Mechanical locking mechanism having a switching element having a secure

Abstract

The invention relates to a locking mechanism for an electromechanical brake for a motor vehicle. The invention relates to an electromechanical brake with a locking mechanism and a method for operating the locking mechanism. The locking mechanism includes a ratchet and a locking pawl for blocking rotation of the ratchet in a locked state of the locking mechanism and for releasing rotation of the ratchet in an unlocked state of the locking mechanism. The locking mechanism further comprises a switching element which, in its rest state, fixes the locking pawl in the unlocked state of the locking mechanism; the locking mechanism also includes an actuator. The switching element can be shifted by means of a rotational displacement and / or by means of a translational displacement from a rest state into a first switching state in which a movement of the locking pawl, preferably a rotation about the axis of rotation, is released, the switching element being functionally arranged between the actuator and the locking pawl, and the switching element being functionally arranged between the actuator and the locking pawl. The switching element can be switched by means of an actuator, and the actuator also acts on the locking pawl by means of the switching element.

Description

Technical Field

[0001] The present invention relates to a locking mechanism used in electromechanical brakes, and more particularly to a locking mechanism for locking the operating direction of an electromechanical brake. Background Technology

[0002] Various technical solutions are known in the prior art for implementing parking brake functionality in electromechanical brakes. Document DE 10 224 688 A1 describes a method for operating a parking brake device integrated into an electromechanical service brake. To operate the parking brake, the brake actuator is used to operate the brake while the vehicle is stationary, and a locking mechanism is used to lock it in the operated position. This locking mechanism includes a locking pawl and a ratchet connected to the brake actuator. To lock, the restriction on the movement of the locking pawl is released by a locking element, and then the locking pawl engages with the ratchet. The unlocking and actuation of the locking pawl are respectively achieved by electromagnets. The locking element here ensures that the locking pawl will not accidentally engage with the ratchet, for example, due to vibrations during operation. The disadvantage of this solution is increased cost, as two actuators are required to operate the locking mechanism, leading to increased costs for wiring, control technology, and installation space.

[0003] Document DE 10 234 848 discloses a similar mechanism for locking an electromechanical service brake. It is also generally known that, as can be used in electromechanical service brakes, a rotatable locking pawl is used to lock a ratchet to form a locking mechanism for a parking brake. To apply the necessary locking force, the locking pawl must be designed to be sufficiently robust and durable, resulting in greater weight. The locking pawl can be held in the unlocked position by an elastic element and transitioned to the locked position by an actuator overcoming this elastic element. A disadvantage here is that even without controlling the actuator, the locking pawl can move to the locked position due to the reaction force generated by acceleration overcoming the elastic force. To prevent this accidental locking, the elastic element can be designed to be correspondingly rigid, but this means that a correspondingly greater force must be applied by the actuator for operation. The disadvantage of this is that a more powerful and therefore larger actuator must be used, resulting in greater material usage and greater energy consumption for operation.

[0004] The purpose of this invention is to provide a locking mechanism for electromechanical service brakes that overcomes the aforementioned disadvantages of the prior art. Summary of the Invention

[0005] The advantages of the locking mechanism with a switching element according to claim 1, the electromechanical brake with the features of claim 8, and the method for operating the locking mechanism according to claim 9 are that a single actuator is used to operate the locking pawl and release the locking pawl. The advantage of this actuator is its low power consumption, and therefore it can be designed to be smaller. This saves installation space and cost. Furthermore, since only one actuator needs to be controlled, control is simplified compared to the prior art.

[0006] This application discloses a locking mechanism for electromechanical brakes, particularly for locking the operating direction of electromechanical brakes. This locking mechanism is preferably used in motor vehicles, especially passenger vehicles. The locking mechanism includes a ratchet and a locking pawl. The locking pawl prevents rotation of the ratchet in the locked state and releases rotation of the ratchet in the unlocked state. The locking mechanism also includes a switching element that, in its stationary state, fixes the locking pawl in the unlocked state. The locking mechanism further includes an actuator, particularly an excitation coil or linear actuator.

[0007] According to the present invention, a switching element can be transitioned from a stationary state to a first switching state by means of rotational displacement and / or translational displacement, in which the movement of the locking pawl, preferably rotation about the rotation axis, is released. Here, the switching element is functionally arranged between the actuator and the locking pawl, such that the switching element can be switched by means of the actuator, and the actuator also acts on the locking pawl by means of the switching element. With this design, the switching element ensures that the locking pawl is reliably fixed in the unlocked state of the locking mechanism even under high acceleration. Therefore, unlike the prior art, an elastic element with a small elastic constant is sufficient as a reset device. Consequently, the operating force of the locking pawl to overcome the elastic force of the reset elastic element is smaller, and thus a lower-power actuator is sufficient for operation.

[0008] Advantageous improvements to the locking mechanism according to the invention are given in the dependent claims.

[0009] To avoid unnecessary repetition, features disclosed in relation to the device should also be considered as disclosed in relation to the method and can be claimed for protection, and vice versa.

[0010] In a first preferred embodiment of the locking mechanism, the switching element can be elastically loaded to its stationary state by means of a first elastic element. Here, the dimensions of the first elastic element can be designed such that the switching element remains stationary when the acceleration is below a limit value, preferably below 50 times the acceleration due to gravity, more preferably below 80 times the acceleration due to gravity, and particularly preferably below 100 times the acceleration due to gravity. This advantageously ensures that even under high accelerations that may occur, for example, when driving over potholes, the switching element can still be reliably fixed in its stationary state. Since the switching element is not arranged in the force transmission path of the locking mechanism, it does not need to bear high mechanical loads, and a design capable of withstanding lower mechanical loads is sufficient. Therefore, the size of the switching element can be designed to be compact, resulting in a small mass. Due to the small mass of the switching element, the correspondingly small restoring force and thus small elastic constant of the elastic element are sufficient to withstand the forces acting on the switching element up to the aforementioned acceleration limit value. Due to the small elastic constant, a small operating force is sufficient to operate the switching element, and therefore a small actuator with low power is sufficient.

[0011] In a next preferred embodiment of the locking mechanism, a recess may be constructed in the switching element, which mechanically interacts with the retaining element of the locking pawl in the stationary state of the switching element, particularly forming a locking connection, and mechanically preventing movement of the locking pawl, particularly rotation about the axis of rotation. The position of the locking pawl is advantageously mechanically fixed, ensuring that the locking pawl is secured in the unlocked state of the locking mechanism against any external load. The embodiment with the recess and retaining element is particularly simple in structure and therefore inexpensive.

[0012] In another preferred embodiment of the locking mechanism, the locking pawl can be elastically loaded into the unlocked state of the locking mechanism by means of a second elastic element. Here, the locking pawl can transition from the locked state to the unlocked state of the locking mechanism by means of the second elastic element, wherein the dimensions of the second elastic element are designed such that the locking pawl can transition from the locked state to the unlocked state of the locking mechanism in any spatial position of the locking mechanism by means of the elastic force of the second elastic element. The second elastic element, serving as a reset device for the locking pawl, ensures that the locking mechanism functions reliably regardless of its spatial location within the vehicle. The elastic element serving as a reset device for the locking pawl is particularly easy to design in terms of construction and is also inexpensive to manufacture. Therefore, this embodiment contributes to achieving a low-cost overall system. Furthermore, the elastic element is durable, resulting in a long service life for the overall system.

[0013] In a next preferred embodiment of the locking mechanism, the switching element may include an actuating device for acting on the locking pawl to move the locking pawl, particularly from the unlocked state of the locking mechanism, to the locked state, preferably a rotation about the axis of rotation of the locking pawl. Here, in a first switching state of the switching element, the actuating device abuts against the locking pawl, and in a second switching state, the movement of the locking pawl is released, and the locking pawl moves, preferably rotates, to the locked state of the locking mechanism by means of a force applied by the actuating device. The actuating device may, for example, be designed as a pin protruding from the switching element. Thus, the combined action of the switching element and the locking pawl is achieved in a structurally advantageous and convenient manner. Furthermore, it is advantageously mechanically ensured that the actuating force of the actuator acts on the locking pawl only in the switching state of the switching element when the movement of the locking pawl is released. Therefore, the control of the entire locking mechanism is very simple. Mechanical forcing ensures that the locking pawl is only actuated in the unlocked state.

[0014] In another preferred embodiment of the locking mechanism, the switching element can be designed in a weight-optimized manner, having the smallest possible mass and / or an advantageously balanced mass distribution. To achieve the smallest possible mass, the switching element can be designed as a lightweight component and / or made of a material with the lowest possible density, preferably aluminum alloy or plastic. Additionally or alternatively, the switching element can be designed in a weight-optimized manner with an eye toward an advantageously balanced mass distribution. Designing the switching element as a lightweight component results in a small mass of the switching element. The small mass of the switching element allows the first elastic element to have a small elastic constant, which is advantageous because the actuator must overcome this elastic force to manipulate the switching element. Additionally or alternatively, a switching element balanced relative to the axis of motion of the switching element can have an advantageous effect because external acceleration acting on the switching element will not generate forces on the switching element that cause translational and / or rotational displacement of the switching element. The elastic force of the first elastic element overcomes these forces to hold the switching element in place, and can be designed to be correspondingly less rigid with smaller forces. Therefore, the weight-optimized design of the switching element allows for the use of actuators with the lowest possible power, and thus low cost and compact size.

[0015] In a next preferred embodiment of the locking mechanism, the switching element can be constructed as a single piece, particularly an integral piece, and is preferably manufactured by injection molding and / or stamping and / or forming. The single-piece construction allows for advantageously simple and cost-effective manufacturing of the switching element. Complex joining processes for manufacturing can be eliminated. Injection molding and / or stamping and / or forming processes are particularly advantageous for high-volume parts, especially in vehicle manufacturing, as they allow for particularly cost-effective mass production.

[0016] Furthermore, the present invention also covers an electromechanical brake, preferably functioning as a parking brake, particularly for motor vehicles, and preferably for passenger vehicles, which includes at least a locking mechanism according to the invention. This electromechanical brake has the advantage of a particularly simple mechanical structure. The parking brake function can be implemented in the electromechanical brake particularly easily using the locking mechanism according to the invention. Therefore, the electromechanical brake as a whole system is also advantageously simple, compact, and easy to control.

[0017] Furthermore, the present invention also covers a method for use, preferably in motor vehicles, particularly passenger vehicles, for operating, and particularly reversibly locking, a locking mechanism for electromechanical brakes, the locking mechanism particularly locking the operating direction of the electromechanical brakes. The method includes the following steps:

[0018] -The switching element is rotated and / or translated from a stationary state to the first switching state by means of the action of the actuator to overcome the elastic effect of the first elastic element;

[0019] - The locking pawl is released by the switching element, thereby enabling the locking pawl to move;

[0020] - This causes the locking pawl to shift against the elastic action of the second elastic element to engage the ratchet, and causes the locking mechanism to switch from the unlocked state to the locked state.

[0021] According to the present invention, the switching element is shifted from a first switching state to a second switching state by an actuator, and hereby acts on a locking pawl by means of a manipulator, specifically the locking pawl overcoming the elastic action of the second elastic element and shifting from an unlocked state to a locked state, so that the locking pawl, upon reaching the second switching state, acts in a locked manner with the ratchet. Advantageously, controlling a single actuator is sufficient to execute a multi-stage switching process. Therefore, the method is easy to apply in terms of control technology. There is no need to monitor the switching state of the actuator, because the successive processes are mechanically determined. For example, there is no need to monitor the switching state of the switching element to prevent the locking pawl from being manipulated while it is still locked by the switching element. Attached Figure Description

[0022] Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments of the invention and with reference to the accompanying drawings.

[0023] Features disclosed for the device should also be considered as disclosures for the method, and vice versa.

[0024] The same components or components with the same function in the figure are labeled with the same reference numerals.

[0025] Figure 1A schematic diagram of the intercepting section of the locking mechanism according to the present invention is shown, wherein the locking mechanism is in an unlocked state and the switching element is in a stationary state;

[0026] Figure 2 A schematic diagram of the intercepting section of the locking mechanism according to the present invention is shown, wherein the locking mechanism is in an unlocked state and the switching element is in a first switching state;

[0027] Figure 3 A schematic diagram of the intercepting section of the locking mechanism according to the present invention is shown, wherein the locking mechanism is in a locked state and the switching element is in a second switching state. Detailed Implementation

[0028] exist Figure 1 The schematic diagram shows the cut-off section of the locking mechanism 1 of the electromechanical brake. Here, the ratchet 2 can be non-rotatably connected to the operating device of the electromechanical brake. When the electromechanical brake is actuated, the ratchet 2 rotates in the release direction L, and when the electromechanical brake is released, the ratchet 2 rotates in the locking direction S. The locking pawl 3 is supported and can rotate about the rotational hinge 12 of the locking pawl 3. In the illustrated embodiment, the second elastic element 7, designed as a compression spring, loads the locking pawl 3 to the shown unlocked state. The switching element 4 is shown in a stationary state. The switching element 4 is supported and can rotate about the rotational hinge 11 of the switching element, and is elastically loaded towards the shown stationary state by the first elastic element 6, designed as a compression spring in the illustrated embodiment.

[0029] The first elastic element 6 holds the switching element 4 in the stationary state shown. In the stationary state, the recess 8 of the switching element 4 and the retaining element 9 of the locking pawl 3 form a locking connection with each other, which secures the locking pawl 3 in the unlocked position. This locking connection reliably holds the locking pawl 3 in the unlocked state even under high acceleration. The switching element 4 is a lightweight component made of light metal and is a one-piece structure. The locking pawl 3 and its rotating hinge 12 are designed according to the load of the corresponding application and can be loaded. The elastic constant of the first elastic element 6 is selected such that the switching element 4 remains in the stationary state shown even under accelerations reaching 80 times the force of gravity. In the stationary state of the switching element 4, the actuating device 10 does not contact the locking pawl 3. (Reference) Figure 2 and Figure 3 The second elastic element 7 is further described.

[0030] In order to achieve the switching element 4 Figure 2In the first switching state shown, the operating force F of a suitable actuator (not shown) is applied to the switching element 4. The switching element 4 rotates against the elastic force of the first elastic element 6. The locking connection between the recess 8 and the retaining element 9 is released. In the first switching state, the operating device 10 of the switching element 4 abuts against the locking pawl 3. The locking pawl 3 remains unlocked and does not engage with the ratchet 2, which can rotate in both directions.

[0031] Through the further action of the actuator's operating force F, it will reach Figure 3 The state is shown. To this end, the switching element 4 rotates further against the elastic force of the first elastic element 6 via an actuator (not shown). The operating device 10 of the switching element 4 acts on the locking pawl 3, causing it to rotate against the elastic force of the second elastic element 7. The locking pawl 3 is in a locked state with the ratchet 2. The locking direction S of the ratchet 2 is blocked by the locking pawl 3. The release direction L of the ratchet 2 is not blocked as before. Due to the non-rotatable connection between the ratchet 2 and the operating device of the electromechanical brake, the electromechanical brake cannot be released in this state and can only remain blocked. This provides the function of a parking brake.

[0032] To release the locking mechanism 1 and thus the parking brake function of the electromechanical brake, the actuator is further actuated in the direction of the actuating force F, causing the form-fit connection between the ratchet 2 and the locking pawl 3 to be disengaged. After the form-fit connection is disengaged, the actuator is deactivated and switched to a force-free mode. With the elastic force of the first elastic element 6 and the second elastic element 7, the switching element 4 rotates toward its initial state, and the locking pawl 3 moves away from the ratchet 2 and toward its initial state. Here, a form-fit connection is established between the recess 8 and the retaining element 9. The switching element 4 acts on the actuator switched to the force-free mode, thereby pushing it into its initial position. In an alternative embodiment, the actuator can also be activated in a controlled manner upon release, causing the switching element 4, the locking pawl 3, and the actuator to move to the initial position more slowly, which advantageously reduces noise generated during release.

Claims

1. A locking mechanism (1) for electromechanical brakes, particularly for locking the operating direction of electromechanical brakes, preferably used in motor vehicles, particularly passenger vehicles, the locking mechanism comprising a ratchet (2) and a locking pawl (3), the locking pawl being used to prevent rotation of the ratchet (2) in the locked state of the locking mechanism (1) and to release rotation of the ratchet (2) in the unlocked state of the locking mechanism (1); the locking mechanism further comprising a switching element (4), in the stationary state of the switching element, the switching element fixing the locking pawl (3) in the unlocked state of the locking mechanism (1); the locking mechanism further comprising an actuator, particularly an excitation coil or linear actuator. Its features are, The switching element (4) can be switched from the stationary state to a first switching state by means of rotational displacement and / or translational displacement, in which the movement of the locking pawl (3) is released, preferably the rotation about the rotation axis is released, wherein the switching element (4) is functionally arranged between the actuator and the locking pawl (3), so that the switching element (4) can be switched by means of the actuator, and the actuator also acts on the locking pawl (3) by means of the switching element (4).

2. The locking mechanism (1) for an electromechanical brake according to claim 1, Its features are, The switching element (4) is elastically loaded to the stationary state of the switching element by means of a first elastic element (6), wherein the size of the first elastic element (6) is designed such that the switching element (4) remains in the stationary state of the switching element when the acceleration is below a limit value, preferably below 50 times the gravitational acceleration, more preferably below 80 times the gravitational acceleration, and particularly preferably below 100 times the gravitational acceleration.

3. The locking mechanism (1) for an electromechanical brake according to any one of the preceding claims, Its features are, A recess (8) is constructed in the switching element (4). In the stationary state of the switching element, the recess and the retaining element (9) of the locking pawl (3) work together mechanically, in particular forming a locking connection, and mechanically preventing the movement of the locking pawl (3), in particular preventing rotation about the axis of rotation.

4. The locking mechanism (1) for an electromechanical brake according to any one of the preceding claims, Its features are, The locking pawl (3) is elastically loaded to the unlocked state of the locking mechanism by means of a second elastic element (7), wherein the locking pawl (3) can switch from the locked state of the locking mechanism to the unlocked state by means of the second elastic element (7), wherein the size of the second elastic element (7) is designed such that the locking pawl (3) can switch from the locked state of the locking mechanism to the unlocked state at any spatial position of the locking mechanism by means of the elastic force of the second elastic element.

5. The locking mechanism (1) for an electromechanical brake according to any one of the preceding claims, Its features are, The switching element (4) includes an actuating device (10) that acts on the locking pawl (3), particularly for moving the locking pawl (3) from the unlocked state of the locking mechanism to the locked state, the movement preferably being a rotation about the axis of rotation of the locking pawl (3), wherein in a first switching state of the switching element the actuating device (10) is in contact with the locking pawl (3), and wherein in a second switching state of the switching element the movement of the locking pawl is released, and the locking pawl (3) moves, preferably rotates, to the locked state of the locking mechanism by means of a force applied by the actuating device (10).

6. The locking mechanism (1) for an electromechanical brake according to any one of the preceding claims, Its features are, The switching element (4) is designed in a weight-optimized manner, having the smallest possible mass and / or a favorable balanced mass distribution.

7. The locking mechanism (1) for an electromechanical brake according to any one of the preceding claims, Its features are, The switching element (4) is constructed in one piece, particularly integrally, and is preferably manufactured by means of injection molding and / or stamping and / or forming.

8. An electromechanical brake, preferably having the function of a parking brake, particularly used in motor vehicles, preferably passenger vehicles, the electromechanical brake comprising a locking mechanism (1) according to any one of claims 1 to 7.

9. A preferred method for use in motor vehicles, particularly passenger vehicles, for operating, and especially for reversibly locking, a locking mechanism (1) for electromechanical brakes, wherein the locking mechanism particularly locks the operating direction of the electromechanical brake. The method includes the following steps: -The switching element (4) is rotated and / or translated from a stationary state to the first switching state by means of the action of the actuator to overcome the elastic action of the first elastic element (6); - The locking pawl (3) is released by the switching element (4) so ​​that the locking pawl (3) can move; - This causes the locking pawl (3) to shift against the elastic action of the second elastic element (7) to engage the ratchet (2), and causes the locking mechanism (1) to switch from the unlocked state to the locked state. Its features are, The switching element (4) is shifted from the first switching state to the second switching state by the actuator, and hereby acts on the locking pawl (3) by means of the manipulator (10), in particular causing the locking pawl (3) to overcome the elastic action of the second elastic element (7) and shift from the unlocked state to the locked state, so that the locking pawl (3) works together with the ratchet (2) in a locked manner when it reaches the second switching state.

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