Method of operating a brake system, brake system, program product, module and vehicle

Abstract

The invention relates to a method for operating a parking brake system (FSY) with a spring-loaded brake (FSB) and a control module (EH, AM) in a motor vehicle (ZG) or trailer (AG), wherein the control module (EH, AM) is coupled to a parking brake circuit (BK3, BK4), supplies the parking brake circuit (BK3, BK4) with a reserve pressure (pV) and loads a spring-loaded brake cylinder (FBA, FBZ) with a spring-loaded accumulator holding pressure (pH) in order to occupy a release position of the spring-loaded brake (FSB), and wherein the spring-loaded brake cylinder (FBA, FBZ) is loaded with a spring-loaded accumulator holding pressure (pH) which is lower than the reserve pressure (pV) in the parking brake circuit (BK3, BK4).

Description

Technical Field

[0001] This invention relates to a method for operating an electro-pneumatic parking brake system. Furthermore, the invention also relates to an electro-pneumatic parking brake system, a computer program product, an electro-pneumatic control module, and a vehicle having a parking brake system.

[0002] In particular, the present invention relates to a method for a parking brake system having a spring-accumulated brake and a control module for use in a powered vehicle or trailer, wherein the control module is connected to the parking brake circuit, supplies reserve pressure to the parking brake circuit and applies spring accumulator holding pressure to the spring-accumulated brake cylinder to cause the spring-accumulated brake to occupy the release position. Background Technology

[0003] In vehicles with electro-pneumatic braking systems, especially commercial vehicles, an electronic control unit drives an electro-pneumatic valve to regulate braking pressure. This electro-pneumatic valve transmits braking pressure pneumatically to the brake cylinder of the braking system in accordance with the required vehicle rated deceleration.

[0004] Electro-pneumatic braking systems for vehicles include service brake systems and parking brake systems. The service brake system has an electronic control unit for driving the electro-pneumatic valve assembly, thereby applying braking pressure to the brake cylinder of the service brake.

[0005] The parking brake system has a spring-accumulated brake. The force used to operate this brake is applied through a spring accumulator located in the spring-accumulated brake cylinder. The spring-accumulated brake cylinder is only inflated to release the spring-accumulated brake. When the spring-accumulated brake cylinder is deflated, the spring-accumulated brake engages and brakes the vehicle.

[0006] For example, DE 10 2017 006 356 A1 discloses an electro-pneumatic braking system with a spring-storage brake.

[0007] To operate a spring-accumulated brake, an electric switch can be installed in the vehicle's cab, which sends a corresponding signal to the electronic control unit of the parking brake system. The electronic control unit then switches one or more electro-pneumatic valve assemblies, causing the spring-accumulated brake cylinder to either deflate or refill. This system is also known as an electro-pneumatic handbrake.

[0008] The electro-pneumatic handbrake also includes an electro-pneumatic control module, which has a pneumatic input for connection to the brake circuit of the electro-pneumatic braking system and a pneumatic output for connection to a spring-accumulated brake cylinder. The reserve pressure of the connected brake circuit is typically applied at the input. The output pressure at the output is the pressure applied to the spring-accumulated brake cylinder. If the output pressure is zero, the spring-accumulated brake cylinder is deflated. If the output pressure equals the reserve pressure, the spring-accumulated brake cylinder is inflated and the spring-accumulated brake is released. Here, the output pressure present when the spring-accumulated brake is released is called the spring accumulator holding pressure.

[0009] Spring-stored brakes are operated not only by an electric switch in the cab, but also by other electronic or pneumatic systems present in the vehicle, such as when the reserve pressure in the vehicle's brake circuit drops, when a break occurs in the wiring between the tractor and trailer, when the trailer and tractor become detached, or for other reasons. In certain situations, it may be necessary or useful to operate the spring-stored brakes particularly quickly.

[0010] Depending on the implementation plan and intended use, the parking brake system can be implemented wholly or partially pneumatically. Accordingly, a pneumatic or electro-pneumatic control module can be provided.

[0011] The reserve pressure in a parking brake system is predetermined by laws, regulations, and / or technical standards. The same applies to the spring accumulator release pressure. This spring accumulator release pressure is the lowest pressure at which the spring accumulator has not yet transmitted any force to the lever in the spring-accumulated brake, i.e., the lowest pressure at which there is no braking effect caused by the spring-accumulated brake cylinder. Once the pressure drops below the spring accumulator release pressure, braking effect occurs. The spring accumulator release pressure can also be specified by the brake system manufacturer within a range of predetermined parameters. The spring accumulator release pressure is significantly lower than the reserve pressure to ensure that the spring-accumulated brake can be fully released. Summary of the Invention

[0012] The objective of this invention is to provide a method by which a spring-loaded brake can be switched particularly quickly from a fully released state to a braking state.

[0013] To solve this problem, the method according to the invention has the following features. Specifically, a spring accumulator holding pressure lower than the reserve pressure in the parking brake circuit is applied to the spring accumulator brake cylinder. Of course, the spring accumulator holding pressure is still higher than the spring accumulator release pressure. However, the range between the spring accumulator release pressure and the spring accumulator release pressure is lower than that commonly seen to date. This results in a lower mass of air required to bleed the spring accumulator brake cylinder compared to previous methods. Therefore, the spring accumulator brake can be engaged more quickly. The method according to the invention shortens the time until the spring accumulator brake engages.

[0014] The holding pressure of the spring accumulator is not necessarily the highest pressure at the output of the preferred electro-pneumatic control module. For example, a higher pressure can be briefly adjusted to quickly release the spring accumulator. After releasing the spring-accumulated brake, the holding pressure of the spring accumulator is then adjusted back to the previous setting.

[0015] According to another aspect of the invention, the spring accumulator holding pressure can be 1 to 5 bar lower than the reserve pressure. Advantageously, the spring accumulator holding pressure can be adjusted accordingly. In Europe, the reserve pressure in the braking circuit is preferably 8.5 bar. Starting from this pressure or other pressures, the spring accumulator holding pressure is adjusted to be 1 to 5 bar lower.

[0016] Advantageously, the spring accumulator holding pressure is 1.5 to 3 bar lower than the reserve pressure, or is adjusted accordingly. In Europe, the spring accumulator release pressure is typically 5 to 5.5 bar. Holding the spring accumulator at a pressure 1.5 to 3 bar lower than the reserve pressure ensures, on the one hand, a sufficient range between the spring accumulator release pressure and on the other hand, significantly higher speeds when engaging the spring-accumulated brake.

[0017] According to another aspect of the invention, the spring accumulator holding pressure is at least higher than the spring accumulator release pressure by a safe range, preferably at least 1 to 2 bar. The desired safe range is used to calculate and adjust the spring accumulator holding pressure, and deviations or fluctuations in the spring accumulator release pressure that may occur in practice should be taken into account. The spring accumulator release pressure is related to the characteristics of the spring-accumulated brake and can be determined either by testing or as information from the manufacturer. The characteristics of the spring-accumulated brake may also change due to wear and corrosion.

[0018] According to another concept of the invention, the holding pressure of the spring accumulator can be determined by a valve assembly that functions as a pressure limiter, pressure reducer, or pressure regulator. Preferably, this relates to a purely pneumatic solution that is effective even in the event of a power outage or control module failure, and is particularly suitable for trailers.

[0019] According to another aspect of the invention, the holding pressure of the spring accumulator can be adjusted by regulating the valve assembly in a computer-controlled manner. This computer-controlled adjustment allows for precise and reproducible settings, particularly in electro-pneumatic braking systems. Further adjustments can then be made to the program control.

[0020] The method according to the invention can be advantageously used in parking brake systems in tractor-trailers or power vehicles and trailers.

[0021] The invention also includes a parking brake system for use in powered vehicles or trailers, and particularly for performing the method according to the invention. Advantageously, the parking brake system comprises a spring-accumulated brake and a control module, wherein the control module is connected to a brake circuit, supplies a reserve pressure to the brake circuit, and is capable of loading a spring accumulator holding pressure onto the spring-accumulated brake cylinder to position the spring-accumulated brake in the released position. According to the invention, an adjusting device is provided for adjusting the spring accumulator holding pressure to a value lower than the reserve pressure in the brake circuit. Thus, the parking brake system can deflate the spring-accumulated brake significantly faster than previously possible. Preferably, the invention relates to an electro-pneumatic parking brake system, and particularly to an electro-pneumatic control module.

[0022] According to another aspect of the invention, the parking brake system may include a valve assembly having an input pressure and an output pressure, wherein the valve assembly provides a spring accumulator holding pressure as the output pressure. The input pressure is preferably a reserve pressure of the relevant braking circuit. The valve assembly is here used to determine or adjust the spring accumulator holding pressure. Advantageously, the valve assembly is or includes at least one pressure regulating valve with or without a venting function, alternatively a pressure limiting valve or a pressure reducing valve. Their purpose is to provide the desired spring accumulator holding pressure, respectively.

[0023] According to another aspect of the invention, the parking brake system may have an electronic control device that can regulate the output pressure of the valve assembly. The electronic control device and the valve assembly work together to regulate the output pressure.

[0024] According to another aspect of the invention, the parking brake system may have a pressure sensor for sensing the output pressure and transmitting it to the electronic control unit. The pressure sensor enables a rapid adjustment loop.

[0025] According to another concept of the invention, the valve assembly can have a pneumatic relay valve and an electro-pneumatic proportional valve, wherein an output pressure is applied at the output end of the valve assembly, the relay valve receives control pressure from the proportional valve, and the proportional valve is driven by an electronic control device to adjust the output pressure. Thus, the output pressure can be effectively adjusted with minimal equipment cost. The proportional valve can also be implemented using a time-controlled switching valve or an assembly composed of time-controlled switching valves.

[0026] According to another concept of the invention, the valve assembly and electronic control device can be components of the control module. This achieves a high degree of integration of the required components.

[0027] According to another aspect of the invention, the valve assembly may include a pressure-limiting valve. The pressure-limiting valve enables the setting of a defined output pressure without electronic components. This is a particularly robust solution, preferably suitable for purely pneumatic parking brake systems.

[0028] According to another concept of the invention, the valve assembly may have a check valve connected in parallel with the pressure relief valve. This allows for adjustment of potentially higher output pressures based on lower input pressures.

[0029] According to another concept of the invention, the valve assembly can be integrated into the control module. This avoids the need for additional components outside the control module, especially for electro-pneumatic systems.

[0030] According to another concept of the invention, the valve assembly can be integrated into the pneumatic control circuit between the parking valve assembly and the control module. This arrangement allows for easy retrofitting to existing parking brake systems.

[0031] According to another concept of the invention, the valve assembly can be integrated into the brake cylinder assembly. Each brake cylinder is provided with a valve assembly containing a pressure relief valve. The brake cylinder is preferably a combined brake cylinder comprising a service brake cylinder and a spring-accumulated brake cylinder. This is more expensive than a central valve assembly, but provides greater redundancy.

[0032] According to another concept of the invention, the valve assembly can be integrated into the pneumatic operating circuit between the control module and the spring-accumulated brake cylinder. The spring-accumulated brake cylinder can be a component of a combined brake cylinder. This embodiment allows for simple retrofitting and high redundancy.

[0033] According to another concept of the invention, the control module is an axle modulator. This improves integration and avoids the need for additional structural space beyond the existing components of the parking brake system. Advantageously, the axle modulator is also a component of the service brake system and also controls the service brake.

[0034] The invention also includes computer program products. These computer program products particularly include instructions that, when executed on the electronic control unit of the control module in the parking brake system, implement the method according to the invention.

[0035] Furthermore, the subject of this invention is an electro-pneumatic control module having an electronic control device, which is used in the parking brake system according to the invention.

[0036] Finally, the subject of this invention is a vehicle having a parking brake system according to the invention.

[0037] All aspects of this invention are applicable to or can be applied to tractor units and trailers, provided they have an electro-pneumatic or pneumatic parking brake system. Attached Figure Description

[0038] Further features of the invention will become apparent from the following description. Advantageous embodiments of the invention will now be explained in more detail with reference to the accompanying drawings. Wherein: Figure 1 A schematic diagram of the electro-pneumatic braking system in the tractor unit is shown. Figure 2 The electro-pneumatic control module of the electro-pneumatic parking brake system within the electro-pneumatic braking system is shown. Figure 3 A schematic diagram of a valve assembly with a pressure relief valve and a check valve is shown. Figure 4 This diagram shows a highly simplified illustration of a parking brake system in a trailer, which features an integrated... Figure 3 The modulator of the valve assembly; Figure 5 Show similar Figure 4 The implementation method is different, but it has a valve assembly integrated in the control circuit between the parking valve and the modulator. Figure 6 Show similar Figure 4 The implementation method is the same, but with a valve assembly integrated into the parking valve; Figure 7 Show similar Figure 4 The implementation method is the same, but it has a valve assembly integrated into the combined brake cylinder; Figure 8 Show similar Figure 4 The implementation method, but with a valve assembly integrated in the working circuit between the modulator and the spring-accumulated brake cylinder; Figure 9 A qualitative diagram showing the time-dependent pressure change curve during the deflation of a spring-accumulated brake cylinder. Detailed Implementation

[0039] Figure 1 A simplified diagram shows an electro-pneumatic braking system 10 for a tractor ZG having a front axle 11 and a rear axle 12. The basic structure of the braking system 10 is known and similarly disclosed in DE 10 2017 006 356 A1.

[0040] The following description will only consider components relevant to understanding the invention. Here, the braking system 10 has three pneumatic braking circuits BK1, BK2, and BK3, each with a ballast I, II, and III, respectively. The compressor serving as the compressed air source is not shown, nor are any multi-circuit protection valves that may be present.

[0041] An axle modulator MV for the front axle 11 is provided in the braking circuit BK2. The front axle service brake cylinder BZV of the front axle 11 is connected to the axle modulator MV.

[0042] An axle modulator for the rear axle 12 (not shown in detail) is assembled with a central controller (also not shown in detail) into a central unit ECM. This central unit also controls the axle modulator MV for the front axle 11.

[0043] The combined brake cylinder KBZ is connected to the central unit ECM, and the rear axle brake cylinder BZH and the spring-accumulated brake cylinder FSZ of the rear axle 12 are integrated into this combined brake cylinder. In order to pneumatically load the rear axle brake cylinder BZH, the central unit ECM is connected to or a part thereof to the brake circuit BK1.

[0044] To inflate the front axle brake cylinder BZV and the rear axle brake cylinder BZH, the driver can operate the brake value transmitter P (brake pedal). The corresponding signal from the brake value transmitter P reaches the central unit ECM. This signal controls the integrated axle modulator for the rear axle 12 and the front axle modulator MV.

[0045] The spring-accumulated brake cylinder FSZ is a component of the spring-accumulated brake FSB within the parking brake system FSY, a subsystem of the electro-pneumatic brake system 10, and includes an electro-pneumatic control module EH. The control module EH is connected to the brake circuit BK3 and outputs pressure to inflate the spring-accumulated brake cylinder FBZ when the spring-accumulated brake FSB is released. To deflate the spring-accumulated brake cylinder FBZ and thus operate the spring-accumulated brake FSB, an electrical switch H connected to the control module EH is provided. This switch, like the brake value transmitter P, is operated by the driver.

[0046] The electro-pneumatic control module EH is also connected to the trailer control module TC, which is fed by the brake circuit BK3, but is not relevant in this diagram.

[0047] according to Figure 2 In the electro-pneumatic control module EH, an electronic control unit (ECU) and a valve assembly 13 are specifically provided, wherein the valve assembly 13 is controlled by the control unit (ECU).

[0048] The electro-pneumatic braking system 10 is connected to the CAN bus of the vehicle ZG (see [link]). Figure 1 The system can connect via CAN (the CAN bus in the vehicle) or other typical vehicle bus systems. Through the CAN bus, the central unit (ECM), the electro-pneumatic control module (EH), and another electronic control unit (not shown) of the vehicle (ZG) can communicate with each other, and, for example, can transmit commands to the electro-pneumatic control module (EH) for operating the spring-accumulated brake (FSB). Furthermore, the electronic control unit (ECU) in the control module (EH) can have software that operates or releases the spring-accumulated brake (FSB) or deflates or inflates the spring-accumulated brake cylinder (FBZ) under defined boundary conditions and / or defined signal inputs.

[0049] Figure 2 The diagram illustrates a possible structure of the electro-pneumatic control module EH. The main components of valve assembly 13 are relay valve 14 and electro-pneumatic proportional valve 15. A bistable switching valve 16 is arranged upstream of proportional valve 15, which is used to activate or deactivate the spring-loaded brake FSB. For this purpose, switching valve 16 connects proportional valve 15 to or disconnects the input terminal 17 of control module EH. According to… Figure 2 In this position, the connection is blocked, and the spring-loaded brake FSB is deflated, i.e. activated.

[0050] A reserve pressure pV from the brake circuit BK3 is applied at input terminal 17 of control module EH. An output pressure pA for the spring-accumulated brake cylinder FBZ is provided at output terminal 18 of control module EH. Relay valve 14 is connected to input terminal 17 and, via its valve output terminal 19, to output terminal 20, and receives control pressure from proportional valve 15.

[0051] The proportional valve 15 here is a 2 / 2 directional valve, which is opened when there is no current and closed when there is current. By modulating the proportional valve 15, a specific control pressure can be modulated for the relay valve 14, and thus a specific output pressure pA can be set at the output terminal 18 for charging the spring-loaded brake cylinder FBZ. Therefore, the relay valve 14 and the proportional valve 15 together form a pressure regulating valve for the output pressure pA.

[0052] A pressure sensor 20 is connected to output 18 and relay valve 14, and its signal is received and processed by the electronic control unit (ECU). Here, the valve output VTA of the monostable switching valve VT is connected to the trailer control module TC. The first valve input VTE1 is loaded with a reserve pressure pV, while the second valve input VTE2 is connected to valve output 19. This makes it possible to maintain valve output VTA and trailer control module TC at the reserve pressure pV while simultaneously regulating the pressure at output 18 via relay valve 14. This advantageously prevents the pressure regulation from affecting the pressure acting on the (not shown) output of trailer control module TC.

[0053] The electronic control unit (ECU) controls the output pressure pA applied to the output terminal 18 by manipulating valves 15 and 16, taking into account the signal from pressure sensor 20. To release the spring-accumulated brake FSB or to charge the spring-accumulated brake cylinder FBZ, switching valve 16 is switched to the open position (not shown), and proportional valve 15 is modulated. The aim is to ensure that the spring accumulator holding pressure pH, which is the output pressure pA at the output terminal 18, is lower than the reserve pressure pV at the input terminal 17 and higher than the spring accumulator release pressure pL. Preferably, the spring accumulator holding pressure pH is 1 to 2 bar higher than the spring accumulator release pressure pL and / or 1 to 3 bar lower than the reserve pressure pV.

[0054] In this case, the venting of the spring-accumulated brake cylinder FBZ for operating the spring-accumulated brake FSB is performed via the venting section 21 on the relay valve 14 or the venting section connected thereto. Because the spring accumulator holding pressure pH is relatively low, the spring-accumulated brake FSB can be vented significantly faster compared to when the output pressure pA is equivalent to the reserve pressure pV in the brake circuit BK3.

[0055] Figure 3 An additional valve assembly 22 for reducing the output pressure pA is shown, here as a purely pneumatic solution. The main component of the valve assembly 22 is a pressure relief valve 23 having an input 24 and an output 25, with a check valve 26 connected in parallel to the pressure relief valve 23, i.e., it is connected to both the input 24 and the output 25.

[0056] The pressure relief valve 23 is configured and / or selected such that the desired output pressure pA is applied at the output 25 without applying a higher reserve pressure pV. If the pressure at the input 24 drops, the check valve 26 will balance the pressure at the output 25.

[0057] Valve assembly 22 is preferably used in a parking brake system FSY with a spring-loaded brake FSB that is purely pneumatically controlled. However, it is also possible to use it in an electro-pneumatic parking brake system FSY.

[0058] A particular advantage of its application in trailers is that the activation of the spring-storage brake (FSB) is faster, it can also be used for emergency braking, and it reduces the risk of the trailer rolling accidentally when uncoupling, because the transition from the braking effect of the service brake to the spring-storage brake (FSB) is faster.

[0059] Figure 4 The embodiments relate to a trailer braking system ASY in a trailer AG (such as a semi-trailer). The components of the trailer braking system ASY are a reserve port 27, a parking valve 28 (also called a parking release valve), a reserve IV, a modulator AM, and a combined brake cylinder KBZ on two axles 29 and 30, while the other axle 31 only has a trailer service brake cylinder BZA. Figure 1 Similar to the previous implementation, the combined brake cylinder KBZ is divided into the trailer service brake cylinder BZA and the trailer spring accumulator brake cylinder FBA.

[0060] The trailer braking system ASY also includes an electro-pneumatic parking brake system FSY, which comprises the trailer spring accumulator brake cylinder FBA. For simplicity, Figure 4 Only the important wiring related to the spring-storage braking system FSY is shown. The delivery and distribution of control pressure, similar to that of the storage interface 27, is not shown. The parking brake system FSY can also be purely pneumatic.

[0061] The modulator AM regulates all functions of the trailer braking system ASY (including the parking brake system FSY for the trailer AG and containing all valve assemblies and controls required for this). Figure 4 In this embodiment, valve assembly 22 is integrated into modulator AM, i.e., it is a component of modulator AM. The reserve pressure pV delivered via parking valve 28 is applied at input 24. Output 25 is connected to trailer spring accumulator brake cylinder FBA via lines 32 and 33. A reserve line 35 leads from reserve interface 27 to parking valve 28, and another reserve line 36 extends from parking valve 28 to accumulator IV and from there to modulator AM. Alternatively, modulator AM can also be connected between accumulator IV and parking valve 28.

[0062] exist Figure 5 In this embodiment, valve assembly 22 is connected in control line 34 from parking valve 28 to modulator AM. Input terminal 24 faces parking valve 28, while output terminal 25 points towards module AM. Valve assembly 22 can be easily modified in this manner.

[0063] exist Figure 6In this embodiment, valve assembly 22 is integrated into or part of parking valve 28. The interconnection between input 24 and output 25 is not shown. Preferably, output 25 is connected to control line 34. Within module AM, input 24 is connected to a line (not shown) guiding the reserve pressure pV, a line (not shown) connecting the reservoir IV, or a vent (not shown). The actual connection depends on the positioning of the manual operating mechanism VBO on parking valve 28 and requires only minor additional cost within parking valve 28.

[0064] exist Figure 7 In this embodiment, a valve assembly 22 is integrated into each combined brake cylinder KBZ. The input terminal 24 can be connected to lines 32 and 33, while the output terminal 25 is connected to the trailer spring accumulator brake cylinder FBA. For simplicity, the trailer spring accumulator brake cylinder is not included in... Figure 7 As shown, but for example in Figure 4 As can be seen in the text. According to... Figure 7 Valve assembly 22 is integrated into all existing combined brake cylinders KBZ. It is also possible to select or limit it to a single axle 29, 30 or wheel.

[0065] exist Figure 8 In this embodiment, valve assembly 22 is arranged in each of the lines 32, 33 between modulator AM and combined brake cylinder KBZ. Here, input 24 is connected to modulator AM, and output 25 is connected to trailer spring accumulator brake cylinder FBA within combined brake cylinder KBZ. This solution is also particularly suitable for retrofitting.

[0066] from Figure 9 The significant advantages of this invention are evident. The time-varying curve of the output pressure pA with respect to time t can be seen. In the prior art, the inflated spring-accumulated brake cylinder FBZ and trailer spring-accumulated brake cylinder FBA are loaded with a reserve pressure pV. According to this invention, valve assemblies 13 and 22 have an output pressure pA at the level of the spring accumulator holding pressure pH. The spring accumulator holding pressure pH is lower than the reserve pressure pV and lies above the spring accumulator release pressure pL via the safety interval DS. Pressure variation curves P1 and P2 under two different conditions are shown.

[0067] When releasing air from the spring-accumulated brake cylinder FBZ and the trailer spring-accumulated brake cylinder FBA, possible time-varying curves corresponding to the dashed pressure change curves P1 and P2 were obtained, starting from the reserve pressure pV in the first case and from the spring reserve holding pressure pH in the second case. The intersection points S1 and S2 of the pressure change curves P1 and P2 with the spring accumulator release pressure pL are of interest. The pressure change curve P1 only reaches the spring accumulator release pressure pL at intersection point S1 at time point t3, while intersection point S2 is located at a significantly earlier time point t2. Therefore, the spring accumulator release time t2-t1 obtained by combining this invention is significantly shorter than the previously possible spring accumulator release time t3-t1.

[0068] The aforementioned safe range DS is selected such that, taking into account the dispersion of the spring accumulator release pressure pL and subsequent fluctuations due to wear and corrosion, the spring accumulator holding pressure pH will not reach or fall below the spring accumulator release pressure pL.

[0069] Figure 9 The diagrams in the diagrams are idealized, purely qualitative, and are only used to explain the shortening of the time until the spring accumulator release pressure pL is reached.

[0070] All embodiments shown herein relate to or can be transferred to traction machinery / powered vehicles and to trailers, especially saddle-type semi-trailers.

[0071] List of reference numerals (part of the instruction manual)

Claims

1. A method for operating a parking brake system (FSY) with a spring-storage brake (FSB) and a control module in a powered vehicle or trailer, wherein, The control module is connected to the parking brake circuit (BK3, BK4), supplies reserve pressure to the parking brake circuit (BK3, BK4), and applies spring accumulator holding pressure (pH) to the spring accumulator brake cylinder (FBA, FBZ) to enable the spring accumulator brake (FSB) to occupy the release position. The feature is that a spring accumulator holding pressure (pH) lower than the reserve pressure in the parking brake circuit (BK3, BK4) is applied to the spring accumulator brake cylinder (FBA, FBZ), thereby shortening the time period until the spring accumulator brake takes effect, wherein the spring accumulator holding pressure (pH) is higher than the spring accumulator release pressure (pL) by a safe range (DS).

2. The method according to claim 1, characterized in that, The spring accumulator maintains a pressure (pH) 1-5 bar lower than the storage pressure.

3. The method according to claim 2, characterized in that, The spring accumulator maintains a pressure (pH) 1.5-3 bar lower than the storage pressure.

4. The method according to claim 1, characterized in that, The safe zone (DS) is 1-2 bar.

5. The method according to any one of claims 1 to 3, characterized in that, The pressure (pH) maintained by the spring accumulator is determined by a valve assembly that limits, reduces, or regulates the pressure.

6. The method according to any one of claims 1 to 3, characterized in that, The spring accumulator maintains a pressure (pH) that is adjusted by computer-controlled regulation of the valve assembly.

7. A parking brake system (FSY), said parking brake system being used in a powered vehicle or trailer and having a spring-loaded brake (FSB) and a control module, wherein, The control module is connected to the braking circuit (BK3, BK4), supplies reserve pressure to the braking circuit (BK3, BK4), and can load the spring accumulator holding pressure (pH) onto the spring accumulator brake cylinder (FBA, FBZ) to cause the spring accumulator brake (FSB) to occupy the release position. It is characterized by having an adjustment device for adjusting the spring accumulator holding pressure (pH) to a value lower than the reserve pressure in the braking circuit (BK3, BK4), thereby shortening the time until the spring accumulator brake engages, wherein the spring accumulator holding pressure (pH) is higher than the spring accumulator release pressure (pL) by a safe range (DS).

8. The parking brake system (FSY) according to claim 7, characterized in that... The device includes a valve assembly having an input pressure and an output pressure (pA), wherein the valve assembly provides the spring accumulator holding pressure (pH) as the output pressure (pA).

9. The parking brake system (FSY) according to claim 8, characterized in that... It has an electronic control unit (ECU) that can regulate the output pressure (pA) of the valve assembly.

10. The parking brake system (FSY) according to claim 9, characterized in that... It has a pressure sensor (20) for sensing the output pressure (pA) and transmitting it to the electronic control unit (ECU).

11. The parking brake system (FSY) according to claim 9 or 10, characterized in that, The valve assembly has a pneumatic relay valve (14) and an electro-pneumatic proportional valve (15), and the output pressure (pA) is applied at the output end (18, 19) of the valve assembly. The relay valve (14) receives control pressure from the proportional valve (15), and the proportional valve (15) is driven by the electronic control unit (ECU) to adjust the output pressure (pA).

12. The parking brake system (FSY) according to claim 9 or 10, characterized in that, The valve assembly and the electronic control unit (ECU) are components of the control module.

13. The parking brake system (FSY) according to any one of claims 8 to 10, characterized in that, The valve assembly includes a pressure relief valve (23).

14. The parking brake system (FSY) according to claim 13, characterized in that, The valve assembly has a check valve (26) connected in parallel with the pressure relief valve (23).

15. The parking brake system (FSY) according to any one of claims 8 to 10, characterized in that, The valve assembly is integrated into the control module.

16. The parking brake system (FSY) according to any one of claims 8 to 10, characterized in that, The valve assembly is integrated into the pneumatic control circuit (34) between the parking valve assembly (28) and the control module.

17. The parking brake system (FSY) according to any one of claims 8 to 10, characterized in that, The valve assembly is integrated into the parking valve assembly (28), which is connected to the control module via a pneumatic control line (34).

18. The parking brake system (FSY) according to any one of claims 8 to 10, characterized in that, The valve assembly is integrated into the brake cylinder assembly (KBZ).

19. The parking brake system (FSY) according to any one of claims 8 to 10, characterized in that, The valve assembly is integrated into the pneumatic working circuit (32, 33) between the control module and the spring-accumulated brake cylinder.

20. The parking brake system (FSY) according to any one of claims 7 to 10, characterized in that, The control module is an axle modulator.

21. A computer program product comprising instructions that, when executed on an electronic control unit (ECU) of a control module in a parking brake system (FSY), implement the method according to claim 6.

22. An electro-pneumatic control module having an electronic control unit (ECU) and used in a parking brake system (FSY) according to any one of claims 7 to 20.

23. A vehicle having a parking brake system (FSY) according to any one of claims 7 to 20.

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