Brake system for a vehicle with at least two axes and method for operating the brake system

Abstract

[Solution] The present invention relates to a brake system for a vehicle with at least two axles, having a first axle unit (10) including a first motor-driven brake pressure generating device (12), a first wheel brake cylinder (14a) hydraulically connected to the first motor-driven brake pressure generating device (12) and mountable on a first wheel of a first axle of the vehicle, and a second wheel brake cylinder (14b) hydraulically connected to the first motor-driven brake pressure generating device (12) and mountable on a second wheel of the first axle, and a second axle unit hydraulically separated from the first axle unit (10), wherein the first axle unit (10) further has, in addition to the first motor-driven brake pressure generating device (12), a second motor-driven brake pressure generating device (16) to which the first wheel brake cylinder (14a) and the second wheel brake cylinder (14b) are hydraulically connected. The invention also relates to a method for actuating a braking system of a vehicle with at least two axles.

Description

Technical Field

[0001] The present invention relates to a braking system for at least a two-axle vehicle. Similarly, the present invention relates to a method for operating a braking system of at least a two-axle vehicle.

Background Art

[0002] From the prior art such as Patent Document 1, for example, there is known a braking system for at least a two-axle vehicle, each having four wheel brake cylinders, each of which is hydraulically connected to a master brake cylinder of each braking system having a brake pedal pre-positioned to the master brake cylinder.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] The present invention provides a braking system for at least a two-axle vehicle having the constituent features of claim 1, and a method for operating a braking system of at least a two-axle vehicle having the constituent features of claim 10.

[0005] The present invention provides a braking system for at least a two-axle vehicle having a relatively compact structure and being producible at a relatively low manufacturing cost. As will become apparent with reference to the following description, in the braking system according to the present invention, the conventional hydraulic piping between at least two axles of the vehicle in which each braking system is mounted becomes unnecessary. This results in a relatively large reduction in the design space in each vehicle. In addition, the assembly of each braking system according to the present invention to each vehicle is also simplified accordingly.

[0006] As will become even more apparent with reference to the following description, in the braking system according to the invention, the respective braking pressures in the wheel brake cylinders of the first axle unit can be adjusted in a fully automatic / fully autonomous manner, i.e., without the provision of a driver braking force by the driver. This can also be referred to as fully automatic / fully autonomous pressure regulation. Furthermore, a failure of one of the two motor-driven brake pressure generating devices of the first axle unit of the braking system according to the invention can be easily compensated for by the use of the other (enhanced or alternative) of the two motor-driven brake pressure generating devices. Accordingly, the braking system according to the invention has the advantage of being suitable for application in vehicle types for autonomous driving.

[0007] The first axle unit is preferably a "front axle unit". Thus, in the braking system according to the invention, the first braking pressure in the first wheel brake cylinder used as the front axle wheel brake cylinder and the second braking pressure in the second wheel brake cylinder also used as the front axle wheel brake cylinder can be adjusted in a fully automatic / fully autonomous manner, i.e., without the provision of a driver braking force by the driver of each vehicle.

[0008] In a preferred embodiment of the braking system, the first control device of the first axle unit controls the first motor-driven brake pressure generating device and the second motor-driven brake pressure generating device taking into account at least one brake setting signal output to the first control device from at least one brake operating member sensor of the vehicle, the vehicle speed control automatic, the second control device of the second axle unit, and / or other stabilizing devices of the braking system, so that the operation of the first motor-driven brake pressure generating device can transfer brake fluid to the first wheel brake cylinder and the second wheel brake cylinder at least temporarily, and the operation of the second motor-driven brake pressure generating device can transfer brake fluid to the first wheel brake cylinder and the second wheel brake cylinder at least temporarily. Thus, the first control device responds to a failure of one of the two motor-driven brake pressure generating devices of the first axle unit with compensatory utilization of the other of the two motor-driven brake pressure generating devices of the first axle unit. Thus, active pressure generation in the first wheel brake cylinder and / or the second wheel brake cylinder is also possible at the "non-mechanical" fallback level of the first axle unit caused in such a manner. In particular, at the "non-mechanical" fallback level, it is also possible to autonomously brake each vehicle by means of its first axle unit.

[0009] The first axle unit is preferably hydraulically separated from the second axle unit such that the first axle unit and the second axle unit are connected to each other via at least one signal line and / or bus line connected to the first control device and the second control device at most. Accordingly, in the embodiment of the braking system described herein, the conventional hydraulic piping between the first axle and the second axle of the vehicle equipped with the braking system described herein becomes unnecessary.

[0010] For example, the first motor-driven brake pressure generating device may be hydraulically connected to the first wheel brake cylinder and the second wheel brake cylinder via a first hydraulic path that branches off from each other, and the first isolation valve and / or the second isolation valve may be arranged in the first hydraulic path so that the first wheel brake cylinder can be blocked from the first motor-driven brake pressure generating device through the closing of the first isolation valve while the brake fluid can be transferred to the second wheel brake cylinder by the first motor-driven brake pressure generating device, and / or the second wheel brake cylinder can be blocked from the first motor-driven brake pressure generating device through the closing of the second isolation valve while the brake fluid can be transferred to the first wheel brake cylinder by the first motor-driven brake pressure generating device. Thus, by the operation of the first motor-driven brake pressure generating device, in the embodiment of the brake system described herein, wheel-specific pressure regulation can be performed on both wheel brake cylinders of the first axle unit. This can also be described as wheel-specific fully automatic / fully autonomous pressure regulation in the wheel brake cylinders of the first axle unit of the brake system according to the present invention described herein. However, it should be noted that the switching of the first isolation valve and / or the second isolation valve for wheel-specific fully automatic / fully autonomous pressure regulation in the wheel brake cylinder is usually only required for modulation such as ESP control or ABS control. Therefore, during the operation of the brake system according to the present invention described herein, only relatively rare valve switching sounds are generated. Therefore, it is also possible to use the expression of good NVH characteristics (Noise Vibration Harshness-Characteristic, noise, vibration, harshness characteristics) of the brake system according to the present invention described herein.

[0011] In particular, the second motor-driven brake pressure generating device may be hydraulically connected to the first wheel brake cylinder and the second wheel brake cylinder via second hydraulic paths that branch from each other, and a third isolation valve and / or a fourth isolation valve are arranged in the second hydraulic path such that the first wheel brake cylinder can be blocked from the second motor-driven brake pressure generating device through closing of the third isolation valve while the brake fluid can be transferred to the second wheel brake cylinder by the second motor-driven brake pressure generating device, and / or the second wheel brake cylinder can be blocked from the second motor-driven brake pressure generating device through closing of the fourth isolation valve while the brake fluid can be transferred to the first wheel brake cylinder by the second motor-driven brake pressure generating device. Thus, the embodiment of the brake system described herein also provides, as a preferred development example, the possibility of performing wheel-specific pressure regulation in both wheel brake cylinders of the first axle unit by operation of the second motor-driven brake pressure generating device.

[0012] The first axle unit preferably additionally includes a master brake cylinder to which a brake operating member of the vehicle is connectable or is connected, whereby at least one piston of the master brake cylinder delimiting at least one chamber of the master brake cylinder is adjustable in position by operation of the brake operating member by the driver of the vehicle, and at least one chamber of the master brake cylinder is hydraulically connected via at least one connection line that is valve-less or equipped with a valve to the first motor-operated brake pressure generating device, the second motor-operated brake pressure generating device, the first hydraulic path, and / or the second hydraulic path. In this way, the driver can directly brake intervene with the wheel brake cylinder of the first axle unit by his own driver braking force and thus has the possibility of further inducing (additional) brake pressure generation in the wheel brake cylinder of the first axle unit. Along with this, the embodiment of the brake system described here also has a mechanical fallback level.

[0013] The first motor-operated brake pressure generating device is preferably a first plunger device, and a single chamber of the master brake cylinder or at least one of a plurality of chambers is hydraulically connected to the first plunger chamber of the first plunger device via a single connecting pipe or at least one of a plurality of connecting pipes. The first communication portion of the single connecting pipe or at least one of the plurality of connecting pipes to the first plunger chamber allows brake fluid to be transferred from the master brake cylinder through the first communication portion into the first plunger chamber when the position-adjustable first plunger piston of the first plunger device is in the initial position. In contrast, when the first plunger piston is position-adjusted to move out of the initial position, the transfer of brake fluid from the master brake cylinder through the first communication portion into the first plunger chamber is configured to be blocked by the first plunger piston and / or at least one first seal member attached to the first plunger chamber. Thus, during the operation of the first plunger device, the master brake cylinder is automatically "blocked" from the first plunger device. Nevertheless, the embodiment of the brake system described herein automatically shifts to a fallback level where, when the first plunger device fails, the driver can intervene with the brake by the driver's braking force to the wheel brake cylinder of the first axle unit via the master brake cylinder and the first plunger device. Thus, no valve switching is required to shift the embodiment of the brake system described herein to the mechanical fallback level.

[0014] As a preferred development example, the second motor-driven brake pressure generating device may also be a second plunger device, and a single chamber of the master brake cylinder, or at least one of a plurality of chambers, may be hydraulically connected to a second plunger chamber of the second plunger device via at least one of a plurality of connecting pipes. A second communication portion of at least one of the plurality of connecting pipes to the second plunger chamber is configured such that when the position-adjustable second plunger piston of the second plunger device is in the initial position, brake fluid can be transferred from the master brake cylinder through the second communication portion into the second plunger chamber. On the other hand, when the second plunger piston is position-adjusted to move out of the initial position, the transfer of brake fluid from the master brake cylinder through the second communication portion into the second plunger chamber is blocked by at least one second seal member attached to the second plunger piston and / or the second plunger chamber. This improves the transition of the brake system to the mechanical fallback level described in the above paragraph.

[0015] As an alternative or supplement thereto, at least one master brake cylinder shut-off valve may be arranged in at least one connecting pipe. In this way, the transition of the brake system embodiments described herein to the mechanical fallback level is also possible through the switching of at least one master brake cylinder shut-off valve.

[0016] The advantages described above are also guaranteed when a corresponding method for operating the brake system of a vehicle with at least two axles is implemented. Specifically stated, the method for operating the brake system of a vehicle with at least two axles can be developed in a developed form according to each embodiment of the brake system described above.

[0017] Other components and advantages of the present invention will be described below with reference to the drawings. The drawings show the following.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0019] FIG. 1 shows a schematic partial view of a first embodiment of a braking system.

[0020] The braking system schematically shown in FIG. 1 can be assembled to / has been assembled to a vehicle / motor vehicle with at least two axes, but the applicability of this braking system is not limited to a special vehicle type / motor vehicle type of a two-axle vehicle / motor vehicle.

[0021] The braking system of FIG. 1 has a first axle unit 10 including a first motor-driven brake pressure generating device 12, a first wheel brake cylinder 14a hydraulically connected to the first motor-driven brake pressure generating device 12, and a second wheel brake cylinder 14b also hydraulically connected to the first motor-driven brake pressure generating device 12. Thus, both the first brake pressure in the first wheel brake cylinder 14a and the second brake pressure in the second wheel brake cylinder 14b can be adjusted to at least the same pressure value in a fully automatic / fully autonomous manner by the first motor-driven brake pressure generating device 12, that is, without the provision of a driver braking force by the driver of each vehicle. Further, the first axle unit 10 further has a second motor-driven brake pressure generating device 16 in addition to the first motor-driven brake pressure generating device 12, to which the first wheel brake cylinder 14a and the second wheel brake cylinder 14b are also hydraulically connected. Therefore, it is possible to cause fully automatic / fully autonomous brake pressure generation in the first wheel brake cylinder 14a and the second wheel brake cylinder 14b more quickly by the second motor-driven brake pressure generating device 16 or without the first motor-driven brake pressure generating device 12. The first motor-driven brake pressure generating device 12 and / or the second brake pressure generating device 16 may be, for example, a plunger device and / or at least one pump respectively. Accordingly, the first axle unit can be configured at a relatively low cost. The configurations of the first motor-driven brake pressure generating device 12 as a plunger device and the second motor-driven brake pressure generating device 16 as a pump, which are concretely shown in FIG. 1, should be interpreted as illustrative only.

[0022] The first wheel brake cylinder 14a can be assembled to / is assembled to a first wheel (not shown) of the first axle of the vehicle, while the second wheel brake cylinder 14b can be assembled to / is assembled to a second wheel (not shown) of the first axle. The braking system also has a second axle unit configured to be hydraulically separated from the first axle unit, which is not shown concretely in FIG. 1. The second axle unit includes at least one motorized device, a first wheel braking device hydraulically or mechanically coupled to the at least one motorized device, and a second wheel braking device hydraulically or mechanically coupled to the at least one motorized device. The first wheel braking device can be assembled to / is assembled to the first wheel of the second axle of the vehicle, while the second wheel braking device can be assembled to / is assembled to the second wheel of the second axle.

[0023] The second axle unit can include, for example, as the motorized device, a third motorized brake pressure generating device, as the first wheel braking device, a third wheel brake cylinder hydraulically connected to the third motorized brake pressure generating device, and as the second wheel braking device, a fourth wheel brake cylinder hydraulically connected to the third motorized brake pressure generating device. The third motorized brake pressure generating device can be, for example, a plunger device and / or at least one pump. However, as an alternative, the first wheel braking device and the second wheel braking device can each be an electromechanical wheel brake, and an electric motor attached thereto is mechanically coupled as the at least one motorized device so that each electromechanical wheel brake can be operated by its attached electric motor. Thus, the second axle unit can be selectively configured as a "hydraulic" axle unit or an "electric" axle unit. Accordingly, the second axle unit can also be configured at a relatively low cost.

[0024] The configuration of the first axle unit 10 hydraulically separated from the second axle unit means that no hydraulic piping extends between the first axle unit 10 and the second axle unit. Since the first axle unit 10 is configured to be hydraulically separated from the second axle unit, in the braking system of FIG. 1, the hydraulic piping that is conventionally required between each axle equipped with a wheel brake cylinder becomes unnecessary. Accordingly, this braking system has a very compact structure that saves design space. In particular, the modular structure of the braking system can be realized at a relatively low manufacturing cost. Further, the first axle unit 10 and the second axle unit can be assembled as two separate units to a two-axle vehicle equipped with them. This simplifies the assembly of the braking system described herein.

[0025] In the braking system of FIG. 1, a high redundancy of the first axle unit 10 is achieved with slight modifications. Further, a number of "identical" parts, i.e., parts of the same type, can be used for the first axle unit 10. Therefore, the first axle unit 10 is relatively low-cost and can be manufactured using braking system components that have already been conventionally used.

[0026] For example, the first motor-operated brake pressure generating device 12 may be hydraulically connected to the first wheel brake cylinder 14a and the second wheel brake cylinder 14b via a first hydraulic path that branches from each other. The first isolation valve 18a and / or the second isolation valve 18b may be disposed in the first hydraulic path. While the brake fluid can be transferred to the second wheel brake cylinder 14b by the first motor-operated brake pressure generating device 12, the first wheel brake cylinder 14a can be blocked from the first motor-operated brake pressure generating device 12 through the closing of the first isolation valve 18a / and is configured to block it. And / or while the brake fluid can be transferred to the first wheel brake cylinder 14a by the first motor-operated brake pressure generating device 12, the second wheel brake cylinder 14b can be blocked from the first motor-operated brake pressure generating device 12 through the closing of the second isolation valve 18b / and is configured to block it. In this way, by equipping the first axle unit 10 with the first isolation valve 18a and / or the second isolation valve 18b, it is possible to perform wheel individual pressure regulation on both wheel brake cylinders 14a and 14b of the first axle unit 10 of the brake system. As wheel individual fully automatic / fully autonomous pressure regulation in the wheel brake cylinders 14a and 14b, for example, ESP control or ABS control is possible.

[0027] As an alternative or addition thereto, the second motor-operated brake pressure generating device 16 may also be hydraulically connected to the first wheel brake cylinder 14a and the second wheel brake cylinder 14b via second hydraulic paths that branch from each other. In this case as well, the third isolation valve 20a and / or the fourth isolation valve 20b may be arranged in the second hydraulic path. Also in this case, while the brake fluid can be transferred to the second wheel brake cylinder 14b by the second motor-operated brake pressure generating device 16, the first wheel brake cylinder 14a can be blocked from the second motor-operated brake pressure generating device 16 through closing of the third isolation valve 20a / may be blocked, and / or while the brake fluid can be transferred to the first wheel brake cylinder 14a by the second motor-operated brake pressure generating device 16, the second wheel brake cylinder 14b can be blocked from the second motor-operated brake pressure generating device 16 through closing of the fourth isolation valve 20b / may be blocked. Accordingly, the second motor-operated brake pressure generating device 16 can also be used for individual wheel pressure adjustment at both wheel brake cylinders 14a and 14b of the first axle unit 10.

[0028] At least one of the isolation valves 18a, 18b, 20a, and 20b of the first axle unit 10 may selectively be a switching valve or a continuously adjustable valve suitable for differential pressure adjustment. It is preferable that at least one of the isolation valves 18a, 18b, 20a, and 20b is a normally open valve. It is equally preferable that the first isolation valve 18a and the fourth isolation valve 20b are each a normally open valve, and the second isolation valve 18b and the third isolation valve 20a are each a normally closed valve. As an alternative thereto, the first isolation valve 18a and the fourth isolation valve 20b may each be a normally closed valve, and the second isolation valve 18b and the third isolation valve 20a may each be a normally open valve.

[0029] As a preferred development example, the first axle unit, taking into account at least one brake setting signal 24, controls at least the first motor-operated brake pressure generating device 12 and the second motor-operated brake pressure generating device 16 (and optionally further at least one of the separating valves 18a, 18b, 20a and 20b of the first axle unit 10) by means of at least one control signal 22a, so that the operation of the first motor-operated brake pressure generating device 12 can transfer / transfers the brake fluid to the first wheel brake cylinder 14a and / or the second wheel brake cylinder 14b at least temporarily, and so that the second motor-operated brake pressure generating device 16 can transfer / transfers the brake fluid to the first wheel brake cylinder 14a and / or the second wheel brake cylinder 14b at least temporarily, and can have a first control device 22 designed and / or programmed therefor. The at least one brake setting signal 24 can be output to the first control device 22 from at least one brake operating member sensor of the vehicle, a speed control automatic of the vehicle, a second control device of the second axle unit, and / or other stabilizing devices of the brake system. The at least one brake operating member sensor can be, for example, a rod stroke sensor and / or a stroke difference sensor. The speed control automatic can be, for example, an automatic for driverless driving of the vehicle, a cruise control of the vehicle distance, and / or an emergency brake system. The other stabilizing devices of the vehicle can be understood in particular as an ESP control unit or an ABS control unit. Thus, the first axle unit 10 can cooperate with a number of different electronic components for pressure regulation in the wheel brake cylinders 14a and 14b.As a preferred development example, the first control device 22 may be configured to receive and evaluate the sensor signals of a feed pressure sensor (not shown) of the first axle unit 10, the sensor signals of at least one wheel pressure sensor (not shown) of the first axle unit 10, the sensor signals of at least one wheel rotation speed sensor (not shown in detail) of at least one wheel of the first axle of the vehicle, the yaw rate sensor, and / or the acceleration sensor. As another preferred development example, the control device 22 may be designed to jointly control at least one motor of the vehicle that is used as a generator for the regenerative braking of the vehicle (not shown in FIG. 1), or to notify the motor of preferred information for the regenerative braking of the vehicle. The first axle unit 10 and the second axle unit (not shown) are preferably hydraulically separated from each other such that the first axle unit 10 and the second axle unit are connected to each other via at least one signal line and / or bus line connected to the first control device 22 and the second control device of the second axle unit at most. In this way, in this case, the connection between the first axle unit 10 and the second axle unit embodied by the signal line and / or bus line saves design space and, nevertheless, enables good cooperation between the first axle unit 10 and the second axle unit. The at least one signal line and / or bus line may be, for example, the vehicle bus of the vehicle.

[0030] The first axle unit 10 can be assembled to, or preferably is assembled to, a first axle that can be called the front axle of the vehicle as the "front axle unit", while the second axle unit can be assembled to, or is assembled to, a second axle that can be called the rear axle of the vehicle as the "rear axle unit". In this case, the first axle unit 10 serves to brake the front wheels of the vehicle, while the second axle unit can brake the rear wheels of the vehicle. As an alternative, the first axle unit 10 can be assembled to, or may be assembled to, a first axle that can be called the rear axle of the vehicle as the "rear axle unit", while the second axle unit can be assembled to, or is assembled to, a second axle that can be called the front axle of the vehicle as the "front axle unit".

[0031] Figure 2 shows a schematic partial view of a second embodiment of the braking system.

[0032] The braking system schematically shown in Figure 2, as a development of the embodiment of Figure 1, further has a master brake cylinder 30 in the first axle unit 10, to which a brake operating member 32 of the vehicle can be connected or is connected, whereby at least one piston of the master brake cylinder 30 separating at least one chamber of the master brake cylinder 30 is adjustable in position or is adjusted in position by the operation of the brake operating member 32 by the driver of the vehicle. Further, at least one chamber of the master brake cylinder 30 is hydraulically connected via at least one valveless or valve-equipped connecting pipe 34 to the first motor-operated brake pressure generating device 12, the second motor-operated brake pressure generating device 16, the first hydraulic path, and / or the second hydraulic path.

[0033] The brake operation member 32 may be, for example, a brake pedal 32. In the brake system of FIG. 2 in this way, particularly when the first motor-driven brake pressure generating device 12 and / or the second motor-driven brake pressure generating device 16 fails, the driver can still cause brake pressure generation in the wheel brake cylinders 14a and 14b by the driver's braking force applied to the brake operation member 32, and a mechanical fallback level is configured. In this way, the driver can still reliably shift the vehicle to a stop by the increase in brake pressure caused in the wheel brake cylinders 14a and 14b even when the vehicle electrical system of the vehicle fails.

[0034] At least one master brake cylinder shut-off valve 36 may be inserted into at least one connecting pipe 34. In this way, during the operation of the first motor-driven brake pressure generating device 12 and / or the second motor-driven brake pressure generating device 16, by closing at least one master brake cylinder shut-off valve 36, the master brake cylinder 40 may be / is able to be blocked from the first motor-driven brake pressure generating device 12 and / or the second motor-driven brake pressure generating device 16, so that the driver's braking force applied to the brake operation member 32 does not affect the brake pressure generated each time in the wheel brake cylinders 14a and 14b. At least one master brake cylinder shut-off valve 36 is preferably a normally open valve. Although not shown in FIG. 1, a simulator may be further connected to the master brake cylinder 30, so that the driver operating the brake operation member 32 receives a standard brake operation feeling / pedal feeling in the closed state of at least one master brake cylinder shut-off valve 36.

[0035] As a supplement thereto, at least one brake pressure generating device shut-off valve 38 may be further utilized in the first axle unit 10, whereby the first motor-operated brake pressure generating device 12 and / or the second motor-operated brake pressure generating device 16 can be shut off from at least one connecting pipe 34 by closing at least one brake pressure generating device shut-off valve 38 during the mechanical fallback mode, so that it does not adversely affect the brake pressure increase in the wheel brake cylinders 14a and 14b caused by the driver's braking force as a "volume sink". For at least one brake pressure generating device shut-off valve 38, a normally closed valve is preferred.

[0036] As an example only, in the first axle unit 10 of FIG. 2, a single connecting pipe 34 equipped with a master brake cylinder shut-off valve 36 communicates with the area of the first hydraulic path between the brake pressure generating device shut-off valve 38 pre-positioned in front of the first motor-operated brake pressure generating device 12 and the wheel brake cylinders 14a and 14b.

[0037] Regarding other components, characteristics and advantages of the brake system of FIG. 2, reference may be made to the embodiment of FIG. 1 described above.

[0038] FIG. 3 shows a schematic partial view of a third embodiment of the brake system.

[0039] In the brake system schematically shown in FIG. 3, the difference in the first axle unit 10 from the embodiment described above is only that a single connecting pipe 34 branches such that the first communication part of the connecting pipe 34 communicates with the area of the first hydraulic path between the first brake pressure generating device shut-off valve 38a pre-positioned in front of the first motor-operated brake pressure generating device 12 and the wheel brake cylinders 14a and 14b, and the second communication part of the connecting pipe 34 communicates with the area of the second hydraulic path between the second brake pressure generating device shut-off valve 38b pre-positioned in front of the second motor-operated brake pressure generating device 16 and the wheel brake cylinders 14a and 14b.

[0040] For other components, characteristics, and advantages of the braking system of FIG. 3, refer to the embodiments of FIGS. 1 and 2 described above.

[0041] FIG. 4 shows a schematic partial view of a fourth embodiment of the braking system.

[0042] The braking system of FIG. 4 has a first master brake cylinder shut-off valve 36a inserted in the section of the connecting pipe 34 between the branch section and the first communication section, and a second master brake cylinder shut-off valve 36b inserted in the section of the connecting pipe 34 between the branch section and the second communication section, instead of the single master brake cylinder shut-off valve 36 of the embodiments described above.

[0043] For other components, characteristics, and advantages of the braking system of FIG. 4, refer to the embodiments of FIGS. 1 to 3 described above.

[0044] FIG. 5 shows a schematic partial view of a fifth embodiment of the braking system.

[0045] In the braking system of FIG. 5, the master brake cylinder 30 is a tandem-type master brake cylinder 30, and the first chamber of the master brake cylinder 30 is connected by a first connecting pipe 34a having a first master brake cylinder shut-off valve 36a to the section of the first hydraulic path between the first brake pressure generating device / shut-off valve 38a and the wheel brake cylinders 14a and 14b, and the second chamber of the master brake cylinder 40 is connected by a second connecting pipe 34b having a second master brake cylinder shut-off valve 36b to the section of the second hydraulic path between the second brake pressure generating device / shut-off valve 38b and the wheel brake cylinders 14a and 14b.

[0046] For other components, characteristics, and advantages of the braking system of FIG. 5, refer to the embodiments of FIGS. 1 to 4 described above.

[0047] FIG. 6 shows a schematic partial view of a sixth embodiment of the braking system.

[0048] In the first axle unit 10 schematically shown in FIG. 6, the first motor-driven brake pressure generating device 12 is a plunger device 12. A single chamber of the master brake cylinder 30 is hydraulically connected to the plunger chamber 12a of the plunger device 12 via a connecting pipe 34. The communication part of the connecting pipe 34 to the plunger chamber 12a of the plunger device 12 is configured such that when the position-adjustable plunger pistons 12b of the plunger device 12 are in their respective initial positions, brake fluid can be transferred / moved from the master brake cylinder 30 through the communication part of the connecting pipe 34 to the plunger chamber 12a of the plunger device 12. However, when the position-adjustable plunger pistons 12b of the plunger device 12 are adjusted to move out of their respective initial positions, the transfer of brake fluid from the master brake cylinder 30 through the communication part of the connecting pipe 34 to the plunger chamber 12a of the plunger device 12 is blocked by at least one seal member 40a, 40b and 40 attached to the plunger piston 12b of the plunger device 12 and / or the plunger chamber 12a of the plunger device 12. Thus, the preferably configured communication part of the connecting pipe 34, and at least one seal member 40a, 40b and 40c attached to the plunger piston 12b and / or the plunger chamber 12a ensure that when the plunger device 12 in a functional state is operating, the master brake cylinder 30 is "automatically" blocked from the plunger device 12, and thus the driver braking force applied to the brake operating member 32 does not affect the brake pressure generated each time in the wheel brake cylinders 14a and 14b. When the plunger device 12 and / or the vehicle electrical system of the vehicle fails, the position-adjustable plunger pistons 12b of the plunger device 12 are normally in their respective initial positions, whereby the brake system "automatically" shifts to a mechanical fallback level where the driver can still reliably cause a sufficient brake pressure increase in the wheel brake cylinders 14a and 14b for braking the vehicle with the driver's braking force.Therefore, it is not necessary to equip the brake system of FIG. 6 with the master brake cylinder shut-off valve 36.

[0049] As an example, in the brake system of FIG. 6, the plunger piston 12b of the plunger device 12 carries three seal members 40a, 40b, and 40c attached thereto. When the plunger piston 12b of the plunger device 12 is in the initial position, the first seal member 40a located closest to the communication portion of the connecting pipe 34 is blocking with respect to the pressure from the direction of the communication portion and conductive with respect to the pressure from the direction of the motor (in the opposite direction). The second seal member 40b adjacent to the first seal member 40a is conductive with respect to the pressure from the direction of the first seal member 40a and blocking with respect to the pressure from the direction of the motor (in the opposite direction). In addition to this, the third seal member 40c located closest to the motor of the plunger device 12 is blocking with respect to the pressure from the directions of the first seal member 40a and the second seal member 40b and conductive with respect to the pressure from the direction of the motor (in the opposite direction).

[0050] Regarding the other components, characteristics, and advantages of the brake system of FIG. 6, refer to the embodiments of FIGS. 1 to 5 described above.

[0051] FIG. 7 shows a schematic partial view of a seventh embodiment of the brake system.

[0052] As a development example for the embodiment described above, in the braking system of FIG. 7, the plunger chamber 16a of the second motor-type brake pressure generating device 16 configured as the plunger device 16 is also hydraulically connected to the connection pipe 34. The communication part of the connection pipe 34 to the plunger chamber 16a of the plunger device 16 is configured such that when the position-adjustable plunger piston 16b of the plunger device 16 is in the initial position, the brake fluid can be transferred / is transferred from the master brake cylinder 30 through the communication part of the connection pipe 34 to the plunger chamber 16a of the plunger device 16. However, when the position-adjustable plunger piston 16b of the plunger device 16 is adjusted so as to move out of the initial position, the transfer of the brake fluid from the master brake cylinder 30 through the communication part of the connection pipe 34 to the plunger chamber 16a of the plunger device 16 is blocked by at least one of the seal members 42a, 42b, and 42c attached to the plunger piston 16b of the plunger device 16 and / or the plunger chamber 16a of the plunger device 16. Therefore, when the plunger device 16 in a functional state is operating, the master brake cylinder 30 is "automatically" blocked from the plunger device 16, whereby the driver braking force applied to the brake operation member 32 does not affect the brake pressure generated each time in the wheel brake cylinders 14a and 14b. However, when the plunger device 16 and / or the vehicle electrical system of the vehicle fails, the braking system of FIG. 7 also "automatically" shifts to a mechanical fallback level where the driver can still reliably cause a sufficient increase in brake pressure for braking the vehicle with the driver braking force in the wheel brake cylinders 14a and 14b.

[0053] As an example, the plunger piston 16b of the plunger device 16 has three seal members 42a, 42b, and 42c attached thereto. When the plunger piston 16b of the plunger device 16 is in the initial position, the first seal member 42a located closest to the communication portion of the connection pipe 34 is blocking with respect to the pressure from the direction of the communication portion and conductive with respect to the pressure from the direction of the motor (in the opposite direction). The second seal member 42b adjacent to the first seal member 42a is conductive with respect to the pressure from the direction of the first seal member 42a and blocking with respect to the pressure from the direction of the motor (in the opposite direction). The third seal member 42c located closest to the motor of the plunger device 16 is also blocking with respect to the pressure from the directions of the first seal member 42a and the second seal member 42b and conductive with respect to the pressure from the direction of the motor (in the opposite direction).

[0054] Regarding the other components, characteristics, and advantages of the braking system of FIG. 7, refer to the embodiments of FIGS. 1 to 6 described above.

[0055] FIG. 8 shows a schematic partial view of an eighth embodiment of the braking system.

[0056] Also in the braking system of FIG. 8, the master brake cylinder 30 is a tandem type master brake cylinder 30. The first chamber of the master brake cylinder 30 is connected to the plunger chamber 12a of the plunger device 12 via the first connection pipe 34a. Correspondingly, the second chamber of the master brake cylinder 30 is connected to the plunger chamber 16a of the plunger device 16 via the second connection pipe 34b. The communication portions of the respective connection pipes 34a and 34b to the plunger chambers 12a or 16a assigned thereto are configured according to FIGS. 6 and 7. Further, each of the plunger pistons 12b and 16b of both the plunger devices 12 and 16 carries the seal members 40a, 40b, 40c, 42a, 42b, and 42c already described above.

[0057] For other components, characteristics and advantages of the braking system of FIG. 8, reference should be made to the embodiments of FIGS. 1 to 7 described above.

[0058] FIG. 9 shows a flowchart for explaining an embodiment of a method of operating a braking system for a vehicle with at least two axles.

[0059] The method described below can be implemented, for example, by one of the braking systems described above. However, the feasibility of this method is not limited only to the use of such a braking system. Instead, this method can be implemented in a number of different braking system types configured to respectively have a first axle unit including a first wheel brake cylinder assembled to a first wheel of a first axle of the vehicle / automobile and a second wheel brake cylinder assembled to a second wheel of the first axle, and a second axle unit hydraulically separated from the first axle and including a first wheel brake device assembled to a first wheel of a second axle of the vehicle / automobile and a second wheel brake device assembled to a second wheel of the second axle. The feasibility of this method is not limited to a special vehicle type / automobile type of a two-axle vehicle / automobile.

[0060] In method step S1, a first motorized brake pressure generating device of a first axle unit, which is hydraulically connected to a first wheel brake cylinder and a second wheel brake cylinder, operates so that a first wheel of the first axle and / or a second wheel of the first axle is braked. Further, as method step S2, at least one motorized device of a second axle unit, which is hydraulically or mechanically connected to a first wheel brake device and a second wheel brake device, operates so that a first wheel of the second axle and / or a second wheel of the second axle is braked. Further, in method step S3, a second motorized brake pressure generating device of the first axle unit, which is hydraulically connected to the first wheel brake cylinder and the second wheel brake cylinder, operates so that the first wheel of the first axle and / or the second wheel of the first axle is braked. Method steps S1 to S3 can be executed in any order, intersecting in time, or simultaneously. In this way, the method described here also brings the advantages described above.

Explanation of Signs

[0061] 10 First axle unit 12 First motorized brake pressure generating device 12a First plunger chamber 12b First plunger piston 14a First wheel brake cylinder 14b Second wheel brake cylinder 16 Second motorized brake pressure generating device 16a Second plunger chamber 16b Second plunger piston 18a First isolation valve 18b Second isolation valve 20a Third isolation valve 20b Fourth isolation valve 22 First control device 24 Brake setting signal 30 master brake cylinder 32 brake operating member 34, 34a, 34b connecting pipe 36, 36a, 36b master brake cylinder shut-off valve 40a, 40b, 40c first sealing member 42a, 42b, 42c second sealing member

Claims

Claim 1 A first motor-driven brake pressure generating device (12), a first wheel brake cylinder (14a) that can be assembled to a first wheel of a first axle of a vehicle and is hydraulically connected to the first motor-driven brake pressure generating device (12), and a second wheel brake cylinder (14b) that can be assembled to a second wheel of the first axle and is hydraulically connected to the first motor-driven brake pressure generating device (12), a first axle unit (10); In a brake system for at least a two-axle vehicle, having a second axle unit that is hydraulically separated from the first axle unit (10) and includes at least one motor-driven device, a first wheel brake device that is hydraulically or mechanically connected to at least one of the motor-driven devices and can be assembled to a first wheel of a second axle of the vehicle, and a second wheel brake device that is hydraulically or mechanically connected to at least one of the motor-driven devices and can be assembled to a second wheel of the second axle; The first axle unit (10) further has, in addition to the first motor-driven brake pressure generating device (12), a second motor-driven brake pressure generating device (16) to which the first wheel brake cylinder (14a) and the second wheel brake cylinder (14b) are hydraulically connected; The first control device (22) of the first axle unit (10) controls the first motor-driven brake pressure generating device (12) and the second motor-driven brake pressure generating device (16) in consideration of at least one brake setting signal (24) output to the first control device (22) from at least one brake operating member sensor of the vehicle, a speed control automatic of the vehicle, a second control device of the second axle unit, and / or other stabilizing devices of the brake system, so that the operation of the first motor-driven brake pressure generating device (12) can transfer brake fluid to the first wheel brake cylinder (14a) and the second wheel brake cylinder (14b) at least temporarily, and the operation of the second motor-driven brake pressure generating device (16) can transfer brake fluid to the first wheel brake cylinder (14a) and the second wheel brake cylinder (14b) at least temporarily, and is designed and / or programmed accordingly. The first axle unit (10) is hydraulically separated from the second axle unit such that the first axle unit (10) and the second axle unit are connected to each other via at least one signal line and / or bus line connected to the first control device (22) and the second control device, and is a brake system. **Claim 2**: A first axle unit (10) including a first motor-driven brake pressure generating device (12), a first wheel brake cylinder (14a) that can be assembled to a first wheel of a first axle of a vehicle and is hydraulically connected to the first motor-driven brake pressure generating device (12), and a second wheel brake cylinder (14b) that can be assembled to a second wheel of the first axle and is hydraulically connected to the first motor-driven brake pressure generating device (12). A braking system for at least a two-axle vehicle, comprising at least one motor-driven device, a first wheel brake device hydraulically or mechanically connected to at least one said motor-driven device and assemblable to a first wheel of a second axle of the vehicle, and a second wheel brake device hydraulically or mechanically connected to at least one said motor-driven device and assemblable to a second wheel of the second axle, the second axle unit being configured to be hydraulically separated from the first axle unit (10). The first axle unit (10) further has a second motor-driven brake pressure generating device (16) to which the first wheel brake cylinder (14a) and the second wheel brake cylinder (14b) are hydraulically connected, in addition to the first motor-driven brake pressure generating device (12). The first motor-driven brake pressure generating device (12) is hydraulically connected to the first wheel brake cylinder (14a) and the second wheel brake cylinder (14b) via a first hydraulic path that branches out, and a first isolation valve (18a) and / or a second isolation valve (18b) is disposed in the first hydraulic path so that the first wheel brake cylinder (14a) can be blocked from the first motor-driven brake pressure generating device (12) through closing of the first isolation valve (18a) while brake fluid can be transferred from the first motor-driven brake pressure generating device (12) to the second wheel brake cylinder (14b), and / or the second wheel brake cylinder (14b) can be blocked from the first motor-driven brake pressure generating device (12) through closing of the second isolation valve (18b) while brake fluid can be transferred from the first motor-driven brake pressure generating device (12) to the first wheel brake cylinder (14a). The second motor-operated brake pressure generating device (16) is hydraulically connected to the first wheel brake cylinder (14a) and the second wheel brake cylinder (14b) via second hydraulic paths that branch from each other, and a third isolation valve (20a) and / or a fourth isolation valve (20b) is disposed in the second hydraulic path, such that while brake fluid can be transferred by the second motor-operated brake pressure generating device (16) to the second wheel brake cylinder (14b), the first wheel brake cylinder (14a) can be blocked from the second motor-operated brake pressure generating device (16) through closing of the third isolation valve (20a), and / or while brake fluid can be transferred by the second motor-operated brake pressure generating device (16) to the first wheel brake cylinder (14a), the second wheel brake cylinder (14b) can be blocked from the second motor-operated brake pressure generating device (16) through closing of the fourth isolation valve (20b). Brake system.

3. The first axle unit (10) additionally includes a master brake cylinder (30) to which a brake operating member (32) of the vehicle can be connected or is connected, whereby at least one piston of the master brake cylinder (30), which separates at least one chamber of the master brake cylinder (30), can be adjusted in position by operation of the brake operating member (32) by the driver of the vehicle, and at least one of the chambers of the master brake cylinder (30) is hydraulically connected to the first motor-operated brake pressure generating device (12), the second motor-operated brake pressure generating device (16), the first hydraulic path, and / or the second hydraulic path via at least one connection pipe (34, 34a, 34b) that is valve-less or equipped with a valve. The brake system according to claim 2. Claim 4. The first motor-operated brake pressure generating device (12) is a first plunger device (12), and a single chamber of the master brake cylinder (30), or at least one of the plurality of chambers, is hydraulically connected to the first plunger chamber (12a) of the first plunger device (12) via a single connection pipe (34) or at least one of the plurality of connection pipes (34a, 34b). When the first communication portion of at least one of the single connection pipe (34) or the plurality of connection pipes (34a, 34b) to the first plunger chamber (12a) is in the initial position of the position-adjustable first plunger piston (12b) of the first plunger device (12), brake fluid can be transferred from the master brake cylinder (30) through the first communication portion into the first plunger chamber (12a). On the contrary, when the first plunger piston (12b) is adjusted to move out of the initial position, the transfer of brake fluid from the master brake cylinder (30) through the first communication portion into the first plunger chamber (12a) is configured to be blocked by the first plunger piston (12b) and / or at least one first seal member (40a, 40b, 40c) attached to the first plunger chamber (12a). The brake system according to claim 3.

5. The second motor-operated brake pressure generating device (16) is a second plunger device (16), and at least one of the single chamber or a plurality of chambers of the master brake cylinder (30) is connected hydraulically to the second plunger chamber (16b) of the second plunger device (16) via at least one of a plurality of connecting pipes (34, 34a, 34b). A second communication portion of at least one of the plurality of connecting pipes (34, 34a, 34b) to the second plunger chamber (16a) is such that when the position-adjustable second plunger piston (16b) of the second plunger device (16) is in the initial position, brake fluid can be transferred from the master brake cylinder (30) through the second communication portion into the second plunger chamber (16a). On the other hand, when the second plunger piston (16b) is position-adjusted to move out of the initial position, the transfer of brake fluid from the master brake cylinder (30) through the second communication portion into the second plunger chamber (16a) is configured to be blocked by the second plunger piston (16b) and / or at least one second sealing member (42a, 42b, 42c) attached to the second plunger chamber (16a). The brake system according to claim 4.

6. The brake system according to any one of claims 3 to 5, wherein at least one master brake cylinder shut-off valve (36, 36a, 36b) is arranged in at least one of the connecting pipes (34, 34a, 34b).

Images