operates the foot brake sensor (30) for normal service brake needs and the parking brake control, if a movement of the vehicle in standstill is to be prevented. The electric signal is passed to both ECUs 10a, 10b, where a necessary braking force is calculated, according to which the ECUs 10a, 10b control the wheel brake units 50a, 50b, 50c, 50d of the motor vehicle via the corresponding digital electric signal lines 80. Further, the information of a brake pressure, which needs to be applied to the pneumatic brake system of the trailer is passed via electric signals to the TCM 20 via the analog or digital electric line 90. With the given signals by the ECUs 10a, 10b and the constant pressure of the air pressure source 60, the TCM adjusts the demanded brake pressure and provides it to the brake system of the trailer. Further, information of either one of the ECUs 10a, 10b is provided to the trailer according to the position of the multiplexer 70 via the CAN-bus.

[0024] FIG. 2 shows a schematic layout of the architecture of a TCM according to an embodiment of the invention. The pneumatic pressure of the air pressure source 60 is provided at an air pressure source inlet A. The air pressure source inlet A is connected via an air pressure source pressure line 23 with a hold back valve 25 and two solenoid valves 21b and 21c. Both of them are in the following also referred to as load valves 21b, 21c and are in a normally closed state. At each side of the load valves 21b, 21c, two further solenoid valves 21a, 21d are positioned, which are also referred to as exhaust valves 21a, 21d, the exhaust valve 21a being in a normally opened state and the exhaust valve 21d being in a normally closed state. All of the four solenoid valves 21a-21d are controlled by the electric signals of the two ECUs 10a, 10b of the brake system of the motor vehicle. The solenoid valves 21a, 21b form one group controlled by the first ECU 10a and the solenoid valves 21c, 21d form a second group controlled by the second ECU 10b.

[0025] From both of the load valves 21b, 21c, a control pressure line 24 to the hold back valve 25 and to the corresponding exhaust valve 21a, 21d of each group is formed. Further the control pressure lines 24 from the load valves 21b, 21c also connect a dual channel relay valve 26 and an orifice 27. A further pressure line, referred to as exhaust pressure line 22, leads from the outlets of the exhaust valves 21a, 21d and the dual channel relay valve 26 to an exhaust outlet terminal B, where pressure, which is not needed anymore in the system, can be released to the atmosphere.

[0026] Moreover, one outlet of the hold back valve 25 is connected to one inlet of the dual channel relay valve 26 via a first outlet brake pressure supply line 29a, which also leads to a first outlet brake pressure terminal C. As mentioned above, one outlet of the dual relay valve 26 is connected to the exhaust outlet terminal B. Another outlet of the dual relay valve 26 is connected to a second outlet brake pressure control terminal D by a second outlet brake pressure line 29b. The pressure in the second outlet brake pressure line 29b is measured by two pressure sensors 28a, 28b, which are permanently connected via an analog or digital line with both ECUs 10a, 10b.

[0027] In the embodiment of the invention shown in FIG. 2, the pressure provided by the air pressure source 60 at the air pressure source inlet A is provided directly at the first outlet brake pressure supply terminal C under normal operation and switches to its orifice position in case of an unexpected trailer disconnection to introduce an emergency braking to the trailer.

[0028] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.

REFERENCE LIST

[0029] 10a first electronic control unit [0030] 10b second electronic control unit [0031] 20 Trailer control module [0032] 201a, 201b electrical terminal [0033] 21a, 21d solenoid valve: exhaust valve [0034] 21b, 21c solenoid valve: load valve [0035] 22 exhaust pressure line [0036] 23 air pressure source pressure line [0037] 24 control pressure line [0038] 25 hold back valve [0039] 26 dual channel relay valve [0040] 27 orifice [0041] 28a, 28b pressure sensors [0042] 29a compressed air brake supply outlet [0043] 29b compressed air brake control outlet [0044] 30 foot brake sensor [0045] 31 parking brake control [0046] 40a first electric energy source [0047] 40b second electric energy source [0048] 50a, 50b, 50c, 50d wheel brake unit [0049] 60 air pressure source [0050] 70 multiplexer [0051] 80 digital electric signal line [0052] 90 analog or digital electric line [0053] A air pressure source inlet [0054] B exhaust outlet terminal [0055] C compressed air brake supply terminal to the trailer ??? [0056] D compressed air brake control terminal to the trailer