Method for setting setting pressure of vehicle brake and associated vehicle brake

Abstract

The invention relates to a method for setting a setting pressure pa of a vehicle brake (2) of a motor vehicle (1), in particular of a commercial vehicle (3) having a commercial vehicle disc brake (4), in which the vehicle brake (2) advances a brake lining (10) against an air gap L in the direction of a brake disc (22) by a brake feed path d when a brake pressure p increases in a first pressure range (16), in the second pressure range (18), as the brake pressure p further increases, the brake disc (22) completes the feed and a further increase in the friction torque Mr occurs on the vehicle brake (2). According to the invention, the following method steps are proposed: detecting (104) a brake feed path d dependent on the brake pressure p; identifying (106) a first pressure range (16) on the basis of the detected brake feed path d dependent on the brake pressure p; the setting pressure pa of the vehicle brake (2) is set (108) to a pressure pa lying within the first pressure range (16). The invention also relates to an associated controller (202), a computer program product (302), a vehicle brake (2) and a vehicle (1).

Description

Technical Field

[0001] The invention relates to a method for adjusting the set pressure of a vehicle brake of a motor vehicle, in particular a commercial vehicle with a commercial vehicle disc brake, wherein in a first pressure range, when the brake pressure increases, the vehicle brake advances the brake lining over an air gap (L) in the direction of the brake disc by a braking advance stroke, thereby increasing the friction torque, and in a second pressure range, as the brake pressure increases further, the brake disc is advanced and a further increase in the friction torque occurs at the vehicle brake. The increase in the friction torque also results in an increase in the braking force. Background Art

[0002] The settling pressure is understood to be the brake pressure applied to the brake system when the brake should remain ready for operation but there is no deceleration expectation. The brake pressure is usually selected so that it is just large enough to overcome the mechanical friction of the brake caliper and reduce the distance between the brake disc and the brake lining, the so-called air gap, to almost zero, but the brake simultaneously causes minimal friction losses. The settling pressure is therefore subject to a stress field between providing the lowest possible brake response time on the one hand and generating the lowest possible friction torque on the other hand.

[0003] Methods for adjusting the set pressure of vehicle brakes are known from the prior art and are based, for example, on parameterizing the set pressure and storing it in a brake control system.

[0004] Although these methods have proven to ensure a favorable response behavior of the vehicle brakes by applying a rest pressure, it has been observed that applying a rest pressure can actually lead to considerable friction torques and thus braking forces, even if deceleration is not required and desired. As a result, kinetic energy is lost, which is then no longer available for recovery. At the same time, the wear of the vehicle brakes increases. Summary of the invention

[0005] Against this background, the object of the present invention is to improve a method of the type mentioned at the outset so that the disadvantages found in the prior art are eliminated as much as possible. In particular, a method is described which optimizes the setting pressure in a vehicle brake in order to reduce undesirable friction torques on the brake.

[0006] According to the invention, in a method of the above type, this task is solved by the following steps: detecting a brake feed stroke that is dependent on the brake pressure; identifying a first pressure range based on the detected brake feed stroke that is dependent on the brake pressure; and adjusting the setting pressure of the vehicle brake to a pressure within the first pressure range.

[0007] The invention makes use of the knowledge that within the scope of braking performed during vehicle operation, a relationship between brake feed distance and brake pressure can be detected, in particular for each wheel brake individually. A first pressure range is thereby identified and a settling pressure is set within the first pressure range determined. Within the first pressure range, the brake lining is advanced by a brake feed distance in the direction of the brake disc overcoming the air gap, thereby increasing the friction torque. In other words, within the first pressure range, the air gap is overcome and the brake lining comes to rest at least partially on the brake disc. In a second pressure range, the brake disc is advanced, wherein a further increase in the friction torque occurs at the vehicle brake when the brake pressure increases.

[0008] By setting the set pressure in the first pressure range, the vehicle brake ensures a rapid provision of braking force with minimal friction losses. In contrast to methods known from the prior art, in which the set pressure is only stored in a parameterized and fixed manner, the method according to the invention makes it possible to set the set pressure more precisely, taking into account the actual braking state, such as lining wear and other properties. As a result, the efficiency of the vehicle brake is improved overall.

[0009] The invention is developed in that the brake pressure-dependent brake travel is detected by means of a continuous lining wear sensor arranged on the vehicle brake. Preferably, the vehicle brake has two brake linings, wherein a lining wear sensor is preferably arranged on each vehicle brake.

[0010] According to a preferred embodiment, the settling pressure is set to a pressure in the lower third of the total range width about the first pressure range. The selection of the settling pressure in the lower third of the first pressure range has proven to be particularly suitable for ensuring a fast braking response on the one hand and minimizing friction losses on the other hand.

[0011] According to a preferred refinement, the settling pressure is set to a pressure in the middle third of the total range width with respect to the first pressure range. For some brake types and applications, it has proven useful to increase the settling pressure compared to the previous embodiments, so that the brake response time can be shortened, although this is associated with a tendency towards higher lining wear.

[0012] According to an alternative embodiment, the settling pressure is set to a pressure in the upper third of the total range width with respect to the first pressure range. This setting has also proven to be preferred for some applications and brake types. In principle, the reaction time of the brake can be further reduced thereby, but this may be accompanied by higher brake wear.

[0013] The invention is developed in such a way that the set set pressure is checked during vehicle operation, in particular by means of at least one test brake. In this respect, in suitable driving situations, for example in so-called sliding or rolling, with knowledge of all other acting force-applying actuators, the set pressure can be applied and the vehicle's reaction can be observed. It can thus be determined whether the set pressure provides the desired deceleration or wear behavior.

[0014] The invention is improved in that the setting pressure is checked by means of an electric vehicle drive, in particular by detecting the change in the drive power or drive torque for carrying out the test brake. In other words, the electric drive can be adjusted precisely so that the vehicle movement can be maintained, for example, without changing the topology. The actual deceleration caused by the setting pressure can be monitored by the drive power or drive torque of the electric drive required for this purpose, and the size of the setting pressure can be further optimized.

[0015] The invention is described above with reference to a method. In another aspect, the invention relates to a control unit for a vehicle brake of a commercial vehicle. The invention achieves the object mentioned at the outset with respect to the control unit in that the control unit is set up to carry out a method according to one of the above-described exemplary embodiments.

[0016] Preferably, the controller is designed as a dedicated controller or a central controller. A dedicated controller is understood to be a controller that is directly assigned to at least one of the vehicle brakes or is arranged thereon. The controller utilizes the same advantages and preferred embodiments as the method according to the invention, and vice versa. In this regard, reference is made to the above-mentioned embodiments and their contents are included here.

[0017] In a third aspect, the invention relates to a computer program product. The invention solves the object mentioned at the outset with respect to the computer program product in that the computer program product contains instructions which, when executed on a computer, cause the computer to form a controller according to one of the aforementioned embodiments and / or to implement a method according to one of the aforementioned embodiments. The computer program product also utilizes the same advantages and preferred embodiments as the method according to the invention and the controller according to the invention, and vice versa. In this regard, reference is made to the above-mentioned embodiments and their contents are included here.

[0018] In a fourth aspect, the present invention relates to a vehicle brake, in particular a commercial vehicle disc brake, comprising: a brake carrier having at least one brake lining receptacle; at least one brake lining which is guided and supported axially movably in the brake lining receptacle; a brake caliper which is axially movable relative to the brake carrier; and a measuring device which is designed to detect a brake feed stroke of the vehicle brake that is dependent on the brake pressure, wherein within a first pressure range, when the brake pressure increases, the vehicle brake feeds the brake lining in the direction of the brake disc overcoming an air gap by a brake feed stroke, thereby increasing the friction torque, and within a second pressure range, as the brake pressure further increases, the brake disc completes the feed and a further increase in the friction torque occurs on the vehicle brake.

[0019] The present invention solves the task mentioned at the outset regarding a vehicle brake in that the vehicle brake is configured to adjust a set pressure to a pressure within a first pressure range. The vehicle brake according to the present invention is also based on the recognition that a set pressure can be determined and adjusted based on the relationship between the brake feed stroke and the brake pressure, which allows the vehicle brake to quickly provide a braking force while minimizing friction losses.

[0020] The invention is developed in that the measuring device has a lining wear sensor which is designed to detect a brake pressure-dependent brake feed travel of a vehicle brake.

[0021] Preferably, the settling pressure is adjusted to a pressure in the lower third of the total range width with respect to the first pressure range. According to an alternative preferred embodiment, the settling pressure is adjusted to a pressure in the middle third of the total range width with respect to the first pressure range. According to a further alternative preferred embodiment, the settling pressure is adjusted to a range in the upper third of the total range width with respect to the first pressure range.

[0022] The vehicle brake utilizes the same advantages and preferred embodiments as the method according to the invention, the controller according to the invention and the computer program product according to the invention, and vice versa. In this regard, reference is made to the above-described embodiments and their contents are included here.

[0023] In another aspect, the invention relates to a motor vehicle, in particular a commercial vehicle. The invention achieves the object mentioned at the outset with respect to a motor vehicle in that the motor vehicle has at least one vehicle brake, wherein at least one vehicle brake is designed according to one of the above-described exemplary embodiments. The invention is further developed in that the motor vehicle has a control unit according to one of the above-described claims.

[0024] The motor vehicle utilizes the same advantages and preferred embodiments as the method according to the invention, the control device according to the invention, the computer program product according to the invention and the vehicle brake according to the invention, and vice versa. In this regard, reference is made to the above-mentioned embodiments and their contents are included here.

[0025] The following describes an embodiment of the present invention with the aid of the drawings. These drawings do not necessarily show the embodiment to scale, but in the case of helping to explain, the drawings are implemented in a schematic and / or slightly distorted form. With regard to the supplement of the teachings that can be directly identified from the drawings, reference is made to the relevant prior art. It should be taken into account that various modifications and changes in the shape and details of the embodiments can be performed without departing from the overall concept of the present invention. The features disclosed in the specification, drawings and claims of the present invention can be important for the improvement scheme of the present invention alone and in any combination. In addition, all combinations of at least two features of the features disclosed in the specification, drawings and / or claims fall within the scope of the present invention. The overall concept of the present invention is not limited to the precise shape or details of the preferred embodiments shown and described later, or to the subject matter that is restricted compared to the subject matter claimed in the claims. In the measurement range described, the values ​​within the mentioned boundaries should also be disclosed as limit values ​​and can be used and claimed at will. For simplicity, the same or identical parts or parts with the same or similar functions are provided with the same reference numerals. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 An exemplary embodiment of a motor vehicle according to the invention having a vehicle brake according to the invention is shown in a schematic diagram;

[0027] Figure 2 shows a diagram depicting an exemplary relationship between brake pressure and brake feed travel in a vehicle brake according to the present invention;

[0028] Figure 3 A block diagram showing a method for adjusting the set pressure of a vehicle brake is shown;

[0029] Figure 4 shows a schematic diagram of a controller according to the present invention; and

[0030] Figure 5 A schematic diagram of a computer program product according to the present invention is shown. DETAILED DESCRIPTION

[0031] Figure 1A motor vehicle 1 is shown, which is shown only schematically here and is in particular designed as a commercial vehicle 3. The motor vehicle 1 has a vehicle brake 2. The vehicle brake 2 is designed in the present case as a commercial vehicle disc brake 4. The vehicle brake 2 has a brake carrier 6. The brake carrier 6 has a brake lining receptacle 8. Two brake linings 10 are arranged in the brake lining receptacle 8, in which the brake linings are guided and supported in an axially movable manner. The vehicle brake 2 also has a brake caliper 12 which is axially movable relative to the brake carrier 6.

[0032] The vehicle brake 2 also has a measuring device 14. The measuring device 14 is designed to detect a braking feed distance d of the vehicle brake 2 as a function of the brake pressure p. Figure 1 In the state shown, the vehicle brake 2 has an air gap L which describes the distance between the brake disk 22 and the brake lining 10. The measuring device 14 has a lining wear sensor 20. The lining wear sensor 20 is designed to detect a brake feed travel d of the vehicle brake 2 as a function of the brake pressure p.

[0033] The relationship is Figure 2 Shown in. Figure 2 An exemplary diagram is shown, in which the brake pressure p is plotted on the horizontal axis. Figure 2 The pressure range of the brake pressure p from 0 bar to approximately 2.5 bar is plotted in the figure. The brake feed distance d is plotted on the vertical axis, which is indicated here by way of example in millimeters. Three pressure ranges can be derived from the diagram. As the brake pressure p increases, a static range 19 is first reached. In the static range 19, an increase in the brake pressure p does not lead to a change in the brake feed distance d. In other words, a pressure increase in this range does not yet lead to an advance of the brake lining 10 in the direction of the brake disc 22. Figure 2 In the example shown, static range 19 reaches, for example, a brake pressure p of up to 0.3 bar.

[0034] When the brake pressure p is further increased, the first pressure range 16 is reached. In this range, when the brake pressure p increases, the vehicle brake 2 is fed a brake feed distance d in the direction of the brake disk 22 overcoming the air gap L, thereby increasing the friction torque M r At the end of the first pressure range 16 , which in the example shown is, for example, approximately 0.8 bar, the brake disk 22 has been advanced. In the second pressure range 18 , with a further increase in the brake pressure p, a friction torque M on the vehicle brake 2 is achieved. r The first pressure range 16 now has a total range width b. The total range width b is divided into a lower third 24, a middle third 26 and an upper third 28.

[0035] The vehicle brake 2 is designed to set a set pressure p in a first pressure range 16. a Preferably, the pressure p a The pressure p is set to lie in the lower third 24 of the total range width b with respect to the first pressure range 16. a This is Figure 2 In the diagram, this is shown schematically by, for example, setting the pressure p a The pressure is set to 0.4 bar, where the pressure p a The pressure p is in the lower third 24 of the first pressure range 16. The pressure p is set in this range. a It is ensured that the vehicle brake 2 can quickly provide a braking force from the relevant ready state and that minimal friction losses occur in this ready state.

[0036] Figure 3 1 shows a method according to the invention for adjusting the set pressure p of a vehicle brake 2 of a motor vehicle 1 , in particular a commercial vehicle disk brake 4 . a 1 , wherein, in a first pressure range 16, when the brake pressure p increases, the vehicle brake 2 overcomes the air gap L to advance the brake lining 10 in the direction of the brake disk 22 by a braking advance distance d, thereby increasing the friction torque M r , and in the second pressure range 18, as the brake pressure p further increases, the brake disc 22 completes the feed, and a friction torque M occurs on the vehicle brake 2 r further increase.

[0037] The method has a step 104 in which a braking travel distance d is detected as a function of the braking pressure p. According to a step 106, a first pressure range 16 is identified based on the detected braking travel distance d as a function of the braking pressure p. Finally, according to a step 108, the setting pressure p is set to a The pressure is set to a pressure in the first pressure range 16. Preferably, the method further comprises the step of checking 110 the set pressure p during vehicle operation, in particular by means of at least one test brake. a .

[0038] Figure 4 A control unit 202 for a vehicle brake 2 of a motor vehicle 1 is schematically shown. The control unit 202 is configured to implement a control according to Figure 3 The controller 202 may be configured as a dedicated controller 202 or a central controller 202.

[0039] Figure 5The computer program 203 is schematically shown. The computer program product 203 contains instructions 304. When the instructions are executed on a computer, the instructions 304 cause the computer (not shown) to form a computer program according to Figure 4 The controller 202 and / or implementation according to Figure 3 Method 102.

[0040] List of reference numerals (part of the description)

[0041] 1 Motor Vehicle

[0042] 2 Vehicle brakes

[0043] 3 Commercial vehicles

[0044] 4 Commercial vehicle disc brakes

[0045] 6 Brake carrier

[0046] 8 Brake lining receptacle

[0047] 10 Brake linings

[0048] 12 Brake calipers

[0049] 14. Measuring device

[0050] 16 First pressure range

[0051] 18 Second pressure range

[0052] 19 Static Scope

[0053] 20 Lining wear sensor

[0054] 22 Brake disc

[0055] 24 Lower third

[0056] 26 in one third

[0057] 28 Upper third

[0058] 102 Adjustment Method

[0059] 104 Detection of brake feed travel dependent on brake pressure

[0060] 106 Identify the first pressure range

[0061] 108 Adjust the installation pressure to a pressure value within the first pressure range

[0062] 110 Checking the set setting pressure using a test brake

[0063] 202 Controller

[0064] 302 Computer software products

[0065] 304 Directive

[0066] b Total range width of the first pressure range

[0067] d Braking feed stroke

[0068] L Air Gap

[0069] M r Friction torque

[0070] p Brake pressure

[0071] p a Placement pressure

Claims

1. For adjusting the set pressure (p) of a vehicle brake (2) of a motor vehicle (1), in particular a commercial vehicle (3) having a commercial vehicle disc brake (4). a ) method (102), in, In the case of an increase in the brake pressure (p) within a first pressure range (16), the vehicle brake (2) advances the brake lining (10) over the air gap (L) in the direction of the brake disk (22) by a braking advance distance (d), thereby increasing the friction torque (M r ), And in the second pressure range (18), as the brake pressure (p) further increases, the brake disc (22) completes the feed and a friction torque (M) is generated on the vehicle brake (2). r ), the method comprises the following steps: - detecting (104) the braking feed distance (d) as a function of the braking pressure (p), - identifying (106) the first pressure range (16) based on the detected brake feed travel (d) as a function of the brake pressure (p), - the vehicle brake (2) is set to a pressure (p a ) is adjusted (108) to a pressure (p) within the first pressure range (16) a ).

2. The method (102) according to claim 1, in, A brake feed distance (d) is detected as a function of a brake pressure (p) by means of a continuous lining wear sensor (20) arranged on the vehicle brake (2).

3. The method (102) according to claim 1, in, The installation pressure (p a ) is set to a pressure (p ) in the lower third (24) of the total range width (b) of the first pressure range (16). a ).

4. The method (102) according to claim 1 or 2, in, The installation pressure (p a ) is set to a pressure (p ) which is in the middle third (26) of the total range width (b) with respect to the first pressure range (16). a ).

5. The method (102) according to claim 1 or 2, in, The installation pressure (p a ) is set to a pressure (p ) which is in the upper third (28) of the total range width (b) of the first pressure range (16). a ).

6. The method (102) according to any one of the preceding claims, The method further comprises the following steps: - during operation of the vehicle (1), checking (110) the set setting pressure (p a ).

7. The method (102) according to claim 6, in, The setting pressure (p ) is adjusted by means of an electric vehicle drive, in particular by determining a change in the drive power or drive torque when carrying out the test braking. a ) inspection (110).

8. A controller (202) for a vehicle brake (2) of a commercial vehicle, It is characterized in that The control unit (202) is configured to carry out the method (100) according to any one of claims 1 to 7.

9. The controller (202) according to claim 8, in, The controller (202) is configured as a dedicated controller (202) or a central controller (202).

10. A computer program product (302), comprising instructions (304) which, when executed on a computer, cause the computer to form a controller (202) according to claim 8 or 9 and / or to implement a method (102) according to any one of claims 1 to 7.

11. A vehicle brake (2), in particular a commercial vehicle disc brake (4), comprising: - a brake carrier (6) having at least one brake lining receptacle (8), - at least one brake lining (10), which is guided and supported in an axially displaceable manner in the brake lining receptacle (8), - a brake caliper (12) movable axially relative to the brake carrier (6), and - a measuring device (14) which is designed to detect a braking feed distance (d) of the vehicle brake (2) as a function of a braking pressure (p), in, In the case of an increase in the brake pressure (p) within a first pressure range (16), the vehicle brake (2) advances the brake lining (10) over the air gap (L) in the direction of the brake disk (22) by a braking advance distance (d), thereby increasing the friction torque (M r ), And in the second pressure range (18), as the brake pressure (p) further increases, the brake disc (22) completes the feed and a friction torque (M) is generated on the vehicle brake (2). r ) further increases, characterised in that the vehicle brake (2) is designed to set the pressure (p a ) is adjusted to a pressure (p a ).

12. The vehicle brake (2) according to claim 10, in, The measuring device (14) has a lining wear sensor (20) which is designed to detect a brake feed travel (d) of the vehicle brake (2) as a function of a brake pressure (p).

13. The vehicle brake (2) according to claim 11 or 12, in, The placement pressure (p a ) is set to a pressure (p ) which is in the lower third (24) of the total range width (b) of the first pressure range (16). a ).

14. The vehicle brake (2) according to claim 11 or 12, in, The placement pressure (p a ) is set to a pressure (p ) which is in the middle third (26) of the total range width (b) of the first pressure range (16). a ).

15. Vehicle brake (2) according to claim 11 or 12, in, The placement pressure (p a ) is set to a pressure (p ) which is in the upper third (28) of the total range width (b) of the first pressure range (16). a ).

16. A motor vehicle (1), in particular a commercial vehicle (3), comprising: - At least one vehicle brake (2), wherein at least one vehicle brake (2) is designed according to any one of claims 11 to 15.

17. A motor vehicle (1) according to claim 16, Features A controller (202) according to claim 8 or 9 is provided.

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