US-12623646-B2 - Emergency brake system for a heavy-duty vehicle

US12623646B2US 12623646 B2US12623646 B2US 12623646B2US-12623646-B2

Abstract

An emergency brake system for a heavy-duty vehicle, comprising: a pressure sensor arrangement configured to issue a first signal, S 1 , upon determination that the pressure in a regular brake circuit is zero or below a predefined pressure threshold value, a speed sensor configured to issue a second signal, S 2 , upon determination that the speed of the heavy-duty vehicle exceeds a predefined speed threshold, a parking-brake sensor configured to issue a third signal, S 3 , upon determination that the parking brake is in an applied state, a retarder brake configured to decelerate the heavy-duty vehicle upon activation of the retarder brake, a processing circuitry configured to activate the retarder brake upon receiving all of said three signals S 1 , S 2 and S 3.

Inventors

Maheshwari SARANGAMATH
Amarnath JEYAKAR M R
Pravin ELANGOVAN
Dilip Kumar

Assignees

VOLVO TRUCK CORPORATION

Dates

Publication Date: 20260512
Application Date: 20241021
Priority Date: 20231102

Claims (12)

1 . An emergency brake system for a heavy-duty vehicle, comprising: a pressure sensor arrangement configured to determine the pressure in a first regular brake circuit of a service brake system of the heavy-duty vehicle, wherein said pressure sensor arrangement is further configured to determine the pressure in a second regular brake circuit of the service brake system of the heavy-duty vehicle, wherein upon determination by the pressure sensor arrangement that the pressure in each of the first and the second regular brake circuits is zero or below a predefined pressure threshold value, the pressure sensor arrangement is configured to issue a first signal, S 1 ; a speed sensor configured to determine the speed of the heavy-duty vehicle, wherein upon determination by the speed sensor that the speed of the heavy-duty vehicle exceeds a predefined speed threshold, the speed sensor is configured to issue a second signal, S 2 ; a parking-brake sensor configured to determine a state of a parking brake of the heavy-duty vehicle, wherein upon determination by the parking-brake sensor that the parking brake is in an applied state, the parking-brake sensor is configured to issue a third signal, S 3 ; a retarder brake configured to decelerate the heavy-duty vehicle upon activation of the retarder brake; and processing circuitry operatively connected to said pressure sensor arrangement, said speed sensor and said parking-brake sensor, wherein, upon receiving all of said three signals S 1 , S 2 and S 3 , the processing circuitry is configured to activate the retarder brake.
2 . The emergency brake system of claim 1 , further comprising: an auxiliary valve provided in an auxiliary brake circuit extending from an auxiliary pressure source to brake chambers of service brakes of the heavy-duty vehicle, wherein the auxiliary valve has an open state in which pressurized air is allowed to flow from the auxiliary pressure source via the auxiliary brake circuit to said brake chambers, and a closed state in which pressurized air is prevented from flowing from the auxiliary pressure source via the auxiliary brake circuit to said brake chambers, wherein, upon receiving all of said three signals S 1 , S 2 and S 3 , the processing circuitry is configured to open the auxiliary valve to allow pressurized air from the auxiliary pressure source to actuate said service brakes.
3 . The emergency brake system of claim 2 , wherein the auxiliary valve comprises an exhaust port, wherein in the closed state of the auxiliary valve, pressurized air present in the part of the auxiliary brake circuit that extends between the auxiliary valve and said brake chambers is allowed to be evacuated through the exhaust port.
4 . The emergency brake system of claim 2 , wherein said brake chambers form part of front axle service brakes of the heavy-duty vehicle.
5 . The emergency brake system of claim 2 , wherein the auxiliary valve is a solenoid valve actuated into an open state by an electric signal from the processing circuitry.
6 . The emergency brake system of claim 2 , further comprising: a shuttle valve having three openings, a first opening to a brake chamber of the service brake of the heavy-duty vehicle, a second opening to said auxiliary brake circuit, and a third opening to the first regular brake circuit, wherein when the first regular brake circuit supplies pressurized air to the shuttle valve, the shuttle valve closes fluid communication between the brake chamber and the auxiliary brake circuit.
7 . The emergency brake system of claim 1 , further comprising: a driver alert interface, wherein upon receiving all of said three signals S 1 , S 2 and S 3 , the processing circuitry is configured to send an alert message or signal to the driver alert interface so as to alert the driver to downshift to a lower gear.
8 . The emergency brake system of claim 1 , wherein upon receiving all of said three signals S 1 , S 2 and S 3 , the processing circuitry is configured to activate a brake taillight and/or hazard light of the heavy-duty vehicle in order to warn drivers in other vehicles.
9 . A heavy-duty vehicle comprising the emergency brake system according to claim 1 .
10 . The heavy-duty vehicle of claim 9 , further comprising a manual retarder brake switch which is manually controllable by a driver to activate the retarder brake independently of the emergency brake system.
11 . An emergency brake system for a heavy-duty vehicle, comprising: a pressure sensor arrangement configured to determine the pressure in a regular brake circuit of a service brake system of the heavy-duty vehicle, wherein upon determination by the pressure sensor arrangement that the pressure in the regular brake circuit is zero or below a predefined pressure threshold value, the pressure sensor arrangement is configured to issue a first signal, S 1 ; a speed sensor configured to determine the speed of the heavy-duty vehicle, wherein upon determination by the speed sensor that the speed of the heavy-duty vehicle exceeds a predefined speed threshold, the speed sensor is configured to issue a second signal, S 2 ; a parking-brake sensor configured to determine a state of a parking brake of the heavy-duty vehicle, wherein upon determination by the parking-brake sensor that the parking brake is in an applied state, the parking-brake sensor is configured to issue a third signal, S 3 ; a retarder brake configured to decelerate the heavy-duty vehicle upon activation of the retarder brake; processing circuitry operatively connected to said pressure sensor arrangement, said speed sensor and said parking-brake sensor, wherein, upon receiving all of said three signals S 1 , S 2 and S 3 , the processing circuitry is configured to activate the retarder brake; and a gear box, wherein upon receiving all of said three signals S 1 , S 2 and S 3 , the processing circuitry is configured to control the gear box of the heavy-duty vehicle to downshift to a lower gear.
12 . An emergency brake system for a heavy-duty vehicle, comprising: a pressure sensor arrangement configured to determine the pressure in a regular brake circuit of a service brake system of the heavy-duty vehicle, wherein upon determination by the pressure sensor arrangement that the pressure in the regular brake circuit is zero or below a predefined pressure threshold value, the pressure sensor arrangement is configured to issue a first signal, S 1 ; a speed sensor configured to determine the speed of the heavy-duty vehicle, wherein upon determination by the speed sensor that the speed of the heavy-duty vehicle exceeds a predefined speed threshold, the speed sensor is configured to issue a second signal, S 2 ; a parking-brake sensor configured to determine a state of a parking brake of the heavy-duty vehicle, wherein upon determination by the parking-brake sensor that the parking brake is in an applied state, the parking-brake sensor is configured to issue a third signal, S 3 ; a retarder brake configured to decelerate the heavy-duty vehicle upon activation of the retarder brake; and processing circuitry operatively connected to said pressure sensor arrangement, said speed sensor and said parking-brake sensor, wherein, upon receiving all of said three signals S 1 , S 2 and S 3 , the processing circuitry is configured to activate the retarder brake, wherein the processing circuitry comprises, in series connection, a first switch, a second switch and a third switch, each switch having an open state and a closed state, wherein the first, second and third switches are configured to become closed by the signals S 1 , S 2 , and S 3 , respectively, wherein when at least one of the first, second and third switches is open, the processing circuitry is prevented from activating the retarder brake, wherein when each one of the first, second and third switches is closed, an electrical signal is sent to the retarder brake so as to activate the retarder brake.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority to European Patent Application No. 23207445.0, filed on Nov. 2, 2023, the disclosure and content of which is incorporated by reference herein in its entirety. TECHNICAL FIELD The disclosure relates generally to brake systems. In particular aspects, the disclosure relates to an emergency brake system for a heavy-duty vehicle. The disclosure can be applied to heavy-duty vehicles, such as trucks, buses, and construction equipment, among other vehicle types. Although the disclosure may be described with respect to a particular vehicle, the disclosure is not restricted to any particular vehicle. BACKGROUND Heavy-duty vehicles are provided with brake circuits in which pressurized air is used for providing a braking action. Many heavy-duty vehicles have a primary and a secondary brake circuit. If brake circuit pressure fails so that satisfactory braking action is not available, the parking brake may still be used to help stopping the heavy-duty vehicle. However, the stopping distance is very long when using the parking brake. For emergency situations, it would therefore be desirable to shorten the stopping distance in case of brake circuit pressure failure. SUMMARY According to a first aspect of the disclosure, there is provided an emergency brake system for a heavy-duty vehicle. The emergency brake system comprises: a pressure sensor arrangement configured to determine the pressure in a regular brake circuit of a service brake system of the heavy-duty vehicle, wherein upon determination by the pressure sensor arrangement that the pressure in the regular brake circuit is zero or below a predefined pressure threshold value, the pressure sensor arrangement is configured to issue a first signal, S1, a speed sensor configured to determine the speed of the heavy-duty vehicle, wherein upon determination by the speed sensor that the speed of the heavy-duty vehicle exceeds a predefined speed threshold, the speed sensor is configured to issue a second signal, S2, a parking-brake sensor configured to determine a state of a parking brake of the heavy-duty vehicle, wherein upon determination by the parking-brake sensor that the parking brake is in an applied state, the parking-brake sensor is configured to issue a third signal, S3, a retarder brake configured to decelerate the heavy-duty vehicle upon activation of the retarder brake, a processing circuitry operatively connected to said pressure sensor arrangement, said speed sensor and said parking-brake sensor, wherein, upon receiving all of said three signals S1, S2 and S3, the processing circuitry is configured to activate the retarder brake. The first aspect of the disclosure may seek to reduce the stopping distance of a heavy-duty vehicle in an emergency situation when the regular brake circuit to the service brakes does not work properly. A technical benefit may include that by enabling retarder braking in addition to parking braking, the stopping distance will be reduced compared to if only parking braking would be used. The processing circuitry may thus get information through the first signal S1 that the pressure in the brake circuit is too low. The pressure sensor arrangement may suitably have a pressure measuring point between a pressurized air tank and a foot brake valve of the heavy-duty vehicle. Through the second signal S2, the processing circuitry may get information that the heavy-duty vehicle is currently travelling at a relatively high speed. Through the third signal S3, the processing circuitry may get information that the parking brake has been applied. These three pieces of information, i.e., non-working brake circuit, high speed, and applied parking brake, may collectively be interpreted by the processing circuitry as an emergency situation, wherefore the processing circuitry may activate the retarder brake in order to shorten the stopping distance. The retarder brake may be located at the propeller shaft of the heavy-duty vehicle, in particular, the retarder brake may be located between a vehicle engine/motor and a differential in the propeller shaft. Under normal driving conditions, the retarder may suitably be activated by a driver, for example by controlling a retarder switch, when the driver desires retarder braking. When the driver manually activates the retarder brake switch, the retarder brake may receive an electrical signal through the retarder switch. Activation of the retarder brake creates resistance in the propeller shaft rotation, thereby providing a braking force to the heavy-duty vehicle. The present disclosure, however, is focused on automatic activation of the retarder brake in an emergency situation, without requiring the driver to manually activate the retarder brake. By automatically adding the retarder brake during an emergency event, the stopping distance can be reduced for the heavy-duty vehicle. The retarder brake may, for example, be an electrical retarde