WO2004110835A1 - Electromagnetically actuatable parking brake for motor vehicles - Google Patents

Electromagnetically actuatable parking brake for motor vehicles Download PDF

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Publication number
WO2004110835A1
WO2004110835A1 PCT/EP2004/051060 EP2004051060W WO2004110835A1 WO 2004110835 A1 WO2004110835 A1 WO 2004110835A1 EP 2004051060 W EP2004051060 W EP 2004051060W WO 2004110835 A1 WO2004110835 A1 WO 2004110835A1
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WO
WIPO (PCT)
Prior art keywords
brake
force
parking brake
encoder
brake cable
Prior art date
Application number
PCT/EP2004/051060
Other languages
German (de)
French (fr)
Inventor
Andreas Emmerich
Thomas Ewert
Original Assignee
Continental Teves Ag & Co. Ohg
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE102004025361A external-priority patent/DE102004025361A1/en
Application filed by Continental Teves Ag & Co. Ohg filed Critical Continental Teves Ag & Co. Ohg
Publication of WO2004110835A1 publication Critical patent/WO2004110835A1/en

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
    • G01D5/142—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices
    • G01D5/145—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices influenced by the relative movement between the Hall device and magnetic fields
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T11/00—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant
    • B60T11/04—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant transmitting mechanically
    • B60T11/046—Using cables
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
    • B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
    • B60T13/66—Electrical control in fluid-pressure brake systems
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
    • B60T13/74—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive
    • B60T13/746—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive and mechanical transmission of the braking action
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T7/00—Brake-action initiating means
    • B60T7/02—Brake-action initiating means for personal initiation
    • B60T7/08—Brake-action initiating means for personal initiation hand actuated
    • B60T7/10—Disposition of hand control
    • B60T7/107—Disposition of hand control with electrical power assistance

Definitions

  • the present invention relates to an electromechanically actuated parking brake for motor vehicles, which essentially consists of at least one device for generating an application force, an electronic control unit and mechanically lockable braking devices on at least one axis, the braking devices being able to be applied by the device by means of at least one brake cable and Clamping force is determined by means of a force measuring device.
  • a parking brake system for vehicles is known from international application WO 98/56633, which has an actuating unit for generating an application force.
  • the application force is transmitted to an actuating cable via an actuator.
  • a force measuring device is integrated into the actuator in such a way that relative movements between the actuating cable and the actuator are detected. It is considered less advantageous in this parking brake system that the structure is complicated and that the production is complex.
  • the present invention is therefore based on the object of an electromechanically actuated parking brake to improve the type mentioned at the outset in such a way that the application force can be determined reliably by a simply constructed and cost-effectively implemented force measuring device.
  • the force measuring device consists of an encoder and at least one magnetoresistive sensor element, the part of the force measuring device being formed by the encoder.
  • a spring element or a rubber-elastic element is arranged downstream of the part.
  • a further advantageous development provides that the brake cable is designed in such a way that it allows mechanical deformation and has a hard magnetic effect which is detected by means of a magnetoresistive sensor element.
  • FIG. 1 shows a schematically illustrated circuit diagram of a hydraulic brake system which has an electromechanical actuating unit for carrying out parking brake operations, _ O _
  • FIG. 2a, b, c each show a schematically illustrated, only partially illustrated embodiment of a force measuring device for detecting the clamping force from the electromechanical actuating unit shown in FIG. 1,
  • Fig. 3a, b the embodiment shown in Fig. 2c with an untensioned and tensioned brake cable.
  • a circuit diagram of a hydraulic brake system is shown schematically.
  • the hydraulic brake system has wheel brakes 2 on a first axle, the front axle, which can be pressurized during service braking via a hydraulic line 20.
  • the wheels of the front axle are assigned wheel speed sensors 12, the output signals of which are fed to an electronic control and regulating unit (ECU) 5.
  • ECU electronic control and regulating unit
  • This electronic control unit 5 is assigned to the service brake system.
  • Wheel brakes 3 are also provided on a second axle, the rear axle, which can be pressurized during service braking via a second hydraulic line 10.
  • the wheel speeds of the wheels of the rear axle are determined by wheel speed sensors 13 and supplied to the electronic control unit 5 just mentioned.
  • the wheels of the rear axle can be braked by the wheel brakes 3 just mentioned as well as by an electromechanically actuated parking brake.
  • the electromechanically actuated parking brake has two mechanically lockable braking devices 4 on the rear axle, which are designed as drum brakes 4, each with an expansion lock (not shown in more detail).
  • the expansion locks just mentioned are by means of two brake cables 11 of one Electromechanical actuator 1 can be actuated, after which the drum brakes 4 are applied.
  • a parking brake operation is carried out after the operator has actuated an operating element 7.
  • the output signals of the operating element 7 are fed to an electronic control unit (ECU) 6 assigned to the electromechanical parking brake, which controls the already mentioned electromechanical actuating unit 1 accordingly.
  • ECU electronice control unit
  • a force measuring device 9 is necessary to determine the application force of the electromechanically actuated parking brake.
  • the force measuring device 9 consists of an encoder 14 and a fixed magneto-resistive sensor element 15.
  • the encoder 14, which consists of individual hard magnets joined together, is integrated into the brake cable in such a way that a transmission of the application force from the electromechanical control unit 1 to the drum brakes 4 of the rear axle via the encoder 14.
  • the electrical resistance of the magnetoresistive sensor element 15 changes when a magnetic field acts vertically on a current applied to the magnetoresistive sensor element 15. This changed electrical resistance in the magnetoresistive sensor element 15, which depends on the acting magnetic field and thus on the position of the encoder 14 relative to the magnetoresistive sensor element 15, is measured.
  • the force measuring device 9 is used to count the number of hard magnetic elements of the encoder 14 which are pulled past the magneto-resistive sensor element 15 which is attached in a stationary manner.
  • intermediate positions of the hard magnetic elements of the encoder 14 can also be determined.
  • a brake cable 11 normally used is not sufficiently elastic
  • a spring element 16 as shown in FIG. 2a, is integrated in the brake cable 11. The application force is transmitted from the electromechanical actuating unit 1 to the drum brakes 4 via the spring element 16.
  • the electromechanical actuating unit 1 pulls the brake cable 11 to the left in FIG. 2a in order to apply the drum brakes 4 to the rear axle, the application force is transmitted via the encoder 14 and the spring element 16 just described, spring element 16 being stretched. As a result, the encoder 14 is pulled past the magnetoresistive sensor element 15 and the position of the encoder 14 is determined relative to the magnetoresistive sensor element 15 which is attached in a stationary manner. The application force applied by the electromechanical actuating unit 1 is calculated from the position of the encoder 15 and the previously determined spring constants of the spring element 16.
  • FIG. 2b The embodiment shown in FIG. 2b is very similar to the force measuring device 9 described with reference to FIG. 2a. The only difference is that instead of the spring element 16, a rubber-elastic element 17 is integrated in the brake cable 11. When a clamping force is transmitted from the electromechanical actuating unit 1 to the drum brakes 4, the rubber-elastic element 17 is stretched and the encoder 14 is pulled past the magneto-resistive element 15 as already described with reference to FIG. 2a. If the elasticity of the rubber-elastic element 17 is determined beforehand, then in connection with the position of the encoder 14 relative to the fixed magneto-resistive element 16, that of the electromechanical element Actuator 1 applied clamping force can be determined.
  • the encoder 14 is dispensed with, since the brake cable 11 is designed such that it itself has a hard magnetic effect 24, which is shown schematically in FIG. 2c by the individual magnets 24.
  • the brake cable 11 allows mechanical deformation in this embodiment, so that additional elastic elements such as the spring element in FIG. 2a or the rubber-elastic element in FIG. 2b can be dispensed with.
  • the electromechanical control unit 1 transmits an application force to the drum brakes 4 of the rear axle, the brake cable undergoes a mechanical deformation in the form of an elongation.
  • a section of the brake cable 11 is pulled past the magneto-resistive sensor element 150 and since the brake cable 11 has a hard magnetic effect 24, as already mentioned, the position of the brake cable 11 can be determined relative to the magnetoresistive sensor element 150 which is attached in a fixed position. Together with the previously determined degree of mechanical deformation of the brake cable 11, which is composed of an elastic component and a plastic component caused by aging, this results in the application force applied by the electromechanical actuating unit 1.
  • FIG. 3a shows the force measuring device described with reference to FIG. 2c in a state in which no application force is applied by the electromechanical actuating unit 1 to the drum brakes 4 via the brake cable 11.
  • the individual magnets which are intended to schematically represent the hard magnetic effect 24 of the brake cable 11, are in this untensioned state the distance ⁇ 0 separated from each other. If the electromechanical actuating unit 1 now applies an application force via the brake cable 11 to the drum brakes 4, this expands
  • Brake cable 11 by the amount .DELTA.L and the distance between the individual magnets of the hard magnetic effect 24 is greater, as shown in Fig. 3b.
  • the distance between the individual magnets is then ⁇ i. This increase in the distance between the individual magnets or the expansion of the hard magnetic effect 24 of the brake cable 11 must be taken into account when calculating the application force.
  • the plastic deformation (elongation) of the brake cable 11 caused by aging can be determined with the arrangement shown in FIGS. 3a, 3b. If the electromechanical actuating unit 1 applies a clamping force via the brake cable 11, the distance ⁇ between the individual magnets of the hard magnetic effect 24 will increase with increasing aging of the brake cable 11. This change in the distance ⁇ of the individual magnets of the hard magnetic effect 24 caused by the aging of the brake cable 11 can be determined with the aid of the magneto-resistive sensor element 15 not shown in FIG. 3b and from which the elastic deformation which transmits the application force can be subtracted.
  • the application force of an electromechanical actuating unit 1 on two drum brakes 4 of the rear axle can be reliably determined and the manufacturing costs of the force measuring device 9 and its production can be described as advantageous.

Abstract

The invention relates to an electromechanically actuatable parking brake for motor vehicles, said brake essentially consisting of at least one device (1) for generating a brake application force, an electronic control unit (6), and brake components (4) which can be mechanically locked on at least one axle. Said brake components (4) can be applied by the device (1) by means of at least one brake cable (11), and the brake application force is determined by means of a force-sensing device (9). The aim of the invention is to reliably determine the brake application force using a structurally simple and economically produced force-sensing device. To this end, an encoder (14) is integrated into the brake cable (11), the position of said encoder being determined by a fixed magnetoresistive sensor element.

Description

Elektromechanisch betätigbare Feststellbremse für KraftfahrzeugeElectromechanically actuated parking brake for motor vehicles
Die vorliegende Erfindung betrifft eine elektromechanisch betätigbare Feststellbremse für Kraftfahrzeuge, die im wesentlichen aus mindestens einer Vorrichtung zur Erzeugung einer Zuspannkraft, einer elektronischen Steuereinheit und mechanisch verriegelbaren Bremseinrichtungen an wenigstens einer Achse besteht, wobei die Bremseinrichtungen durch die Vorrichtung mittels mindestens eines Bremsseiles zuspannbar sind und die Zuspannkraft mittels einer Kraftmesseinrichtung ermittelt wird.The present invention relates to an electromechanically actuated parking brake for motor vehicles, which essentially consists of at least one device for generating an application force, an electronic control unit and mechanically lockable braking devices on at least one axis, the braking devices being able to be applied by the device by means of at least one brake cable and Clamping force is determined by means of a force measuring device.
Aus der internationalen Anmeldung WO 98/56633 ist eine Feststellbremsanlage für Fahrzeuge bekannt, die eine Stelleinheit zur Erzeugung eine Zuspannkraft aufweist. Die Zuspannkraft wird bei der vorbekannten Feststellbremsanlage über ein Stellglied auf einen Betätigungszug übertragen. Eine Kraftmessvorrichtung ist dabei derart in das Stellglied integriert, dass Relativbewegungen zwischen dem Betätigungszug und dem Stellglied erfasst werden. Als weniger vorteilhaft wird bei dieser Feststellbremsanlage angesehen, dass der Aufbau kompliziert ist und die Fertigung aufwendig ist.A parking brake system for vehicles is known from international application WO 98/56633, which has an actuating unit for generating an application force. In the known parking brake system, the application force is transmitted to an actuating cable via an actuator. A force measuring device is integrated into the actuator in such a way that relative movements between the actuating cable and the actuator are detected. It is considered less advantageous in this parking brake system that the structure is complicated and that the production is complex.
Der vorliegenden Erfindung liegt daher die Aufgabe zu Grunde, eine elektromechanisch betätigbare Feststellbremse der eingangs genannten Gattung dahingehend zu verbessern, dass die Zuspannkraft zuverlässig durch eine einfach aufgebaute und kostengünstig realisierbare Kraftmesseinrichtung bestimmt werden kann.The present invention is therefore based on the object of an electromechanically actuated parking brake to improve the type mentioned at the outset in such a way that the application force can be determined reliably by a simply constructed and cost-effectively implemented force measuring device.
Diese Aufgabe wird erfindungsgemäß dadurch gelöst, dass zumindest ein Teil der Kraftmesseinrichtung in mindestens einem Bremsseil derart integriert ist, dass die Übertragung der Zuspannkraft über das Teil erfolgt.This object is achieved according to the invention in that at least part of the force measuring device is integrated in at least one brake cable in such a way that the application force is transmitted via the part.
Bei einer vorteilhaften Weiterbildung des erfindungsgemäßen Gegenstandes besteht die Kraftmesseinrichtung aus einem Encoder und mindestens einem magneto-resistiven Sensorelement, wobei das Teil der Kraftmesseinrichtung durch den Encoder gebildet wird.In an advantageous development of the subject matter according to the invention, the force measuring device consists of an encoder and at least one magnetoresistive sensor element, the part of the force measuring device being formed by the encoder.
Außerdem ist vorgesehen, dass dem Teil ein Federelement oder ein gummi-elastisches Element nachgeordnet ist.It is also provided that a spring element or a rubber-elastic element is arranged downstream of the part.
Ein weitere vorteilhafte Weiterbildung sieht vor, dass das Bremsseil derart ausgeführt ist, dass es eine mechanische Verformung zulässt und einen hartmagnetischen Effekt aufweist, der mittels eines magneto-resisitiven Sensorelementes erfasst wird.A further advantageous development provides that the brake cable is designed in such a way that it allows mechanical deformation and has a hard magnetic effect which is detected by means of a magnetoresistive sensor element.
Die Erfindung wird nachfolgend im Zusammenhang mit der beiliegenden Zeichnung näher erläutert. In der Zeichnung zeigen :The invention is explained in more detail below in connection with the accompanying drawing. The drawing shows:
Fig.l ein schematisch dargestelltes Schaltbild eines hydraulischen Bremssystems, das eine elektromecha- nische Stelleinheit zur Durchführung von Feststellbremsvorgängen aufweist, _ O _1 shows a schematically illustrated circuit diagram of a hydraulic brake system which has an electromechanical actuating unit for carrying out parking brake operations, _ O _
Fig. 2a, b, c jeweils ein schematisch dargestelltes, lediglich teilweise dargestelltes Ausführungsbeispiel einer Kraftmesseinrichtung zur Erfassung der Zu- spannkraft von der in Fig. 1 dargestellten elekt- romechanischen Stelleinheit,2a, b, c each show a schematically illustrated, only partially illustrated embodiment of a force measuring device for detecting the clamping force from the electromechanical actuating unit shown in FIG. 1,
Fig. 3a, b das in Fig. 2c dargestellte Ausführungsbeispiel mit ungespanntem und gespanntem Bremsseil.Fig. 3a, b, the embodiment shown in Fig. 2c with an untensioned and tensioned brake cable.
In Fig. 1 ist ein Schaltbild einer hydraulischen Bremsanlage schematisch dargestellt. Die hydraulische Bremsanlage weist an einer ersten Achse, der Vorderachse, Radbremsen 2 auf, die während Betriebsbremsungen über eine hydraulische Leitung 20 mit Druck beaufschlagbar sind. Zur Kontrolle der gewünschten Bremsverzögerung und zur Realisierung einer Blockierschutz-Regelung (ABS) sind den Rädern der Vorderachse Raddrehzahlsensoren 12 zugeordnet, deren Ausgangssignale einer elektronischen Steuer- und Regeleinheit (ECU) 5 zugeführt werden. Diese elektronische Steuer- und Regeleinheit 5 ist dem Betriebsbremssystem zugeordnet. An einer zweiten Achse, der Hinterachse, sind ebenfalls Radbremsen 3 vorgesehen, die während Betriebsbremsungen über eine zweite hydraulische Leitung 10 mit Druck beaufschlagbar sind. Die Raddrehzahlen der Räder der Hinterachse werden durch Raddrehzahlsensoren 13 ermittelt und der eben erwähnten elektronischen Steuer- und Regeleinheit 5 zugeführt. Die Räder der Hinterachse können durch die eben erwähnten Radbremsen 3 gebremst werden als auch durch eine elektromechanisch betätigbare Feststellbremse. Die elektromechanisch betätigbare Feststellbremse weist zu diesem Zweck an der Hinterachse zwei mechanisch verriegelbare Bremseinrichtungen 4, die als Trommelbremsen 4 mit jeweils einem nicht näher dargestellten Spreizschloss ausgebildet sind, auf. Die eben genannten Spreizschlösser sind mittels zweier Bremsseile 11 von einer elektromechanischen Stelleinheit 1 betätigbar, wonach die Trommelbremsen 4 zugespannt werden. Ein Feststellbremsvorgang wird nach der Betätigung eines Bedienelementes 7 durch den Fahrzeugfuhrer durchgeführt. Dabei werden die Ausgangssignale des Bedienelementes 7 einer der elektromechanischen Feststellbremse zugeordneten elektronischen Steuereinheit (ECU) 6 zugeführt, die die bereits erwähnte elektromechani- sche Stelleinheit 1 entsprechend ansteuert.In Fig. 1, a circuit diagram of a hydraulic brake system is shown schematically. The hydraulic brake system has wheel brakes 2 on a first axle, the front axle, which can be pressurized during service braking via a hydraulic line 20. To control the desired braking deceleration and to implement anti-lock control (ABS), the wheels of the front axle are assigned wheel speed sensors 12, the output signals of which are fed to an electronic control and regulating unit (ECU) 5. This electronic control unit 5 is assigned to the service brake system. Wheel brakes 3 are also provided on a second axle, the rear axle, which can be pressurized during service braking via a second hydraulic line 10. The wheel speeds of the wheels of the rear axle are determined by wheel speed sensors 13 and supplied to the electronic control unit 5 just mentioned. The wheels of the rear axle can be braked by the wheel brakes 3 just mentioned as well as by an electromechanically actuated parking brake. For this purpose, the electromechanically actuated parking brake has two mechanically lockable braking devices 4 on the rear axle, which are designed as drum brakes 4, each with an expansion lock (not shown in more detail). The expansion locks just mentioned are by means of two brake cables 11 of one Electromechanical actuator 1 can be actuated, after which the drum brakes 4 are applied. A parking brake operation is carried out after the operator has actuated an operating element 7. The output signals of the operating element 7 are fed to an electronic control unit (ECU) 6 assigned to the electromechanical parking brake, which controls the already mentioned electromechanical actuating unit 1 accordingly.
Um die Zuspannkraft der elektromechanisch betatigbaren Feststellbremse zu ermitteln ist eine Kraftmesseinrichtung 9 notwendig. Wie in Fig. 2a dargestellt, besteht die Kraftmesseinrichtung 9 aus einem Encoder 14 und einem ortsfest angebrachten magneto-resisitiven Sensorelement 15. Dabei ist der Encoder 14, der aus einzelnen aneinander gefugten Hartmagneten besteht, in das Bremsseil derart integriert, dass eine Übertragung der Zuspannkraft von der elektromechanischen Stelleinheit 1 auf die Trommelbremsen 4 der Hinterachse über den Encoder 14 erfolgt. Der elektrische Widerstand des magneto-resisitiven Sensorelements 15 verändert sich, wenn ein Magnetfeld senkrecht auf einen an das magneto- resistive Sensorelement 15 angelegten Strom einwirkt. Dieser veränderte elektrische Widerstand im magneto-resisitiven Sensorelement 15, der von dem einwirkenden Magnetfeld und damit von der Stellung des Encoders 14 relativ zum magneto- resistiven Sensorelement 15 abhangt, wird gemessen. Vereinfacht kann man sagen, dass mit der Kraftmesseinrichtung 9 die Anzahl der hartmagnetischen Elemente des Encoders 14, die an dem ortsfest angebrachten magneto-resisitiven Sensorelement 15 vorbei gezogen werden, gezählt werden. Bei der Verwendung mehrerer magneto-resisitiver Sensorelemente 15 können auch Zwischenpositionen der hartmagnetischen Elemente des Encoders 14 ermittelt werden. Da ein normalerweise verwendetes Bremsseil 11 jedoch nicht ausreichend elastisch ist, um einen für die Messgenauigkeit der Kraftmesseinrichtung 9 ausreichend großen Abschnitt des Encoders 14 an dem magneto-resisitiven Sensorelement 15 vorbei zu bewegen, ist in dem Bremsseil 11 ein Federelement 16, wie in Fig. 2a dargestellt, integriert. Dabei wird die Zuspannkraft von der elektromechanischen Stelleinheit 1 auf die Trommelbremsen 4 über das Federelement 16 übertragen.A force measuring device 9 is necessary to determine the application force of the electromechanically actuated parking brake. As shown in Fig. 2a, the force measuring device 9 consists of an encoder 14 and a fixed magneto-resistive sensor element 15. The encoder 14, which consists of individual hard magnets joined together, is integrated into the brake cable in such a way that a transmission of the application force from the electromechanical control unit 1 to the drum brakes 4 of the rear axle via the encoder 14. The electrical resistance of the magnetoresistive sensor element 15 changes when a magnetic field acts vertically on a current applied to the magnetoresistive sensor element 15. This changed electrical resistance in the magnetoresistive sensor element 15, which depends on the acting magnetic field and thus on the position of the encoder 14 relative to the magnetoresistive sensor element 15, is measured. To put it simply, it can be said that the force measuring device 9 is used to count the number of hard magnetic elements of the encoder 14 which are pulled past the magneto-resistive sensor element 15 which is attached in a stationary manner. When using a plurality of magneto-resistive sensor elements 15, intermediate positions of the hard magnetic elements of the encoder 14 can also be determined. However, since a brake cable 11 normally used is not sufficiently elastic In order to move a section of the encoder 14 which is sufficiently large for the measuring accuracy of the force measuring device 9 past the magneto-resistive sensor element 15, a spring element 16, as shown in FIG. 2a, is integrated in the brake cable 11. The application force is transmitted from the electromechanical actuating unit 1 to the drum brakes 4 via the spring element 16.
Wenn die elektromechanische Stelleinheit 1 das Bremsseil 11 in Fig. 2a nach links zieht, um die Trommelbremsen 4 der Hinterachse zuzuspannen, wird die Zuspannkraft über den Encoder 14 und das eben beschriebene Federelement 16 übertragen, wobei Federelement 16 gedehnt wird. Dadurch wird der Encoder 14 an dem magneto-resisitiven Sensorelement 15 vorbei gezogen und die Stellung des Encoders 14 relativ zum ortsfest angebrachten magneto-resisitiven Sensorelement 15 ermittelt. Aus der Stellung des Encoders 15 und der zuvor ermittelten Federkonstanten des Federelementes 16 wird die von der elektromechanischen Stelleinheit 1 aufgebrachte Zuspannkraft berechnet .When the electromechanical actuating unit 1 pulls the brake cable 11 to the left in FIG. 2a in order to apply the drum brakes 4 to the rear axle, the application force is transmitted via the encoder 14 and the spring element 16 just described, spring element 16 being stretched. As a result, the encoder 14 is pulled past the magnetoresistive sensor element 15 and the position of the encoder 14 is determined relative to the magnetoresistive sensor element 15 which is attached in a stationary manner. The application force applied by the electromechanical actuating unit 1 is calculated from the position of the encoder 15 and the previously determined spring constants of the spring element 16.
Das in Fig. 2b dargestellte Ausführungsbeispiel ist der anhand von Fig. 2a beschriebenen Kraftmesseinrichtung 9 sehr ähnlich. Der einzige Unterschied besteht darin, dass anstelle des Federelements 16 ein gummi-elastisches Element 17 in das Bremsseil 11 integriert ist. Wenn eine Zuspannkraft von der elektromechanischen Stelleinheit 1 auf die Trommelbremsen 4 übertragen wird, wird das gummi-elastische Element 17 gedehnt und der Encoder 14 wie bereits anhand von Fig. 2a beschrieben an dem magneto-resisitiven Element 15 vorbei gezogen. Wird zuvor die Elastizität des gummi-elastischen Elementes 17 bestimmt, so kann in Zusammenhang mit der Stellung des Encoders 14 relativ zum ortsfest angebrachten magneto- resisitiven Element 16 die von der elektromechanischen Stelleinheit 1 aufgebrachten Zuspannkraft ermittelt werden.The embodiment shown in FIG. 2b is very similar to the force measuring device 9 described with reference to FIG. 2a. The only difference is that instead of the spring element 16, a rubber-elastic element 17 is integrated in the brake cable 11. When a clamping force is transmitted from the electromechanical actuating unit 1 to the drum brakes 4, the rubber-elastic element 17 is stretched and the encoder 14 is pulled past the magneto-resistive element 15 as already described with reference to FIG. 2a. If the elasticity of the rubber-elastic element 17 is determined beforehand, then in connection with the position of the encoder 14 relative to the fixed magneto-resistive element 16, that of the electromechanical element Actuator 1 applied clamping force can be determined.
Bei der in Fig. 2c dargestellten Kraftmesseinrichtung 9 wird auf den Encoder 14 verzichtet, da das Bremsseil 11 derart ausgeführt ist, dass es selbst einen hartmagnetischen Effekt 24 aufweist, was in Fig. 2c schematisch durch die einzelnen Magnete 24 dargestellt ist. Außerdem lässt das Bremsseil 11 bei dieser Ausführung eine mechanische Verformung zu, sodass auf zusätzliche elastische Elemente wie das Federelement in Fig. 2a oder das gummi-elastische Element in Fig. 2b verzichtet werden kann. Wenn die elektromechanische Stelleinheit 1 eine Zuspannkraft auf die Trommelbremsen 4 der Hinterachse überträgt, erfährt das Bremsseil eine mechanische Verformung in Form einer Längung. Ein Abschnitt des Bremsseils 11 wird an dem magneto-resisitiven Sensorelement 150 vorbei gezogen und da das Bremsseil 11 wie bereits erwähnt einen hartmagnetischen Effekt 24 aufweist, kann die Stellung des Bremsseils 11 relativ zum ortsfest angebrachten magneto- resistiven Sensorelement 150 ermittelt werden. Daraus wird zusammen mit dem zuvor ermittelten Maß der mechanischen Verformung des Bremsseils 11, die sich aus einem elastischen und einem durch Alterung bedingten plastischen Anteil zusammensetzt, die von der elektromechanischen Stelleinheit 1 aufgebrachte Zuspannkraft ermittelt.In the force measuring device 9 shown in FIG. 2c, the encoder 14 is dispensed with, since the brake cable 11 is designed such that it itself has a hard magnetic effect 24, which is shown schematically in FIG. 2c by the individual magnets 24. In addition, the brake cable 11 allows mechanical deformation in this embodiment, so that additional elastic elements such as the spring element in FIG. 2a or the rubber-elastic element in FIG. 2b can be dispensed with. When the electromechanical control unit 1 transmits an application force to the drum brakes 4 of the rear axle, the brake cable undergoes a mechanical deformation in the form of an elongation. A section of the brake cable 11 is pulled past the magneto-resistive sensor element 150 and since the brake cable 11 has a hard magnetic effect 24, as already mentioned, the position of the brake cable 11 can be determined relative to the magnetoresistive sensor element 150 which is attached in a fixed position. Together with the previously determined degree of mechanical deformation of the brake cable 11, which is composed of an elastic component and a plastic component caused by aging, this results in the application force applied by the electromechanical actuating unit 1.
Bei dem eine mechanische Verformung zulassenden Bremsseil 11 ist jedoch auch zu beachten, dass sich der hartmagnetische Effekt des Bremsseils 11 dehnt. In Fig. 3a ist die anhand von Fig. 2c beschriebene Kraftmesseinrichtung in einem Zustand abgebildet, in dem keine Zuspannkraft von der elektromechanischen Stelleinheit 1 über das Bremsseil 11 auf die Trommelbremsen 4 aufgebracht ist. Die einzelnen Magnete, die schematisch den hartmagnetischen Effekt 24 des Bremsseils 11 darstellen sollen, sind in diesem ungespannten Zustand um den Abstand λ0 voneinander getrennt. Bringt nun die elektro- mechanische Stelleinheit 1 eine Zuspannkraft über das Bremsseil 11 auf die Trommelbremsen 4 auf, so dehnt sich dasIn the case of the brake cable 11 that allows mechanical deformation, however, it should also be noted that the hard magnetic effect of the brake cable 11 expands. FIG. 3a shows the force measuring device described with reference to FIG. 2c in a state in which no application force is applied by the electromechanical actuating unit 1 to the drum brakes 4 via the brake cable 11. The individual magnets, which are intended to schematically represent the hard magnetic effect 24 of the brake cable 11, are in this untensioned state the distance λ 0 separated from each other. If the electromechanical actuating unit 1 now applies an application force via the brake cable 11 to the drum brakes 4, this expands
Bremsseil 11 um den Betrag ΔL und der Abstand der einzelnen Magnete des hartmagnetischen Effektes 24 wird größer, wie es in Fig. 3b dargestellt ist. Der Abstand der einzelnen Magnete beträgt dann λi . Diese Abstandsvergrößerung der einzelnen Magnete bzw. die Dehnung des hartmagnetischen Effekts 24 des Bremsseils 11 ist bei der Berechnung der Zuspannkraft zu berücksichtigen .Brake cable 11 by the amount .DELTA.L and the distance between the individual magnets of the hard magnetic effect 24 is greater, as shown in Fig. 3b. The distance between the individual magnets is then λi. This increase in the distance between the individual magnets or the expansion of the hard magnetic effect 24 of the brake cable 11 must be taken into account when calculating the application force.
Die durch Alterung hervorgerufene plastische Verformung (Längung) des Bremsseils 11 kann mit der in Fig. 3a, 3b dargestellten Anordnung bestimmt werden. Wenn die elektromecha- nischen Stelleinheit 1 über das Bremsseil 11 eine Zuspannkraft aufbringt, wird der Abstand λ der einzelnen Magnete des hartmagnetischen Effektes 24 mit zunehmender Alterung des Bremsseils 11 zunehmen. Diese durch die Alterung des Bremsseils 11 verursachte Veränderung des Abstands λ der einzelnen Magnete des hartmagnetischen Effektes 24 kann mit Hilfe des in Fig. 3b nicht dargestellten magneto-resisitiven Sensorelementes 15 bestimmt werden und von der die Zuspannkraft übertragende elastische Verformung abgezogen werden.The plastic deformation (elongation) of the brake cable 11 caused by aging can be determined with the arrangement shown in FIGS. 3a, 3b. If the electromechanical actuating unit 1 applies a clamping force via the brake cable 11, the distance λ between the individual magnets of the hard magnetic effect 24 will increase with increasing aging of the brake cable 11. This change in the distance λ of the individual magnets of the hard magnetic effect 24 caused by the aging of the brake cable 11 can be determined with the aid of the magneto-resistive sensor element 15 not shown in FIG. 3b and from which the elastic deformation which transmits the application force can be subtracted.
Mit allen drei beschriebenen Ausführungsbeispielen ist die Zuspannkraft einer elektromechanischen Stelleinheit 1 auf zwei Trommelbremsen 4 der Hinterachse zuverlässig zu ermitteln und die Herstellungskosten der Kraftmesseinrichtung 9 und deren Produktion sind als vorteilhaft zu beschreiben. With all three described exemplary embodiments, the application force of an electromechanical actuating unit 1 on two drum brakes 4 of the rear axle can be reliably determined and the manufacturing costs of the force measuring device 9 and its production can be described as advantageous.

Claims

Patentansprüche claims
1. Elektromechanisch betätigbare Feststellbremse für Kraftfahrzeuge, die im wesentlichen aus mindestens einer Vorrichtung (1) zur Erzeugung einer Zuspannkraft, einer e- lektronischen Steuereinheit (6) und mechanisch verriegelbaren Bremseinrichtungen (4) an wenigstens einer Achse besteht, wobei die Bremseinrichtungen (4) durch die Vorrichtung (1) mittels mindestens eines Bremsseiles1. Electromechanically actuated parking brake for motor vehicles, which essentially consists of at least one device (1) for generating an application force, an electronic control unit (6) and mechanically lockable braking devices (4) on at least one axle, the braking devices (4) through the device (1) by means of at least one brake cable
(11) zuspannbar sind und die Zuspannkraft mittels einer Kraftmesseinrichtung (9) ermittelt wird, dadurch gekennzeichnet, dass zumindest ein Teil (14) der Kraftmesseinrichtung (9) in mindestens einem Bremsseil (11) derart integriert ist, dass die Übertragung der Zuspannkraft über das Teil (14) erfolgt.(11) can be applied and the application force is determined by means of a force measuring device (9), characterized in that at least a part (14) of the force measurement device (9) is integrated in at least one brake cable (11) in such a way that the application of the application force via the Part (14) is done.
2. Elektromechanisch betätigbare Feststellbremse nach Anspruch 1, dadurch gekennzeichnet, dass die Kraftmesseinrichtung (9) aus einem Encoder (14) und mindestens einem magneto-resistiven Sensorelement (15) besteht, wobei das Teil (14) der Kraftmesseinrichtung (9) durch den Encoder gebildet wird.2. Electromechanically actuated parking brake according to claim 1, characterized in that the force measuring device (9) consists of an encoder (14) and at least one magnetoresistive sensor element (15), the part (14) of the force measuring device (9) by the encoder is formed.
3. Elektromechanisch betätigbare Feststellbremse nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass dem Teil (14) ein Federelement (16) oder ein gummi-elastisches3. Electromechanically actuated parking brake according to claim 1 or 2, characterized in that the part (14) is a spring element (16) or a rubber-elastic
Element (17) nachgeordnet ist.Element (17) is subordinate.
4. Elektromechanisch betätigbare Feststellbremse nach Anspruch 1, dadurch gekennzeichnet, dass das Bremsseil (11) derart ausgeführt ist, dass es eine mechanische4. Electromechanically actuated parking brake according to claim 1, characterized in that the brake cable (11) is designed such that it is a mechanical
Verformung zulässt und einen hartmagnetischen Effekt (24) aufweist, der mittels eines magneto-resisitiven Sensorelementes (150) erfasst wird. Allows deformation and has a hard magnetic effect (24), which is detected by means of a magneto-resistive sensor element (150).
PCT/EP2004/051060 2003-06-12 2004-06-08 Electromagnetically actuatable parking brake for motor vehicles WO2004110835A1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE10326371 2003-06-12
DE10326371.3 2003-06-12
DE102004025361A DE102004025361A1 (en) 2003-06-12 2004-05-19 Electromechanically actuated parking brake for motor vehicles
DE102004025361.7 2004-05-19

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1593569A1 (en) * 2004-05-06 2005-11-09 Sila Holding Industriale Spa Device for controlling a motor-vehicle servo-assisted brake
EP1655190A1 (en) * 2004-11-08 2006-05-10 Peugeot Citroën Automobiles S.A. Vehicle parking brake actuator with electric force feedback
WO2007088105A1 (en) * 2006-02-01 2007-08-09 Siemens Aktiengesellschaft Device for operating a brake
DE102006013216A1 (en) * 2006-03-22 2007-09-27 Siemens Ag Force measuring device for a parking brake of a vehicle, in particular a passenger car
WO2012068014A3 (en) * 2010-11-19 2012-06-21 Thomas Patrick Fitzsimons Treatment of nail disease

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5195377A (en) * 1990-04-17 1993-03-23 Garshelis Ivan J Magnetoelastic force transducer for sensing force applied to a ferromagnetic member using leakage flux measurement
US6249737B1 (en) * 1997-03-12 2001-06-19 Kuster & Co. Gmbh Vehicle parking brake system
DE10043739A1 (en) * 2000-09-05 2002-03-21 Fico Cables Sa hand brake

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5195377A (en) * 1990-04-17 1993-03-23 Garshelis Ivan J Magnetoelastic force transducer for sensing force applied to a ferromagnetic member using leakage flux measurement
US6249737B1 (en) * 1997-03-12 2001-06-19 Kuster & Co. Gmbh Vehicle parking brake system
DE10043739A1 (en) * 2000-09-05 2002-03-21 Fico Cables Sa hand brake

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1593569A1 (en) * 2004-05-06 2005-11-09 Sila Holding Industriale Spa Device for controlling a motor-vehicle servo-assisted brake
US7448475B2 (en) 2004-05-06 2008-11-11 Sila Holding Industriale S.P.A. Device for controlling a motor-vehicle servo-assisted brake
EP1655190A1 (en) * 2004-11-08 2006-05-10 Peugeot Citroën Automobiles S.A. Vehicle parking brake actuator with electric force feedback
FR2877628A1 (en) * 2004-11-08 2006-05-12 Peugeot Citroen Automobiles Sa AUTOMOBILE ELECTRIC SECONDARY BRAKE EFFORT RETURN CONTROL.
WO2007088105A1 (en) * 2006-02-01 2007-08-09 Siemens Aktiengesellschaft Device for operating a brake
DE102006013216A1 (en) * 2006-03-22 2007-09-27 Siemens Ag Force measuring device for a parking brake of a vehicle, in particular a passenger car
US7971488B2 (en) 2006-03-22 2011-07-05 Continental Automotive Gmbh Force measuring device for a parking brake of a vehicle, in particular of a passenger vehicle
WO2012068014A3 (en) * 2010-11-19 2012-06-21 Thomas Patrick Fitzsimons Treatment of nail disease

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