Sensor

Abstract

The invention relates to a sensor (1), in particular for a brake of a vehicle, comprising: - a force application element (2); - a counter element (3); - an elastic spring element (4); and - a detection unit (5) having at least one detection means (6) and an indicator element (7), wherein the force application element (2) is designed to be subjected to a force (F) in a force application direction (X), and the counter element (3) is designed to come into contact with another element to which the force (F) is to be transmitted. The spring element (4) is positioned, in the force application direction (X), between the force application element (2) and the counter element (3) in such a way that the force (F) is completely supported on the spring element (4) and the spring element (4) is completely supported on the counter element (3). The force application element (2), the counter element (3) and the spring element (4) are coordinated in such a way that a specified relative displacement between the force application element (2) and the counter element (3) occurs when the force (F) has a specified magnitude; the at least one detection means (6) and the indicator element (7) are provided in such a way that a relative displacement between the at least one detection means (6) and the indicator element (7) is produced as a result of the relative displacement between the force application element (2) and the counter element (3); and the detection unit (5) is designed to generate, on the basis of the relative displacement between the at least one detection means (6) and the indicator element (7), an output signal from which the magnitude of the force (F) can be determined. The invention additionally relates to a brake.

Description

[0001] DESCRIPTION

[0002] sensor

[0003] The present invention relates to a sensor for a brake, in particular for an electromechanical brake. Furthermore, the invention relates to a brake with such a sensor.

[0004] With the development of vehicle brakes, fluid-actuated (pneumatic or hydraulic) brakes are gradually being replaced or superseded by electromechanically actuated brakes. An electrical machine, such as an electric motor, generates a corresponding force or torque. This force or torque is converted accordingly via a transmission mechanism if necessary. The generated force or torque then causes the brake pads to engage a corresponding counterpart, such as a brake drum or brake disc, to produce a braking effect on the vehicle in which the brake is installed.

[0005] Since such brakes do not contain any fluid that would allow a conclusion to be drawn about the force acting between the brake pads and the counterpart, for example through a pressure measurement (brake pressure measurement), there is a need for alternative ways to measure such a force.

[0006] The object of the invention is therefore to solve this problem.

[0007] This problem is solved by the subject matter of the independent claims. Advantageous further developments are the subject matter of the dependent claims.

[0008] #A1#

[0009] Disclosed is a sensor, in particular for a brake of a vehicle, comprising:

[0010] - a force introduction element;

[0011] - a counter element; - an elastic spring element;

[0012] - a detection unit with at least one detection means and an indicator element, wherein the force introduction element is designed to be subjected to a force in a force introduction direction, the counter element is designed to come into contact with another element to which the force F is to be transmitted, the spring element is arranged in the force introduction direction between the force introduction element and the counter element such that the force is completely supported on the spring element and the spring element is completely supported on the counter element, wherein the force introduction element, the counter element and the spring element are coordinated with one another such that, at a predetermined amount of force, a predetermined relative displacement occurs between the force introduction element and the counter element, and the at least one detection means and the indicator element are provided such thatthat a relative displacement caused by the relative displacement between the force introduction element and the counter element occurs between the at least one detection means and the indicator element, wherein the detection unit is designed to generate an output signal from the relative displacement between the at least one detection means and the indicator element, from which the amount of force can be determined.

[0013] The output signal can directly contain or correspond to a value of the force F. Alternatively, the output signal can also merely contain information about the relative displacement between the at least one detection means and the indicator element.

[0014] The force that can be applied to the force introduction element and which can act on another element via the counter element makes it possible to position the sensor directly in the force flow caused by the force. Brakes in which the electric motor for generating the required force or torque is not located close to or directly on the brake or brake caliper, but instead is positioned closer to the vehicle's centerline, typically have a pressure piece such as a tappet, via which the force can be transmitted to the brake for contacting the brake pads with the counter element. The sensor disclosed here is preferably designed so that it can be placed on the pressure piece or in front of or behind it.

[0015] The sensor is best positioned as close to the brake as possible to minimize elasticities that arise during the mechanical transmission of power from the electric motor to the brake. This makes it possible to approximately measure the force acting between the brake pads and their counterparts. If a plunger is used for power transmission as described above, the sensor is preferably placed on the side of the plunger where the end of the plunger is located, which faces away from the electric motor and towards the brake. The sensor can be placed directly on the plunger, or additional elements can be provided between the plunger and the sensor.

[0016] The spring element is particularly intended to counteract the force introduced into the sensor and to keep it in balance in order to keep the relative displacement between the at least one detection means and the indicator element static.

[0017] #A2#

[0018] The detection unit preferably comprises an electrical or electronic data processing means which is designed to generate the output signal.

[0019] For this purpose, the data processing means is preferably connected to the recording means of the recording unit.

[0020] The recording unit can be implemented as a structural unit comprising the recording device, the indicator element, and the data processing device. This creates a structural unit that can be installed and removed as a whole.

[0021] Alternatively, the detection unit can also be designed so that the detection element is a separate structural unit, detached from the detection element and the indicator element. This allows for a smaller sensor. In this case, the detection element can be freely positioned, for example, and connected to the detection element via a corresponding data connection to receive its output signals.

[0022] Preferably, the indicator element is provided on the force introduction element and the detection means on the counter element. Alternatively, the indicator element is provided on the counter element and the detection means on the force introduction element.

[0023] The indicator element preferably has a magnet or is preferably designed as a magnet.

[0024] The detection means is preferably designed to detect the indicator element when it is located in a detection range of the detection means.

[0025] #A3#

[0026] Preferably, the at least one detection means and the indicator element are designed to interact according to the Hall principle, so that the relative displacement between the at least one detection means and the indicator element generates a Hall voltage. In this way, a contactless and thus wear-free detection of the relative displacement between the at least one detection means and the indicator element is possible.

[0027] In particular, the detection means can be designed as a Hall chip.

[0028] Preferably, the detection unit is designed to detect the Hall voltage as

[0029] Output the output signal or generate the output signal based on the Hall voltage. Preferably, the data processing means of the detection unit is configured to process the Hall voltage accordingly.

[0030] #A4#

[0031] Preferably, the at least one detection means and the indicator element are designed for magneto-resistive interaction, so that a change in electrical resistance is caused by the relative displacement between the at least one detection means and the indicator element.

[0032] In particular, the detection means can be designed as a magneto-resistive element.

[0033] Preferably, the detection unit is configured to output the value or the changed value of the electrical resistance as an output signal or to generate the output signal based on the value or the changed value of the electrical resistance. Preferably, the data processing means of the detection unit is configured to process the value of the electrical resistance accordingly.

[0034] Both a Hall voltage-based measuring principle and a magneto-resistive measuring principle enable contactless and therefore wear-free measurement, thus enabling the realization of a sensor designed to last the entire service life of a vehicle equipped with a brake equipped with such a sensor. This is particularly useful for brakes intended for service braking, since recurring deceleration and thus recurring relative movement between the indicator element and at least one detection device occurs during vehicle operation.

[0035] #A5#

[0036] In general, the at least one detection means is preferably embodied as an electronic structure. The electronic structure can be embodied as a chip and / or on a lead frame, a PCB, or a flexible foil. The aforementioned Hall chip or the aforementioned magneto-resistive element can be embodied in this way.

[0037] Due to the relatively limited installation space, it is generally advantageous if the electronic structure has small dimensions and, if possible, is thin in an extension direction oriented transversely to the force introduction direction, in particular perpendicular to the force introduction direction, compared to an extension in the force introduction direction. Preferably, the electronic structure extends in the extension direction oriented transversely to the force introduction direction, in particular perpendicular to the force introduction direction, only 10% or less, preferably only 5% or less, of the extension of the electronic structure in the force introduction direction.

[0038] #A6# The sensor preferably has a damping element which is designed to dampen vibrations between the force introduction element and the counter-element. Since the force introduction element and the counter-element are displaceable relative to one another and the spring element is additionally provided between the force introduction element and the counter-element, vibrations can occur which result in an oscillating relative movement between the force introduction element and the counter-element and ultimately between the at least one detection means and the indicator element. On the one hand, this is disadvantageous for the rapid and reliable detection of the force acting on the brake. On the other hand, there is also a disadvantage in that the sensor and thus the spring element is part of the above-mentioned force flow which is provided for the transmission of force to the brake. Thus, further elasticity is created by the spring element.Particularly when a force is applied suddenly, similar to a control signal, an undesirable vibration can occur. The damping element can counteract this problem by designing it to dampen or eliminate vibrations or frequencies that are expected, particularly during vehicle or brake operation, and / or by specifically designing it to dampen such abruptly applied forces.

[0039] Preferably, the spring element and the damping element are combined in a single structural unit, or they are implemented as one and the same element. In particular, a spring element made of rubber or similar material can simultaneously function as a damping element. In general, any spring element with sufficient internal damping for the intended application is suitable for simultaneously implementing a damping element.

[0040] #A7#

[0041] Preferably, the detection unit is configured to determine the output signal from the spring stiffness of the spring element and the relative displacement between the at least one detection means and the indicator element. The spring stiffness can be configured accordingly as a design parameter when designing the sensor. It can be configured to be constant or variable (as a spring characteristic) in the relevant range in which the relative displacement between the at least one detection means and the indicator element or between the force introduction element and the counter element occurs during operation of the sensor.

[0042] #A8#

[0043] Preferably, the spring stiffness of the spring element is stored in the detection unit. In particular, a storage means can be provided for this purpose, which is provided in the detection unit and is preferably designed as part of the data processing means. In particular, a value can be stored here for a constant spring stiffness, and a corresponding spring characteristic curve can be stored for a variable spring stiffness. Together with the relative displacement between the at least one detection means and the indicator element, the applied force can thus be determined, in particular by the data processing means.

[0044] #A9#

[0045] The spring element preferably has a linearly increasing, a progressively increasing, or a degressively increasing spring characteristic. "Increasing" here means that, when a force is applied to the sensor, the force generated by the spring element increases disproportionately with increasing relative displacement between the at least one detection means and the indicator element, or with increasing relative displacement between the force introduction element and the counter element. In this way, with an appropriately designed spring element, it can be prevented that the spring element is completely compressed and damaged or destroyed when a sudden force is applied.

[0046] #A10#

[0047] Preferably, the relative displacement between the force introduction element and the counter element and / or the relative displacement between the at least one detection means and the indicator element is parallel to the force introduction direction. The force introduction direction is preferably parallel to an axis of the sensor. If both relative displacements are oriented parallel to the force introduction direction, both relative displacements are equal; no transmission should be provided in the sensor.

[0048] #A11#

[0049] Preferably, the sensor, in particular the force introduction element, has an opening through which the sensor can be mounted on a force-introducing element, such as the aforementioned plunger. In this way, the sensor can be easily positioned in the force flow.

[0050] #A12#

[0051] Preferably, the opening is circular and / or coaxial with the force application direction, with the sensor having an outer contour extending radially outward from the force application direction, the ratio of the maximum distance of the outer contour from the force application direction to the diameter of the opening being less than 2. In this way, a sensor is realized that, if possible, does not excessively increase the outer dimensions of the element on which it is provided when the sensor is attached to it via the opening. #A13#

[0052] The sensor preferably has an anti-twist device designed to prevent the at least one detection means and the indicator element from twisting relative to each other. This prevents incorrect measurements caused by elements that are twisted relative to each other. The anti-twist device can, in particular, be implemented with a positive fit.

[0053] #A14#

[0054] Disclosed is a brake for a vehicle, in particular an electromechanical brake for a vehicle, with

[0055] - a power generator;

[0056] - a sensor as described above; and

[0057] - a friction pairing which is designed to generate a corresponding braking force or a corresponding braking torque in response to a force introduced by the force generator, wherein the sensor is positioned between the force generator and the friction pairing in such a way that the force from the force generator is introduced into the force introduction element and is supported on the counter element via the elastic spring element, wherein the counter element is designed to transmit the force directly or via intermediate elements of the brake to the friction pairing in order to generate the braking force or the braking torque, wherein the output signal is output via the detection unit.

[0058] #A15#

[0059] The brake preferably has a control unit designed to control and / or regulate the force generator based on the output signal. In this way, it is possible to adjust the required contact force and thus the generated braking torque or braking force. The control unit can be part of the above-mentioned data processing means of the sensor or be designed separately therefrom. The control unit is preferably designed to receive a default value that serves as an input value for the control and / or regulation. This can be, for example, a target contact force of the friction pair, a target deceleration, a target braking force or a target braking torque. The control unit is preferably designed to implement stabilizing functions of the brake control, such as an anti-lock function or driving dynamics stabilization via targeted braking interventions.

[0060] A preferred embodiment of the invention is described in more detail below with reference to the accompanying drawings.

[0061] The attached figure shows a sensor according to an embodiment.

[0062] Shown is a sensor 1 , in particular for a brake of a vehicle, with:

[0063] - a force introduction element 2;

[0064] - a counter element 3;

[0065] - an elastic spring element 4;

[0066] - a detection unit 5 with a detection means 6 and an indicator element 7, wherein the force introduction element 2 is designed to be subjected to a force F in a force introduction direction X, the counter element 3 is designed to come into contact with another element to which the force F is to be transmitted, the spring element 4 is arranged in the force introduction direction X between the force introduction element 2 and the counter element 3 such that the force F is fully supported on the spring element 4 and the spring element 4 is fully supported on the counter element 3, wherein the force introduction element 2, the counter element 3 and the spring element 4 are coordinated with one another such that, at a predetermined amount of the force F, a predetermined relative displacement occurs between the force introduction element 2 and the counter element 3, and the detection means 6 and the indicator element 7 are provided such thatthat a relative displacement between the detection means 6 and the indicator element 7 caused by the relative displacement between the force introduction element 2 and the counter element 3 occurs, wherein the detection unit 5 is designed to generate an output signal from the relative displacement between the detection means 6 and the indicator element 7, from which the amount of force F can be determined.

[0067] The detection unit 5 here has a data processing device that is not provided directly on the sensor 1. This device is provided separately and can receive output signals from the detection device 6 via the data connection 8 shown and generate an output signal therefrom, as described above. The output signal can correspond directly to the value of the force F or be a value from which the force F can be determined.

[0068] Other embodiments of the sensor 1 (not shown), in which the data processing means is placed in the region of the detection means 6, can be designed such that the output signal generated by the data processing means is output directly via the data connection 8.

[0069] The illustrated configuration of sensor 1 is a preferred coaxial configuration in which the force introduction direction X is coaxial with a sensor axis, which is represented in the drawing by the horizontal dash-dotted line. Both the force introduction element 2 and the counter element 3 are arranged coaxially with the sensor axis.

[0070] LIST OF REFERENCE SYMBOLS

[0071] 1 sensor

[0072] 2 Force introduction element 3 Counter element

[0073] 4 spring element

[0074] 5 Recording unit

[0075] 6 Recording tools

[0076] 7 Indicator element 8 Data connection

[0077] F Force

[0078] X Direction of force application

Claims

PATENT CLAIMS 1 . Sensor (1 ), in particular for a brake of a vehicle, comprising: - a force introduction element (2); - a counter element (3); - an elastic spring element (4); - a detection unit (5) with at least one detection means (6) and an indicator element (7), wherein the force introduction element (2) is designed to be subjected to a force (F) in a force introduction direction (X), the counter element (3) is designed to come into contact with another element to which the force (F) is to be transmitted, the spring element (4) is arranged in the force introduction direction (X) between the force introduction element (2) and the counter element (3) such that the force (F) is fully supported on the spring element (4) and the spring element (4) is fully supported on the counter element (3), wherein the force introduction element (2), the counter element (3), and the spring element (4) are coordinated with one another such that, at a predetermined amount of force (F), a predetermined relative displacement occurs between the force introduction element (2) and the counter element (3),and the at least one detection means (6) and the indicator element (7) are provided such that a relative displacement caused by the relative displacement between the force introduction element (2) and the counter element (3) occurs between the at least one detection means (6) and the indicator element (7), wherein the detection unit (5) is designed to generate an output signal from the relative displacement between the at least one detection means (6) and the indicator element (7), from which the magnitude of the force (F) can be determined.

2. Sensor (1) according to claim 1, wherein the detection unit (5) comprises an electrical or electronic data processing means which is designed to generate the output signal.

3. Sensor (1) according to claim 1 or 2, wherein the at least one detection means (6) and the indicator element (7) are designed to interact according to the Hall principle, so that a Hall voltage is caused by the relative displacement between the at least one detection means (6) and the indicator element (7).

4. Sensor (1) according to claim 1 or 2, wherein the at least one detection means (6) and the indicator element (7) are designed for magneto-resistive interaction, so that a change in an electrical resistance is caused by the relative displacement between the at least one detection means (6) and the indicator element (7).

5. Sensor (1) according to one of the preceding claims, wherein the at least one detection means (6) is designed as an electronic structure, wherein the electronic structure is preferably designed as a chip and / or on a lead frame or as a PCB or on a flexible film.

6. Sensor (1) according to one of the preceding claims, wherein the sensor (1) has a damping element which is designed to dampen vibrations between the force introduction element (2) and the counter element (3).

7. Sensor (1) according to one of the preceding claims, wherein the detection unit (5) is designed to determine the output signal from a spring stiffness of the spring element (4) and the relative displacement between the at least one detection means (6) and the indicator element (7).

8. Sensor (1) according to claim 7, wherein the spring stiffness of the spring element (4) is stored in the detection unit (5).

9. Sensor (1) according to one of claims 7 or 8, wherein the spring element (4) has a linearly increasing, a progressively increasing or a degressively increasing spring characteristic curve.

10. Sensor (1) according to one of the preceding claims, wherein the relative displacement between the force introduction element (2) and the counter element (3) and / or the relative displacement between the at least one detection means (6) and the indicator element (7) is parallel to the force introduction direction (X).

11. Sensor (1) according to one of the preceding claims, wherein the sensor (1), in particular the force introduction element (2), has an opening with which the sensor (1) can be attached to a force introduction element.

12. Sensor (1) according to claim 11, wherein the opening is circular and / or is provided coaxially to the force introduction direction (X), wherein the sensor (1) has an outer contour radially outwardly from the force introduction direction (X), wherein the ratio of the maximum distance of the outer contour to the force introduction direction (X) to the diameter of the opening is less than 2.

13. Sensor (1) according to one of the preceding claims, wherein the sensor (1) has an anti-twist device which is designed to prevent the at least one detection means (6) and the indicator element (7) from twisting relative to one another.

14. Brake for a vehicle, in particular electromechanical brake for a vehicle, with - a power generator; - a sensor (1) according to one of the preceding claims; and - a friction pairing which is designed to generate a corresponding braking force or a corresponding braking torque in response to a force (F) introduced by the force generator, wherein the sensor (1) is positioned between the force generator and the friction pairing in such a way that the force (F) is introduced from the force generator into the force introduction element (2) and is supported on the counter element (3) via the elastic spring element (4), wherein the counter element (3) is designed to transmit the force (F) directly or via intermediate elements of the brake to the friction pairing in order to generate the braking force or the braking torque, wherein the output signal is output via the detection unit (5).

15. Brake according to claim 14, comprising a control unit configured to control and / or regulate the force generator based on the output signal.

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