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DE-102024210833-A1 - Acceleration-compensated locking mechanism for electromechanical service brake, electromechanical service brake and method for operating a locking mechanism

DE102024210833A1DE 102024210833 A1DE102024210833 A1DE 102024210833A1DE-102024210833-A1

Abstract

Locking mechanism (01) for locking a movement, in particular a release movement to reduce a contact force of two friction partners, of an electromechanical service brake, preferably for use in a motor vehicle, in particular in a passenger car, comprising a locking bolt (03) which, in a locked state of the locking mechanism (01), engages in a locking element (02) of the electromechanical service brake in a locking manner and, in an unlocked state of the locking mechanism (01), is arranged to release the locking element (02), further comprising an actuator (04), in particular an electromagnetic linear actuator (05) or a linear drive, for moving the locking bolt (03) between the locked state and the unlocked state.

Inventors

  • Frank Baehrle-Miller

Assignees

  • Robert Bosch Gesellschaft mit beschränkter Haftung

Dates

Publication Date
20260513
Application Date
20241112

Claims (10)

  1. Locking mechanism (01) for locking a movement, in particular a release movement to reduce a contact force between two friction partners, of an electromechanical service brake, preferably for use in a motor vehicle, in particular in a passenger car, comprising a locking bolt (03) which, in a locked state of the locking mechanism (01), engages in a locking element (02) of the electromechanical service brake, thus blocking the movement, and in an unlocked state of the locking mechanism (01) is arranged to release the locking element (02), further comprising an actuator (04), in particular an electromagnetic linear actuator (05) or a linear drive, for moving the locking bolt (03) between the locked state and the unlocked state, characterized in that a lever mechanism (06), in particular dimensioned to compensate for mass, connects the actuator (04) to the locking bolt (03), wherein a lever length (r1) effective for the locking bolt (03) and a lever length (r2) effective for the The actuator (04) and the effective lever length (r2) of the lever mechanism (06) are related to each other in such a way that inertial forces (F1, F2) which act on the locking bolt (03), the actuator (04) and/or the lever mechanism (06) due to an external acceleration (a) acting on the locking mechanism (01) are balanced in such a way that the locking bolt (03) remains in the unlocked state from an unlocked state regardless of the magnitude and/or direction of the external acceleration (a).
  2. Locking mechanism (01) for an electromechanical service brake according to Claim 1 , characterized by a rocker arm (07) rotatably mounted about an axis of rotation (08), to which the locking bolt (03) and the actuator (04) are articulated on different sides with respect to the axis of rotation (08), so that inertial forces (F1, F2) which act on the locking bolt (03), the actuator (04) and the rocker arm (07) due to the external acceleration (a) generate opposing moments (M1, M2) with respect to the axis of rotation (08).
  3. Locking mechanism (01) for an electromechanical service brake according to Claim 2 , characterized in that the lever length (r1) effective for the locking bolt (03) and the lever length (r2) effective for the actuator (04) of the rocker arm (07) are in such a relationship to each other that the opposing moments (M1, M2) generate a moment equilibrium with respect to the axis of rotation (08).
  4. Locking mechanism (01) for an electromechanical service brake according to one of the preceding claims, characterized by a damping means (09) which dampens a movement of the locking mechanism (01) and is in particular articulated to the locking bolt (03), the actuator (04) or the lever mechanism (06).
  5. Locking mechanism (01) for an electromechanical service brake according to one of the preceding claims, characterized by a spring means (10) which biases the locking mechanism (01) towards the unlocked state and is in particular articulated to the locking bolt (03), the actuator (04) or the lever mechanism (06).
  6. Locking mechanism (01) for an electromechanical service brake according to Claim 5 , characterized in that the spring means (10) has a spring force which is 1.3 times, preferably 1.2 times, more preferably 1.1 times a minimum mechanically required restoring force due to tolerance and/or friction.
  7. Locking mechanism (01) for an electromechanical service brake according to one of the preceding claims, characterized in that a direction of movement (D) of the locking bolt (03) and a direction of movement (E) of the actuator (04) for displacing the locking bolt (03) between the unlocked and the locked state are arranged parallel to each other.
  8. Locking mechanism (01) for an electromechanical service brake according to one of the Claims 1 until 6 , characterized in that a direction of movement (D) of the locking bolt (03) and a direction of movement (E) of the actuator (04) for displacing the locking bolt (03) between the unlocked and the locked state are arranged at an angle (b) to each other, wherein an angle bisector (G) of the angle (b) is arranged parallel to a principal direction of action (H) of the external acceleration (a).
  9. An electromechanical service brake, in particular with a function as a parking brake, preferably for use in a motor vehicle, in particular in a passenger car, comprising a locking mechanism (01) according to one of the Claims 1 until 8 .
  10. Method for operating a locking mechanism (01) for locking a movement, in particular a release movement to reduce a contact force of two friction partners, of an electromechanical service brake, preferably for use in a motor vehicle, in particular in a A passenger car comprising a locking bolt (03) which, in a locked state of the locking mechanism (01), engages in a locking element (02) of the electromechanical service brake, thus blocking the movement of the electromechanical service brake, and in an unlocked state of the locking mechanism (01), is arranged to release the locking element (02), further comprising an actuator (04), in particular an electromagnetic linear actuator (05) or a linear drive, for moving the locking bolt (03) between the locked state and the unlocked state, characterized in that inertial forces (F1, F2), which act on the locking bolt (03), the actuator (04) and/or a lever mechanism (06), which connects the actuator (04) to the locking bolt (03), in particular dimensioned to compensate for mass, due to an external acceleration (a) acting on the locking mechanism (01), act by means of a lever length (r1) effective for the locking bolt (03). and a lever length (r2) of the lever mechanism (06) effective for the actuator (04) is balanced in such a way that the locking bolt (03) remains in the unlocked state from an unlocked state regardless of the amount and/or direction of the external acceleration (a).

Description

Technical field The invention relates to a locking mechanism for use in an electromechanical service brake, preferably for use in a motor vehicle. The invention further relates to an electromechanical service brake with a locking mechanism and a method for operating a locking mechanism. State of the art Various technical solutions are known in the prior art for implementing a parking brake function in electromechanical service brakes. DE 10 224 688 A1 This describes a method for actuating a parking brake system integrated into an electromechanical service brake. To actuate the parking brake, the electromechanical service brake is applied via its brake actuator when the vehicle is stationary and locked in the actuated position by a locking mechanism, thus preventing any release movement. The locking mechanism comprises a pawl and a ratchet wheel connected to the brake actuator. To lock the pawl, its movement is released by means of a latch, and then the pawl engages with the ratchet wheel. The release and engagement of the pawl are each achieved by an electromagnet. The latch ensures that the pawl does not unintentionally engage with the ratchet wheel, as could happen, for example, due to vibrations during driving. A disadvantage of this solution is the increased effort, as two actuators are required to operate the locking mechanism, which entails increased cabling, control technology and installation space. The DE 10 234 848 Figure 1 shows an alternative locking mechanism for securing an electromechanical service brake. A locking bolt is linearly movable to engage a ratchet wheel. To lock the ratchet wheel, a linear actuator is driven, causing the locking bolt to move against the spring force of a return spring into a position that locks the ratchet wheel. The spring force is chosen to be large enough to reliably prevent unintentional movement of the locking bolt when the mechanism is subjected to external acceleration. Overcoming this strong spring force when activating the locking mechanism requires a powerful linear actuator, which is disadvantageous in terms of cost, installation space, mass, and electrical power consumption. The object of the invention is to provide a locking mechanism, an electromechanical service brake and a method for operating a locking mechanism, which overcome the aforementioned disadvantages of the prior art. Disclosure of the invention The locking mechanism according to the invention, comprising the features of claim 1, the electromechanical service brake comprising the features of claim 9, and the method for operating the locking mechanism according to the invention, comprising the features of claim 10, have the advantage that external accelerations do not cause the locking mechanism to be unintentionally moved into a locked state. Furthermore, the locking mechanism according to the invention is advantageously mechanically simple in design, in particular without additional actuators. Moreover, a particularly powerful actuator is not required, which results in advantageously low costs with regard to the dimensioning of the electronic and/or electrical components. Thus, a locking mechanism according to the invention is advantageously compact and lightweight. Consequently, an electromechanical service brake with a locking mechanism according to the invention is also advantageously simple and compact in design. The locking mechanism according to the invention for blocking a movement, in particular a release movement to reduce the contact force between two friction partners, of an electromechanical service brake, preferably for use in a motor vehicle, especially a passenger car, comprises a locking bolt which, in a locked state of the locking mechanism, engages in a locking element of the electromechanical service brake, thus blocking the movement of the electromechanical service brake, and is arranged to release the locking element in an unlocked state of the locking mechanism. The locking mechanism further comprises an actuator, in particular an electromagnetic linear actuator or a linear drive, for moving the locking bolt between the locked and unlocked states. According to the invention, a lever mechanism, in particular dimensioned to compensate for mass, connects the actuator to the locking bolt, wherein a lever length effective for the locking bolt and a lever length effective for the actuator of the lever mechanism are in such a ratio to each other that inertial forces acting on the locking bolt, the actuator and/or the lever mechanism due to an external acceleration acting on the locking mechanism are balanced in such a way that the locking bolt, starting from an unlocked state, is independent of the magnitude and/or the direction of the external acceleration remains in the unlocked state. External accelerations, as used here, are those accelerations that occur during the operation of a vehicle and act from the outside on a wheel and all components on the wheel, including a