Vehicle brake device

Abstract

Provided is a vehicle brake device including: a caliper body configured to have a cylinder; a piston portion movably disposed in the cylinder and arranged to face a brake pad; a nut threaded portion disposed in the piston portion and configured to receive a rotational force from an actuator portion and rotate accordingly; and a bolt threaded portion configured to include a bolt body and a bolt head; the bolt body connected to the nut threaded portion and receiving the rotational force from the nut threaded portion; the bolt head formed separately from the bolt body, connected to the bolt body, and arranged to face the piston portion, wherein, when the bolt body moves within the cylinder in response to the rotation of the nut threaded portion, the bolt head presses the piston portion. According to the brake device of the present disclosure, since the nut threaded portion is press-fitted into the bearing portion, and the position fixing ring portion contacts and supports the nut threaded portion, the durability of the device can be improved.

Description

Technical Field

[0001] Exemplary embodiments of this disclosure relate to a vehicle braking device, and more specifically to a vehicle braking device capable of ensuring stable braking performance. Background Technology

[0002] Typically, vehicle braking systems use driving force to press the piston to make the brake pads and brake discs come into close contact, and use the friction between the brake pads and brake discs to brake the vehicle.

[0003] In vehicle braking systems, electromechanical brakes (EMBs) generate braking force by pressing a piston through a mechanism that does not use hydraulic pressure. Instead, an electric motor-driven actuator is mounted on the caliper and converts the rotational motion of the bolt into the linear motion of the nut, or vice versa.

[0004] EMB enables active and independent braking for each wheel, allowing not only general main braking but also additional functions such as anti-lock braking system (ABS), electronic stability control (ESC), traction control system (TCS), and automatic emergency braking (AEB), and can achieve enhanced performance due to the absence of hydraulic transmission delay.

[0005] The use of bolt-driven braking systems typically makes it difficult to reduce the axial length (total length) of EMB calipers. Furthermore, when the piston is tilted relative to the central axis, it cannot consistently generate braking loads, and durability is compromised.

[0006] When thrust bearings are used in bolt thread drive braking systems, problems may arise such as increased axial length (total length) of EMB calipers, inability to adequately ensure the efficiency of thrust bearings, and compromised durability.

[0007] The related technology disclosed herein is disclosed in Korean Patent Application Publication No. 10-2024-0054695 (published on April 26, 2024, and entitled "Vehicle Braking Device"). Summary of the Invention

[0008] Various aspects of this disclosure are intended to provide a nut-thread driven braking device for vehicles that reduces the axial length of EMB calipers.

[0009] One aspect of this disclosure aims to provide a vehicle braking device in which the bolt head and the bolt body and bolt thread portion are manufactured as separate components.

[0010] One aspect of this disclosure aims to provide a vehicle braking device capable of increasing the contact diameter of the bolt head that contacts the piston portion.

[0011] One aspect of this disclosure aims to provide a vehicle braking device that allows rolling motion between the threaded portion of a bolt and the threaded portion of a nut.

[0012] One aspect of this disclosure aims to provide a vehicle braking device capable of securely fixing a bearing portion to a suitable position on a nut thread portion.

[0013] A vehicle braking device according to one aspect of this disclosure includes: a caliper body configured to have a cylinder; a piston portion movably disposed in the cylinder and arranged to face the brake pads; a nut thread portion disposed in the piston portion and configured to receive rotational force from an actuator portion and rotate accordingly; and a bolt thread portion configured to include a bolt body and a bolt head; the bolt body being connected to the nut thread portion and receiving rotational force from the nut thread portion; the bolt head being separately formed from the bolt body, connected to the bolt body, and arranged to face the piston portion, wherein the bolt head presses against the piston portion when the bolt body moves within the cylinder in response to rotation of the nut thread portion.

[0014] The bolt head may have an outer diameter larger than that of the bolt body.

[0015] The bolt head may include: a head connection portion connected to the bolt body; and a head extension portion configured to extend from the head connection portion toward the piston portion and having a larger outer diameter than the head connection portion.

[0016] The head extension may include a curved surface portion located on the outer periphery facing the piston portion, and the head extension may contact the piston portion on the curved surface portion.

[0017] In response to the tilting of the piston portion relative to the central axis, the head extension portion can roll relative to the piston portion on the curved surface portion.

[0018] The piston portion may have a planar portion in the area that contacts the curved portion.

[0019] The bolt body can be connected to the nut thread portion via ball bearings on the inner surface of the nut thread portion.

[0020] The vehicle braking device may further include: a bearing portion disposed between the cylinder and the nut thread portion, and configured to support the nut thread portion to allow the nut thread portion to rotate within the cylinder.

[0021] In response to the tilting of the piston portion relative to the central axis, the threaded portion of the nut can roll relative to the bearing portion.

[0022] The bearing portion may include: an outer ring portion that contacts the inner surface of the cylinder; and bearing balls disposed between the outer ring portion and the nut thread portion, wherein the nut thread portion has a rolling contact portion in the area facing the bearing balls.

[0023] A vehicle braking device according to another aspect of this disclosure includes: a caliper body configured to have a cylinder; a piston portion movably disposed in the cylinder and arranged to face the brake pads; a nut thread portion disposed in the piston portion and configured to receive rotational force from an actuator portion and rotate accordingly; a bolt thread portion configured to move within the cylinder in response to rotation of the nut thread portion and press against the piston portion; a bearing portion disposed between the cylinder and the nut thread portion and configured to support the nut thread portion to allow rotation of the nut thread portion within the cylinder; and a position retaining ring portion configured to contact and support the bearing portion to secure the bearing portion in a suitable position on the nut thread portion.

[0024] The bearing portion may include: an outer ring portion that contacts the inner surface of the cylinder; an inner ring portion that is rotatably disposed inside the outer ring portion and configured to contact the threaded portion of the nut; and bearing balls disposed between the outer ring portion and the inner ring portion.

[0025] The position fixing ring portion may include a contact plate portion that is at least partially in contact with the outer ring portion.

[0026] The insertion groove portion into which the position fixing ring portion is inserted can be located on the outer surface of the threaded portion of the nut.

[0027] The position fixing ring portion may have a V-shaped cross-section, and the edge portion of the position fixing ring portion may be inserted into the insertion slot portion.

[0028] The positioning ring portion may include a material that can be elastically deformed.

[0029] The inner ring portion may have a rolling contact portion in the area facing the bearing balls.

[0030] The inner ring portion may include: a lower bottom portion connected to one side of the rolling contact portion; and an upper step portion connected to the opposite side of the rolling contact portion and configured to protrude outward relative to the lower bottom portion.

[0031] The rolling contact portion can be formed as an inwardly facing concave curved surface and is formed along the entire outer periphery of the inner ring portion.

[0032] In vehicle braking systems, the bolt head is manufactured separately from the bolt body, which allows for greater flexibility in the shape of the bolt head.

[0033] In vehicle braking systems, as the contact diameter of the bolt head that contacts the piston increases, the load can be stably transmitted to the piston.

[0034] In vehicle braking systems, since rolling can be performed at the front of the bolt thread and outside the nut thread, the load can be prevented from being concentrated on the ball bearings, thereby improving the durability of the system and ensuring robustness against piston tilt.

[0035] In vehicle braking systems, the bearing portion can be securely fixed at the appropriate position on the threaded portion of the nut.

[0036] In vehicle braking systems, the durability of the device can be improved because the threaded portion of the nut is press-fitted into the bearing portion, and the positioning ring portion contacts and supports the threaded portion of the nut.

[0037] In vehicle braking systems, since rolling can be performed at the front of the bolt thread and outside the nut thread, the load can be prevented from being concentrated on the ball bearings, thereby improving the durability of the system and ensuring robustness against piston tilt. Attached Figure Description

[0038] Figure 1 This is a perspective view showing a vehicle braking device according to an embodiment of the present disclosure.

[0039] Figure 2 This is a schematic cross-sectional view of a vehicle braking device according to an embodiment of the present disclosure.

[0040] Figure 3 yes Figure 2 A magnified view of a portion of the image.

[0041] Figure 4 yes Figure 3 A magnified view of a portion of the image.

[0042] Figure 5This is a perspective view showing the actuator portion of a vehicle braking device according to an embodiment of the present disclosure.

[0043] Figure 6 This is a perspective view showing a vehicle braking device according to another embodiment of the present disclosure.

[0044] Figure 7 This is a schematic cross-sectional view of a vehicle braking device according to an embodiment of the present disclosure.

[0045] Figure 8 yes Figure 7 A magnified view of a portion of the image.

[0046] Figure 9 yes Figure 8 A magnified view of a portion of the image.

[0047] Figure 10 This is a view showing the position fixing portion of a vehicle braking device according to an embodiment of the present disclosure being installed onto the threaded portion of a nut.

[0048] Figure 11 It is a perspective view of the fixed portion according to the embodiment of this disclosure.

[0049] Figure 12 This is a perspective view showing the actuator portion of a vehicle braking device according to an embodiment of the present disclosure. Detailed Implementation

[0050] In the following, embodiments of the vehicle braking device according to the present disclosure will be described in detail with reference to the accompanying drawings. During this process, for clarity and convenience, the thickness of lines and the dimensions of elements shown in the drawings may be exaggerated. Furthermore, the terminology used below is defined with regard to its function in this disclosure and may be changed according to the intention or practice of the user or operator. Therefore, these terms should be defined in the context of this specification.

[0051] Figure 1 This is a perspective view showing a vehicle braking device according to an embodiment of the present disclosure. Figure 2 This is a schematic cross-sectional view of a vehicle braking device according to an embodiment of the present disclosure. Figure 3 yes Figure 2 A magnified view of a portion of the image. Figure 4 yes Figure 3 A magnified view of a portion of the image. Figure 5 This is a perspective view showing the actuator portion of a vehicle braking device according to an embodiment of the present disclosure.

[0052] Reference Figures 1 to 5The vehicle braking device according to the embodiments of this disclosure may include a caliper body 100, a piston portion 200, a nut threaded portion 300, and a bolt threaded portion 400.

[0053] The caliper body 100 can form the shape of a vehicle braking device and surround or support the piston portion 200, the nut thread portion 300, and the bolt thread portion 400.

[0054] The caliper body 100 may include a bridge-shaped member 110, a finger-shaped member 120, and a cylinder 130.

[0055] The bridge-shaped member 110 can form the appearance of the central portion of the caliper body 100 and support the finger member 120 and the cylinder 130. The bridge-shaped member 110 can be connected to a carrier (not shown), which is fixed to the steering knuckle (not shown) or the like via a guide rod (not shown).

[0056] The lower surface of the bridge-shaped member 110 can be arranged as a circumferential surface facing the brake disc 20, with a predetermined distance between them. The two sides of the bridge-shaped member 110 can be positioned relative to the brake disc 20 along a first direction (…). Figure 2 The +X direction) and the second direction opposite to the first direction ( Figure 2 (Extends in the -X direction).

[0057] A pair of brake pads 30 can be arranged below the bridge-shaped member 110. The pair of brake pads 30 can be arranged facing each other, with the brake disc 20 inserted between them.

[0058] A friction pad may be attached to one surface of the brake pad 30 facing the brake disc 20, the friction pad comprising a material having a high coefficient of friction, such as rubber.

[0059] The finger 120 can extend downward from one side of the bridge 110. The finger 120 can be arranged to face one of the pair of brake pads 30.

[0060] Cylinder 130 can extend downward from the other side of bridge-shaped member 110. Cylinder 130 can have a hollow cylindrical shape. One side of cylinder 130 ( Figure 2 The left side of the pair of brake pads 30 can be arranged to face the other one of the pair.

[0061] One side of the cylinder 130 may be open, and the open side of the cylinder 130 may be spaced apart from the brake pad 30 by a predetermined distance. The brake pad 30 is spaced apart from the brake disc 20 in the second direction.

[0062] The central axis of cylinder 130 can be arranged parallel to the central axis C1 of brake disc 20. The central axis of cylinder 130 can be along a third direction ( Figure 2 The +Z direction is spaced apart from the central axis C1 of the brake disc 20.

[0063] The third direction can be perpendicular to the first and second directions, and can be exemplified as the direction from the central axis C1 of the brake disc 20 toward the central axis of the cylinder 130.

[0064] When the lower surface of the bridge-shaped member 110 is arranged parallel to the ground, the third direction can be a direction perpendicular to the ground, that is, based on Figure 2 The upward direction along the Z-axis.

[0065] Piston portion 200 can move within cylinder 130 in a first direction ( Figure 2 (in the +X direction) or the second direction ( Figure 2 The piston section 200 can be movably arranged in the -X direction. The piston section 200 can be arranged within the cylinder 130.

[0066] The piston portion 200 may have a hollow cylindrical shape. The side of the piston portion 200 facing the brake pad 30 may be closed. The piston portion 200 may be arranged along the longitudinal direction of the cylinder 130.

[0067] The outer surface of the piston portion 200 can be slidably supported by the inner surface of the cylinder 130. Alternatively, the outer surface of the piston portion 200 can be spaced apart from the inner surface of the cylinder 130 by a predetermined distance.

[0068] The piston portion 200 can protrude outward from the cylinder 130 by moving in a first direction, pressing the brake pad 30, which is arranged facing the cylinder 130, against the brake disc 20. This allows the vehicle braking system to generate braking force.

[0069] In response to the movement of the piston portion 200 in the second direction, the piston portion 200 can separate from the brake pad 30. Therefore, the pressing force applied to the brake pad 30 by the piston portion 200 is released, and the braking force of the vehicle braking device disappears.

[0070] The piston portion 200 may include a piston body 210 and a piston head 220.

[0071] The piston body 210 may have a hollow cylindrical shape, and the piston head 220 may be connected to the piston body 210 to close one side of the piston body 210. Figure 3 (Left side of the piston body 210). The piston head 220 is arranged between the two open sides of the piston body 210 facing the brake pad 30, and closes the open area of ​​the piston body 210.

[0072] The bolt thread portion 400 can be arranged inside the piston portion 200. The bolt body 410 and bolt head 420 of the bolt thread portion 400 are surrounded by the piston body 210. The bolt head 420 can be arranged to be inserted into the piston head 220.

[0073] Piston cover 260 can be installed inside cylinder 130 to prevent external impurities from entering and to seal the interior of cylinder 130. Piston cover 260 can be installed between cylinder 130 and piston portion 200. Piston cover 260 can be connected to piston body 210 or piston head 220 and press-fitted into cylinder 130.

[0074] The piston cover 260 may be formed to surround the piston portion 200. The piston cover 260 may include an elastically deformable material. For example, the piston cover 260 may be made of a rubber material. The piston cover 260 may be formed to have a corrugated shape.

[0075] The nut threaded portion 300 can be rotatably arranged in the cylinder 130 and connected to the bolt threaded portion 400. The bearing portion 500, which rotatably supports the nut threaded portion 300, can be installed inside the cylinder 130. The bearing portion 500 can be a ball bearing arranged between the cylinder 130 and the nut threaded portion 300.

[0076] The nut threaded portion 300 may have a hollow cylindrical shape with open ends. The nut threaded portion 300 may be arranged inside the cylinder 130, and its central axis may be coaxially aligned with the central axis of the cylinder.

[0077] One side of the nut threaded portion 300 ( Figure 2 The left side of the piston section 200 can be arranged to face the inner surface of the piston section 200. Figure 2 (on the right side), with a predetermined distance between them. The other side of the nut threaded portion 300 ( Figure 2 The right side of the cylinder can pass through the cylinder 130 and protrude outward from the cylinder 130.

[0078] The inner surface of the nut threaded portion 300 can be arranged to face the outer surface of the bolt threaded portion 400. A ball track can be formed on the inner circumferential surface of the nut threaded portion 300, with one periphery of the spherical ball member B located on this ball track. This ball track can extend helically along the longitudinal direction of the nut threaded portion 300 to provide a circulation path for the ball member B.

[0079] During operation of the actuator section 600, the nut threaded section 300 can receive the rotational force generated from the actuator section 600 through the power transmission section, and can rotate clockwise or counterclockwise about the central axis.

[0080] The nut thread portion 300 may include a nut thread body 310 and a nut thread tail 320.

[0081] The majority of the nut thread body 310 can be located inside the cylinder 130, and the nut thread tail 320 can be completely or mostly exposed outside the cylinder 130. The nut thread body 310 can be surrounded by the piston body 210.

[0082] The threaded tail 320 of the nut may have a non-circular cylindrical shape. Non-circular means a shape that is not perfectly circular, including shapes such as ellipses, polygons, and others. In this embodiment, the threaded tail 320 of the nut has a polygonal cylindrical shape, specifically a generally hexagonal cylindrical shape.

[0083] In response to rotation of the nut thread portion 300, the bolt thread portion 400 can move within the cylinder 130 in a first direction and a second direction. The bolt thread portion 400 can be arranged inside the nut thread portion 300. The bolt thread portion 400 can be arranged to pass through both ends of the nut thread portion 300.

[0084] The bolt threaded portion 400 can move in a first direction toward the brake pad 30, causing the piston portion 200 to press against the brake pad 30. Furthermore, the bolt threaded portion 400 can move in a second direction opposite to the first direction to release pressure on the piston portion 200.

[0085] The bolt thread portion 400 may include a bolt body 410 and a bolt head 420.

[0086] The bolt body 410 can be connected to the threaded portion 300 of the nut and receive rotational force from the threaded portion 300. The bolt head 420 can be separate from the bolt body 410. The bolt body 410 can be press-fitted to the bolt head 420 and integrated together. For example, the bolt body 410 can be press-fitted to the bolt head 420 via serrations.

[0087] Because the bolt head 420 is manufactured separately from the bolt body 410, the shape flexibility of the bolt head 420 can be increased. In particular, the shape of the bolt head 420 can be changed according to the specifications of the vehicle braking system. Forming the bolt head 420 separately from the relatively easily standardized bolt body 410 facilitates customization and increases design freedom. According to this embodiment, based on changes in the dimensions of the piston portion 200, the contact diameter of the bolt head 420 can be easily changed accordingly.

[0088] When the bolt body 410 translates in the first direction within the cylinder 130 in response to the rotation of the nut thread portion 300, it is positioned in front of the bolt body 410. Figure 2 The bolt head 420 on the left side of the middle presses against the piston part 200.

[0089] The bolt body 410 may have a cylindrical shape with a generally circular cross-section. The bolt body 410 may be arranged inside the cylinder 130, and its central axis may be coaxially aligned with the central axis of the cylinder 130. The bolt body 410 may be connected to the threaded portion of the nut 300 via a ball bearing member B.

[0090] A ball track (not shown) may be formed on the outer peripheral surface of the bolt body 410, and the ball component B is located on the ball track. The ball track may be along the longitudinal direction of the bolt body 410. Figure 2 The ball bearing component B extends helically (in the left and right directions) to provide a circulation path for the ball bearing component B. Therefore, in response to the rotation of the nut thread portion 300, the bolt body 410 can move in either the first or second direction via the circulatory movement of the ball bearing component B.

[0091] Bolt head 420 can be disposed between bolt body 410 and piston portion 200. Bolt head 420 can be formed with an approximately circular cross-section. Bolt head 420 can be arranged to be inserted into piston head 220. Bolt head 420 can be arranged facing the inner surface of piston head 220, with a predetermined distance between them. When no braking force is generated or released in the vehicle braking device, bolt head 420 can be spaced apart from piston head 220.

[0092] The bolt head 420 can press the piston head 220. Depending on the direction of movement of the bolt body 410, the bolt head 420 can press the piston head 220 or release pressure in a first direction.

[0093] The bolt head 420 may have an outer diameter larger than that of the bolt body 410. Therefore, when the bolt thread portion 400 presses against the piston portion 200 to move toward the brake pad 30, the contact diameter of the bolt thread portion 400 that contacts the piston portion 200 may be increased.

[0094] When the outer diameter of the bolt head 420 contacting the piston head 220 is greater than, but not equal to or smaller than, the outer diameter of the bolt body 410, the contact diameter of the bolt head 420 contacting the piston head 220 further increases, thereby improving the load transfer efficiency to the piston portion 200 through the bolt head 420. Furthermore, as the contact diameter of the bolt head 420 contacting the piston head 220 increases, the load can be stably transferred to the piston portion 200, and the centering of the bolt thread portion 400 can be stably maintained.

[0095] The bolt head 420 may include a head connection portion 421 and a head extension portion 422.

[0096] The head connection portion 421 is the part of the bolt head 420 facing the bolt body 410 and is connected to the bolt body 410. The head extension portion 422 can extend from the head connection portion 421 toward the piston head 210 and can have a larger outer diameter than the head connection portion 421. Therefore, the contact diameter of the bolt thread portion 400 that contacts the piston portion 200 can be increased.

[0097] When the outer diameter of the head extension portion 422 that contacts the piston head 220 is larger than, but not equal to, the outer diameter of the head connecting portion 421, the contact diameter of the head extension portion 422 that contacts the piston head 220 further increases, thereby improving the load transfer efficiency from the bolt head 420 to the piston portion 200. Furthermore, as the contact diameter of the head extension portion 422 that contacts the piston head 220 increases, the load can be stably transferred to the piston portion 200.

[0098] The head extension portion 422 may include a curved surface portion 422a facing the outer periphery of the piston head 220. The curved surface portion 422a may have a convex curved surface facing the piston head 220 and may be formed along the entire outer periphery of the head extension portion 422. The head extension portion 422 may contact the piston head 220 on the curved surface portion 422a.

[0099] The head extension portion 422 can roll in contact with the piston head 220 on the curved surface portion 422a. In other words, the head extension portion 422 is able to roll relative to the piston head 220 on the curved surface portion 422a.

[0100] The piston head 220 may include a flat portion 220a in the area that contacts the curved portion 422a. Therefore, when the head extension portion 422 contacts the piston head 220 due to the movement of the bolt thread portion 400 in the first direction, the head extension portion 422 having the convex curved portion 422a and the piston head 220 having the flat portion 220a can remain in contact even if the head extension portion 422 rolls relative to the piston head 220.

[0101] When braking force is generated by the friction between the brake disc 20 and the brake pad 30 due to the movement of the piston portion 200, the caliper body 100 may undergo local deformation in response to the reaction force of the braking force. As a result, compared to the non-braking state, the cylinder 130 and the piston portion 200 may tilt slightly relative to the central axis. In other words, in the braking state, the cylinder 130 and / or the piston portion 200 may tilt at a small angle relative to the central axis.

[0102] When the cylinder 130 and / or piston portion 200 are tilted relative to their respective central axes, the head extension portion 422 can roll in contact with the piston head 220 on the curved surface portion 422a. In other words, when the cylinder 130 and / or piston portion 200 are tilted relative to the central axis, the head extension portion 422 can roll relative to the piston head 220 on the curved surface portion 422a.

[0103] When the cylinder 130 and / or piston portion 200 is tilted relative to the central axis, the head extension portion 422 rolls relative to the piston head 220. This causes the bolt body 410 connected to the bolt head 420 to tilt at the same angle as the bolt head 420 rolls.

[0104] When the cylinder 130 and / or piston portion 200 is tilted relative to the central axis as described above, the bolt head 420 and bolt body 410 also tilt, which prevents the load from being concentrated on any particular ball member B among the plurality of ball members B arranged in the longitudinal direction of the bolt body 410. This ensures the robustness of the bolt thread portion 400 against the tilting of the cylinder 130 and / or piston portion 200 and improves the durability of the vehicle braking system.

[0105] The bearing portion 500 can be arranged between the cylinder 130 and the nut thread portion 300, and supports the nut thread portion 300 so that the nut thread portion 300 can rotate within the cylinder 130.

[0106] When the cylinder 130 and / or piston portion 200 are tilted relative to their respective central axes, the nut thread portion 300 can roll into contact with the bearing portion 500. In other words, when the cylinder 130 and / or piston portion 200 are tilted relative to the central axis, the nut thread portion 300 can roll against the bearing portion 500.

[0107] When the cylinder 130 and / or piston portion 200 is tilted relative to the central axis as described above, the nut thread portion 300 also tilts. This prevents the load on the nut thread portion 300 from being concentrated on any particular ball member B among the plurality of ball members B arranged in the longitudinal direction of the bolt body 410. This ensures the robustness of the bolt thread portion 400 against the tilting of the cylinder 130 and / or piston portion 200 and improves the durability of the vehicle braking system.

[0108] The bearing portion 500 may include an outer ring portion 510 and bearing balls 520.

[0109] The outer ring portion 510 contacts the inner surface of the cylinder 130. The outer ring portion 510 can be press-fitted into the cylinder 130 to securely fix it in place. Bearing balls 520 can be arranged between the outer ring portion 510 and the nut thread body 310. In this embodiment, the nut thread body 310 is shown as serving as the inner ring portion. However, as in this embodiment, the inner ring portion can be integrally formed with the nut thread body 310, or it can be formed separately from the nut thread body 310.

[0110] The nut thread body 310 may include a rolling contact portion 315, an upper step portion 316, and a lower bottom portion 317.

[0111] Since the nut thread body 310 serves as the inner ring portion, which is the rotating part of the bearing portion 500, the nut thread body 310 can rotate relative to the outer ring portion 510. Furthermore, the nut thread body 310 has a rolling contact portion 315 in the area facing the bearing ball 520, which allows it to roll relative to the bearing ball 520. Because the nut thread body 310 can roll relative to the bearing ball 520, the angle between the nut thread body 310 and the outer ring portion 510 can be changed.

[0112] The nut thread body 310 may have an upper step portion 316 formed on the piston head 220 side relative to the rolling contact portion 315, and a lower bottom portion 317 formed on the nut thread tail portion 320 side. The upper step portion 316 is a portion that protrudes outward relative to the lower bottom portion 317, and the rolling contact portion 315 may be formed between the upper step portion 316 and the lower bottom portion 317.

[0113] The rolling contact portion 315 may have an inwardly facing concave surface and may be formed along the entire outer periphery of the nut thread body 310. The bearing ball 520 may directly contact the rolling contact portion 315 or indirectly contact the rolling contact portion 315 through another component.

[0114] Since the rolling contact portion 315 includes a curved portion, the nut thread body 310 can roll relative to the bearing ball 520 or the outer ring portion 510 on the rolling contact portion 315.

[0115] During braking of the vehicle braking system, the piston portion 200 may tilt relative to the central axis due to braking torque or the disengagement of the caliper body 100, or the cylinder 130 may tilt relative to the central axis. According to this embodiment, the bolt head 420 is capable of rolling relative to the piston portion 200, which prevents load concentration on any particular ball member B among the plurality of ball members B arranged on the outer surface of the bolt thread portion 400. According to this embodiment, the nut thread portion 300 is capable of rolling relative to the bearing portion 500, which prevents load concentration on any particular ball member B among the plurality of ball members B arranged on the inner surface of the nut thread portion 300.

[0116] The vehicle braking device according to this embodiment can roll at the front of the bolt thread portion 400, outside the nut thread portion 300, or at both the front of the bolt thread portion 400 and outside the nut thread portion 300. Therefore, even when the piston portion 200 is tilted relative to the central axis or the cylinder 130 is tilted relative to the central axis, the load can be prevented from concentrating on any particular ball bearing member B. This ensures the robustness of the vehicle braking device according to this embodiment against tilting and improves the durability of the device.

[0117] The vehicle braking device according to the embodiments of this disclosure may also include an actuator portion 600.

[0118] The actuator section 600 can receive power from the motor section 660 and provide rotational force to the nut thread section 300.

[0119] The actuator portion 600 may include a power transmission portion. The power transmission portion may engage with the nut thread portion 300 and transmit rotational force to the nut thread portion 300. The rotational force provided by the actuator portion 600 causes the nut thread portion 300 to rotate, resulting in the translation of the bolt thread portion 400.

[0120] This embodiment is a nut-thread driven braking device for vehicles, wherein the nut thread portion 300 first rotates by receiving rotational force from the actuator portion 600, and the bolt thread portion 400, which is mechanically connected to the nut thread portion 300 via a ball member B, subsequently rotates. Therefore, according to this embodiment, the axial length can be reduced compared to a bolt-thread driven braking device for vehicles.

[0121] The power transmission section may include multiple gears that are sequentially engaged and connected between the motor section 660 and the nut threaded section 300. The power transmission section is not limited to the above-described configuration and may be modified to be a different type of power transmission device capable of receiving rotational force from the motor section 660 and rotating the nut threaded section 300.

[0122] The power transmission section may include a power transmission recess 620 disposed within the actuator housing 610.

[0123] The power transmission groove portion 620 can be arranged around the anti-rotation protrusion 630, and the nut thread tail 320 of the nut thread portion 300 can be inserted therein.

[0124] The power transmission groove portion 620 may have a shape corresponding to the nut thread tail 320 to engage with the nut thread tail 320. The power transmission groove portion 620 may be formed as a non-circular groove portion. Non-circular means a shape that is not perfectly circular, including shapes such as ellipses, polygons, and other shapes. In this embodiment, the power transmission groove portion 620 is formed as a polygonal groove portion, specifically an approximately hexagonal groove portion.

[0125] The nut thread tail 320 and the power transmission groove portion 620 each have the same or corresponding non-circular shapes. Therefore, when the nut thread tail 320 is inserted into the power transmission groove portion 620, the nut thread tail 320 and the power transmission groove portion 620 engage with each other. Therefore, when the power transmission groove portion 620 rotates during operation of the actuator portion 600, the nut thread tail 320 engaging with the power transmission groove portion 620 also rotates in the same direction. Therefore, the rotational force of the actuator portion 600 can be stably transmitted to the nut thread portion 300 without loss.

[0126] The actuator portion 600 may include an anti-rotation portion. The anti-rotation portion may engage with the bolt thread portion 400 to limit rotation of the bolt thread portion 400. The rotational force provided by the actuator portion 600 causes the nut thread portion 300 to rotate, thereby translating the bolt thread portion 400.

[0127] Since the nut thread portion 300 and the bolt thread portion 400 are mechanically connected by the ball bearing component B, the rotation of the bolt thread portion 400 is prevented by the anti-rotation part, thus the rotation of the nut thread portion 300 is converted into the translational motion of the bolt thread portion 400.

[0128] The anti-rotation portion may include an anti-rotation protrusion 630. The anti-rotation protrusion 630 may be disposed within the actuator housing 610 and protrude outward from the actuator housing 610. The anti-rotation protrusion 630 may be disposed inside the power transmission recess portion 620.

[0129] When the nut thread tail 320 is inserted into and engages the power transmission groove portion 620, the anti-rotation protrusion 630 can be inserted into and engage the anti-rotation groove portion 411 of the bolt body 410. According to this embodiment as described above, since power transmission to the nut thread portion 300 and rotation prevention of the bolt thread portion 400 can be achieved by a single component, assemblability can be significantly improved.

[0130] The anti-rotation protrusion 630 may have a non-circular columnar shape. Non-circular means not perfectly circular, including shapes such as ellipses, polygons, and other shapes. In this embodiment, the anti-rotation protrusion 630 has a polygonal columnar shape, specifically a generally hexagonal columnar shape.

[0131] An anti-rotation groove portion 411 may be formed on the bolt body 410, its shape corresponding to the anti-rotation protrusion 630 for engagement with the anti-rotation protrusion 630. The anti-rotation groove portion 411 may be formed as a non-circular groove portion. Non-circular refers to a shape that is not perfectly circular, including shapes such as ellipses, polygons, and other shapes. In this embodiment, the anti-rotation groove portion 411 is formed as a polygonal groove portion, specifically an approximately hexagonal groove portion.

[0132] The anti-rotation protrusion 630 and the anti-rotation groove portion 411 each have the same or corresponding non-circular shapes. Therefore, when the anti-rotation protrusion 630 is inserted into the anti-rotation groove portion 411, the anti-rotation protrusion 630 and the anti-rotation groove portion 411 engage with each other. Therefore, when the power transmission groove portion 620 rotates during the operation of the actuator portion 600, the nut thread tail 320 engaging with the power transmission groove portion 620 rotates in the same direction, but the rotation of the bolt body 410 is prevented. Therefore, the rotational force of the actuator portion 600 can be stably converted into the translational motion of the bolt thread portion 400 without loss.

[0133] Since the anti-rotation protrusion 630 and the anti-rotation groove portion 411 are in surface contact, frictional loss can be reduced when an axially forward load is generated, and the bolt body 410 can be kept centered. In addition, since the anti-rotation groove portion 411 can be integrally formed with the bolt body 410, there is no need to manufacture the anti-rotation structure separately, thereby improving space utilization.

[0134] The anti-rotation recess portion 411 may include an extended inclined surface 411a that extends outward to guide precise insertion of the anti-rotation protrusion 630. The anti-rotation protrusion 630 may include a tapered inclined surface portion 630a on the outer side of its tip portion to facilitate insertion into the anti-rotation recess portion 411.

[0135] The anti-rotation protrusion 630 can be inserted into the bolt body 410 for a length greater than the maximum stroke of the piston portion 200. The maximum stroke of the piston portion 200 refers to the distance the piston portion 200 travels from its initial position to its fully forward position. The stroke of the piston portion 200 can increase the amount of wear corresponding to the brake pad 30. Therefore, since the length of the anti-rotation protrusion 630 inserted into the bolt body 410 is greater than the maximum stroke of the piston portion 200, the anti-rotation protrusion 630 maintains a constant engagement with the anti-rotation groove portion 411 of the bolt body 410, thereby continuously preventing rotation of the bolt thread portion 400.

[0136] Figure 6 This is a perspective view showing a vehicle braking device according to another embodiment of the present disclosure. Figure 7 This is a schematic cross-sectional view of a vehicle braking device according to an embodiment of the present disclosure. Figure 8 yes Figure 7 A magnified view of a portion of the image. Figure 9 yes Figure 8 A magnified view of a portion of the image. Figure 10 This is a view showing the position fixing portion of a vehicle braking device according to an embodiment of the present disclosure being installed onto the threaded portion of a nut. Figure 11It is a perspective view of the fixed portion according to the embodiment of this disclosure. Figure 12 This is a perspective view showing the actuator portion of a vehicle braking device according to an embodiment of the present disclosure.

[0137] Reference Figures 6 to 12 According to another embodiment of the present disclosure, a vehicle braking device may include a caliper body 100, a piston portion 200, a nut threaded portion 300, a bolt threaded portion 400, and a bearing portion 500.

[0138] The caliper body 100 can form the shape of a vehicle braking device and surround or support the piston portion 200, the nut thread portion 300, and the bolt thread portion 400.

[0139] The caliper body 100 may include a bridge-shaped member 110, a finger-shaped member 120, and a cylinder 130.

[0140] The bridge-shaped member 110 can form the appearance of the central portion of the caliper body 100 and support the finger member 120 and the cylinder 130. The bridge-shaped member 110 can be connected to a carrier (not shown), which is fixed to the steering knuckle (not shown) or the like via a guide rod (not shown).

[0141] The lower surface of the bridge-shaped member 110 can be arranged as a circumferential surface facing the brake disc 20, with a predetermined distance between them. The two sides of the bridge-shaped member 110 can be positioned relative to the brake disc 20 along a first direction (…). Figure 2 The +X direction) and the second direction opposite to the first direction ( Figure 2 (Extends in the -X direction).

[0142] A pair of brake pads 30 can be arranged below the bridge-shaped member 110. The pair of brake pads 30 can be arranged facing each other, with the brake disc 20 inserted between them.

[0143] A friction pad, comprising a material having a high coefficient of friction, such as rubber, may be attached to one surface of the brake pad 30 facing the brake disc 20.

[0144] The finger 120 can extend downward from one side of the bridge 110. The finger 120 can be arranged to face one of the pair of brake pads 30.

[0145] Cylinder 130 can extend downward from the opposite side of bridge-shaped member 110. Cylinder 130 can have a hollow cylindrical shape. One side of cylinder 130 ( Figure 2 The left side of the pair of brake pads 30 can be arranged to face the other one of the pair.

[0146] One side of the cylinder 130 may be open, and the open side of the cylinder 130 may be spaced apart from the brake pad 30 by a predetermined distance. The brake pad 30 is spaced apart from the brake disc 20 in the second direction.

[0147] The central axis of cylinder 130 can be arranged parallel to the central axis C1 of brake disc 20. The central axis of cylinder 130 can be along a third direction ( Figure 2 The +Z direction is spaced apart from the central axis C1 of the brake disc 20.

[0148] The third direction can be perpendicular to the first and second directions, and can be exemplified as the direction from the central axis C1 of the brake disc 20 toward the central axis of the cylinder 130.

[0149] When the lower surface of the bridge-shaped member 110 is arranged parallel to the ground, the third direction can be a direction perpendicular to the ground, that is, based on Figure 2 Along the upward direction of the Z-axis.

[0150] Piston portion 200 can move within cylinder 130 in a first direction ( Figure 2 (in the +X direction) or the second direction ( Figure 2 The piston section 200 can be movably arranged in the -X direction. The piston section 200 can be arranged within the cylinder 130.

[0151] The piston portion 200 may have a hollow cylindrical shape. The side of the piston portion 200 facing the brake pad 30 may be closed. The piston portion 200 may be arranged along the longitudinal direction of the cylinder 130.

[0152] The outer surface of the piston portion 200 can be slidably supported by the inner surface of the cylinder 130. Alternatively, the outer surface of the piston portion 200 can be spaced apart from the inner surface of the cylinder 130 by a predetermined distance.

[0153] The piston portion 200 can protrude outward from the cylinder 130 by moving in a first direction, pressing the brake pad 30, which is arranged facing the cylinder 130, against the brake disc 20. This allows the vehicle braking system to generate braking force.

[0154] In response to the movement of the piston portion 200 in the second direction, the piston portion 200 can separate from the brake pad 30. Therefore, the pressure applied to the brake pad 30 by the piston portion 200 is released, and the braking force of the vehicle braking device disappears.

[0155] The piston portion 200 may include a piston body 210 and a piston head 220.

[0156] The piston body 210 may have a hollow cylindrical shape, and the piston head 220 may be connected to the piston body 210 to close one side of the piston body 210. Figure 2 (Left side of the piston body 210). The piston head 220 is arranged between the two open sides of the piston body 210 facing the brake pad 30, and closes the open area of ​​the piston body 210.

[0157] The bolt thread portion 400 can be arranged inside the piston portion 200. The bolt body 410 and bolt head 420 of the bolt thread portion 400 are surrounded by the piston body 210. The bolt head 420 can be arranged to be inserted into the piston head 220.

[0158] Piston cover 260 can be installed inside cylinder 130 to prevent external impurities from entering and to seal the interior of cylinder 130. Piston cover 260 can be installed between cylinder 130 and piston portion 200. Piston cover 260 can be connected to piston body 210 or piston head 220 and press-fitted into cylinder 130.

[0159] The piston cover 260 may be formed to surround the piston portion 200. The piston cover 260 may include an elastically deformable material. For example, the piston cover 260 may be made of a rubber material. The piston cover 260 may be formed to have a corrugated shape.

[0160] The nut threaded portion 300 can be rotatably arranged in the cylinder 130 and connected to the bolt threaded portion 400. The bearing portion 500, which rotatably supports the nut threaded portion 300, can be installed inside the cylinder 130. The bearing portion 500 can be a ball bearing arranged between the cylinder 130 and the nut threaded portion 300.

[0161] The nut threaded portion 300 may have a hollow cylindrical shape with open ends. The nut threaded portion 300 may be arranged inside the cylinder 130, and its central axis may be coaxially aligned with the central axis of the cylinder.

[0162] One side of the nut threaded portion 300 ( Figure 2 The left side of the piston section 200 can be arranged to face the inner surface of the piston section 200. Figure 2 (on the right side), with a predetermined distance between them. The other side of the nut threaded portion 300 ( Figure 2 The right side of the cylinder can pass through the cylinder 130 and protrude outward from the cylinder 130.

[0163] The inner surface of the nut threaded portion 300 can be arranged to face the outer surface of the bolt threaded portion 400. A ball track can be formed on the inner circumferential surface of the nut threaded portion 300, with one periphery of the spherical ball member B located on this ball track. This ball track can extend helically along the longitudinal direction of the nut threaded portion 300 to provide a circulation path for the ball member B.

[0164] During operation of the actuator section 600, the nut threaded section 300 can receive the rotational force generated from the actuator section 600 through the power transmission section, and can rotate clockwise or counterclockwise about the central axis.

[0165] The nut thread portion 300 may include a nut thread body 310 and a nut thread tail 320.

[0166] The majority of the nut thread body 310 can be located inside the cylinder 130, and the nut thread tail 320 can be completely or mostly exposed outside the cylinder 130. The nut thread body 310 can be surrounded by the piston body 210.

[0167] The threaded tail 320 of the nut may have a non-circular cylindrical shape. Non-circular means a shape that is not perfectly circular, including shapes such as ellipses, polygons, and others. In this embodiment, the threaded tail 320 of the nut has a polygonal cylindrical shape, specifically a generally hexagonal cylindrical shape.

[0168] In response to rotation of the nut thread portion 300, the bolt thread portion 400 can move within the cylinder 130 in a first direction and a second direction. The bolt thread portion 400 can be arranged inside the nut thread portion 300. The bolt thread portion 400 can be arranged to pass through both ends of the nut thread portion 300.

[0169] The bolt threaded portion 400 can move in a first direction toward the brake pad 30, causing the piston portion 200 to press against the brake pad 30. Furthermore, the bolt threaded portion 400 can move in a second direction opposite to the first direction to release pressure on the piston portion 200.

[0170] The bolt thread portion 400 may include a bolt body 410 and a bolt head 420.

[0171] The bolt body 410 can be connected to the threaded portion 300 of the nut and receive rotational force from the threaded portion 300. The bolt head 420 can be separate from the bolt body 410. The bolt body 410 can be press-fitted to the bolt head 420 and integrated together. For example, the bolt body 410 can be press-fitted to the bolt head 420 via serrations.

[0172] Because the bolt head 420 is manufactured separately from the bolt body 410, the shape flexibility of the bolt head 420 can be increased. In particular, the shape of the bolt head 420 can be changed according to the specifications of the vehicle braking system. Forming the bolt head 420 separately from the relatively easily standardized bolt body 410 facilitates customization and increases design freedom. According to this embodiment, based on changes in the dimensions of the piston portion 200, the contact diameter of the bolt head 420 can be easily changed accordingly.

[0173] When the bolt body 410 translates in the first direction within the cylinder 130 in response to the rotation of the nut thread portion 300, it is positioned in front of the bolt body 410. Figure 2The bolt head 420 on the left side of the middle presses against the piston part 200.

[0174] The bolt body 410 may have a cylindrical shape with a generally circular cross-section. The bolt body 410 may be arranged inside the cylinder 130, and its central axis may be coaxially aligned with the central axis of the cylinder 130. The bolt body 410 may be connected to the threaded portion of the nut 300 via a ball bearing member B.

[0175] A ball track (not shown) may be formed on the outer peripheral surface of the bolt body 410, and the ball component B is located on the ball track. The ball track may be along the longitudinal direction of the bolt body 410. Figure 2 The ball bearing component B extends helically (in the left and right directions) to provide a circulation path for the ball bearing component B. Therefore, in response to the rotation of the nut thread portion 300, the bolt body 410 can move in either the first or second direction via the circulatory movement of the ball bearing component B.

[0176] Bolt head 420 can be disposed between bolt body 410 and piston portion 200. Bolt head 420 can be formed with an approximately circular cross-section. Bolt head 420 can be arranged to be inserted into piston head 220. Bolt head 420 can be arranged facing the inner surface of piston head 220, with a predetermined distance between them. When no braking force is generated or released in the vehicle braking device, bolt head 420 can be spaced apart from piston head 220.

[0177] The bolt head 420 can press the piston head 220. Depending on the direction of movement of the bolt body 410, the bolt head 420 can press the piston head 220 or release pressure in a first direction.

[0178] The bolt head 420 may have an outer diameter larger than that of the bolt body 410. Therefore, when the bolt thread portion 400 presses against the piston portion 200 to move toward the brake pad 30, the contact diameter of the bolt thread portion 400 that contacts the piston portion 200 may be increased.

[0179] When the outer diameter of the bolt head 420 contacting the piston head 220 is greater than, but not equal to or smaller than, the outer diameter of the bolt body 410, the contact diameter of the bolt head 420 contacting the piston head 220 further increases, thereby improving the load transfer efficiency to the piston portion 200 through the bolt head 420. Furthermore, as the contact diameter of the bolt head 420 contacting the piston head 220 increases, the load can be stably transferred to the piston portion 200, and the centering of the bolt thread portion 400 can be stably maintained.

[0180] The bolt head 420 may include a head connection portion 421 and a head extension portion 422.

[0181] The head connection portion 421 is the part of the bolt head 420 facing the bolt body 410 and is connected to the bolt body 410. The head extension portion 422 can extend from the head connection portion 421 toward the piston head 210 and can have a larger outer diameter than the head connection portion 421. Therefore, the contact diameter of the bolt thread portion 400 that contacts the piston portion 200 can be increased.

[0182] When the outer diameter of the head extension portion 422 that contacts the piston head 220 is larger than, but not equal to, the outer diameter of the head connecting portion 421, the contact diameter of the head extension portion 422 that contacts the piston head 220 further increases, thereby improving the load transfer efficiency from the bolt head 420 to the piston portion 200. Furthermore, as the contact diameter of the head extension portion 422 that contacts the piston head 220 increases, the load can be stably transferred to the piston portion 200.

[0183] The head extension portion 422 may include a curved surface portion 422a facing the outer periphery of the piston head 220. The curved surface portion 422a may have a convex curved surface facing the piston head 220 and may be formed along the entire outer periphery of the head extension portion 422. The head extension portion 422 may contact the piston head 220 on the curved surface portion 422a.

[0184] The head extension portion 422 can roll in contact with the piston head 220 on the curved surface portion 422a. In other words, the head extension portion 422 is able to roll relative to the piston head 220 on the curved surface portion 422a.

[0185] The piston head 220 may include a flat portion 220a in the area that contacts the curved portion 422a. Therefore, when the head extension portion 422 contacts the piston head 220 due to the movement of the bolt thread portion 400 in the first direction, the head extension portion 422 having the convex curved portion 422a and the piston head 220 having the flat portion 220a can remain in contact even if the head extension portion 422 rolls relative to the piston head 220.

[0186] When braking force is generated by the friction between the brake disc 20 and the brake pad 30 due to the movement of the piston portion 200, the caliper body 100 may undergo local deformation in response to the reaction force of the braking force. As a result, compared to the non-braking state, the cylinder 130 and the piston portion 200 may tilt slightly relative to the central axis. In other words, in the braking state, the cylinder 130 and / or the piston portion 200 may tilt at a small angle relative to the central axis.

[0187] When the cylinder 130 and / or piston portion 200 are tilted relative to their respective central axes, the head extension portion 422 can roll in contact with the piston head 220 on the curved surface portion 422a. In other words, when the cylinder 130 and / or piston portion 200 are tilted relative to the central axis, the head extension portion 422 can roll relative to the piston head 220 on the curved surface portion 422a.

[0188] When the cylinder 130 and / or piston portion 200 is tilted relative to the central axis, the head extension portion 422 rolls relative to the piston head 220. This causes the bolt body 410 connected to the bolt head 420 to tilt at the same angle as the bolt head 420 rolls.

[0189] When the cylinder 130 and / or piston portion 200 is tilted relative to the central axis as described above, the bolt head 420 and bolt body 410 also tilt, which prevents the load from being concentrated on any particular ball member B among the plurality of ball members B arranged in the longitudinal direction of the bolt body 410. This ensures the robustness of the bolt thread portion 400 against the tilting of the cylinder 130 and / or piston portion 200 and improves the durability of the vehicle braking system.

[0190] The bearing portion 500 can be arranged between the cylinder 130 and the nut thread portion 300, and supports the nut thread portion 300 so that the nut thread portion 300 can rotate within the cylinder 130.

[0191] The bearing portion 500 may include an outer ring portion 510, bearing balls 520, and an inner ring portion 530.

[0192] The outer ring portion 510 contacts the inner surface of the cylinder 130. The outer ring portion 510 can be press-fitted into the cylinder 130 to securely fix it in place. The inner ring portion 530 can be rotatably arranged inside the outer ring portion 510 and connected to the nut thread portion 300. The inner ring portion 530 can be press-fitted with and integrated with the nut thread body 310. Bearing balls 520 can be arranged between the outer ring portion 510 and the inner ring portion 530 to reduce friction during rotation of the inner ring portion 530.

[0193] According to another embodiment of this disclosure, the vehicle braking device may include a position retaining ring portion 550. The position retaining ring portion 550 may contact and support the bearing portion 500 from the rear side of the piston head 220, such that the bearing portion 500 can be secured in the appropriate position on the nut thread portion 300.

[0194] The positioning ring portion 550 may include a contact plate portion 551. The contact plate portion 551 may have a ring shape and contact and support the bearing portion 500 from the rear. The contact plate portion 551 may be formed extending from a portion facing the inner ring portion 530 to a portion facing the outer ring portion 510. Therefore, the contact plate portion 551 can contact not only the inner ring portion 530 but also at least a portion of the outer ring portion 510, thereby stably supporting the bearing portion 500.

[0195] The positioning retaining ring portion 550 may have an approximately V-shaped cross-section. The positioning retaining ring portion 550 may include a contact plate portion 551 that contacts the bearing portion 500 and an inclined plate portion 552 connected to the contact plate portion 551. The connection area between the contact plate portion 551 and the inclined plate portion 552 may be an edge portion 553 forming a V-shaped corner. The edge portion 553 may be sharply formed or may be more gently formed.

[0196] The nut thread body 310 of the nut thread portion 300 may be provided with an insertion groove portion 316 into which the positioning retaining ring portion 550 (particularly the edge portion 553) is inserted. During installation onto the nut thread portion 300, the positioning retaining ring portion 550 is installed by inserting it into the insertion groove portion 316, thereby securely fixing the positioning retaining ring portion 550 to the nut thread body 310. This allows the positioning retaining ring portion 550 to securely fix the bearing portion 500 to the appropriate position on the nut thread body 310.

[0197] The positioning retaining ring portion 550 may comprise an elastically deformable material. The positioning retaining ring portion 550 can elastically deform and expand as it moves along the periphery of the nut thread body 310, and elastically recover when it is installed into the insertion slot portion 316. Therefore, the positioning retaining ring portion 550 can be more easily installed into the insertion slot portion 316.

[0198] When the cylinder 130 and / or piston portion 200 is tilted relative to their respective central axes, the inner ring portion 530 or the outer ring portion 510 can roll into contact with the bearing balls 520. In other words, when the cylinder 130 and / or piston portion 200 is tilted relative to the central axis, the inner ring portion 530 or the outer ring portion 510 can roll relative to the bearing balls 520.

[0199] When the cylinder 130 and / or piston portion 200 tilts relative to the central axis as described above, the nut thread portion 300 also tilts as the inner ring portion rolls. This prevents the load on the nut thread portion 300 from being concentrated on any particular ball member B among the plurality of ball members B arranged in the longitudinal direction of the bolt body 410. This ensures the robustness of the bolt thread portion 400 against the tilting of the cylinder 130 and / or piston portion 200, thereby improving the durability of the vehicle braking system.

[0200] The inner ring portion 530 may include a rolling contact portion 535, an upper step portion 536, and a lower bottom portion 537.

[0201] Because the inner ring portion 530 has a rolling contact portion 535 in the area facing or contacting the bearing ball 520, the inner ring portion 530 can roll relative to the bearing ball 520. Because the outer ring portion 510 has a rolling contact portion (not shown) in the area facing or contacting the bearing ball 520, the outer ring portion 510 can roll relative to the bearing ball 520.

[0202] The inner ring portion 530 may have an upper stepped portion 536 formed on the piston head 220 side relative to the rolling contact portion 535, and a lower bottom portion 537 formed on the nut thread tail portion 320 side. The upper stepped portion 536 is a portion that protrudes outward relative to the lower bottom portion 537, and the rolling contact portion 535 may be formed between the upper stepped portion 536 and the lower bottom portion 537.

[0203] The rolling contact portion 535 can be formed as an inwardly facing concave curved surface and can be formed along the entire outer periphery of the inner ring portion 530. The bearing ball 520 can directly contact the rolling contact portion 535 or indirectly contact it through another component.

[0204] Because the rolling contact portion 535 includes a curved surface, the nut thread body 310 is able to roll relative to the cylinder 130.

[0205] During braking of the vehicle braking system, the piston portion 200 may tilt relative to the central axis due to braking torque or the disengagement of the caliper body 100, or the cylinder 130 may tilt relative to the central axis. According to this embodiment, the bolt head 420 is capable of rolling relative to the piston portion 200, which prevents the load from being concentrated on any particular ball member B among the plurality of ball members B arranged on the outer surface of the bolt thread portion 400. Furthermore, according to this embodiment, the nut thread portion 300 is capable of rolling relative to the cylinder 130 because the inner ring portion 530 rolls relative to the bearing balls 520. Therefore, this prevents the load from being concentrated on any particular ball member B among the plurality of ball members B arranged on the inner surface of the nut thread portion 300.

[0206] The vehicle braking device according to this embodiment can roll at the front of the bolt thread portion 400, outside the nut thread portion 300, or at both the front of the bolt thread portion 400 and outside the nut thread portion 300. Therefore, even when the piston portion 200 is tilted relative to the central axis or the cylinder 130 is tilted relative to the central axis, the load can be prevented from concentrating on any particular ball bearing member B. This ensures the robustness of the vehicle braking device according to this embodiment against tilting and improves the durability of the device.

[0207] According to another embodiment of this disclosure, the vehicle braking device may also include an actuator portion 600.

[0208] The actuator section 600 can receive power from the motor section 660 and provide rotational force to the nut thread section 300.

[0209] The actuator portion 600 may include a power transmission portion. The power transmission portion may engage with the nut thread portion 300 and transmit rotational force to the nut thread portion 300. The rotational force provided by the actuator portion 600 causes the nut thread portion 300 to rotate, resulting in the translation of the bolt thread portion 400.

[0210] This embodiment is a nut-thread driven braking device for vehicles, wherein the nut thread portion 300 first rotates by receiving rotational force from the actuator portion 600, and the bolt thread portion 400, which is mechanically connected to the nut thread portion 300 via a ball member B, subsequently rotates. Therefore, according to this embodiment, the axial length can be reduced compared to a bolt-thread driven braking device for vehicles.

[0211] The power transmission section may include multiple gears that are sequentially engaged and connected between the motor section 660 and the nut threaded section 300. The power transmission section is not limited to the above-described configuration and may be modified to be a different type of power transmission device capable of receiving rotational force from the motor section 660 and rotating the nut threaded section 300.

[0212] The power transmission section may include a power transmission recess 620 disposed within the actuator housing 610.

[0213] The power transmission groove portion 620 can be arranged around the anti-rotation protrusion 630, and the nut thread tail 320 of the nut thread portion 300 can be inserted therein.

[0214] The power transmission groove portion 620 may have a shape corresponding to the nut thread tail 320 to engage with the nut thread tail 320. The power transmission groove portion 620 may be formed as a non-circular groove portion. Non-circular means a shape that is not perfectly circular, including shapes such as ellipses, polygons, and other shapes. In this embodiment, the power transmission groove portion 620 is formed as a polygonal groove portion, specifically an approximately hexagonal groove portion.

[0215] The nut thread tail 320 and the power transmission groove portion 620 each have the same or corresponding non-circular shapes. Therefore, when the nut thread tail 320 is inserted into the power transmission groove portion 620, the nut thread tail 320 and the power transmission groove portion 620 engage with each other. Therefore, when the power transmission groove portion 620 rotates during operation of the actuator portion 600, the nut thread tail 320 engaging with the power transmission groove portion 620 also rotates in the same direction. Therefore, the rotational force of the actuator portion 600 can be stably transmitted to the nut thread portion 300 without loss.

[0216] The actuator portion 600 may include an anti-rotation portion. The anti-rotation portion may engage with the bolt thread portion 400 to limit rotation of the bolt thread portion 400. The rotational force provided by the actuator portion 600 causes the nut thread portion 300 to rotate, thereby translating the bolt thread portion 400.

[0217] Since the nut thread portion 300 and the bolt thread portion 400 are mechanically connected by the ball bearing component B, the rotation of the bolt thread portion 400 is prevented by the anti-rotation part, thus the rotation of the nut thread portion 300 is converted into the translational motion of the bolt thread portion 400.

[0218] The anti-rotation portion may include an anti-rotation protrusion 630. The anti-rotation protrusion 630 may be disposed within the actuator housing 610 and protrude outward from the actuator housing 610. The anti-rotation protrusion 630 may be disposed inside the power transmission recess portion 620.

[0219] When the nut thread tail 320 is inserted into and engages the power transmission groove portion 620, the anti-rotation protrusion 630 can be inserted into and engage the anti-rotation groove portion 411 of the bolt body 410. According to this embodiment as described above, since power transmission to the nut thread portion 300 and rotation prevention of the bolt thread portion 400 can be achieved by a single component, assemblability can be significantly improved.

[0220] The anti-rotation protrusion 630 may have a non-circular columnar shape. Non-circular means not perfectly circular, including shapes such as ellipses, polygons, and other shapes. In this embodiment, the anti-rotation protrusion 630 has a polygonal columnar shape, specifically a generally hexagonal columnar shape.

[0221] An anti-rotation groove portion 411 may be formed on the bolt body 410, its shape corresponding to the anti-rotation protrusion 630 for engagement with the anti-rotation protrusion 630. The anti-rotation groove portion 411 may be formed as a non-circular groove portion. Non-circular refers to a shape that is not perfectly circular, including shapes such as ellipses, polygons, and other shapes. In this embodiment, the anti-rotation groove portion 411 is formed as a polygonal groove portion, specifically an approximately hexagonal groove portion.

[0222] The anti-rotation protrusion 630 and the anti-rotation groove portion 411 each have the same or corresponding non-circular shapes. Therefore, when the anti-rotation protrusion 630 is inserted into the anti-rotation groove portion 411, the anti-rotation protrusion 630 and the anti-rotation groove portion 411 engage with each other. Therefore, when the power transmission groove portion 620 rotates during the operation of the actuator portion 600, the nut thread tail 320 engaging with the power transmission groove portion 620 rotates in the same direction, but the rotation of the bolt body 410 is prevented. Therefore, the rotational force of the actuator portion 600 can be stably converted into the translational motion of the bolt thread portion 400 without loss.

[0223] Since the anti-rotation protrusion 630 and the anti-rotation groove portion 411 are in surface contact, frictional loss can be reduced when an axially forward load is generated, and the bolt body 410 can be kept centered. In addition, since the anti-rotation groove portion 411 can be integrally formed with the bolt body 410, there is no need to manufacture the anti-rotation structure separately, thereby improving space utilization.

[0224] The anti-rotation recess portion 411 may include an extended inclined surface 411a that extends outward to guide precise insertion of the anti-rotation protrusion 630. The anti-rotation protrusion 630 may include a tapered inclined surface portion 630a on the outer side of its tip portion to facilitate insertion into the anti-rotation recess portion 411.

[0225] The anti-rotation protrusion 630 can be inserted into the bolt body 410 for a length greater than the maximum stroke of the piston portion 200. The maximum stroke of the piston portion 200 refers to the distance the piston portion 200 travels from its initial position to its fully forward position. The stroke of the piston portion 200 can increase the amount of wear corresponding to the brake pad 30. Therefore, since the length of the anti-rotation protrusion 630 inserted into the bolt body 410 is greater than the maximum stroke of the piston portion 200, the anti-rotation protrusion 630 maintains a constant engagement with the anti-rotation groove portion 411 of the bolt body 410, thereby continuously preventing rotation of the bolt thread portion 400.

[0226] Although embodiments of the present disclosure have been described with reference to the accompanying drawings, these embodiments are merely exemplary, and those skilled in the art will understand that various modifications and other equivalent embodiments can be made from these disclosed embodiments.

Claims

1. A vehicle braking device, the braking device comprising: The caliper body is configured to have a cylinder; The piston portion is movably arranged in the cylinder and positioned to face the brake pads; The nut threaded portion, which is arranged in the piston portion and configured to receive rotational force from the actuator portion and rotate accordingly; and A bolt thread portion is configured to include a bolt body and a bolt head; the bolt body is connected to the nut thread portion and receives rotational force from the nut thread portion; the bolt head is separately formed from the bolt body, connected to the bolt body, and arranged to face the piston portion, wherein the bolt head presses against the piston portion when the bolt body moves within the cylinder in response to rotation of the nut thread portion.

2. The vehicle braking device according to claim 1, wherein, The bolt head has an outer diameter larger than that of the bolt body.

3. The vehicle braking device according to claim 2, wherein, The bolt head includes: The head connection portion, which is connected to the bolt body; and The head extension portion is configured to extend from the head connection portion toward the piston portion and has a larger outer diameter than the head connection portion.

4. The vehicle braking device according to claim 3, wherein, The head extension includes a curved surface portion located on the outer periphery facing the piston portion, and the head extension portion contacts the piston portion on the curved surface portion.

5. The vehicle braking device according to claim 4, wherein, In response to the tilting of the piston portion relative to the central axis, the head extension portion rolls relative to the piston portion on the curved surface portion.

6. The vehicle braking device according to claim 5, wherein, The piston portion has a planar portion in the area that contacts the curved surface portion.

7. The vehicle braking device according to claim 1, wherein, The bolt body is connected to the nut thread portion via ball bearings on the inner surface of the nut thread portion.

8. The vehicle braking device according to claim 1, further comprising: A bearing portion is disposed between the cylinder and the nut thread portion and is configured to support the nut thread portion to allow the nut thread portion to rotate within the cylinder.

9. The vehicle braking device according to claim 8, wherein, In response to the tilting of the piston portion relative to the central axis, the threaded portion of the nut rolls relative to the bearing portion.

10. The vehicle braking device according to claim 9, wherein, The bearing portion includes: The outer ring portion contacts the inner surface of the cylinder; and Bearing balls are arranged between the outer ring portion and the threaded portion of the nut. The nut thread portion has a rolling contact portion in the area facing the bearing balls.

11. A vehicle braking device, the braking device comprising: The caliper body is configured to have a cylinder; The piston portion is movably arranged in the cylinder and positioned to face the brake pads; The nut thread portion, which is arranged in the piston portion, is configured to receive rotational force from the actuator portion and rotate accordingly; The bolt thread portion is configured to move within the cylinder in response to rotation of the nut thread portion and press the piston portion; A bearing portion is disposed between the cylinder and the nut thread portion and is configured to support the nut thread portion to allow the nut thread portion to rotate in the cylinder; as well as The positioning ring portion is configured to contact and support the bearing portion to secure the bearing portion in the appropriate position on the nut thread portion.

12. The vehicle braking device according to claim 11, wherein, The bearing portion includes: The outer ring portion contacts the inner surface of the cylinder; An inner ring portion, rotatably disposed inside the outer ring portion, and configured to contact the threaded portion of the nut; and Bearing balls are arranged between the outer ring portion and the inner ring portion.

13. The vehicle braking device according to claim 12, wherein, The position fixing ring portion includes a contact plate portion that is at least partially in contact with the outer ring portion.

14. The vehicle braking device according to claim 13, wherein, The insertion groove portion into which the positioning ring portion is inserted is located on the outer surface of the threaded portion of the nut.

15. The vehicle braking device according to claim 14, wherein, The position fixing ring portion has a V-shaped cross-section, and the edge portion of the position fixing ring portion is inserted into the insertion groove portion.

16. The vehicle braking device according to claim 14, wherein, The position fixing ring portion comprises an elastically deformable material.

17. The vehicle braking device according to claim 12, wherein, The inner ring portion has a rolling contact portion in the area facing the bearing balls.

18. The vehicle braking device according to claim 17, wherein, The inner ring portion includes: The lower bottom, which is connected to one side of the rolling contact portion; and The upper step portion, which connects to the other side of the rolling contact portion, is configured to protrude outward relative to the lower bottom.

19. The vehicle braking device according to claim 18, wherein, The rolling contact portion is formed as an inwardly facing concave curved surface and is formed along the entire outer periphery of the inner ring portion.

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