Electromechanical brake system and corresponding method of operation

Abstract

The invention relates to an electromechanical brake system comprising a brake actuator (2) having a power transmission for transmitting a driving force to a brake pad, said power transmission comprising a rotatable shaft (81), a coupling device having a locking element (35), wherein the coupling device can be controlled to either engage the locking element (35) with the rotatable shaft (81) and prevent it from rotating or to disengage the locking element (35) from the rotatable shaft (81) so that the rotatable shaft (81) can rotate, wherein the brake actuator (2) comprises an interface (31) configured to be connectable with the locking element (35) and to be able to engage or disengage the locking element (35) with the rotatable shaft (81).

Description

Technical Field

[0001] This invention relates to an electromechanical braking system and a corresponding operating method. Background Technology

[0002] Today, electro-pneumatic brake actuators are frequently used in commercial vehicles. In most cases, these actuators use pneumatic energy via cylinders to actuate the service and parking brakes. The parking brake function is achieved by an actuator independent of the service brake and can be operated independently. Due to the spring design of the parking brake actuator, single-stroke braking can be achieved even without compressed air as an energy source. In the event of system depressurization, the preloaded spring in the parking brake chamber provides sufficient braking energy to stop or keep the vehicle stationary. When there is no compressed air supply to the vehicle, the parking brake cylinder must be released to allow the vehicle to be towed. In combined pneumatic brake chambers, this release is achieved via a threaded mechanism. A threaded shaft is led out of the brake chamber and is accessible to the operator. The brake can be released by turning this shaft with a common tool.

[0003] In the future, the actuation of electromechanical brakes will become increasingly common. These brakes must also be able to be released externally. In the event of a malfunction, if the brake remains engaged and cannot be released during normal operation, there needs to be a possibility of releasing the brake to allow the vehicle to be towed. Due to the complexity of electromechanical actuators, a new solution for emergency brake release is necessary. Summary of the Invention

[0004] The purpose of this application is to provide an electromechanical braking system with a brake release tool and a corresponding method for allowing the electromechanical brake to be released from the outside.

[0005] This objective is achieved by a braking system comprising the features of claim 1 and a method comprising the features of claim 11.

[0006] According to the present invention, a parking brake mechanism for a disc brake with an external brake release function is provided. According to one aspect, the braking system includes: a brake actuator having a power transmission means for transmitting actuating force to brake pads, the power transmission means including a rotatable shaft; and a coupling device having a locking element, wherein the coupling device can be controlled to engage the locking element with the rotatable shaft and prevent its rotation, or to disengage the locking element from the rotatable shaft to allow the rotatable shaft to rotate, wherein the brake actuator includes an interface configured to connect to the locking element and engage or disengage the locking element from the rotatable shaft.

[0007] Releasing the locking element is a prerequisite before releasing the brake using a tool, because when the brake actuator and the rotatable shaft are locked by the locking element, they cannot be rotated. In the braking system, the locking element is held against the rotatable shaft by a spring mechanism or other means, such as a permanent magnet, when the parking brake is applied. Alternatively or additionally, a spring mechanism can be provided to push or pull the locking element in the opposite direction and assist the interface in releasing the locking element.

[0008] To release the brake, a tool element, such as a wrench, is arranged in the brake actuator of the braking system so that it engages with a rotatable shaft, and once the locking element disengages or is released from the rotatable shaft, it can be used to manually move the brake actuator and release or clamp the brake. This allows the braking system to be released and activated from the outside, even when the vehicle is not in operation.

[0009] Disc brakes are particularly suitable for parking brake mechanisms in heavy vehicles, and especially for parking brakes in electromechanical braking (EMB) systems.

[0010] According to one embodiment, the interface includes an interface member configured to be pulled or pushed to disengage a locking element from a rotatable shaft. Therefore, as an alternative, a pull-type interface can be provided, wherein the interface member is configured to be pulled to disengage the locking element from the rotatable shaft, or a push-type interface can be provided, wherein the interface member is configured to be pushed to disengage the locking element from the rotatable shaft. Pulling or pushing can be achieved by a mechanical lever or power tool, such as an actuator or solenoid coil.

[0011] According to one embodiment, the interface includes a sealed connection structure through which interface components can be accessed. In particular, the sealed connection structure can be waterproof. Furthermore, the sealed connection structure can be configured to be accessible only with special tools.

[0012] According to another embodiment, the rotatable shaft includes a disc-shaped rotating member. This rotating member may be disposed at an end of the rotatable shaft.

[0013] According to one embodiment, the coupling device includes a spring mechanism for moving the locking element to a position engaging with one of the sides of the rotating member. The spring mechanism may include one or more springs. In alternative braking systems, the coupling device includes other means, such as a permanent magnet, for holding the locking element in the position engaging with one of the sides of the rotating member. Furthermore, a spring mechanism may be provided to push or pull the locking element in the opposite direction and assist the interface in releasing the locking element.

[0014] According to one embodiment, the coupling device includes a bistable clutch comprising a spring, a permanent magnet, and an electromagnetic coil. The spring holds a locking element in a first position, such as when the locking element is engaged with the rotating member. The permanent magnet holds the locking element in a second position, such as when the locking element is disengaged from the rotating member. The electromagnetic coil is capable of switching between these two positions during electrical operation. However, according to another embodiment, the first and second positions can be interchanged for engagement or disengagement between the locking element and the rotating member, respectively.

[0015] According to yet another embodiment, the braking system includes a receiver into which a tool element can be inserted so that the tool element engages with a rotatable shaft and transmits rotation to the rotatable shaft.

[0016] According to one embodiment, the locking element has a disc shape and is arranged on the coupling device such that it can move toward the rotating member, and one of its sides is formed to engage with one of the sides of the rotating member to prevent its rotation. The locking element can also be moved so that one of its sides disengages from said one of the sides of the rotating member, thereby allowing it to rotate.

[0017] The locking element and the rotating member of the rotatable shaft can be arranged in a releasable coupling, wherein locking is achieved by means of a mechanism through engagement between two opposing surfaces of the locking element and the rotating member, which presses the locking element against the rotating member to achieve a parking brake state. This mechanism can be a spring mechanism with one or more springs, or other tools such as a permanent magnet. The mechanism can also be arranged in another way, where one of the locking element or the rotating member is pulled toward the corresponding other to achieve a parking brake state. The braking system can include means, such as an electromagnetic actuator, for moving the locking element relative to the rotating member during normal operation.

[0018] According to one embodiment, the locking element is disc-shaped with one or more grooves or openings that allow an engaging interface member to move the locking element. The interface member may be a lever or a fork-like element.

[0019] According to one embodiment, the locking element, the rotatable shaft, and the rotating member are arranged coaxially with respect to their axis of symmetry.

[0020] According to one embodiment, the power transmission device is electrically driven and causes rotational movement of a rotatable shaft. An electric motor can be used as an actuator.

[0021] According to one embodiment, the coupling device and the locking device are arranged in the electromagnetic parking brake locking mechanism for locking the brake actuator.

[0022] According to the present invention, a method for releasing an electromechanical brake is also provided. The method includes the following actions or steps: inserting an interface member into a locking element of the brake actuator using an interface of the brake actuator, the locking element locking the movement of the brake actuator; disengaging the locking element from a rotatable shaft of the brake actuator via the interface member; and moving or rotating a tool element to transmit power to the rotatable shaft to release the brake.

[0023] Alternatively or additionally, the method may include the following steps: inserting a tool element into the brake actuator of the electromechanical brake so that the tool element engages with the rotatable shaft of the brake actuator; moving the tool element to transmit torque to the rotatable shaft of the brake actuator to rotate the rotatable shaft and lock the brake; and controlling the interface to engage a locking element with the rotatable shaft of the brake actuator so that the locking element locks the movement of the brake actuator and the rotatable shaft in a locked brake state.

[0024] According to one embodiment, the method includes the step of rotating a tool element to release the torque applied to the locking element by the rotatable shaft in a locked braking state before disengaging the locking element from the rotatable shaft.

[0025] The method may also include the action of moving the locking element to engage with the rotatable shaft. This action can be performed as part of a parking rest operation, before using the aforementioned tool element for disengaging the locking element from the rotatable shaft, but it can also be performed after these actions, for example, when the vehicle has been towed and needs to be parked safely. The engagement of the locking element with the rotatable shaft can be maintained by a magnet, particularly a permanent magnet of the coupling device, or by a spring mechanism that maintains the engagement of the locking element with the rotatable shaft.

[0026] This method may include other steps and the features of the braking system described above. This method can be used with electromechanical brakes having an electromagnetic parking brake lock, wherein the electromagnetic lock, such as a coupler, is first released, and then the brake preload is gently released using a tool element. External operation of the brake can be performed as a combination of one or more of the above-described release steps. Attached Figure Description

[0027] Other features, characteristics, and advantages of the present invention will arise from the following description of embodiments with reference to the accompanying drawings, wherein,

[0028] Figure 1 A schematic diagram of an electromechanical braking system with a pull-type release interface according to one embodiment is shown;

[0029] Figure 2 It shows that according to Figure 1 The coupling components of the electromechanical braking system shown in the embodiment;

[0030] Figure 3 A schematic diagram of an electromechanical braking system with a push-release interface according to another embodiment is shown; and

[0031] Figure 4 It shows that according to Figure 3 The coupling component of the electromechanical braking system shown in the embodiment.

[0032] Embodiments of the electromechanical braking system according to the present invention will be described below with reference to the accompanying drawings. Detailed Implementation

[0033] exist Figure 1 The diagram illustrates an electromechanical braking system comprising a brake caliper 1 and a brake actuator 2 connected to the brake caliper 1. The brake actuator 2 includes a force transmission mechanism comprising a shaft assembly 8 and a lever assembly connected to the shaft assembly 8 via a push-pull or push-pull joint 9. The lever assembly transmits actuating force from a motor 4, such as an electric motor, to one or more brake pads 10b via a thrust mechanism 10 connected to a lever 7 of the lever assembly. The brake actuator 2 is configured such that the actuating force generated by the motor 4 connected to a rotatable shaft 81 is transmitted as a translational force to the lever 7 via a translational element 82 of the shaft assembly 8 through a rotational translation conversion mechanism. The lever 7 transmits this force to one or more brake pads 10b by rotating about a fixed point at its end, which can contact a brake disc 10c during braking operation. The brake actuator 2 also includes an electromagnetic coupler or clutch assembly 3.

[0034] The rotatable shaft 81 of the shaft assembly 8 extends throughout the brake actuator 2 and acts outside the actuator housing via the electromagnetic clutch unit 3. The rotatable shaft 81 of the shaft assembly 8 can be designed as a single component 81, or as two separate components 81 and 84, in which case the second component 84 is rotatably fixed to the first component 81. In this case, the second component 84 of the rotatable shaft 81 of the shaft assembly 8 can be an essential part of the clutch assembly 3.

[0035] exist Figure 2The clutch assembly 3, shown in more detail, has a rotating member 36 connected to a rotatable shaft 81 of the shaft assembly 8. The clutch assembly 3 also includes a coupling body 34 with an internal electromagnetic actuator and a locking element 35 movable by the electromagnetic actuator. The clutch assembly 3 includes a bistable clutch comprising one or more springs, a permanent magnet, and an electromagnet (not shown). The springs hold the locking element 35 in a first position, for example, a position where the locking element 35 is engaged with the rotating member 36 of the rotatable shaft 81. The permanent magnet holds the locking element 35 in a second position, for example, a position where the locking element 35 is disengaged from the rotating member 36. The coupling body 34 includes an electromagnet capable of switching between the two positions during electrical operation. This is just one example of a clutch assembly. Another coupling mechanism can be used instead. In particular, a clutch assembly can be provided in which the functions of one or more springs and the permanent magnet are interchanged, such that the permanent magnet holds the locking element 35 in a first position where the locking element 35 is engaged with the rotating member 36, while one or more springs hold the locking element 35 in a second position where the locking element 35 is disengaged from the rotating member 36.

[0036] In the locked position, the coupling 34 forces the locking element 35 into contact with the rotating member 36 of the rotatable shaft 81. In the contact position, the rotating member 36 and the locking element 35, as well as the rotating member 36 and the coupling 34, are anti-torsional. In this way, if the locking element 35 is activated after the brake actuator 2 applies a clamping force to one or more brake pads 10b, the coupling 3 can fix the rotatable shaft 81 in one position and provide a constant braking force.

[0037] To release the parking brake from the outside, an interface 31 is provided at the end of the actuator housing. This interface 31 is sealed, preferably waterproof, and includes an interface member 32, such as a release element 33 that can only be accessed with a special tool. Figure 2 A pull-type release interface 31 is shown, wherein the interface member is configured or arranged to be pulled by means of a fork-shaped release element 33 in contact with the locking element 35 to separate the locking element 35 from the rotating member 36. The fork-shaped release element 33 engages with a groove or opening in the locking element 35 and can be pulled mechanically or magnetically by an actuator.

[0038] To facilitate the release of the brake, the rotatable shaft 81 can be held in place by means of a wrench (not shown) that engages with the rotatable shaft 81 or the rotating member 36 connected thereto. After the locking element 35 disengages from the rotatable shaft 81, the preloaded brake can be released by rotating the rotatable shaft 81 with the wrench.

[0039] exist Figure 3In the illustrated embodiment, a push-release interface 31 is provided, wherein the interface member 32 is configured to be pushed by means of a lever-shaped release element 33 in contact with the locking element 35 to separate the locking element 35 of the clutch assembly 3 from the rotating member 36. Figure 4 The clutch assembly 3 with push-type release port 31 is shown in more detail. Besides the push-type release port 31, Figure 3 and Figure 4 The electromechanical brake shown is Figure 1 and Figure 2 The electromechanical brakes shown correspond to those shown. The same or corresponding reference numerals are used throughout the figure.

[0040] Various modifications may be provided in the embodiments shown in the figures without departing from the scope of the invention.

[0041] List of reference numerals

[0042] 1. Brake caliper

[0043] 2 Brake Actuator

[0044] 3 Electromagnetic Coupler Assembly

[0045] 4 Electric motors

[0046] 7-bar assembly

[0047] 8-axis assembly

[0048] 9 connectors

[0049] 10. Promoting Organizations

[0050] 10b brake pads

[0051] 10c Brake Disc

[0052] 31 Interface

[0053] 32 Interface Components

[0054] 33 Release element

[0055] 34 Coupler

[0056] 35 Coupler moving element

[0057] 36 Rotating components

[0058] 81 Rotatable shaft

[0059] 82 Translation elements

Claims

1. An electromechanical braking system, comprising: Brake actuator (2) having a power transmission device for transmitting actuating force to brake pads, the power transmission device including a rotatable shaft (81). A coupling device having a locking element (35), wherein the coupling device can be controlled to engage the locking element (35) with the rotatable shaft (81) and prevent its rotation, or to disengage the locking element (35) from the rotatable shaft (81) to allow the rotatable shaft (81) to rotate, wherein the brake actuator (2) includes an interface (31) configured to connect to the locking element (35) and to engage or disengage the locking element (35) from the rotatable shaft (81). The locking element (35) is disc-shaped and has one or more grooves or openings to allow engagement of the interface member.

2. The braking system according to claim 1, wherein, The interface (31) includes an interface member (32) configured to be pulled or pushed to disengage the locking element from the rotatable shaft (81).

3. The braking system according to claim 2, wherein, The interface (31) includes a sealed connection structure that allows contact with the interface component (32) via the sealed connection structure.

4. The braking system according to any one of claims 1 to 3, wherein, The rotatable shaft (81) includes a disc-shaped rotating component (36).

5. The braking system according to claim 4, wherein, The coupling device includes a spring for moving the locking element (35) to a position engaging one of the sides of the rotating member (36).

6. The braking system according to any one of claims 1-3 and 5, wherein, The braking system also includes a first receiver into which a tool element can be inserted to engage the tool element with the rotatable shaft (81) and transmit rotation to the rotatable shaft (81).

7. The braking system according to claim 4, wherein, The locking element (35) has the shape of a disc and is arranged on the coupling device so that the locking element can move to engage one of its sides with one of the sides of the rotating member (36) to prevent the rotating member from rotating, and can disengage from one of the sides of the rotating member (36) to allow it to rotate.

8. The braking system according to any one of claims 1-3, 5, and 7, wherein, The power transmission device is electrically driven and causes the rotatable shaft (81) to rotate.

9. The braking system according to any one of claims 1-3, 5, and 7, wherein, The coupling device is arranged in the electromagnetic parking brake locking mechanism for locking the brake actuator.

10. A method for releasing an electromechanical brake, comprising: Using the interface of the brake actuator (2), the interface member (32) is inserted into the locking element (35) of the brake actuator, the locking element (35) locking the movement of the brake actuator, the locking element (35) having a disc shape with one or more grooves or openings to allow engagement of the interface member; The locking element (35) is disengaged from the rotatable shaft (81) of the brake actuator via the interface member (32). as well as The moving tool element transmits power to the rotatable shaft (81) to release the brake.

11. The method of claim 10, wherein, The method further includes rotating the tool element to release the torque applied to the locking element (35) by the rotatable shaft (81) in the locked braking state before disengaging the locking element (35) from the rotatable shaft (81).

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