ELECTROMECHANICAL BRAKE

Abstract

Electromechanical brake (100) comprising: an energy converter (110) having a nut (111) provided in a cylinder part (25) of a brake caliper housing (20) slidably coupled to a carrier (10) and configured to rotate by receiving a driving force from an actuator (130), and having a spindle (115) connected to the nut (111) and configured to move forward or backward by rotating the nut (111) in a first direction or a second direction; a pressure element (120) coupled to a front side of the spindle (115) and configured to press a brake pad plate (11); and a position adjustment device (140) screwed into the cylinder part (25) such that the energy converter (110) is mounted and is adapted to adjust a relative position of the brake caliper housing (20) in response to operation of the energy converter (110), wherein the position adjustment device (140) comprises: a transmission part (143) provided between the energy converter (110) and the cylinder part (25); a first screw thread (141) formed on an outer peripheral surface of the transmission part (143); a second screw thread (142) formed on an inner peripheral surface of the cylinder part (25) and engaging with the first screw thread (141); and an adjusting device (145) configured to rotate the transmission part (143) by rotating the nut (111) in the first direction or the second direction to move a relative position of the brake caliper housing (20) backward or forward with respect to the transmission part (143), wherein the adjusting device (145) comprises: a first projection (146) projecting from the nut (111); and a second projection (147) configured to protrude from the transmission member (143) and configured to move the relative position of the caliper housing (20) rearward when the nut (111) rotates in the first direction by being engaged by the first projection (146) to cause the nut (111) and the transmission member (143) to rotate in the first direction.

Description

TECHNICAL FIELD

[0001] The disclosure relates to an electromechanical brake, in particular an electromechanical brake for braking a vehicle using the rotating drive force of a motor. BACKGROUND

[0002] Vehicles are essentially equipped with a braking system to perform braking, and various types of braking systems have been proposed for the safety of drivers and passengers.

[0003] In conventional braking systems, a method of supplying the hydraulic pressure required for braking to the wheel cylinders via a mechanically connected brake booster when the driver depresses the brake pedal has been primarily used. However, as a next-generation braking system, an electromechanical braking system is being developed that receives the driver's braking intention as an electrical signal and operates an electronic device, such as a motor, based on the electronic signal to provide braking force for a vehicle.

[0004] Such an electromechanical braking system converts the rotational force of a motor into a linear movement through the motor and a reduction gear to exert a clamping pressure on a brake disc and thereby perform a service brake and a parking brake of a vehicle.

[0005] On the other hand, a friction lining of a brake pad, which is in direct contact with and presses against a vehicle's brake disc, is gradually worn down by the vehicle's repeated braking. To maintain a vehicle's braking performance despite friction pad wear, compensation for friction pad wear is necessary. However, compensating for friction pad wear results in an increase in the size or axial length of a brake system, thus deteriorating the vehicle's serviceability.

[0006] From JP 2005-233 224 A, an electromechanical brake system is known, comprising an energy converter with a nut provided in a cylinder part of a brake caliper housing, which is slidably coupled to a carrier and configured to rotate by receiving a driving force from an actuator, and with a spindle connected to the nut and configured to move forward or backward by rotation of the nut in a first direction or a second direction; a pressure element coupled to a front side of the spindle and configured to press a brake pad; and a position adjustment device screwed into the cylinder part such that the energy converter is mounted and configured to adjust a relative position of the brake caliper housing in response to operation of the energy converter. Further electromechanical brakes are known from DE 10 2008 043 035 A1 and JP 2008-115 880 A. DEMOLITION

[0007] The above-mentioned problems are solved by an electromechanical brake according to claim 1. One aspect of the disclosure is the provision of an electromechanical brake capable of maintaining and improving the braking performance of a vehicle despite the wear of a friction lining attached to a brake lining plate.

[0008] Another aspect of the disclosure is the provision of an electromechanical brake that improves the usability of a vehicle by reducing size and weight and promoting the space utilization of the vehicle.

[0009] Another aspect of the disclosure is the provision of an electromechanical brake capable of easily compensating for the wear of a friction lining with a simple structure.

[0010] Additional aspects of the disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the disclosure.

[0011] In accordance with one aspect of the disclosure, an electromechanical brake includes an energy converter having a nut provided in a cylinder portion of a caliper housing, which is slidably coupled to a carrier and configured to rotate by receiving a driving force from an actuator, and having a spindle connected to the nut and configured to move forward or backward by rotation of the nut in a first direction or a second direction; a pressure element coupled to a front side of the spindle and configured to press on a brake pad plate; and a position adjusting device threaded into the cylinder portion such that the energy converter is mounted and configured to adjust a relative position of the caliper housing in response to operation of the energy converter.

[0012] The position adjusting device includes a transmission part provided between the energy converter and the cylinder part; a first screw thread formed on an outer peripheral surface of the transmission part; a second screw thread formed on an inner peripheral surface of the cylinder part and engaged with the first screw thread; and an adjuster configured to rotate the transmission part by rotating the nut in the first direction or the second direction to move a relative position of the caliper housing backward or forward with respect to the transmission part.

[0013] The transmission part may be provided in a hollow cylindrical shape to surround an outer side of the nut and to be spaced apart from the nut by a predetermined distance.

[0014] The adjustment device includes a first projection projecting from the nut and a second projection shaped to project from the transmission member and configured to move the relative position of the caliper housing rearwardly when the nut rotates in the first direction by being engaged by the first projection to cause rotation of the nut and the transmission member in the first direction.

[0015] A first angle between the first protrusion and the second protrusion in a brake release state of a vehicle may be greater than a second angle at which the first protrusion rotates from the brake release state of the vehicle to a braking state of a vehicle.

[0016] The first projection may be shaped to protrude from an outer peripheral surface of the nut to be spaced from an inner peripheral surface of the transmission part, and the second projection is shaped to protrude from the inner peripheral surface of the transmission part to be spaced from the outer peripheral surface of the nut.

[0017] The electromechanical brake may further include an electronic control unit (ECU) configured to control the operation of the actuator; and a detector configured to measure the locking force between the pad and the disc rotating together with a wheel of a vehicle.

[0018] The pressure element can be pressed or screwed onto the front of the spindle to move together with the spindle.

[0019] The pressure element may be provided with an anti-rotation device so that its rotation is restricted, wherein the anti-rotation device may comprise an anti-rotation groove or an anti-rotation projection formed in a front side of the pressure element facing the brake pad plate, and an anti-rotation projection or groove formed on a rear side of the pad plate facing the pressure element, wherein the anti-rotation projection or groove mates with the anti-rotation groove or the anti-rotation projection.

[0020] The electromechanical brake may also include a boot or bellows to prevent foreign matter from entering the cylinder part of the brake caliper housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] These and / or other aspects of the disclosure will become apparent from the following description of the embodiments and will be more easily understood when considered in conjunction with the accompanying drawings, in which: Fig. 1 is a perspective view showing an electromechanical brake according to an embodiment of the disclosure. Fig. 2 is a side cross-sectional view showing an electromechanical brake according to an embodiment of the disclosure. Fig. 3 is an enlarged side cross-sectional view showing a main part of an electromechanical brake according to an embodiment of the disclosure. Fig. 4 is an exploded perspective view showing a main part of an electromechanical brake according to an embodiment of the disclosure. Fig. 5 a cross-sectional view along the A-A' direction of Fig. 3 and shows the positions of the first and second projections in a pre-braking state of the vehicle or in a brake release state of the vehicle. Fig. 6 is a side cross-sectional view illustrating operation of an electromechanical brake according to an embodiment of the disclosure in a braking condition of a vehicle. Fig. 7 a cross-sectional view along the B-B' direction of Fig. 6 and shows the positions of the first and second projections in a braking state of the vehicle. Fig. 8 is a side cross-sectional view illustrating operation of an electromechanical brake to compensate for friction lining wear according to one embodiment of the disclosure. Fig. 9 a cross-sectional view along the C-C' direction of Fig. 8 Is and shows the positions of the first and second projection. Fig. 10 is a side cross-sectional view illustrating operation of an electromechanical brake according to an embodiment of the disclosure in a brake release condition of a vehicle after wear compensation of a friction lining. Fig. 11 is a cross-sectional view taken along the D-D' direction of Fig. 10 and showing the positions of the first and second projections in a brake release state of a vehicle after compensation for wear of a friction lining. DETAILED DESCRIPTION

[0022] Hereinafter, the embodiments of the disclosure will be described in detail with reference to the accompanying drawings. The terms used in the specification and the appended claims should not be construed as being limited to generic and dictionary meanings, but should be interpreted based on the meanings and concepts corresponding to the technical aspects of the disclosure, based on the principle that the inventor is allowed to appropriately define terms for the best possible explanation. Therefore, the description proposed here is only a favorable example for illustrative purposes and is not intended to limit the scope of the disclosure, so that other equivalents and modifications may be made thereto without departing from the spirit and scope of the disclosure.

[0023] Fig. 1 is a perspective view showing an electromechanical brake according to an embodiment of the disclosure, and Fig. 2 is a side cross-sectional view showing an electromechanical brake according to an embodiment of the disclosure.

[0024] With reference to the Fig. 1 and Fig. 2, an electromechanical brake 100 according to an embodiment of the disclosure may include a carrier 10 in which a pair of brake pad plates 11 and 12 are installed to press a disc (not shown) that rotates together with the wheels of the vehicle, a brake caliper housing 20 slidably installed on the carrier 10 to actuate the pair of brake pad plates 11 and 12, an actuator 130 that generates and supplies a driving force for moving the pair of brake pad plates 11 and 12, and an energy converter 110 that receives a rotational driving force supplied by the actuator 130 and converts the rotational driving force into a linear movement to realize a forward and backward movement of the pair of brake pad plates 11 and 12, a pressing element 120 that is connected to a spindle 115 of the energy converter 110 coupled to press the lining plate 11, a position adjusting device 140,which compensates for the wear of friction linings 13 attached to the pair of lining plates 11 and 12 by adjusting a position of the caliper housing 20 with respect to the energy converter 110, a control unit 150 which measures the adhesive force between the disc and the pair of lining plates 11 and 12 or the locking force of the pair of lining plates 11 and 12, and an electronic control unit (ECU) (not shown) which controls an operation of the actuator based on information supplied by the control unit 150.

[0025] The pair of pad plates 11 and 12 are provided with the friction pad 13, each fixed to an inner surface. The pair of pad plates 11 and 12 includes the inner pad plate 11, which is arranged to contact the pressing member 120, and the outer pad plate 12, which is arranged to contact a finger part 22 of the caliper housing 20, which will be described later, and which is slidably mounted on the carrier 10. In other words, the two pad plates 11 and 12 are installed on the carrier 10 fixed to the vehicle body and move forward and backward on both sides of the disc to perform braking.

[0026] The brake caliper housing 20 comprises the finger part 22 which is arranged on a front side (left side with respect to Fig. 2) is bent downward to actuate the outer brake pad plate 12, and a cylinder part 25 containing the energy converter 110 and the position adjusting device 140. The caliper housing 20 is slidably mounted on the carrier 10 via the guide rod 21. The cylinder part 25 and the finger part 22 are integrally formed. The caliper housing 20 slides from the carrier 10 and moves toward the disc side due to the reaction force caused by the pressing of the inner brake pad plate 11 during vehicle braking. In addition, the finger part 22 allows the outer brake pad plate 12 to approach the disc side according to the movement of the caliper housing 20, thereby pressing the disc.

[0027] On the other hand, the cylinder part 25 has a hollow shape penetrating its front and back sides. A second thread 142 may be formed on an inner peripheral surface of the cylinder part 25, which engages with a first thread 141 formed in a transmission part 143 of the position adjustment device 140 to be described later. The structure in which the transmission part 143 is screwed to the cylinder part 25 will be described again below.

[0028] Fig. 3 and Fig. 4 are an enlarged side cross-sectional view and an exploded perspective view showing a main part of the electromechanical brake 100 according to an embodiment of the disclosure. As shown in FIGS. Fig. As shown in Figures 1 to 4, the energy converter 110 is located inside the cylinder portion and can be attached to the transmission portion 143 of the position adjustment device 140, which will be described later. Furthermore, the energy converter 110 can be energized via the actuator 130 to press the inner lining plate 11 against the disc. The energy converter 110 can actuate the position adjustment device 140 to adjust a relative position of the caliper housing 20 with respect to the transmission portion 143, and its operation will be described further below.

[0029] The energy converter 110 may include a nut 111 that rotates by receiving a driving force from the actuator 130, a screw 115 disposed within the position adjusting device 140, which is screwed to the cylinder part 25 to be described later, and which is screwed to the nut 111 to move forward in a first direction by the rotation of the nut 111 or move backward in a second direction by the rotation of the nut 111, and a plurality of balls (not shown) arranged between the nut 111 and the screw 115. The energy converter 110 may be provided as a ball screw for converting a rotational motion of the nut 111 into a linear motion.

[0030] The rotation in the first direction of the nut 111 described below refers to a rotation direction in which the spindle 115 is advanced by the rotation of the nut 111 (left side with respect to Fig. 2), and the rotation in the second direction of the nut 111 refers to a rotation direction in which the spindle 115 is retracted by the rotation of the nut 111 as a rotation in the opposite direction to the first direction (right side with respect to Fig. 2).

[0031] The nut 111 may have a cylindrical shape with one side open so that the spindle 115 can be inserted therein and a receiving space is formed therein. Furthermore, an internal thread 112 for connection with the spindle 115 may be formed on an inner peripheral surface of the nut 111. The spindle 115 is inserted into one side (a front side, which is the left side in the drawings) of the nut 111, and the other side (a rear side, which is the right side in the drawings) of the nut 111 is connected to the actuator 130 to receive the driving force. The other side of the nut 111 may be connected, for example, to an output shaft 135 extending from the actuator 130 in a spline manner.

[0032] The spindle 115 has a predetermined length, and an external thread 116 may be formed on its outer peripheral surface, which engages with the internal thread 112 of the nut 111 via balls (not shown). Accordingly, the spindle 115 can move forward or backward according to the rotation of the nut 111 in the first or second direction. At this time, the spindle 115 is in a rotation-restricted state to perform a linear movement corresponding to the rotation in the first direction or in the second direction of the nut 111. The rotation of the spindle 115 may be prevented by the pressure member 120.

[0033] The pressure element 120 is connected to the front side of the spindle 115. As shown in the drawings, the pressure element 120 may include a press-fit boss 127 that is press-fitted into a press-fit groove 117 formed in the front side of the spindle 115. A rotation-preventing groove 124 is formed on the front side of the pressure element 120, which corresponds to an anti-rotation projection 14 so that the anti-rotation projection 14 protruding from the inner lining plate 11 is inserted and captured. Since the rotation of the pressure element 120 is restricted by the inner lining plate 11, the rotation of the spindle 115 is also restricted.

[0034] On the other hand, as described above, the pressure element 120 is illustrated and described as being press-fitted to the spindle 115, but is not limited thereto. The pressure element 120 and the spindle 115 are connected to each other in a splined manner, or the pressure element 120 may be attached to the front of the spindle 115, such as by screwing.

[0035] Furthermore, as an example of an anti-rotation structure, the structure in which the anti-rotation groove 124 is formed in the front side of the pressure member 120 and the anti-rotation protrusion 14 is formed in the inner lining plate 11 has been shown and described, but is not limited thereto. Alternatively, the anti-rotation groove 124 may be formed in the inner lining plate 11 and the anti-rotation protrusion 14 may be formed in the front side of the pressure member 120.

[0036] The actuator 130 may include a motor 132 and a reduction device 134 having a plurality of reduction gears, and may be powered by a power supply device installed in the vehicle to generate and deliver a driving force. The actuator 130 may be connected to the other end of the nut 111 to transmit the generated driving force to the nut 111 as a rotational motion via the output shaft 135 of the reduction device 134. The actuator 130 may be installed outside the caliper housing 20 or inside the vehicle, and the reduction device 134 may reduce the power of the motor 132 to be supplied to the nut 111 by employing various structures, such as a planetary gear or a worm structure.

[0037] The position adjusting device 140 compensates for the wear of the friction lining 13 by adjusting the relative position of the brake caliper housing 20 with respect to the transmission part 143 and is provided in the cylinder part so that the energy converter 110 is mounted.

[0038] The position adjustment device 140 may include the transmission part 143 provided between the energy converter 110 and the cylinder part 25, the first screw thread 141 formed on the outer peripheral surface of the transmission part 143, the second screw thread 142 formed on the inner surface of the cylinder part 25 and engaged with the first screw thread 141, and an adjuster 145 for moving the transmission part 143 forward or backward by rotating the transmission part 143 in the first direction or the second direction by rotating the nut 111. At this time, since the cylinder part 25 screwed to the transmission part moves linearly when the transmission part 143 is rotated by the nut 111, the forward or backward movement of the transmission part 143 corresponds to the movement of the caliper housing 20.In other words, since the caliper housing 20 is slidably mounted on the carrier 10 in a state where its rotation is restricted, the cylinder part 25 formed integrally with the caliper housing 20 can move linearly, resulting in the relative position of the caliper housing 20 being adjusted.

[0039] A first rotational direction of the transmission part 143, which will be described below, is the same rotational direction as the first rotational direction of the nut 111 described above and refers to a rotational direction in which the transmission part 143 moves forward from the cylinder part, but the brake caliper housing 20 is substantially retracted.

[0040] In addition, a second rotational direction of the transmission part 143 is the same rotational direction as the second rotational direction of the nut 111, which was described above as a rotation opposite to the first direction, and refers to a rotational direction in which the transmission part 143 moves rearward from the cylinder part, but the caliper housing 20 is substantially moved forward.

[0041] The transmission part 143 has a hollow cylindrical shape and surrounds an outer side of the nut 111 with a predetermined clearance, and the first screw thread 141 is formed on the outer peripheral surface thereof. The transmission part 143 can rotate together with the nut 111 when the nut 111 is rotated by the adjusting device 145 to be described later. In other words, the first thread 141 of the transmission part 143 is screwed to the second thread 142 of the cylinder part 25, and the caliper housing 20 constituting the cylinder part 25 is coupled to the bracket 10 fixed to the vehicle body, so that its rotation is restricted. Accordingly, the caliper housing 20 moves linearly away from the transmission part 143 when the transmission part 143 rotates.

[0042] The adjustment device 145 can cause rotation of the transmission part 143 through the nut 111 to advance or retard the relative position of the caliper housing 20 with respect to the transmission part 143. The adjustment device 145 can include a first projection 146 protruding from the nut 111 and a second projection 147 protruding from the transmission part 143. During rotation of the nut 111 in the first direction, the second projection 147 is engaged by the first projection 146 to cause rotation of the nut 111 and the transmission part 143 in the first direction, thereby retracting the relative position of the caliper housing 20.

[0043] More precisely, the first projection 146, as shown in the Fig. 2 to 5, may be formed on an outer peripheral surface of the nut 111. Furthermore, the first projection 146 may be shaped to protrude from the outer peripheral surface of the nut 111 and be spaced apart from an inner peripheral surface of the transmission part 143.

[0044] The second protrusion 147 may be formed on the inner peripheral surface of the transmission part 143. Furthermore, the second protrusion 147 may be shaped to protrude from the inner peripheral surface of the transmission part 143 and be spaced apart from the outer peripheral surface of the nut 111.

[0045] The first and second projections 146 and 147 are formed at positions corresponding to each other so that the first and second projections 146 and 147 can be provided to engage with each other when the nut 111 rotates in the first direction or the second direction.

[0046] The first and second projections 146 and 147 may be shaped to protrude at an angle spaced from each other in a pre-braking state of the vehicle or in a brake release state of the vehicle.

[0047] Specifically, an angle between the first and second projections 146 and 147 (hereinafter referred to as first angle θ1) in the pre-braking state of the vehicle or in the brake release state of the vehicle is provided to be larger than a rotation angle of the first projection 146 (see Fig. 7, hereinafter referred to as the second angle θ2) from the brake release state to the braking state of the vehicle. When the second angle θ2 is larger than the first angle θ1, the second protrusion 147 is caught by the first protrusion 146 to generate the rotation of the nut 111 and the transmission part 143 in the first direction during general vehicle braking. As a result, the caliper housing 20 moves back from the transmission part 143, and the finger part 22 moves toward the outer brake pad plate 12. At this time, the energy converter 110 also cooperates, so that the locking force between the pressing member 120 and the inner brake pad plate 11 is rapidly increased, so that the braking force of the vehicle is greater than the braking force required by the driver. In addition, air resistance may occur, which may affect the driving stability of the vehicle and the fuel efficiency of the vehicle.By making the first angle θ1 larger than the second angle θ2, the first and second projections 146 and 147 can be prevented from contacting each other during general vehicle braking, and thus the relative position of the caliper housing 20 with respect to the transmission part 143 can be maintained constant, and the braking ability and driving stability of the driver can be promoted.

[0048] As in the Fig. 2 and Fig. 3, the detector 150 is provided for measuring the adhesive force or clamping force between the disc and the friction pad 13. The detector 150 can be provided as a force sensor that detects a load on the spindle 115 or the actuator 130 to measure the force between the disc and the friction pad 13, but is not limited thereto. The detector 150 can transmit the measured clamping force information of the friction pad 13 to the ECU, and the ECU can determine wear or resistance of the friction pad 13 based on the measured clamping force information by the detector 150. The detector 150 is shown here as being located inside the front side of the pressure element 120, but is not limited thereto. The detector can be provided, for example, in the energy converter 110 or in the actuator 130, which receives the reaction force when the pad plates 11 and 12 are pressed.

[0049] On the other hand, the unspecified numeral 30 refers to a bellows. The bellows 30 prevents foreign matter from entering the cylinder part 25 of the caliper housing 20. As shown in the drawings, the bellows 30 may be attached at one end to the rear of the cylinder part 25 and at the other end to the actuator 130. The bellows 30 has a corrugated shape to be stretchable and may be made of a rubber material to be elastic. Accordingly, the bellows 30 expands or contracts when the relative position of the caliper housing 20 is adjusted, and the function of preventing foreign matter from entering can be smoothly performed.

[0050] Although the bellows 30 is illustrated as only blocking foreign matter between the cylinder part 25 and the actuator 130, it is not limited thereto, and a bellows may additionally be installed such that one end thereof is installed on the pressure member 120 and the other end thereof is installed on the front side of the cylinder part 25.

[0051] The following describes operating states during braking and brake release with the electromechanical brake 100 described above and a mode for compensating the wear of the friction lining 13.

[0052] Fig. 6 is a side cross-sectional view illustrating the operation of the electromechanical brake according to an embodiment of the disclosure in the braking state of the vehicle, and Fig. 7 is a cross-sectional view taken along the B-B' direction of Fig. 2 and illustrates the positions of the first and second projections in the braking state of the vehicle.

[0053] Fig. 2, 3 and 5 to 7: When the driver depresses a brake pedal (not shown) to decelerate the vehicle, a pedal travel sensor (not shown) converts the driver's braking intention into an electrical signal and transmits the signal to the ECU. The control unit controls the operation of the actuator 130 so that the disc and the pair of brake pad plates 11 and 12 are in close contact to perform the braking of the vehicle. In other words, the electromechanical brake according to the disclosure can be made from the Fig. 2, Fig. 3 and Fig. 5 shown brake release state (or pre-braking state) in the Fig. 6 and Fig. 7 shown braking condition.

[0054] Specifically, during vehicle braking, the nut 111 rotates in the first direction by the operation of the actuator 130, and as the spindle 115 advances in response to the rotation of the nut 111 in the first direction, the pressing member 120 also advances toward the inner pad plate 11. When the friction pad 13 mounted on the inner pad plate 11 approaches the disc and fits snugly against it, a locking force is generated. Furthermore, due to the reaction force generated by the pressing of the inner pad plate 11 when the caliper housing 20 is pushed by the carrier 10 toward the disc side, the outer pad plate 12 approaches the disc through the finger portion 22 and presses the disc, thereby braking the vehicle.

[0055] At this time, the first protrusion 146 provided on the nut 111 rotates by the second angle θ from the vehicle brake release state to the vehicle braking state according to the first rotation direction of the nut 111. However, since the first angle θ1 between the first and second protrusions 146 and 147 of the transmission part 143 in the vehicle brake release state is larger than the second angle θ, the first and second protrusions 146 and 147 do not contact each other in a general braking situation. Thereby, the relative position of the caliper housing 20 with respect to the transmission part 143 can be constantly maintained.

[0056] In addition, when the brake caliper housing 20 slides due to the reaction force corresponding to the braking operation, the transmission part 143 bolted to the cylinder part 25 and the actuator 130 can move together. Since the energy converter 110 is in a spaced-apart state from the transmission part 143 at this time, the energy converter 110 is not affected by the movement of the transmission part 143, thereby maintaining a connected state with the actuator 130.

[0057] During the braking of the vehicle, the vehicle can be driven by the Fig. 6 and Fig. 7 shown braking condition in the Fig. 2, Fig. 3 and Fig. 5. Specifically, the nut 111 rotates in the second direction by the actuation of the actuator 130, and when the spindle 115 is retracted in the second direction by the rotation of the nut 111, the pressure element 120 is also spaced apart and retracted together from the inner lining plate 11. Since the brake caliper housing 20 is also returned to its original position, the friction pads 13 mounted on the two lining plates 11 and 12 are spaced apart from the disc, thereby allowing the braking of the vehicle to be released. The first projection 146 on the nut 111 returns to its original position in accordance with the second direction of rotation of the nut 111.

[0058] In order to maintain the braking performance of the vehicle despite the wear of the friction lining 13, a mode in which the electromechanical brake 100 according to the embodiment of the disclosure compensates for the wear of the friction lining 13 is described below.

[0059] Fig. 8 is a side cross-sectional view illustrating the operation of an electromechanical brake according to an embodiment of the disclosure to compensate for friction lining wear, and Fig. 9 is a cross-sectional view taken along the C-C' direction of the Fig. 8 and shows the positions of the first and second projection.

[0060] With reference to the Fig. 8 and Fig. 9, in response to the clamping force or locking force between the disc and the lining plates 11 and 12 measured by the detector 150 in a general braking operating condition being less than a predetermined value within a normal range, the ECU (not shown) determines that there is wear on the friction lining 13 to enter a wear compensation mode.

[0061] For example, if it is determined that the friction lining 13 is worn, the ECU rotates the nut 111 in the first direction by controlling the operation of the actuator 130 to enter a wear compensation mode. At this time, the ECU generates an additional rotation in the first direction (more than the first angle θ1 n Fig. 5), which is greater than the rotation of the nut 111 in the first direction in the general braking condition (see the second angle θ2 in Fig. 7). As a result, the first projection 146 on the nut 111 rotates in contact with the second projection 147 on the transmission part 143. Since the second projection 147 is caught by the first projection 146 to rotate together in the first direction, the nut 111 and the transmission part 143 also rotate in the first direction. The relative position of the cylinder part 25 with respect to the transmission part 143 can be retracted by the rotation of the nut 111 and the transmission part 143 in the first direction. In other words, when the relative position of the caliper housing 20 with respect to the transmission part 143 moves rearward, the outer brake pad plate 12 simultaneously moves toward the disc side, thus compensating for the wear of the friction pad 13.

[0062] After the mode for compensating the wear of the friction lining 13 is terminated, the electromechanical brake 100 according to the present embodiment of the disclosure returns to the brake release state of the vehicle or to the pre-braking state of the vehicle.

[0063] Fig. 10 is a side cross-sectional view illustrating the operation of the electromechanical brake according to an embodiment of the disclosure in the brake release state of the vehicle after compensation for wear of the friction linings, and Fig. 11 is a cross-sectional view along the D-D' direction of Fig. 10 and shows the positions of the first and second projections in the brake release state of the vehicle after compensation for the wear of the friction lining.

[0064] As in the Fig. 10 and Fig.As shown in Figure 11, after compensating for the wear of the friction lining 13, the ECU generates the second rotation direction of the nut 111 by controlling the operation of the actuator 130. Specifically, the actuator 130 rotates the nut 111 in the second direction to restore the brake release state of the vehicle. In other words, the ECU can rotate the nut 111 in the second direction so that the first projection 146 of the nut 111 maintains the first angle θ1 with the second projection 147.

[0065] Accordingly, the spindle 115, which is returned to its original position after performing the wear compensation mode of the friction pad 13, can perform braking when the vehicle braking is again performed according to the first projection 146 of the nut 111 rotating by the second angle θ2. At this time, the braking operation is performed while compensating for the wear of the friction pad 13, so that the vehicle braking can be performed stably.

[0066] On the other hand, after wear compensation, the nut 111 can be returned to the state before the vehicle was braked. In other words, the additional rotation of the nut 111 in the first direction occurs in the wear compensation mode, but the ECU can return the spindle 115 to its original position by rotating the nut 111 in the second direction by an amount equal to the additional rotation in the first direction generated in the wear compensation mode.

[0067] As can be seen from the above, the electromechanical brake according to the embodiments of the disclosure can maintain and improve the braking performance of the vehicle despite the wear of the friction pad attached to the brake pad plate.

[0068] Furthermore, the electromechanical brake according to the embodiments of the disclosure can improve the applicability of the vehicle by reducing the size and weight and promote the space utilization of the vehicle.

[0069] Furthermore, the electromechanical brake according to the embodiments of the disclosure can easily compensate for the wear of the friction lining with a simple structure.

[0070] As described above, the exemplary embodiments of the present disclosure have been described so far with reference to the accompanying drawings. It will be apparent to those skilled in the art that the present disclosure may be embodied in forms other than the exemplary embodiments described above without changing the technical idea or essential features of the present disclosure. The above embodiments are merely examples and should not be construed as being limited thereto.

Claims

[1] Electromechanical brake (100) comprising: an energy converter (110) having a nut (111) provided in a cylinder part (25) of a brake caliper housing (20) slidably coupled to a carrier (10) and configured to rotate by receiving a driving force from an actuator (130), and having a spindle (115) connected to the nut (111) and configured to move forward or backward by rotating the nut (111) in a first direction or a second direction; a pressure element (120) coupled to a front side of the spindle (115) and configured to press a brake pad plate (11); and a position adjustment device (140) screwed into the cylinder part (25) such that the energy converter (110) is mounted and is adapted to adjust a relative position of the brake caliper housing (20) in response to operation of the energy converter (110), wherein the position adjustment device (140) comprises: a transmission part (143) provided between the energy converter (110) and the cylinder part (25); a first screw thread (141) formed on an outer peripheral surface of the transmission part (143); a second screw thread (142) formed on an inner peripheral surface of the cylinder part (25) and engaging with the first screw thread (141); and an adjusting device (145) configured to rotate the transmission part (143) by rotating the nut (111) in the first direction or the second direction to move a relative position of the brake caliper housing (20) backward or forward with respect to the transmission part (143), wherein the adjusting device (145) comprises: a first projection (146) projecting from the nut (111); and a second projection (147) configured to protrude from the transmission member (143) and configured to move the relative position of the caliper housing (20) rearward when the nut (111) rotates in the first direction by being engaged by the first projection (146) to cause the nut (111) and the transmission member (143) to rotate in the first direction. [2] The electromechanical brake (100) according to claim 1, wherein the transmission part (143) is provided in a hollow cylindrical shape to surround an outer side of the nut (111) and to be spaced from the nut (111) by a predetermined distance. [3] The electromechanical brake (100) according to claim 1 or 2, wherein a first angle between the first projection (146) and the second projection (147) in a brake release state of a vehicle is greater than a second angle at which the first projection (146) rotates from the brake release state of the vehicle to a braking state of a vehicle. [4] The electromechanical brake (100) according to any one of claims 1 to 3, wherein the first projection (146) is formed to protrude from an outer peripheral surface of the nut (111) to be spaced from an inner peripheral surface of the transmission part (143), and the second projection (147) is formed to protrude from the inner peripheral surface of the transmission part (143) and to be spaced from the outer peripheral surface of the nut (111). [5] Electromechanical brake (100) according to one of claims 1 to 4, further comprising: an electronic control unit (ECU) configured to control the operation of the actuator (130); and a detector (150) configured to measure a force between the brake pad plate (11) and a disc rotating together with a wheel of a vehicle. [6] Electromechanical brake (100) according to one of claims 1 to 5, wherein the pressure element (120) is pressed into the front side of the spindle (115) or screwed thereto in order to move together with the spindle (115). [7] Electromechanical brake (100) according to one of claims 1 to 6, wherein the pressure element (120) is provided with an anti-rotation device such that its rotation is restricted, and the anti-rotation device comprises: an anti-rotation groove (124) or projection formed in a front side of the pressure element (120) facing the brake pad plate (11); and an anti-rotation projection (14) or groove formed on a rear side of the brake pad plate (11) facing the pressure element (120), wherein the anti-rotation projection (14) or groove mates with the anti-rotation groove (124) or projection. [8] Electromechanical brake (100) according to one of claims 1 to 7, further comprising: a bellows (30) provided for preventing penetration of foreign matter into the cylinder part (25) of the brake caliper housing (20).

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