Floating caliper disc brake and method of operating the same

Abstract

A floating caliper type disc brake and method of operation thereof, the disc brake having a support bracket, a caliper body slidingly connected to the support bracket, a first friction pad on a first side of the caliper body, a second friction pad on a second side of the caliper body and fixed to the caliper body, a first piston connected to the first friction pad, and a second piston freely restable on the first friction pad, the second piston formed with a locating surface restable against a rest surface of the support bracket, the first and second pistons being actuatable independently of each other such that: a rearward movement of the first piston towards the first side separates the first pad from a brake disc, and a rearward movement of the second piston towards the first side, with the locating surface against the rest surface, moves the caliper body and the second pad together towards the second side and separates the second pad from the brake disc.

Description

Technical Field

[0001] The present invention relates to disc brakes with floating calipers and methods of operating disc brakes with floating calipers, particularly to disc brakes with floating calipers for industrial applications in motor vehicles or alternatively for rotating machinery, and methods of operating disc brakes with floating calipers.

[0002] More particularly, the present invention relates to a novel strategy for controlling the position of a floating caliper relative to a brake disc to reduce and / or eliminate residual torque or drag torque, and a novel strategy for implementing the novel control strategy in a floating caliper having an electromechanical actuator. Background Technology

[0003] A floating caliper disc brake includes: a support bracket that can be connected to the suspension of a vehicle; a caliper body that is slidably mounted to the support bracket and forms a first wall disposed on a first side (actuating side) of the brake disc and a second wall disposed on a second side (reaction side) of the brake disc opposite to the first side; one or more first friction pads and one or more second friction pads, the one or more first friction pads and the one or more second friction pads being supported by the support bracket and / or the caliper body on the first side and the second side of the brake disc, respectively; and one or more actuating pistons, the one or more actuating pistons being supported by the caliper body on only the first side of the brake disc and operable to bias the first friction pads toward the second side against the brake disc.

[0004] In this way, the thrust on the brake disc on one side of the first friction pad generates a reaction force, which causes the caliper body to slide relative to the support bracket in the opposite direction to the thrust on one side, i.e., towards the first side of the brake disc. This causes the second wall of the caliper body to bias the second friction pad against the brake disc, thereby achieving alignment of the pad relative to the brake disc and clamping of the brake disc on both sides.

[0005] In floating calipers, the second liner on the reaction side remains in contact with the disc at the end of a service braking event, thus generating residual drag torque, even when the brake pedal is released and braking torque is not required.

[0006] Therefore, it feels necessary to center the floating caliper relative to the brake disc to ensure complete separation of the pad from the brake disc and to eliminate any remaining drag torque.

[0007] However, so far, only the position of the first shim on the piston side can be controlled to a given degree by the configuration of the elastomeric seal and its housing, and by the positioning of the elastomeric seal and its housing within the caliper body, which elastically positions the (unbiased) piston relative to the caliper (rollback effect). The second shim on the reaction side is mounted to the floating caliper, and it is not possible to actively bias the position of the second shim and thus separate the second shim from the brake disc when the brake pedal is released and braking torque is not required. Summary of the Invention

[0008] Therefore, the object of the present invention is to provide a method for operating a floating caliper disc brake, the method having the characteristic of, for example, actively positioning the caliper relative to the brake disc, thereby forming a separation between the brake disc and the bushing on both sides to achieve zero residual drag torque.

[0009] This objective is achieved through a floating caliper disc brake, which includes: - A support bracket that can be connected to the vehicle's suspension. - A caliper body slidably connected to a support bracket along a sliding direction, and the caliper body having a first wall and a second wall. The first wall is disposed on a first side of the caliper body, and the second wall is disposed on a second side of the caliper body opposite to the first side in the sliding direction. The first wall and the second wall together define a disc space for accommodating a portion of the brake band of the brake disc. - A first friction pad, the first friction pad (via a support bracket or a first wall of the caliper body) is supported in the disc space on a first side of the caliper body in a sliding manner relative to the caliper body. - A second friction pad, which is supported in the disc space on the second side of the caliper body by a support bracket or the second wall of the caliper body, and the second friction pad is fixed to the second wall of the caliper body. - A plurality of actuating pistons, each supported on one side in a first wall of the caliper body, operable to push a first friction pad toward a second side in an actuation direction parallel to the sliding direction, thereby abutting against the brake band portion of the brake disc. This causes the first friction pad to move toward a second friction pad and allows the brake caliper body to slide relative to the support bracket, achieving pressing contact between the first and second friction pads on both sides of the brake disc. Its features are, - The plurality of actuating pistons includes at least one or more first pistons and at least one or more second pistons, wherein the first pistons are integrally connected to the first friction pad in terms of translation along the actuation direction, and the second pistons are associated with the first friction pad in a manner that allows them to rest freely and be separable along the actuation direction. - The second piston has a positioning surface that can abut against a corresponding resting surface in the sliding direction toward the first side. The resting surface is integral with the support bracket or the first piston in terms of translation along the traveling direction. The first piston and the second piston can be selectively and independently actuated such that: - The rearward movement of the first piston toward the first side separates the first liner from the brake disc, and - Move the second piston backward toward the first side, and with the positioning surface against the resting surface, move the caliper body and the second pad together toward the second side, and separate the second pad from the brake disc.

[0010] In this way, at the end of each braking event, the first and second pistons can be moved in a defined sequence to position the caliper body and liner in the correct position relative to the brake disc, and thus avoid contact that produces unwanted residual drag torque.

[0011] This reduces liner wear, energy consumption, and pollutant emissions, while increasing vehicle range while ensuring braking performance.

[0012] According to another aspect of the invention, the object of the invention is achieved by a method for operating a disc brake with a floating caliper, the disc brake comprising: - A support bracket that can be connected to the vehicle's suspension. - A caliper body slidably connected to a support bracket along a sliding direction, and the caliper body having a first wall and a second wall. The first wall is disposed on a first side of the caliper body, and the second wall is disposed on a second side of the caliper body opposite to the first side in the sliding direction. The first wall and the second wall together define a disc space for accommodating a portion of the brake band of the brake disc. - A first friction pad, the first friction pad (via a support bracket or a first wall of the caliper body) is supported in the disc space on a first side of the caliper body in a sliding manner relative to the caliper body. - A second friction pad, which is supported in the disc space on the second side of the caliper body via a support bracket or the second wall of the caliper body, and is fixed to the second wall of the caliper body. - A plurality of actuating pistons, each supported on one side in a first wall of the caliper body, operable to push a first friction pad toward a second side in an actuation direction parallel to the sliding direction, thereby abutting against the brake band portion of the brake disc. This causes the first friction pad to move toward a second friction pad and allows the brake caliper body to slide relative to a support bracket, achieving pressing contact between the first and second friction pads on both sides of the brake disc. in: The plurality of actuating pistons includes a first piston and a second piston, the first piston being integrally connected to a first friction pad in terms of translation along the actuation direction, and the second piston being associated with the first friction pad in a manner that allows it to rest freely and be separable along the actuation direction. - The second piston has a positioning surface that can abut against a corresponding resting surface in the sliding direction toward the first side. The resting surface is integral with the support bracket or the first piston in terms of translation along the travel direction. The method is characterized by comprising the following steps: - The first and second pistons are selectively and independently actuated. - After a service braking event, the first piston moves rearward relative to the caliper body toward the first side, separating the first friction pad from the brake disc, and - When the first friction pad separates from the brake disc, the caliper body moves together with the second pad toward the second side, and the second pad separates from the brake disc, performing a rearward movement of the second piston toward the first side, wherein the positioning surface abuts against the resting surface. Attached Figure Description

[0013] To understand the present invention and better appreciate its advantages, a description of non-limiting embodiments will be provided below with reference to the accompanying drawings, in which: Figure 1 This is a perspective view of a disc brake with floating calipers according to an embodiment of the present invention; Figure 2 yes Figure 1 Cross-sectional view of the disc brake in the diagram; Figure 3 yes Figure 1 A three-dimensional view of the first wall of the floating caliper of the brake disc in the image; Figure 4 yes Figure 1 A cross-sectional view of a disc brake in the image, where the brake disc has been removed; Figure 5 and Figure 6 This is a perspective view of the actuating piston of a disc brake according to an embodiment. Figure 7 and Figure 8 This is a schematic block diagram of the liner of a disc brake according to an embodiment; Figures 9A to 9D The operating sequence of a disc brake with floating calipers according to an embodiment is shown, which aims to separate the pads from both sides of the brake disc. Figures 10A to 10D The operating sequence of a disc brake with floating calipers according to another embodiment is shown, which aims to separate the pads from both sides of the brake disc; Figures 11A to 11E The operating sequence of a disc brake with floating calipers according to another embodiment is shown, which is designed to separate the pads from both sides of the brake disc. Detailed Implementation

[0014] Disc brake 1 Referring to the accompanying drawings, the floating caliper type disc brake 1 includes: a support bracket 2, which can be connected to the vehicle's suspension, for example, by screws or bolts; a caliper body 3, which is slidably connected to the support bracket 2 along a sliding direction 4, and the caliper body 3 forms a first wall 5 disposed on a first side 6 (inner side of the vehicle) of the caliper body 3 and a second wall 7 disposed on a second side 8 (outer side of the vehicle) of the caliper body 3 opposite to the first side 6 in the sliding direction 4, the first wall 5 and the second wall 7 together defining a disc space 9 for accommodating a portion of the brake band 10 of the brake disc 11; and a first friction pad 12, which (via the support bracket 2 or the first wall 5 of the caliper body 3) is slidably mounted on the first side 6 of the caliper body 3 relative to the caliper body 3. The first friction pad 12 is supported in the disc space 9; the second friction pad 13 (via the support bracket 2 or the second wall 7 of the caliper body 3) is supported in the disc space 9 on the second side 8 of the caliper body 3 and is fixed to the second wall 7 of the caliper body 3; a plurality of actuating pistons are supported on one side in the first wall 5 of the caliper body 3, and the plurality of actuating pistons are operable to push the first friction pad 12 toward the second side 8 along an actuation direction 14 parallel to the sliding direction 4 to abut against the brake band portion 10 of the brake disc 11, thereby moving the first friction pad 12 toward the second friction pad 13 and causing the brake caliper body 3 to slide relative to the support bracket 2 until the brake disc 11 is tensioned on both sides between the first friction pad 12 and the second friction pad 13.

[0015] The plurality of actuating pistons include: a first piston 15 integrally connected to a first friction pad 12 in terms of translation along the actuation direction 14; and a second piston 16 associated with the first friction pad 12 in a manner that allows it to rest freely (against the first friction pad 12) along the actuation direction 14 and is separable (from the first friction pad 12).

[0016] The second piston 16 forms a positioning surface 17, which can abut against corresponding resting surfaces 18, 18' towards the first side 6 along the sliding direction 4. These resting surfaces 18, 18' are fixed to the support bracket 2 or the first piston 15 in terms of translation along the travel direction 4, or they are integral with the support bracket 2 or the first piston 15 in terms of translation along the travel direction 4. In other words, by retraction, the second piston 16 can abut against a fixed reference point (resting surface 18) formed at the fixed support bracket 4, or by retraction, the second piston 16 can abut against a "relative" reference point (resting surface 18') formed at the first piston 15.

[0017] The first piston 15 and the second piston 16 can be selectively and independently actuated such that: - The rearward movement of the first piston 15 toward the first side 6 separates the first liner 12 from the brake disc 11, and - The second piston 16 moves backward toward the first side 6, and with the positioning surface 17 abutting against the resting surfaces 18, 18', the caliper body 3 and the second pad 13 move together toward the second side 8, and the second pad 13 is separated from the brake disc 11.

[0018] In this way, at the end of each braking event, the first piston 15 and the second piston 16 can be moved in a defined sequence to position the caliper body 3 and the friction pads 12, 13 relative to the brake disc 11 in the planned position, and thus avoid contact that produces unwanted residual drag torque.

[0019] This reduces liner wear, energy consumption, and pollutant emissions, while increasing vehicle range while ensuring braking performance.

[0020] The pistons 15 and 16 can be actuated by a hydraulic actuation system or by an electromechanical actuation system 19, which includes, for example, a dedicated electric motor 20, 20' and an actuation mechanism 21 and a conversion mechanism 22 for each piston 15 and 16. The actuation mechanism 21 is, for example, a gear, and the conversion mechanism 22 is, for example, a screw and nut assembly. The conversion mechanism 22 converts the rotational motion of the actuation mechanism 21 into the translational motion of the pistons 15 and 16.

[0021] The actuation system—for example, electromechanical actuation system 19 or hydraulic actuation system—is connected to and controlled by the electronic control system 27 of the disc brake 1. The electronic control system 27 is connected to the user interface 39—for example, brake pedal, brake lever or brake button—and is configured to selectively and independently actuate the first piston 15 and the second piston 16.

[0022] The front portion 23 of the first piston 15 is connected to the support plate 24 of the first friction pad 12. For example, the front portion 23 of the first piston 15 is connected to the support plate 24 of the first friction pad 12 by gluing, by adhesive film, by snap-fit ​​connection, or by threaded connection.

[0023] The front portion 25 of the second piston 16 is positioned relative to the first friction pad 12 such that the front portion 25 of the second piston 16 can freely contact and push against the support plate 24 of the first friction pad 12, but can also separate from the support plate 24 without resistance. This free contact and separation between the second piston 16 and the first friction pad 12 does not preclude the possible presence of intermediate auxiliary elements, such as an elastic spring placed between the second piston 16 and the first friction pad 12, but preferably occurs without any intermediate auxiliary elements (connectors, guides, or elastic elements).

[0024] According to an embodiment, the positioning surface 17 may be formed by a positioning attachment 28 extending laterally from the front portion 25 of the second piston 16 in a direction relative to the actuation direction 14, the positioning attachment 28 being, for example, a metal plate threadedly connected (in the cavity 29) to the front portion 25. Figure 3 , Figure 5 , Figure 6 ).

[0025] The resting surface 18 can be formed directly on the support bracket 2. For example, the resting surface 18 can be formed directly on the inner surface 26 of the support bracket 2. The inner surface 26 is positioned relative to the brake disc 11 on the first side 6 of the caliper body 3 and faces the second side 8.

[0026] In order to avoid changes in the shape of the support bracket 2 and to compensate for the distance between the first wall 5 and the support bracket 2, as well as to avoid disruption of the space between the positioning accessory 28 and the first friction pad 12, the positioning accessory 28 advantageously has a double fold 30, which forms a stepped portion in the actuation direction 14 between a first portion 31 adjacent to the second piston 16 and a second portion 32 forming the positioning surface 17.

[0027] Advantageously, the resting surface 18 forms a cavity in the inner surface 26 of the support bracket 2. Figure 3In order to allow the resting surface 18 to be formed in the required precise position, without having to form the entire inner surface 26 with the same precision.

[0028] According to an alternative embodiment, the resting surface 18' may be formed in the first piston 15, or in a support appendage extending laterally from the front portion 23 of the first piston 15 relative to the actuation direction 14, such as a support appendage with... Figure 6 The embodiment shown is similar (in the cavity) to the metal plate of the front portion 23, which is threaded together.

[0029] When the second piston 16 retracts and the positioning surface 17 rests against the resting surface 18 of the support bracket 2, the further rearward movement of the second piston 16 relative to the caliper body 3 causes the caliper body 3, together with the first piston, the first friction pad 12 and the second friction pad 13, to slide relative to the support bracket 2 and the brake disc 11 toward the second side 8, thereby forming a gap between the second friction pad 13 and the brake disc 11.

[0030] When the second piston 16 retracts and the positioning surface 17 rests against the resting surface 18' of the first piston 15, the further rearward movement of the second piston 16 relative to the caliper body 3 causes the caliper body 3, together with the second friction pad 13, to slide relative to the first piston 15 and the first friction pad 12 as a whole, and (due to the support friction between the first friction pad 12 and the support bracket 2) also relative to the support bracket 2 and the brake disc 11 toward the second side 8, thereby forming a gap between the second friction pad 13 and the brake disc 11.

[0031] When the resting surface 18' is formed at the first piston 15, the setting of the gap between the second friction pad 13 and the brake disc 11 automatically compensates for the gradual reduction in the thickness of the friction pads 12 and 13 due to wear. This is because the reference for the caliper body 3 to slide toward the second side 8 is the position of the first piston 15, which automatically advances as the wear of the first friction pad 12 and the second friction pad 13 increases.

[0032] When the resting surface 18 is formed at the support bracket 2, the gradual reduction in the thickness of the friction pads 12 and 13 due to wear causes the distance between the contact position 33 (between the positioning surface 17 and the resting surface 18) and the initial position 34 of the first piston 15 and the second pistons 15 and 16 at the end of the braking event to gradually increase. Therefore, with the total length of the second piston 16's rearward movement being the same, the gap between the second friction pad 13 and the brake disc 11 will become increasingly difficult to control and will gradually decrease until the gap is zero. Furthermore, the braking response time will be prolonged due to the additional travel caused by pad wear.

[0033] Therefore, according to the embodiment, the position of the resting surface 18 is adjustable in the sliding direction 4 relative to the reference plane 35 of the support bracket 2, for example relative to the plane of the brake disc 11 (the support bracket 2 is stationary relative to the plane of the brake disc 11), so as to compensate for the offset of the initial position 34 of the rearward movement of the second piston 16 caused by the wear of the friction pads 12, 13.

[0034] The disc brake 1 may include a rest adjustment device 37 configured to adjust the position of the rest surface 18 to compensate for the displacement of the initial position 34 of the rearward movement of the second piston 16 due to wear of the friction pads 12, 13, for example to keep the distance between the rest surface 18 and the initial position 34 of the rearward movement of the first piston 12 and the second piston 13 at the end of the braking event approximately constant.

[0035] The resting adjustment device 37 can be functionally connected to the actuation system 19 of the actuating pistons 15 and 16, or to the first piston 15 or the second piston 16, or to the electronic control system 27, and the resting adjustment device 37 can be configured to adjust the position of the resting surface 18 according to the maximum travel (braking) position of the actuating pistons 15 and 16 toward the second side 8.

[0036] According to an alternative embodiment, the position of the positioning surface 17 is adjustable in the actuation direction 14 relative to the reference plane 36 of the second piston 16, for example, relative to the front end plane of the second piston 16 (the position of the front end of the second piston 16 depends on the wear condition of the friction pads 12, 13), so as to compensate for the offset of the initial position 34 of the rearward movement of the second piston 16 caused by the wear of the friction pads 12, 13.

[0037] The disc brake 1 may include a position adjustment device 38 configured to adjust the position of the positioning surface 17 to compensate for the offset of the initial position 34 of the rearward movement of the second piston 16 due to wear of the friction pads 12, 13, for example, so that the maximum distance between the resting surface 18 and the positioning surface 17 remains substantially constant at the end of braking.

[0038] The position adjustment device 38 can be functionally connected to the actuation system 19 of the actuating pistons 15, 16, or to the first piston 15 or the second piston 16, or to the electronic control system 27, and the position adjustment device 38 can be configured to adjust the position of the positioning surface 17 according to the maximum travel (braking) position of the actuating pistons 15, 16 toward the second side 8.

[0039] Electronic control system and operating method for disc brake 1 According to another aspect of the present invention, the operation method of the disc brake 1 includes the following steps: - The first piston 15 and the second piston 16 are selectively and independently actuated. - Following a service braking event, the first friction pad 12 is separated from the brake disc 11 by the rearward movement of the first piston 15 relative to the caliper body 3 toward the first side 6 (the second piston 16 performs a similar rearward movement to allow the first friction pad 12 to separate from the brake disc 11), and - When the first friction pad 12 separates from the brake disc 11, the caliper body 3 moves together with the second pad 13 toward the second side 8, and the second pad 13 is separated from the brake disc 11, and the second piston 16 moves backward toward the first side 6, wherein the positioning surface 17 abuts against the resting surfaces 18, 18'.

[0040] According to an embodiment, the method includes the following steps: by adjusting the position of the resting surface 18 relative to the reference plane 35 of the support bracket 2, for example relative to the plane of the brake disc 11, along the sliding direction 4, to compensate for the displacement of the initial position 34 of the rearward movement of the second piston 16 caused by the wear of the friction pads 12, 13.

[0041] The compensation phase may include: - Maintain a substantially constant distance between the resting surface 18 and the initial rearward position 34 of the first piston 15 or the second piston 16 at the end of the braking event, and / or - The position of the resting surface 18 is adjusted according to the maximum travel (braking) position of the actuating pistons 15 and 16 toward the second side 8.

[0042] According to an alternative embodiment, the method includes the step of compensating for the displacement of the initial position 34 of the rearward movement of the second piston 16 caused by the wear of the friction pads 12, 13 by adjusting the position of the positioning surface 17 relative to the reference plane 36 of the second piston 16, for example relative to the front end plane of the second piston 16 along the actuation direction 14.

[0043] The steps for compensating for wear of friction pads 12 and 13 may include adjusting the position of the resting surface 18 and / or the positioning surface 17 so that: - The maximum distance between the resting surface 18 and the positioning surface 17 at the end of braking is kept approximately constant. - The position of the positioning surface 17 is adjusted according to the maximum travel (braking) position of the actuating pistons 15 and 16 toward the second side 8.

[0044] According to the implementation method ( Figures 9A to 9DAt the end of the braking event, when the user releases the brake, for example by releasing the brake pedal 39: A) The first piston 15 and the second piston 16 perform a rearward movement (towards the first side 6) with a length of 2*l, where l corresponds to the width of the planned space between the friction pads 12, 13 and the brake disc 11. Figure 9A ), B) The second piston 16 continues to move backward until the positioning surface 17 rests against the resting surface 18. Figure 9B ), C) After positioning surface 17 rests against resting surface 18, the second piston 16 continues to move rearward by an additional length l, causing the caliper body 3 to slide towards the second side 8 by the same length l, so as to form a space of width l between the friction pad 12 and the brake disc 11 on the first side 6, and a space of width l between the friction pad 13 and the brake disc 11 on the second side 8. Figure 9C ), D) Optionally, the second piston 16 performs a forward movement (towards the second side 8) until the second piston 16 contacts the first friction pad 12 again, in preparation for the next braking event. Figure 9D ).

[0045] The contact between the second piston 16 and the first friction pad 12 can be detected by the control system 27 in the following ways: by detecting the cessation of the forward movement of the second piston 15; or by detecting an increase in the resistance of the second piston 16, for example by detecting an increase in the current drawn by the electric motor 20' of the second piston 16; or by detecting an increase in the positioning force of the first piston 15, for example by detecting an increase in the current drawn by the electric motor 20' used to actuate the first piston 15; or by detecting an increase in the resistance of the second piston 16, for example by detecting an increase in the current drawn by the electric motor 20' used to actuate the second piston 16; or by detecting a switch in response to the contact between the second piston 16 and the first friction pad 12.

[0046] at last( Figure 9D Optionally, the electric motor 20 of the first piston 15 can be actuated (forward) to close the gap in the electromechanical actuation system 19, particularly the gap in the transmission mechanism 21 and / or the conversion mechanism 22, for example by the electric motor 20 of the first piston 15 being actuated by a predetermined or appropriately detected gap amount to close the gap in the electromechanical actuation system 19, particularly the gap in the transmission mechanism 21 and / or the conversion mechanism 22.

[0047] The electronic control unit 27 is configured to automatically command the electromechanical actuation system 19 or the universal piston actuation system 15, 16 to perform the aforementioned operation of separating the friction pads 12, 13 from the brake disc 11.

[0048] The complexity of the friction pad separation process lies in Figure 9B The steps shown assume that the ultimate stopping position (the resting position between the positioning surface 17 and the resting surface 18) is known. The exact ultimate stopping position is related to the wear of the friction pads 12, 13, temperature (relaxation of the friction pads and thermal expansion of the material), and the internal clearance of the actuation system 19 of the second piston 16, but in practical engineering methods, this ultimate stopping position may be assumed to be known based on experimental and / or measurement and / or predetermined values ​​or functions of values.

[0049] According to another embodiment ( Figures 10A to 10D At the end of the braking event, when the user releases the brake, for example by releasing the brake pedal 39: A) The second piston 16 performs a rearward movement until the positioning surface 17 rests against the resting surface 18. Figure 10A ), The placement can be detected (e.g., by electronic control system 27), for example, by electronic control system 27 in the following ways: - The suspension can be detected by detecting an increase in the current drawn by the electric motor 20' dedicated to the second piston 16, or The shelving can be detected by detecting the cessation of movement of the second piston 16. The placement can be detected by a force sensor associated with the first piston 15 or the second piston 16. The placement can be detected by a switch responding to contact between the positioning surface 17 and the placement surface 18. B) Subsequently, with the second piston 16 stationary, the first piston 15 performs a rearward movement (towards the first side 6) of length 2*l, where l corresponds to the width of the planned space between the friction pads 12, 13 and the brake disc 11. Figure 10B ), C) Subsequently, with the first piston 15 stationary, the second piston 16 continues to move backward by an additional length l, causing the caliper body 3 to slide towards the second side 8 by the same length l, so as to form a space of width l between the friction pad 12 and the brake disc 11 on the first side 6, and a space of width l between the friction pad 113 and the brake disc 11 on the second side 8. Figure 10C ), D) Optionally, the second piston 16 performs a forward movement (towards the second side 8) until the second piston 16 contacts the first friction pad 12 again in preparation for the next braking event. Figure 10D ).

[0050] The contact between the second piston 16 and the first friction pad 12 can be detected by the control system 27 in the following ways: by detecting the cessation of the forward movement of the second piston 15; or by detecting an increase in the resistance of the second piston 16, for example by detecting an increase in the current drawn by the electric motor 20' of the second piston 16; or by detecting an increase in the positioning force of the first piston 15, for example by detecting an increase in the current drawn by the electric motor 20' used to actuate the first piston 15; or by detecting an increase in the resistance of the second piston 16, for example by detecting an increase in the current drawn by the electric motor 20' used to actuate the second piston 16; or by detecting a switch in response to the contact between the second piston 16 and the first friction pad 12.

[0051] at last( Figure 10D Optionally, the electric motor 20 of the first piston 15 can be actuated (forward) to close the gap in the electromechanical actuation system 19, particularly the gap in the transmission mechanism 21 and / or the conversion mechanism 22, for example by the electric motor 20 of the first piston 15 being actuated by a predetermined or appropriately detected gap amount to close the gap in the electromechanical actuation system 19, particularly the gap in the transmission mechanism 21 and / or the conversion mechanism 22.

[0052] In this embodiment, it is not necessary to know the ultimate stopping position (the resting position between the positioning surface 17 and the supporting surface 18), because reaching... Figure 10A The position shown in the steps will produce a rigid stop and will not cause unplanned slippage of the caliper body 3 relative to the brake disc 11.

[0053] The electronic control unit 27 is configured to automatically command the electromechanical actuation system 19 or the universal piston actuation system 15, 16 to perform the aforementioned operation of separating the friction pads 12, 13 from the brake disc 11.

[0054] According to the implementation method ( Figures 11A to 11E At the end of the braking event, when the user releases the brake, for example by releasing the brake pedal 39: A) The second piston 16 performs a rearward movement until the positioning surface 17 rests against the resting surface 18. Figure 11A ), The placement can be detected (e.g., by electronic control system 27), for example, by electronic control system 27 in the following ways: - The suspension can be detected by detecting an increase in the current drawn by the electric motor 20' dedicated to the second piston 16, or The shelving can be detected by detecting the cessation of movement of the second piston 16. The placement can be detected by a force sensor associated with the first piston 15 or the second piston 16. - The placement can be detected by a switch in response to contact between the positioning surface 17 and the placement surface 18.

[0055] B) Subsequently, with the second piston 16 stationary, the first piston 15 (X, which is not precisely known due to the internal clearance of the actuation system 19 restored by the first piston 15 during its rearward movement) is moved rearward by a length X ( Figure 11B ), C) Subsequently, with the first piston 15 stationary, the second piston 16 continues to move backward, causing the caliper body 3 to slide toward the second side 8 until the caliper body 3 reaches a stop position. At this stop position, the first friction pad 12 rests against the brake disc 11 again, and the second friction pad 13 separates from the brake disc 11 by the same distance X ( Figure 11C ), Reaching the stop position ( Figure 11C The arrival of the stop position can be detected (e.g., by the electronic control system 27) in the following ways: - Reaching the stop position can be detected by increasing the current drawn on the electric motor 20' dedicated to the second piston 16, or - Reaching the stop position can be detected by increasing the current drawn on the electric motor 20' dedicated to the first piston 15, or - Reaching the stop position can be detected by detecting the cessation of the movement of the second piston 16. - Reaching the stop position can be detected by a force sensor associated with the first piston 15 or the second piston 16. - Reaching the stop position can be detected by a switch responding to contact between the positioning surface 17 and the resting surface 18.

[0056] Due to the sliding step of the caliper body 3 ( Figure 11CThe movement is performed by the second piston 16 without restoring the internal clearance, so the distance X (which was not previously known precisely) is now known (for the electronic control system 27) in terms of the angular stroke of the electric motor 20' associated with the second piston 16.

[0057] Furthermore, the internal clearance of the actuator 19 of the first piston 15 is also known by relating the following: - The angular stroke of the electric motor 20' for the second piston 16 that causes the caliper body 3 to slide a distance X; - The angular stroke of the electric motor 20 for moving the first piston 15 backward a distance X, and - The transmission ratio of the actuator 19 of the first piston 15 and the second piston 16, Therefore, the internal clearance of the actuator 19 of the first piston 15 is also known.

[0058] D) Subsequently, with the second piston 16 stationary, the first piston 15 is moved backward by the same length X toward the first side 6, thereby separating the first friction pad 12 from the brake disc 11 by the same measured value X. Figure 11D ).

[0059] In this case, it is unnecessary to define the free clearance of the first piston 15, because the previous movement of the first piston 15 ( Figure 11B The steps in the process are performed in the same direction.

[0060] E) Optionally, the second piston 16 performs a forward movement (towards the second side 8) until the second piston 16 contacts the first friction pad 12 again in preparation for the next braking event. Figure 11E ).

[0061] In the same case, the contact between the second piston 16 and the first friction pad 12 can be detected by the control system 27 in the following ways: by detecting the cessation of the forward movement of the second piston 15; or by detecting an increase in the resistance of the second piston 16, for example by detecting an increase in the current drawn by the electric motor 20' of the second piston 16; or by detecting an increase in the positioning force of the first piston 15, for example by detecting an increase in the current drawn by the electric motor 20 used to actuate the first piston 15.

[0062] at last( Figure 11E Optionally, the electric motor 20 of the first piston 15 can be driven (forward) to close the gap in the electromechanical actuation system 19, particularly the gap in the transmission mechanism 21 and / or the conversion mechanism 22.

[0063] In this case, the amount of the internal clearance of the first piston 15 is known because the amount of the internal clearance of the first piston 15 was determined in advance.

[0064] In this embodiment, it is not necessary to know or determine the internal clearance of the piston actuation system in advance. Instead, more steps involving contact between the pad and the disc are required to generate instantaneous drag torque adjustment.

[0065] The electronic control unit 27 is configured to automatically command the electromechanical actuation system 19 or the universal piston actuation system 15, 16 to perform the aforementioned operation of separating the friction pads 12, 13 from the brake disc 11.

[0066] To accurately set the desired distance between the friction pad and the brake disc, the electronic control system 27 can be configured (or the method may include the following steps): determining or detecting the clearance amplitude (selectively, for the actuation system 19) in the actuation direction 14 for the first piston 15 and the second piston 16. If the movement of the pistons 15, 16 requires clearance recovery, then electric motors 20, 20' dedicated to the movement of the relevant pistons 15, 16 are actuated according to the clearance amplitude of the pistons 15, 16 and the planned travel. In other words, the motors are driven such that the total stroke is the sum of the planned stroke and the clearance amplitude.

[0067] The gap amplitude can be indirectly detected by detecting the amplitude at motors 20 and 20', such as the following: - The rotation angle of the rotor of the electric motor 20, 20' is obtained using a Hall sensor, encoder, or angle position sensor, or - Electrical amplitude of motors 20 and 20', such as current consumption amplitude. And the correlation between the above factors and the gap amplitude, or the gap amplitude can be detected by a position sensor.

[0068] Obviously, those skilled in the art can make other modifications and variations to the disc brake 1 and method according to the invention without departing from the scope of protection of the invention as defined in the appended claims.

Claims

1. A floating caliper type disc brake (1), the disc brake (1) comprising: - Support bracket (2), which can be connected to the vehicle suspension. - A caliper body (3) is slidably connected to the support bracket (2) along the sliding direction (4), and the caliper body (3) has a first wall (5) and a second wall (7). The first wall (5) is arranged on a first side (6) of the caliper body (3), and the second wall (7) is arranged on a second side (8) of the caliper body (3) opposite to the first side (6) in the sliding direction (4). The first wall (5) and the second wall (7) together define a disc space (9) for accommodating a portion of the brake band (10) of the brake disc (11). - A first friction pad (12) is supported on the first side (6) of the caliper body (3) in the disc space (9), and the first friction pad (12) slides relative to the caliper body (3). - A second friction pad (13) is supported on the second side (8) of the caliper body (3) in the disc space (9) and the second friction pad (13) is fixed to the second wall (7) of the caliper body (3). - A plurality of actuating pistons, which are supported in the first wall (5) of the caliper body (3), are operable to push the first friction pad (12) toward the second side (8) along an actuation direction (14) parallel to the sliding direction (4) against the brake disc (11), thereby moving the first friction pad (12) toward the second friction pad (13) and causing the caliper body (3) to slide relative to the support bracket (2) until the brake disc (11) is tensioned on both sides between the first friction pad (12) and the second friction pad (13). Its features are, - The plurality of actuating pistons include a first piston (15) and a second piston (16), the first piston (15) being integrally connected to the first friction pad (12) in terms of translation along the actuation direction (14), and the second piston (16) being associated with the first friction pad (12) in a manner that allows it to rest freely and be detachable along the actuation direction (14). - The second piston (16) has a positioning surface (17) that can abut against a corresponding resting surface (18, 18') along the sliding direction (4) toward the first side (6). The resting surface (18, 18') is fixed to the support bracket (2) or the first piston (15) in terms of translation along the sliding direction (4), or the resting surface (18, 18') is integral with the support bracket (2) or the first piston (15) in terms of translation along the sliding direction (4). The first piston (15) and the second piston (16) can be selectively and independently actuated such that: - The rearward movement of the first piston (15) toward the first side (6) separates the first friction pad (12) from the brake disc (11), and - Move the second piston (16) backward toward the first side (6), and with the positioning surface (17) abutting against the resting surface (18, 18'), move the caliper body (3) and the second friction pad (13) together toward the second side (8), and separate the second friction pad (13) from the brake disc (11).

2. The disc brake (1) according to claim 1, wherein, The plurality of actuating pistons can be actuated by an electromechanical actuation system (19), which for each actuating piston includes a dedicated electric motor (20, 20'), a transmission mechanism (21), and a conversion structure (22). The electromechanical actuation system (19) is connected to and controlled by the electronic control system (27) of the disc brake (1).

3. The disc brake (1) according to claim 1 or 2, wherein, The positioning surface (17) includes a positioning accessory (28) that extends laterally from the front portion (25) of the second piston (16) relative to the actuation direction (14).

4. The disc brake (1) according to claim 1 or 2, wherein, The resting surface is formed on the inner surface (26) of the support bracket (2): the inner surface (26) is positioned relative to the brake disc (11) on the first side (6) and facing the second side (8).

5. The disc brake (1) according to claim 2, wherein, The position of the resting surface is adjustable in the sliding direction (4) relative to the reference plane (35) of the support bracket (2) to compensate for the displacement of the initial position (34) of the rearward movement of the second piston (16) caused by the wear of the first friction pad (12) and the second friction pad (13).

6. The disc brake (1) according to claim 5, the disc brake (1) includes a rest adjustment device (37) configured to adjust the position of the rest surface to keep the distance between the rest surface at the end of the braking event and the initial position (34) of the rearward movement of the second piston (16) constant.

7. The disc brake (1) according to claim 6, wherein, The rest adjustment device (37) is functionally connected to the electromechanical actuation system (19), and the rest adjustment device (37) is configured to adjust the position of the rest surface according to the maximum travel braking position of the plurality of actuating pistons toward the second side (8).

8. The disc brake (1) according to claim 1 or 2, wherein, When the braking event ends and the user releases the disc brake: A) The first piston (15) and the second piston (16) perform a rearward movement toward the first side (6) with a length of 2*l, where l corresponds to the width of the planned space between the first friction pad (12) and the brake disc (11) and between the second friction pad (13) and the brake disc (11). B) The second piston (16) continues to move backward until the positioning surface (17) rests against the resting surface. C) After the positioning surface (17) is positioned against the resting surface, the second piston (16) continues to move backward by an additional length l, causing the caliper body (3) to slide toward the second side (8) by the same length l, so as to form a space of width l between the first friction pad (12) and the brake disc (11) on the first side (6), and a space of width l between the second friction pad (13) and the brake disc (11) on the second side (8). D) The second piston (16) performs a forward movement toward the second side (8) until the second piston (16) contacts the first friction pad (12) again to prepare for the next braking event.

9. The disc brake (1) according to claim 1 or 2, wherein, When the braking event ends and the user releases the disc brake: A) The second piston (16) moves backward until the positioning surface (17) rests against the resting surface. B) Subsequently, with the second piston (16) stationary, the first piston (15) performs a rearward movement toward the first side (6) with a length of 2*l, where l corresponds to the width of the planned space between the first friction pad (12) and the brake disc (11) and between the second friction pad (13) and the brake disc (11). C) Subsequently, with the first piston (15) stationary, the second piston (16) continues to move backward by an additional length l, causing the caliper body (3) to slide toward the second side (8) by the same length l, so as to form a space of width l between the first friction pad (12) and the brake disc (11) on the first side (6), and a space of width l between the second friction pad (13) and the brake disc (11) on the second side (8). D) The second piston (16) performs a forward movement toward the second side (8) until the second piston (16) contacts the first friction pad (12) again to prepare for the next braking event.

10. The disc brake (1) according to claim 8, wherein, After D), the electric motor of the first piston (15) is actuated forward to close the gap in the electromechanical actuation system (19) of the first piston (15).

11. The disc brake (1) according to claim 1 or 2, wherein, When the braking event ends and the user releases the disc brake: A) The second piston (16) moves backward until the positioning surface (17) rests against the resting surface. B) Subsequently, with the second piston (16) stationary, the first piston (15) is moved backward a length X toward the first side (6). C) Subsequently, with the first piston (15) stationary, the second piston (16) continues to move backward, causing the caliper body (3) to slide toward the second side (8) until the caliper body (3) reaches the following stop position: in the stop position, the first friction pad (12) again abuts against the brake disc (11), and the second friction pad (13) separates from the brake disc (11) by the same distance X. D) Subsequently, with the second piston (16) stationary, the first piston (15) is moved backward by the same length X toward the first side (6), thereby separating the first friction pad (12) from the brake disc (11) by the same measurement value X. E) The second piston (16) performs a forward movement toward the second side (8) until the second piston (16) contacts the first friction pad (12) again to prepare for the next braking event.

12. A method of operating the disc brake (1) according to claim 1, the method comprising the following steps: - The first piston (15) and the second piston (16) are selectively and independently actuated. - After a service braking event, the first friction pad (12) is separated from the brake disc (11) by the rearward movement of the first piston (15) relative to the caliper body (3) toward the first side (6), and - When the first friction pad (12) separates from the brake disc (11), the caliper body (3) moves together with the second friction pad (13) toward the second side (8), and the second friction pad (13) separates from the brake disc (11), and the second piston (16) moves backward toward the first side (6), wherein the positioning surface (17) abuts against the resting surface (18, 18').

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