Adjustment of rear axle based on pressure sensor in brake system

Abstract

The invention comprises a brake system (B) for a vehicle (F), in particular a commercial vehicle. The brake system (B) has: a first pressure source (1b); the foot brake valve (2) is used for receiving a deceleration expectation of a driver, and the foot brake valve is connected with the first pressure source (1a); the invention relates to a brake system (1) for a motor vehicle, comprising a first brake module (3), at least one brake actuator (5a, 5b), which is connected to the brake module (3), the first brake module (3) being adapted for adjusting a braking force of the at least one brake actuator (5a, 5b) during each braking, at least one first pressure sensor (9a, 9b) being adapted for detecting the braking force of the at least one brake actuator (5a, 5b), and at least one second pressure sensor (9a, 9b) being adapted for detecting the braking force of the at least one brake actuator (5a, 5b) during each braking. The first pressure sensor is adapted to measure the pressure of the controlled output of the foot brake valve (2). Thus, at each braking, the driver's desire to decelerate can be ascertained by pressure sensing, and the rear axle can be adjusted (for example, in dependence on the load) without the need to implement a complete electronic braking system.

Description

Technical Field

[0001] The invention relates to the regulation of the brakes on a rear axle, which regulation is carried out in a brake system by means of a pressure sensor. Background Art

[0002] The use of anti-lock braking systems (ABS) is common in commercial vehicles, in particular trucks.

[0003] The prior art discloses, for example, document DE 10 2019 202 770 A1, which includes a method for operating an anti-lock braking system of a vehicle to determine road conditions. After the anti-lock braking system is activated, a first braking value is detected. The anti-lock braking system can then be deactivated. A second brake pressure can then be detected, and finally, a pressure difference between the first and second brake pressures can be detected. This pressure difference can be used to determine road conditions.

[0004] In conventional anti-lock braking systems, wheel locking can be prevented or at least reduced during rapid or emergency braking, during which pressure regulation occurs at the brake cylinders (but not during normal service braking).

[0005] More complex systems are so-called electronic brake systems (EBS systems), in which the entire control of all axles and wheels is performed electronically. For example, the driver's braking request is determined by the foot brake module via travel sensing (sensors measure how far the foot brake module is actuated), and the travel signal (the measured distance by which the foot brake module is actuated) is further processed by the brake management system. Various software functions can be implemented, such as ABS (Anti-lock Braking System), ESP (Electronic Stability Program), ASR (Anti-slip Control), coupling force control, and load-dependent control. During normal braking, pressure control occurs on all axles.

[0006] Compared to ABS systems, EBS systems are significantly more complex and more expensive.

[0007] However, it would be desirable to be able to carry out a load-dependent control in a normal ABS system also during each braking operation, in particular also during each braking operation of the rear axle. Summary of the Invention

[0008] The object of the present invention is to enable a load-dependent adjustment of the rear axle during each braking operation in commercial vehicles, without, however, having to implement a complete EBS system.

[0009] This object is achieved by a brake system according to claim 1. Further advantageous embodiments of the invention are the subject matter of the dependent claims.

[0010] The vehicle braking system according to the present invention comprises a first pressure source and a foot brake valve for receiving a driver's deceleration request, the foot brake valve being connected to the first pressure source. The foot brake valve is pneumatically connected to a first brake module, and at least one first brake actuator is connected to the first brake module. Preferably, two first brake actuators are provided for the rear axle, one for each side.

[0011] The first brake module is adapted to regulate the braking force of at least one brake actuator during each braking operation. This means that regulation should occur during each braking operation, not just during rapid or emergency braking. Furthermore, the braking system according to the present invention includes at least one first pressure sensor adapted to measure the pressure of a controlled output of a foot brake valve.

[0012] Therefore, control can be performed during each braking operation, and the driver's desired braking force on the rear axle can be electronically adjusted (while also taking into account the driver's deceleration desire). This eliminates the need for a costly foot brake module, where travel sensing (and therefore electrical signal measurement) takes place. For this reason, a pressure sensor is provided that checks the driver's desired braking force during each braking operation by measuring the set pressure of the foot brake valve and using this pressure for appropriate control. This offers the following advantages over conventional anti-lock braking systems: In particular, the rear axle can be controlled not only during specific braking operations, but during all braking operations. Load-dependent control of the rear axle is thus also possible. The driver's desired braking force can be determined in the same way as in a normal EBS system, but by measuring the set pressure of the foot brake valve, thereby enabling pressure control of the rear axle. This specialized pressure control of the rear axle enables various software functions. The functions of the EBS system can be integrated into the ABS system without the higher costs of the EBS system.

[0013] Preferably, at least one first brake actuator is provided on the rear axle of the vehicle, which first brake actuator can be adjusted by the braking force.

[0014] Thus, all the advantages described above can be achieved at the rear axle of the vehicle.

[0015] Preferably, the first pressure sensor is connected to the first brake module, and the pressure value measured by the first pressure sensor can be read into the brake module. Therefore, electronic regulation can also be performed for the rear axle via the first brake module.

[0016] Preferably, the deceleration demand can be controlled and output via two brake actuators (on the rear axle) using solenoid valves or relay valves. The corresponding solenoid valves or relay valves are preferably integrated into the first brake module. The first brake module preferably includes electronic control components, but also corresponding valves, through which the pressure output to the corresponding brake actuators, such as brake cylinders, can be controlled. This saves at least three cable spaces that would otherwise be required for electromagnetic valve control in conventional systems.

[0017] An additional second pressure sensor is provided between the solenoid valve or relay valve and the corresponding brake actuator. This second pressure sensor is adapted to measure the pressure output by the solenoid valve or relay valve. The second pressure sensor is also connected to the first brake module and can provide the first brake module with the corresponding measured pressure value. Thus, based on the measured value (driver's desired value) of the foot brake module measured by the first pressure sensor and the second pressure sensor measuring the controlled output pressure at the brake actuator of the rear axle, a pressure-based control of the rear axle can be achieved (a closed control loop). While regulating the braking force of the rear axle, it is always possible to respond to the driver's desired value, i.e., a desired deceleration.

[0018] The first brake module is preferably adapted to implement a control system by means of a software function, wherein preferably an anti-lock braking system, an electronic stability program and / or a load-dependent control system can be implemented.

[0019] Preferably, the brake system further comprises an axle load determination device, which is adapted to determine the axle load. The axle load determination device is connected to the first brake module, and the first brake module is adapted to take the axle load into account in the control.

[0020] For example, the axle load determination device is an axle load sensor. However, the axle load can also be calculated based on other data using different calculation steps.

[0021] The load-dependent adjustment possibilities of the rear axle are thus significantly improved.

[0022] Preferably, the braking system also includes a second pressure source, which is also connected to the brake valve. Furthermore, there is a second brake module, which is also connected to the foot brake module, and at least one additional brake actuator, which is connected to the second brake module. The second brake module is adapted to regulate the braking force of the at least one additional brake actuator. This may, for example, involve the front axle. A pressure regulating valve is provided between the second brake module and the at least one additional brake actuator. This pressure regulating valve can be used for fine-tuning the pressure on the front axle. Thus, a second brake circuit is implemented.

[0023] Preferably, at least one first pressure sensor is integrated in the first brake module. Thus, wiring complexity can be avoided, thereby also enabling a very compact and space-saving system to be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will now be described more precisely with reference to the present drawings.

[0025] Figure 1 A brake system according to the invention is shown, in which a pressure measurement is provided by a first pressure sensor in the brake circuit for the front axle.

[0026] Figure 2 A brake system according to the invention is shown, in which a pressure measurement is provided by a first pressure sensor in the brake circuit for the rear axle. DETAILED DESCRIPTION

[0027] Figure 1 The diagram shows the configuration of a brake system B, which has two brake circuits: one for the front axle and one for the rear axle. A second pressure source 1a is connected to a foot brake valve 2. Pressure from the second pressure source 1a can be transmitted from the foot brake valve 2 to the second brake module 4. A first pressure sensor 9a is located between the foot brake valve 2 and the second brake module 4. This first pressure sensor 9a measures the driver's deceleration request, which the driver indicates via the foot brake valve 2. A third pressure sensor 10 is located behind the second brake module 4. This third pressure sensor measures the pressure set on the front axle, as the second brake module 4 is connected to the respective brake cylinders 7a and 7b of the front axle. Pressure regulating valves 6a and 6b are also located between the third pressure sensor 10 and the respective brake cylinders 7a and 7b. These pressure regulating valves are responsible for fine-tuning the brake pressure on the front axle.

[0028] The first pressure source 1b is also equipped with a foot brake valve 2. In this brake circuit, the pressure regulated by the foot brake valve 2 is supplied to the first brake module 3. The first brake module 3 receives the pressure value measured by a first pressure sensor 9a. The pressure from the first brake module 3 is further transmitted to the first brake actuators 5a and 5b, which are responsible for the rear axle. Furthermore, corresponding second pressure sensors 8a and 8b are connected between the first brake module 3 and the respective brake cylinders 5a and 5b for the rear axles. These second pressure sensors measure the regulated pressures of the brake actuators 5a and 5b for the rear axles. These pressures are also read by the second brake module 4, enabling corresponding regulation. An axle load determination device 11, here designed as an axle load sensor, is also provided with the second brake module 4. Furthermore, a trailer control valve 13 is provided, which receives the pressure regulated by the foot brake valve 2. Furthermore, the trailer control valve is connected to the first brake module 3. Furthermore, the trailer control valve 13 is also connected to the second brake module 4, which is provided for the front axle, via the trailer pressure regulating valve 12. Therefore, if the brake system of a trailer is connected to the trailer control valve 13, the brakes of the trailer can also be controlled accordingly.

[0029] Figure 2 A second embodiment of the present invention is shown, in which all components are substantially identical to those of the first embodiment. Here, a first pressure sensor 9b is arranged between foot brake valve 2 and first brake module 3. A pressure measurement, intended for driver or deceleration, is performed between foot brake valve 2 and first brake module 3 assigned to the rear axle.

[0030] Driver expectation for vehicle deceleration (in Figure 1 and Figure 2 The control of the braking process is achieved by actuating the foot brake valve 2, whereby the valve 2, fed by the supply pressure 1a or 1b, correspondingly increases the pressure in the brake control line P4, which leads to the first brake module 3. The pressure in the brake control line P4 is measured by at least one first pressure sensor, 9a or 9b, depending on the embodiment. Figure 1 In the embodiment of FIG, the pressure sensor 9a is installed between the foot brake valve 2 and the second brake module 4 assigned to the front axle. Figure 2 In FIG, the first pressure sensor 9 b is arranged between the foot brake valve 2 and the first brake module 3 assigned to the rear axle.

[0031] However, first pressure sensor 9 a or 9 b may also be integrated in first brake module 3 or foot brake valve 2 .

[0032] The signal from pressure sensor 9a or 9b is read into first brake module 3, which then outputs a setpoint pressure value for the brake circuit of the rear axle. This pressure is adjusted by actuating the solenoid valve or brake valve of the rear axle via at least one relay valve (not shown here) and then measured by second pressure sensors 8a and 8b, respectively, which are located between first brake module 3 and the respective brake actuators 5a and 5b of the rear axle. Thus, taking into account the driver's wishes and based on the measured values of pressure sensors 8a and 8b, a pressure-based control of the rear axle can be performed (via first pressure sensor 9a or 9b), which measures the set pressure of first brake module 3. Consequently, all software-related options for this control can be implemented in first brake module 3. Using axle load determination device 11 (designed here as an axle load sensor), load-dependent control of the rear axle can also be implemented in a more cost-effective ABS system, without requiring the corresponding implementation of all components for the EBS.

[0033] For this reason, not only the assembly effort but also the costs can be significantly saved.

[0034] The present invention is not limited to the above-mentioned embodiment. The first pressure sensor 9a or 9b can also be directly arranged in the foot brake valve 2 or integrated in other components.

[0035] Reference Signs List

[0036] B brake system

[0037] F vehicle

[0038] 1a Second pressure source (pressure supply to the front axle)

[0039] 1b First pressure source (pressure supply to rear axle)

[0040] 2-foot brake valve (FBV)

[0041] 3. First brake module (rear axle + CPU)

[0042] 4 Second brake module (front axle / relay valve / FAM)

[0043] 5a Brake actuator / brake cylinder on the right side of the rear axle

[0044] 5b Brake actuator / brake cylinder on the left side of the rear axle

[0045] 6a Pressure regulating valve (PCV) on the right side of the front axle

[0046] 6b Pressure regulating valve (PCV) on the left side of the front axle

[0047] 7a Brake cylinder on the right side of the front axle

[0048] 7b Brake cylinder on the left side of the front axle

[0049] 8a Second pressure sensor (regulated pressure (P2) on the right side of the rear axle)

[0050] 8b Second pressure sensor (regulated pressure (P2) on the left side of the rear axle)

[0051] 9a 1st pressure sensor (driver's desired value (P4) on the front axle circuit)

[0052] 9b First pressure sensor (driver expectation (P4) on the rear axle circuit (external / integrated))

[0053] 10 Third pressure sensor (regulated pressure (P2) of the front axle)

[0054] 11 Axle load determination equipment (axle load sensor / axle load calculation)

[0055] 12 Trailer Pressure Regulating Valve (TPCV)

[0056] 13Trailer control valve (TCV).

Claims

1. A braking system (B) for a vehicle (F), comprising: a first pressure source (1b); A foot brake valve (2), used for receiving a driver's deceleration desire, the foot brake valve being connected to the first pressure source (1a); a first braking module (3); at least one brake actuator (5a, 5b), which is connected to the brake module (3), wherein the first brake module (3) is adapted to adjust the braking force of the at least one brake actuator (5a, 5b) during each braking operation; At least one first pressure sensor (9a, 9b) adapted to measure the pressure of a controlled output of the foot brake valve (2).

2. The braking system (B) according to claim 1, wherein: The at least one first brake actuator (5a, 5b) is arranged on a rear axle of the vehicle, the braking force of the first brake actuator being adjustable.

3. The braking system (B) according to claim 1 or 2, wherein: The first pressure sensor (9a, 9b) is connected to the first brake module (3), and the pressure value measured by the first pressure sensor (9a, 9b) can be read into the brake module (3).

4. Braking system (B) according to any one of the preceding claims, wherein: The deceleration expectation can be controlled and outputted via two brake actuators (5a, 5b) by means of corresponding solenoid valves (M) or relay valves (R), wherein the corresponding solenoid valves (M) or relay valves (R) are preferably integrated in the first brake module (3).

5. The braking system (B) according to claim 4, wherein: Another second pressure sensor (8a, 8b) is respectively provided between the solenoid valve (M) or the relay valve (R) and the corresponding brake actuator (5a, 5b), and the other second pressure sensor is adapted to measure the pressure output controlled by the solenoid valve (M) or the relay valve (R), wherein the second pressure sensor (8a, 8b) is connected to the first brake module (3).

6. Braking system (B) according to any one of the preceding claims, wherein: The first brake module (3) is adapted to implement the control by means of software functions, wherein preferably an anti-lock braking system, an electronic stability program and / or a load-dependent control can be implemented.

7. The brake system (B) according to claim 1 , further comprising an axle load determination device (11) adapted to determine the axle load, in, The axle load determination device (11) is connected to the brake module (3), and the brake module (3) is adapted to take the axle load into account in the regulation.

8. The braking system (B) according to claim 7, wherein: The axle load determination device (11) is an axle load sensor.

9. The brake system (B) according to claim 2, further comprising: a second pressure source (1b), which is also connected to the foot brake valve (2); a second brake module (4), which is also connected to the foot brake valve (2); at least one further brake actuator (7a, 7b), which is connected to the second brake module (4), wherein: The second brake module (4) is adapted to regulate the braking force of the at least one further brake actuator (7a, 7b), wherein the at least one further brake actuator (7a, 7b) is arranged on the front axle of the vehicle (F), wherein a pressure regulating valve (6a, 6b) is respectively arranged between the second brake module (4) and the corresponding at least one further brake actuator (6a, 6b).

10. Braking system (B) according to any one of the preceding claims, wherein: The at least one first pressure sensor (9a, 9b) is integrated into the first brake module (3).

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