Pneumatic brake device for a vehicle and method for operating a brake device
By evaluating driver control signals and selecting the exhaust gradient through the brake control unit, the noise pollution problem during brake exhaust in commercial vehicles is solved, achieving noise reduction while maintaining vehicle behavior, especially significantly reducing noise interference when the vehicle is parked.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZF CV SYST GLOBAL GMBH
- Filing Date
- 2024-11-14
- Publication Date
- 2026-06-19
AI Technical Summary
Noise pollution is a problem caused by exhaust from the brakes of commercial vehicles, especially when the vehicle is parked or when the parking brake is activated by exhaust. Existing technologies make it difficult to reduce noise emissions while maintaining vehicle behavior.
The brake control unit evaluates the driver's operating signals based on vehicle control commands and selects operating modes with different exhaust gradients, including rapid exhaust and noise-optimized exhaust. It determines the exhaust gradient by evaluating the operation of the brake pedal, accelerator pedal, and clutch pedal to perform rapid exhaust or optimize noise emissions when necessary.
It effectively reduces noise emissions during brake exhaust, meeting the driver's needs for vehicle behavior, and significantly reducing noise interference, especially when the vehicle is parked.
Smart Images
Figure CN122249351A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for operating a braking device for a vehicle according to claim 1, the braking device having a pneumatic brake that is released by venting from an exhaust valve, wherein a brake control unit operates the exhaust valve according to a preset exhaust gradient. The invention also relates to a braking device for a vehicle according to claim 6, the braking device having a pneumatic brake. Furthermore, the invention relates to a vehicle according to claim 7. Background Technology
[0002] In commercial vehicles, wheels are typically braked using pneumatically operated wheel brakes. To operate the pneumatic brakes, braking pressure is applied via an intake valve, and the brakes are bleed by correspondingly operating an exhaust valve. This bleed-out process generates noise, which is particularly noticeable when the brake pressure is significantly reduced and the brakes are released. This noise is often perceived as unpleasant by those around the vehicle, especially when bleed-out while the vehicle is stationary, such as when releasing the parking brake, the service brake's holding function ("auto hold"), or when the parking brake is activated by bleed-out operation.
[0003] In principle, controlling the exhaust valve with a gentler exhaust gradient—that is, reducing pressure more slowly during exhaust—can reduce noise. However, in many cases, a slower exhaust is insufficient to achieve the desired vehicle behavior. A slower exhaust, in particular, often does not meet the vehicle control required by the driver. Summary of the Invention
[0004] The purpose of this invention is to reduce noise emissions from vehicles equipped with pneumatic brakes during brake exhaust.
[0005] This objective is achieved by a method for operating a pneumatic braking device having the features of claim 1. This objective is also achieved by a pneumatic braking device having the features of claim 6. Furthermore, a vehicle having the features of claim 7 also achieves this objective.
[0006] According to the present invention, after evaluating the current vehicle control command it receives, the brake control unit selects from at least two operating modes with different exhaust gradients. In normal operating mode, the brake control unit operates the exhaust valve according to an exhaust gradient preset for quiet exhaust, optimized to reduce noise emissions during exhaust. In rapid exhaust operating mode, it operates the exhaust valve according to an exhaust gradient optimized for rapid exhaust. Here, the exhaust gradient should be understood as the temporal progression of pressure reduction during brake exhaust, which is generated by specifically controlling the exhaust valve using corresponding control signals. The exhaust gradient optimized for reducing noise emissions typically corresponds to a longer exhaust process duration than that required for exhaust and also set in the rapid exhaust operating mode. Here, slower exhaust generally results in significantly quieter exhaust noise.
[0007] Therefore, this invention distinguishes between a rapid exhaust operation mode and a normal operation mode based on the evaluation results. In the rapid exhaust operation mode, an exhaust gradient is preset for rapid exhaust, while in the normal operation mode, an exhaust gradient optimized for low noise emissions is preset, resulting in quieter but slower exhaust. Thus, rapid exhaust with corresponding noise emissions will only occur as an exception when required by vehicle control commands.
[0008] Vehicle control commands are information conveyed by the driver through the operation of pedals within the driver's cab regarding their control decisions or requests for the vehicle's operating mechanisms. Therefore, when selecting operating modes with different exhaust gradients, the brake pedal's operating signals and / or acceleration signals (Fahrsignals) are evaluated. In manual transmission vehicles, it is advantageous to also incorporate clutch operation into the evaluation and selection of preset operating modes with different exhaust gradients.
[0009] For vehicle control commands from driver assistance systems or virtual drivers, it is advantageous to evaluate “release brake” signals and / or acceleration requests to select an operating mode and the exhaust gradient associated with that operating mode.
[0010] Therefore, in order to select an operating mode with an exhaust gradient set for that operating mode according to the present invention, parameters, namely operating mode selection parameters, are derived from the vehicle control commands, from which the vehicle behavior desired by the driver is inferred. Operating mode selection is based on these operating mode selection parameters. Advantageously, the operating mode selection parameters are derived from the vehicle control commands of the current operation of the pedals, particularly the brake pedal and / or accelerator pedal. Here, the position or motion parameters of the relevant pedals can be monitored as operating mode selection parameters, such as the rate of change of the pedal position or parameters derived from that rate. By evaluating these parameters, it is possible to distinguish between situations where exhaust must be exhausted as quickly as possible and situations where an exhaust gradient optimized for noise generation during exhaust is set. To derive the operating mode selection parameters for determining the exhaust gradient, the brake control unit receives displacement sensor signals from each of the pedals via a connection to it.
[0011] To derive operating mode selection parameters from vehicle control commands, such as preset normal values for the travel of relevant pedals and the time required to complete that travel during operation, the deviation from the normal values is evaluated for the selected exhaust gradient during assessment. If the evaluation results indicate that, for example, the brake pedal completes a specific pedal travel in a relatively short time, this indicates a need for rapid exhaust, unlike situations where the brake pedal travel time is relatively long. When the brake pedal travels slowly, there is time for slower exhaust; therefore, in this case, the exhaust gradient that leads to noise optimization in normal operating mode selection is evaluated.
[0012] In a preferred embodiment of the invention, in order to select an operating mode and a corresponding exhaust gradient, motion parameters of the brake pedal position change are evaluated so as to select between an exhaust gradient for rapid exhaust, i.e., a rapid exhaust operating mode, and another operating mode with an exhaust gradient optimized for noise generation.
[0013] In another advantageous embodiment of the invention, motion parameters of the accelerator pedal position and / or changes in accelerator pedal position are evaluated. Here, requesting drive power by manipulating the accelerator pedal indicates a need for brake exhaust. The evaluation of parameters determined by the accelerator pedal is particularly advantageous and persuasive when combined with the evaluation of parameters determined by the brake pedal. Here, it is inferred from pedal switching or pedal interaction whether an exhaust gradient should be preset according to a rapid exhaust operation mode to achieve rapid exhaust, or whether a noise-optimized exhaust gradient can be preset.
[0014] In manual transmission vehicles, the clutch pedal serves as an additional data source when evaluating and selecting the optimal exhaust gradient. For example, if the brake is released but the clutch pedal is not depressed, there is no expectation of moving the vehicle; the driver simply wants to release the brake while the vehicle is stationary. The same applies if the driver remains 100% on the clutch pedal, or has been doing so for an extended period.
[0015] In a preferred embodiment of the invention, when selecting an operating mode, preset limit values for the operating mode selection parameters are used to distinguish the rapid exhaust operating mode from at least one other operating mode in which an exhaust gradient optimized for low noise emissions is preset. If multiple operating modes are provided in addition to the rapid exhaust operating mode, multiple limit values are correspondingly determined to evaluate the operating mode selection parameters and distinguish the corresponding operating modes with their respective preset exhaust gradients, and these limit values are preset to the brake control unit.
[0016] If, within the normal operating mode, other operating modes with their own exhaust gradients are selected based on the operating mode selection parameters derived from vehicle control commands—that is, determined by the driver through the operation of at least one control pedal—the reduction in exhaust noise emissions can be further refined through a preset optimized exhaust gradient. Driving conditions, especially whether the vehicle is traveling at low speeds or even stationary, can also be considered. A noise-optimized exhaust gradient is particularly advantageous for stationary conditions, as exhaust noise can be particularly unpleasant in these situations, such as during parking braking or in the automatic parking mode of the service brake. If the driver releases the brake while the vehicle is stationary, the slower exhaust and correspondingly gentler exhaust gradient can significantly reduce noise generation.
[0017] The brake exhaust according to the invention, based on an exhaust gradient selected according to the operation of at least one pedal, particularly the brake pedal, is particularly advantageous in commercial vehicles, especially trucks or buses. Attached Figure Description
[0018] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Wherein:
[0019] Figure 1 A pneumatic and electrical schematic diagram of an embodiment of a pneumatic braking device for a commercial vehicle is shown;
[0020] Figure 2 It shows the method for running according to Figure 1 A flowchart of an embodiment of a braking device method. Detailed Implementation
[0021] Figure 1An electro-pneumatic schematic diagram of the pneumatic braking device 1 of vehicle 2, a commercial vehicle 2a, is shown. In the illustrated embodiment, the vehicle is a bus 2b equipped with a stop braking function. Electrical wiring is indicated by solid lines, and pneumatic wiring by dashed lines. Each wheel 3 is equipped with a brake 4 for braking, which is pneumatically operated by a brake cylinder 5. The brake 4 applies braking force to the rotating wheel 3 according to the pneumatic braking pressure P present in the brake cylinder 5. In the illustrated embodiment, the front axle wheel brakes 4 are equipped with a common first braking circuit 6, while the rear axle wheel brakes 4 are operated by a second braking circuit 7. Here, a first pressure medium reservoir 8 is associated with the first braking circuit 6 and connected to the brake cylinder 5 of the front axle brake 4. The second braking circuit 7 of the rear axle is supplied with pressure medium through a second pressure medium reservoir 9. The structure of the second braking circuit 7 is similar to that of the first braking circuit 6.
[0022] Each brake cylinder 5 of the brake 4 is connected upstream of a pressure control valve 10, which is electrically operable. To receive control signals, the pressure control valve 4 is connected to a brake control unit 9. The brake control unit 9 is designed and configured to influence the braking pressure P of the brake 4 as needed. In the illustrated embodiment, the pressure control valves 10 are combinations of at least two solenoid valves, namely an intake valve 12 and an exhaust valve 13. Here, the intake valve 12 is primarily used to increase or maintain the pressure in the corresponding brake cylinder 5, while the exhaust valve 13 is opened to reduce the braking pressure and allow the brake 4, specifically, the corresponding connected brake cylinder 5, to exhaust air. The intake valve 12 and the exhaust valve 13 are preferably electrically operable two-position two-way valves.
[0023] To control the intake valve 12 and exhaust valve 13, the brake control unit 11 considers the vehicle control commands 38 preset by the driver of vehicle 2 via the control pedals in the cab—namely, the brake pedal 18 and the accelerator pedal 22—and, in the case of a manual transmission vehicle, the clutch pedal 21. Upon detecting a braking request, the brake control unit 11 sets a corresponding braking pressure P at the brake 3 and outputs a control signal 20 to the intake valve 12 for this purpose. The braking request is conveyed by the driver of vehicle 2 via the brake signal transmitter 17 of the brake pedal 18. The driver conveys a driving request by manipulating the accelerator pedal 22. Braking and / or driving requests can also be preset by a virtual driver, for example, during autonomous driving, or as an external braking request from the driver assistance or stability system 14 of commercial vehicle 2a. Braking requests also include requests for the automatic parking function or parking brake of the braking device 1, which share the common feature of applying a specific braking pressure at the brake actuator to keep vehicle 2 at a stop, and maintaining this braking pressure until the brake 4 is released. Similar to a braking request, for a parking brake, pneumatic pressure is applied to release the brake, which is engaged by venting.
[0024] Releasing the brake 4 by venting air is achieved by opening the corresponding vent valve 13, which is operated by the brake control unit 11 using the control signal 23. The release request can be derived from the evaluation of the brake signal 16 on the brake pedal 18, or from a preset by the virtual driver.
[0025] The brake control unit 11 determines the control signal 23 for operating the exhaust valve 13 based on the exhaust gradient EG, i.e., a preset time dynamic for determining the opening of the exhaust valve 13. Multiple operating modes are set here, each with a different exhaust gradient EG. To perform operating mode selection 26, operating mode selection parameters 25 are derived from the vehicle control command 38. Therefore, operating mode selection parameters 25 are characterized by the operation of at least one pedal. To derive operating mode selection parameters 25 and thus the exhaust gradient EG, the brake signal 16 of the brake pedal 18 is used and evaluated against the vehicle behavior desired by the driver. In the illustrated embodiment, to determine the exhaust gradient EG, the evaluation 15 also considers the acceleration signal 22 of the accelerator pedal 19, which the driver can use to request drive of the vehicle 2. In a manual transmission vehicle, the clutch signal 24 of the clutch pedal 24 is also used to derive the operating mode selection parameters 25 and ultimately evaluate the driver's operating behavior.
[0026] The following reference Figure 2 The preset exhaust gradient and the determination of the control signal 23 for exhaust valve 13 are explained. Here, the same features are used accordingly. Figure 1 The same reference numerals are used in the accompanying drawings. If it is determined from the current operation of one or more pedals that it is necessary to reduce the existing braking pressure by venting the brakes, a specific operating mode 29, 30, 31 is determined, and a preset exhaust gradient EG1, EG2, EG3 is determined in that operating mode, which serves as the basis for the output 33 of the control signal 23 for the exhaust valve 13. The operating mode selection 26 and the determination of the exhaust gradients EG1, EG2, EG3 therefrom are determined by an evaluation 15 of at least one operating mode selection parameter 25, which is characterized by the current operation of the pedals. In operating mode selection 26, the result is to distinguish a rapid exhaust operating mode 30 from at least one other operating mode, in which an exhaust gradient EG for rapid exhaust is preset, and in which exhaust gradients optimized for low noise emissions are preset. In the illustrated embodiment, a normal operating mode 29 and another operating mode 31 (parking operating mode 31) for parking or low-speed driving are provided. When the brakes are to hold the vehicle 2, i.e., the bus 2c equipped with a stop brake in the embodiment, in a stopped state, the stop operation mode 31 is set to the stop braking function of the braking device or automatic parking.
[0027] To select the operating mode 26, and thereby choose between the exhaust gradient EG2 for rapid exhaust (i.e., rapid exhaust operating mode 30) and another operating mode with exhaust gradients EG1 and EG3 optimized for noise generation, the change 34 of the brake pedal 18 position is derived from the brake signal 16 and determined as the decisive operating mode selection parameter 26. The change 34 of the brake pedal 18 position, as a motion parameter, is the speed of movement of the brake pedal 18 or another motion parameter derived therefrom that contains qualitative information about the movement of the brake pedal 18. Optionally, a normal value for the travel of the brake pedal 18 is preset here, taking into account the time required to complete that travel during operation. When evaluating and deriving the operating mode selection parameter 25 and thereby selecting the exhaust gradients EG1, EG2, and EG3 to be set, the determined deviation from the normal value is evaluated. In this embodiment, the rapid exhaust operating mode 30 is then distinguished from the normal operating mode by comparing the determined deviation from the normal value with a preset limit value 27.
[0028] Additionally, when selecting the operating mode 26 and thereby choosing the ideal exhaust gradients EG1, EG2, EG3, the position of the accelerator pedal 22 and / or the motion parameters of changes in the position of the accelerator pedal 22 are also evaluated. Considering the information provided by the accelerator pedal 22 is particularly advantageous and persuasive when the operating mode selection 26 is based on a combined evaluation of the information from the accelerator pedal 22 and the brake pedal 18, in conjunction with the parameters provided by the brake pedal 18. Here, it can be inferred from pedal switching or pedal interaction whether the exhaust gradient EG2 should be preset according to the rapid exhaust operating mode 30 and rapid exhaust should be achieved, or whether a noise-optimized exhaust gradient EG1 can be preset. If the driver releases the brake pedal in a relatively short time, such as 0.3 seconds, and depresses the accelerator pedal in a short transition time, such as less than 0.5 seconds, this emphasizes the desire for immediate start. If no signal is received from the accelerator pedal, the brakes have more time to exhaust, and a noise-optimized exhaust gradient EG2 can be preset and set via the exhaust valve 13.
[0029] The vehicle 2 shown is a manual transmission vehicle, in which the clutch pedal 21 is used as an additional data source when selecting operating mode 26 for different operating modes with different exhaust gradients EG1, EG2, EG3. For example, if the brake is released but the clutch pedal 21 is not depressed, there is no desire to move the vehicle, i.e., the driver only wants to release the brake when the vehicle is stationary.
[0030] List of reference numerals (part of the instruction manual)
[0031] 1. Braking device
[0032] 2 Commercial vehicles
[0033] 3 wheels
[0034] 4. Brake
[0035] 5. Brake cylinder
[0036] 6 First Braking Circuit
[0037] 7 Second Braking Circuit
[0038] 8 First pressure medium storage tank
[0039] 9 Second pressure medium storage tank
[0040] 10 Pressure control valve
[0041] 11 Brake Control Unit
[0042] 12 Intake valve
[0043] 13. Exhaust valve
[0044] 14. Driver Assistance Systems
[0045] 15 Export
[0046] 16 Braking signal
[0047] 17 Braking signal transmitter
[0048] 18. Brake pedal
[0049] 19 Accelerator Pedal
[0050] 20 Intake valve control signal
[0051] 21 Clutch pedal
[0052] 22 Acceleration Signal
[0053] 23 Exhaust valve control signal
[0054] 24 Clutch signal
[0055] 25 Operating Mode Selection Parameters
[0056] 26. Operating Mode Selection
[0057] 27 Limit Values
[0058] 28. Control signal output for exhaust valve
[0059] 29 Normal Operating Mode
[0060] 30. Rapid Exhaust Operation Mode
[0061] 31 Parking Operation Mode
[0062] 32 Presets
[0063] 33 Control signal output
[0064] 34. Changes in the position of the brake pedal
[0065] 35. Position of the accelerator pedal
[0066] 36. Changes in the position of the accelerator pedal
[0067] 37 Clutch pedal operation
[0068] 38 Vehicle Control Commands
[0069] P Braking pressure
[0070] Exhaust gradient in normal operating mode of EG1
[0071] Exhaust gradient in EG2's rapid exhaust operation mode
[0072] Exhaust gradient in EG3 parking mode
Claims
1. A method for operating a braking device (1) for a vehicle (2), the braking device having a pneumatic brake (4) and a brake control unit (11), the brake control unit receiving vehicle control commands (38) (for acceleration and / or braking) and operating the corresponding brake by braking pressure (P) and venting it through an exhaust valve (13), wherein, The brake control unit (11) selects (26) from at least two operating modes (29, 30, 31) with different exhaust gradients (EG1, EG2, EG3) in consideration of the current vehicle control command (38), and operates the exhaust valve (13) in the normal operating mode (29) according to the exhaust gradient (EG1) optimized for reducing noise emissions during exhaust, and operates the exhaust valve (13) in the rapid exhaust operating mode (30) according to the exhaust gradient (EG2) optimized for rapid exhaust.
2. The method according to claim 1, characterized in that, The operating mode selection (26) is based on the operating mode selection parameter (25), which is derived (15) from the vehicle control command (38) currently operated by the brake pedal (18) and / or accelerator pedal (19).
3. The method according to claim 2, characterized in that, The operating mode selection parameter is derived (15) from the position change (34) of the brake pedal (18).
4. The method according to claim 2 or 3, characterized in that, The operating mode selection parameter is derived (15) from the position (35) of the accelerator pedal (19) and / or the change (36) of the position (35) of the accelerator pedal (19).
5. The method according to any one of claims 2 to 4, characterized in that, When selecting an operating mode (26), a preset limit value (27) for the operating mode selection parameter (25) is used to distinguish the rapid exhaust operating mode (30) from at least one other operating mode (29, 31) in which an exhaust gradient (EG) optimized for reducing noise emissions is preset.
6. A braking device (1) for a vehicle (2), the braking device comprising: a pneumatic brake (4) operable by braking pressure (P) and capable of venting exhaust via an exhaust valve (13); and a brake control unit (11) for operating the exhaust valve (13) according to a preset exhaust gradient (EG), wherein, The brake control unit (11) is designed to receive vehicle control commands (38) and, taking into account the current vehicle control command (38), select (26) from at least two operating modes (29, 30, 31) with different exhaust gradients (EG1, EG2, EG3), and operate the exhaust valve (13) in the normal operating mode (29) according to the exhaust gradient (EG1) optimized for reducing noise emissions during exhaust, and in the rapid exhaust operating mode (30) according to the exhaust gradient (EG2) optimized for rapid exhaust.
7. A vehicle (2), particularly a commercial vehicle (2a), having a braking device (1) according to claim 6, particularly for implementing the method according to any one of claims 1 to 5.
8. The vehicle (2) according to claim 7, characterized in that, The vehicle (2) is a bus (2b).