Vehicle braking systems

Abstract

Vehicle braking system, including: a brake caliper body with a cylinder; a piston part that is movably arranged in the cylinder and is arranged so that it faces a brake pad; a nut screw part that is arranged in the piston part and rotates by receiving a rotational force from an actuator; a bolt screw part comprising a bolt body coupled to the nut screw part and receiving the rotational force from the nut screw part, and a bolt head provided separately from the bolt body, coupled to the bolt body and arranged to face the piston part; and a bearing part comprising an outer ring part that is in contact with an inner surface of the cylinder and a bearing ball that is arranged between the outer ring part and the nut screw part.

Description

Background 1. Technical field

[0001] Exemplary embodiments of the present disclosure relate to vehicle braking systems and, in particular, to vehicle braking systems that can ensure stable braking performance. 2. State of the art

[0002] Typically, a vehicle braking system uses a driving force to push a piston into contact with a brake pad and brake disc, utilizing the frictional force between the pad and disc to slow the vehicle. Among vehicle braking systems, an electromechanical braking device (EMB) generates braking force without the use of hydraulic pressure. It does this by mounting a motor-driven actuator on a brake caliper to pressurize a piston through a mechanism in which the actuator converts the rotary motion of a bolt into the linear motion of a nut, or vice versa.

[0003] The EMB device enables active braking and independent braking for each wheel, allowing not only a general main movement but also additional functions such as anti-lock braking system (ABS), electric stability control (ESC), traction control system (TCS) and automatic emergency braking (AEB) to be implemented, and higher performance can be implemented because there is no delay in the hydraulic supply.

[0004] According to the current state of the art, using a thrust bearing in a ball screw increases the axial length of the brake caliper body, which has disadvantages in terms of component arrangement and space efficiency. Furthermore, the conventional four-point ball bearing presents the problem that the ball size is large and the number of balls is limited, resulting in an increased outer diameter in the brake caliper and making assembly more difficult. In addition, with the conventional design, operation of the screw beyond the maximum permissible stroke cannot be controlled, which can lead to malfunctions or failures of the EMB device.

[0005] The background technology of the present disclosure is disclosed in Korean patent publication no. 10-2024-0054695 (published on April 26, 2024, entitled "Braking device for vehicles"). Summary

[0006] Various embodiments relate to vehicle braking systems in which a bolt body and a bolt head of a bolt screw part are manufactured separately.

[0007] Various designs relate to vehicle braking systems in which the contact diameter of the bolt head in contact with a piston part can be enlarged.

[0008] Various designs relate to vehicle braking systems that are able to stably support a nut and bolt part when generating and releasing the braking force.

[0009] Various embodiments relate to vehicle braking systems that are able to reduce the outer diameter of the bolt screw part and nut screw part assembly.

[0010] Various designs relate to vehicle braking systems that can prevent malfunctions or failures by specifying a maximum permissible stroke of the bolt screw part.

[0011] A vehicle braking system according to the first embodiment of the present disclosure can comprise a brake caliper body with a cylinder, a piston part that is movably arranged in the cylinder and is arranged so that it faces a brake pad, a nut screw part that is arranged in the piston part and rotates by receiving a rotational force from an actuator, a bolt screw part that comprises a bolt body that is coupled to the nut screw part and receives the rotational force from the nut screw part, and a bolt head that is provided separately from the bolt body, is coupled to the bolt body and is arranged so that it faces the piston part, and a bearing part that comprises an outer ring part that is in contact with an inner surface of the cylinder and a bearing ball that is arranged between the outer ring part and the nut screw part.

[0012] The outer ring part can be a bearing ball contact part on which the bearing ball sits, an outer ring bottom part which is connected to a first side of the bearing ball contact part and has the same height as a region of the bearing ball contact part which touches the outermost region of the bearing ball, and an outer ring step part which is connected to a second side of the bearing ball contact part and projects further towards the nut screw part than the outer ring bottom part.

[0013] The outer ring base part can protrude towards the nut screw part in order to be positioned further inwards than an outermost area of ​​the bearing ball.

[0014] The nut screw part can comprise a rolling contact part on which the bearing ball sits, a nut base part connected to a first side of the rolling contact part, and a nut step part connected to a second side of the rolling contact part and projecting further towards the outer ring part than the nut base part.

[0015] The nut base part can protrude towards the outer ring part in order to be positioned further outwards than an innermost area of ​​the bearing ball.

[0016] The bearing ball contact part can comprise a first outer contact area located on one side of the outer ring step part with respect to the outermost area of ​​the bearing ball, and a second outer contact area located on one side of the outer ring bottom part, and the rolling contact part can comprise a first inner contact area located on one side of the nut step part with respect to the innermost area of ​​the bearing ball, and a second inner contact area located on one side of the nut bottom part.

[0017] The first outer contact area and the first inner contact area can be arranged so that they are diagonally opposite each other with respect to the bearing ball, and the bearing ball can be supported by contact with the first outer contact area and the first inner contact area as the bolt screw part moves towards the piston part.

[0018] The second outer contact area and the second inner contact area can be arranged such that they are opposite each other in a diagonal direction with respect to the bearing ball, and the bearing ball can be supported by contact with the second outer contact area and the second inner contact area as the bolt screw part moves towards the opposite side of the piston part.

[0019] The bolt head can comprise a head connecting part coupled to the bolt body and having a larger diameter than the outer diameter of the bolt body, and a head extension part extending from the head connecting part towards the piston part and having an outer diameter larger than the outer diameter of the head connecting part.

[0020] The head extension part can have a curved surface area around an outer circumference in the direction of the piston part, and the head extension part can be in rolling contact with the piston part on the curved surface area.

[0021] A vehicle braking system according to the second embodiment of the present disclosure can comprise a brake caliper body with a cylinder, a piston part movably arranged in the cylinder and positioned so that it faces a brake pad, a nut-screw part arranged in the piston part, which rotates by receiving a rotational force from an actuator and comprises an outer ball rail forming a recirculation path of ball elements on an inner circumferential surface, and a bolt-screw part comprising a bolt body coupled to the nut-screw part and receiving the rotational force from the nut-screw part, and a bolt head provided separately from the bolt body, coupled to the bolt body and positioned so that it faces the piston part, wherein an inner ball rail is provided on an outer circumferential surface of the bolt body.so that it faces the outer ball rail and forms a circular path for the ball elements. The nut and bolt part can comprise a first return bore unit through which the ball elements enter and exit, a return channel connected to the first return bore unit, and a second return bore unit connected to the return channel through which the ball elements enter and exit.

[0022] The spherical elements entering the first return bore unit can be guided through the return channel to the second return bore unit, and the spherical elements entering the second return bore unit can be guided through the return channel to the first return bore unit.

[0023] The first return bore unit can be located closer to the piston part than the second return bore unit.

[0024] The vehicle braking system may further comprise a bearing part with an outer ring part in contact with an inner surface of the cylinder and a bearing ball that is arranged between the outer ring part and the nut screw part.

[0025] The outer ring part can comprise a bearing ball contact part on which the bearing ball sits, an outer ring bottom part connected to a first side of the bearing ball contact part, and an outer ring step part connected to a second side of the bearing ball contact part and projecting further towards the nut screw part than the outer ring bottom part.

[0026] The nut screw part can comprise a rolling contact part on which the bearing ball sits, a nut base part which is connected to a first side of the rolling contact part and has the same height as a part of the bearing ball contact part which comes into contact with an innermost part of the bearing ball, and a nut step part which is connected to the other side of the rolling contact part and projects further towards a second ring part than the nut base part.

[0027] The outer ring step part and the nut step part can be arranged so that they are diagonally opposite each other with respect to the bearing ball.

[0028] The bolt head can comprise a head connecting part coupled to the bolt body and having a larger diameter than the outer diameter of the bolt body, and a head extension part extending from the head connecting part towards the piston part and having an outer diameter larger than the outer diameter of the head connecting part.

[0029] The head extension part can have a curved surface area around an outer circumference in the direction of the piston part, and the head extension part can be in contact with the piston part on the curved surface area.

[0030] If the piston part is inclined with respect to a central axis, the head extension part can roll in the curved surface area with respect to the piston part, and the nut bolt part can roll with respect to the bearing part.

[0031] A vehicle braking system according to the third embodiment of the present disclosure can comprise a brake caliper body with a cylinder, a piston part movably arranged in the cylinder and positioned so that it faces a brake pad, a nut screw part arranged in the piston part and rotating by receiving a rotational force from an actuator, and a bolt screw part comprising a bolt body coupled to the nut screw part to receive the rotational force from the nut screw part, and a bolt head provided separately from the bolt body and coupled to the bolt body, and positioned so that it faces the piston part, wherein, when the bolt body is moved by a defined distance in the direction of the piston part, movement in the direction of the piston part is blocked by the nut screw part.

[0032] The bolt body can be provided with a stop projection, and a stop is provided on an inner circumferential surface of the nut screw part, and when the stop projection is in contact with the stop, the bolt body can be prevented from moving within the nut screw part.

[0033] The stop projection can extend further outwards than an outer circumferential surface of the bolt body, and the stop can extend further inwards than an inner circumferential surface of the nut screw part.

[0034] The stop projection can be pressed or screwed to form a unit with the bolt body, and the stop can be pressed or screwed to form a unit with the nut screw part.

[0035] The outer diameter of the bolt head can be larger than the outer diameter of the bolt body.

[0036] The bolt head can comprise a head connecting part that is connected to the bolt body and a head extension part that extends from the head connecting part towards the piston part and has an outside diameter that is larger than the outside diameter of the head connecting part.

[0037] The head extension part can have a curved surface area around an outer circumference in the direction of the piston part, and the head extension part can be in contact with the piston part on the curved surface area.

[0038] If the piston part is inclined with respect to a central axis, the head extension part can roll on the curved surface area with respect to the piston part.

[0039] The vehicle braking system may further include a bearing part that is arranged between the cylinder and the nut screw part and supports the nut screw part in such a way that the nut screw part rotates in the cylinder, and if the piston part is inclined with respect to a central axis, the nut screw part rolls with respect to the bearing part.

[0040] The vehicle braking system may further include a bearing part that is arranged between the cylinder and the nut and bolt part and supports the nut and bolt part in such a way that the nut and bolt part rotates in the cylinder, and if the piston part is inclined with respect to a central axis, the nut and bolt part can roll with respect to the bearing part.

[0041] The bearing part can comprise an outer ring part that comes into contact with an inner surface of the cylinder, and a bearing ball that is arranged between the outer ring part and the nut screw part, and the nut screw part can comprise a rolling contact part on a section facing the bearing ball.

[0042] According to the present disclosure, since the bolt head is manufactured as a separate product from the bolt body, the shape flexibility of the bolt head can be improved.

[0043] According to the present disclosure, a load can be stably transferred to the piston part because the contact diameter of the bolt head, which is in contact with the piston part, is increased.

[0044] According to the present disclosure, when generating and releasing the braking force, bearing balls come into contact with a rolling contact part and a bearing ball contact part, so that the load of the nut screw part can be stably supported.

[0045] Since the bearing part is designed as a two-point bearing according to the present disclosure, the assembly is simple and the ball size can be reduced, so that the outside diameter of the bolt screw part and nut screw part arrangement can be reduced.

[0046] Since, according to the present disclosure, a separate return path is provided in the nut screw part, the ball element can circulate repeatedly and be operated on an outer and an inner ball rail, thereby stably converting and transferring the torque into an axial load.

[0047] Since, according to the present disclosure, the maximum permissible stroke of the bolt screw part is determined by a stop projection and a stop, malfunctions or failures of the vehicle braking system can be prevented in advance. Brief description of the drawings Fig. Figure 1 is a perspective view that schematically represents a vehicle braking system according to the first embodiment of the present disclosure. Fig. Figure 2 is a cross-sectional view that schematically represents a vehicle braking system according to the first embodiment of the present disclosure. Fig. 3 is a partially enlarged view of Fig. 2. Fig. 4 is a partially enlarged view of Fig. 3. Fig. Figure 5 is an enlarged view showing a bearing part of a vehicle brake system according to the first embodiment of the present disclosure. Fig. Figure 6 is a perspective view showing an actuator part of a vehicle braking system according to the first embodiment of the present disclosure. Fig. Figure 7 is a cross-sectional view that schematically represents a vehicle braking system according to the second embodiment of the present disclosure. Fig. Figure 8 is a view that schematically represents a return path of a ball element in a vehicle braking system according to the second embodiment of the present disclosure. Fig. Image 9 is a partially enlarged view of Fig. 7. Fig. 10 is a partially enlarged view of Fig. 9. Fig. Figure 11 is a cross-sectional view schematically representing a vehicle braking system according to the third embodiment of the present disclosure. Fig. Figure 12 is a cross-sectional view showing a nut screw part and a bolt screw part of a vehicle brake system according to the third embodiment of the present disclosure. Fig. Figure 13 is a perspective cross-sectional view showing a nut screw part and a bolt screw part of a vehicle brake system according to the third embodiment of the present disclosure. Fig. 14 is a partially enlarged view of Fig. 11. Fig. 15 is a partially enlarged view of Fig. 14. Detailed description

[0048] Vehicle braking systems according to the present disclosure are described in detail below using various embodiments and with reference to the accompanying drawings. The line thickness and size of the individual components in the drawings may be exaggerated for simplification. The terms described below have been defined in consideration of their function in the present disclosure and may vary depending on the intention or procedure of the user or operator. Therefore, these terms should be interpreted within the context of this description.

[0049] Fig. Figure 1 is a perspective view schematically representing a vehicle braking system according to the first embodiment of the present disclosure, Fig. Figure 2 is a cross-sectional view that schematically represents the vehicle braking system according to the first embodiment of the present disclosure, Fig. 3 is a partially enlarged view of Fig. 2, Fig. 4 is a partially enlarged view of Fig. 3, Fig. Figure 5 is an enlarged view showing a bearing part of the vehicle brake system according to the first embodiment of the present disclosure, and Fig. Figure 6 is a perspective view showing an actuator part of the vehicle braking system according to the first embodiment of the present disclosure.

[0050] With reference to Fig. 1 to Fig. 6 The vehicle braking system according to the embodiment of the present disclosure comprises a brake caliper body 100, a piston part 200, a nut screw part 300 and a bolt screw part 400.

[0051] The brake caliper body 100 forms the outer shape of the vehicle brake system and surrounds or supports the piston part 200, the nut-bolt part 300, and the bolt-bolt part 400. The brake caliper body 100 comprises a bridge 110, a finger 120, and a cylinder 130.

[0052] The bridge 110 forms the appearance of a central section of the brake caliper body 100 and carries the finger 120 and the cylinder 130. The bridge 110 can be connected to a support (not shown) which is attached to a steering knuckle (not shown) or the like via a guide rod (not shown).

[0053] One underside of the bridge 110 is positioned such that it faces a circumferential surface of a brake disc 20 at a defined distance. Both sides of the bridge 110 extend with respect to the brake disc 20 along a first direction (+X direction, as shown in Fig. 2 shown) and a second direction (-X direction, as shown in Fig. 2 shown), which is opposite to the first direction.

[0054] Below the bridge 110 is a pair of brake pads 30. The pair of brake pads 30 is arranged so that they face each other and the brake disc 20 is located between them.

[0055] On one side of each brake pad 30 facing the brake disc 20, a friction lining made of a material with a high coefficient of friction, for example rubber, may be attached.

[0056] The finger 120 extends downwards from a first side of the bridge 110. The finger 120 is positioned so that it faces one of the brake pads 30.

[0057] The cylinder 130 extends downwards from a second side of the bridge 110. The cylinder 130 can have a columnar shape with an empty interior. One side (left side in Fig. 2) of cylinder 130 is arranged so that it faces the other brake pad of the pair of brake pads 30.

[0058] One side of the cylinder 130 is open and the open side of the cylinder 130 is spaced from the brake pad 30 by a fixed distance, which in the second direction is spaced from the brake disc 20.

[0059] A central axis of the cylinder 130 runs parallel to a central axis C1 of the brake disc 20. The central axis of the cylinder 130 is oriented in a third direction (+Z-direction based on Fig. 2) spaced from the central axis C1 of the brake disc 20.

[0060] The third direction can, for example, be represented as a direction perpendicular to the first and second directions and extends from the central axis C1 of the brake disc 20 in the direction of the central axis of the cylinder 130.

[0061] If the lower surface of bridge 110 is parallel to the ground, the third direction can be a direction perpendicular to the ground, i.e., the direction along the Z-axis direction according to Fig. 2 increases.

[0062] The piston part 200 is arranged in the cylinder 130 such that it moves in the first direction (+X direction according to Fig. 2) or the second direction (-X direction according to Fig. 2) is movable. The piston part 200 is arranged in the cylinder 130.

[0063] The piston part 200 has a columnar shape with a hollow interior. The sides of the piston part 200 facing the brake linings 30 may be closed. The piston part 200 may be arranged along a longitudinal direction of the cylinder 130.

[0064] An outer surface of the piston part 200 is slidably mounted on an inner surface of the cylinder 130. Alternatively, the outer surface of the piston part 200 can be spaced a defined distance from the inner surface of the cylinder 130.

[0065] During movement in the first direction, the piston part 200 protrudes from the cylinder 130 and exerts pressure on the brake pads 30 facing the cylinder 130 in the direction of the brake disc 20. As a result, the vehicle braking system generates a braking force.

[0066] When the piston part 200 moves in the second direction, it separates from the brake pads 30. As a result, the pressure force exerted by the piston part 200 on the brake pads 30 is released, and the braking force of the vehicle's braking system disappears.

[0067] The piston part 200 comprises a piston body 210 and a piston head 220.

[0068] The piston body 210 has a hollow column shape and the piston head 220 is connected to the piston body 210 to form one side (left side in Fig. 2) to close the piston body 210. The piston head 220 is arranged on one of the open sides of the piston body 210 and faces the brake pad 30 to close the open area of ​​the piston body 210.

[0069] The bolt screw part 400 is arranged in the piston part 200. A bolt body 410 and a bolt head 420 of the bolt screw part 400 are surrounded by the piston body 210. The bolt head 420 is arranged so that it can be inserted into the piston head 220.

[0070] A piston seal 260 is installed in cylinder 130, preventing the ingress of external foreign objects and sealing the interior of cylinder 130 watertight. The piston seal 260 is installed between cylinder 130 and piston part 200. The piston seal 260 is connected to the piston body 210 or the piston head 220 and pressed into the interior of cylinder 130.

[0071] The piston sleeve 260 is arranged to enclose the piston part 200. The piston sleeve 260 is made of an elastically deformable material. For example, the piston sleeve 260 may contain a rubber material. The piston sleeve 260 may have a corrugated shape.

[0072] The nut-bolt part 300 is rotatably mounted in the cylinder 130 and is coupled to the bolt-bolt part 400. A bearing part 500, which rotatably supports the nut-bolt part 300, is installed in the cylinder 130. The bearing part 500 can be a ball bearing located between the cylinder 130 and the nut-bolt part 300.

[0073] The nut-bolt part 300 has a hollow column shape with open ends. The nut-bolt part 300 is arranged in the cylinder 130, and a central axis of the nut-bolt part 300 can lie on the same axis as the central axis of the cylinder 130.

[0074] A first page (left side based on Fig. 2) of the nut screw part 300 is an inside (right side based on Fig. 2) of the piston part 200 facing at a defined distance. A second side (right side based on Fig. 2) of the nut screw part 300 penetrates the cylinder 130 and protrudes outwards from the cylinder 130.

[0075] The nut-bolt part 300 is arranged such that its inner surface faces an outer surface of the bolt-bolt part 400. An outer ball rail R1, on which spherical ball elements B are mounted, is arranged on an inner circumferential surface of the nut-bolt part 300. The outer ball rail R1 extends in a spiral shape along the longitudinal direction of the nut-bolt part 300. The outer ball rail R1 of the nut-bolt part 300, together with an inner ball rail R2 of the bolt-bolt part 400 on the opposite side, forms a circumferential path for the ball elements B.

[0076] The nut screw part 300 receives a rotational force generated by an actuator 600 via a force transmission part when the actuator 600 is actuated, and rotates clockwise or counterclockwise around a central axis.

[0077] The nut screw part 300 comprises a nut screw body 310 and a nut screw end 320.

[0078] The majority of the nut bolt body 310 is located inside the cylinder 130, and all or most of the nut bolt end 320 is exposed to the outside of the cylinder 130. The nut bolt body 310 is surrounded by the piston body 210.

[0079] The nut end 320 has a non-circular column shape. A non-circular shape is defined as a shape that does not correspond to a regular circle and includes, for example, shapes such as an ellipse and a polygon. In the present embodiment, the nut end 320 has a polygonal column shape, more precisely an approximately hexagonal column shape.

[0080] The bolt-screw part 400 is locked to the rotation of the nut-screw part 300, allowing it to move in the first and second directions within the cylinder 130. The bolt-screw part 400 is positioned within the nut-screw part 300. The bolt-screw part 400 is positioned such that it penetrates both ends of the nut-screw part 300.

[0081] The bolt screw part 400 moves in the first direction, i.e., towards the brake pads 30, to move the piston part 200 and apply pressure to the brake pads 30. Furthermore, when the bolt screw part 400 is moved in the second direction, opposite to the first, the pressure on the piston part 200 can be released.

[0082] The bolt screw part 400 comprises a bolt body 410 and a bolt head 420.

[0083] The bolt body 410 is connected to the nut and bolt part 300 and absorbs the torque from the nut and bolt part 300. The bolt head 420 is separate from the bolt body 410. The bolt body 410 is pressed into the bolt head 420 to form a single unit. For example, the bolt body 410 can be serrated and pressed into the bolt head 420.

[0084] Since the bolt head 420 is provided separately from the bolt body 410, the shape flexibility of the bolt head 420 can be improved. In particular, the shape of the bolt head 420 can be adapted according to the specifications of the vehicle braking system, and since the bolt head 420 is provided separately from the bolt body 410, which can be standardized relatively easily, individual adaptation is possible and the design scope is increased. According to the present embodiment, if the size of the piston part 200 is changed, the contact diameter of the bolt head 420 can be adjusted accordingly.

[0085] The bolt body 410 is locked by the rotation of the nut screw part 300, and the bolt head 420 arranged in front of the bolt body 410 (left side of Fig. 2) presses on the piston part 200 when the bolt body 410 is moved in the first direction inside the cylinder 130.

[0086] The bolt body 410 has a columnar shape with an approximately circular cross-section. The bolt body 410 is arranged in the cylinder 130, and a central axis of the bolt body 410 lies on the same axis as the central axis of the cylinder 130. The bolt body 410 is coupled to the nut-bolt part 300 via the ball elements B.

[0087] The inner ball rail R2, on which the ball elements B are seated, is arranged on the outer circumferential surface of the bolt body 410. The inner ball rail R2 extends in a spiral shape in the longitudinal direction (left and right directions based on Fig. 2) of the bolt body 410 to provide a path of rotation for the ball elements B. When the nut-bolt part 300 rotates, the bolt body 410 can be moved accordingly in the first or second direction by a rotational movement of the ball elements B.

[0088] The outer ball rail R1, arranged on the inner circumferential surface of the nut bolt part 300, and the inner ball rail R2, arranged on the outer circumferential surface of the bolt body 410, are arranged facing each other. The ball elements B can have outer parts that are guided by the outer ball rail R1 and inner parts that are guided by the inner ball rail R2, so that they move in a spiral shape along the outer ball rail R1 and the inner ball rail R2.

[0089] The bolt head 420 is arranged between the bolt body 410 and the piston part 200. The bolt head 420 can have an approximately circular cross-section. The bolt head 420 is arranged so that it can be inserted into the piston head 220. The bolt head 420 is arranged so that it faces an inner surface of the piston head 220 at a defined distance. When no braking force is generated or when the braking force in the vehicle braking system is released, the bolt head 420 can be arranged so that it is spaced away from the piston head 220.

[0090] The bolt head 420 can press against the piston head 220. The bolt head 420 can press against the piston head 220 or release the pressure of the piston head 220 in the first direction, depending on the direction of movement of the bolt body 410.

[0091] The outer diameter of the bolt head 420 can be larger than the outer diameter of the bolt body 410. Accordingly, when the bolt screw part 400 pushes the piston part 200 to move it towards the brake pads 30, the contact diameter of the bolt screw part 400 in contact with the piston part 200 can be increased.

[0092] The contact diameter of the bolt head 420, which is in contact with the piston head 220, is further increased when the outer diameter of the bolt head 420 is larger than the outer diameter of the bolt body 410, rather than when the outer diameter of the bolt head 420, which is in contact with the piston head 220, is equal to or smaller than the outer diameter of the bolt body 410. Accordingly, it is possible to improve the efficiency of the load transfer to the piston part 200 via the bolt head 420. Furthermore, increasing the contact diameter of the bolt head 420, which is in contact with the piston head 220, allows for a more stable load transfer to the piston part 200 and ensures stable centering of the bolt screw part 400.

[0093] The bolt head 420 comprises a head connecting part 421 and a head extension part 422.

[0094] The head connection part 421 is a part that extends from the bolt head 420 to the bolt body 410 and is connected to the bolt body 410. The head extension part 422 extends from the head connection part 421 towards the piston head 220 and has an outer diameter that is larger than the outer diameter of the head connection part 421. Accordingly, the contact diameter of the bolt screw part 400, which is in contact with the piston part 200, can be increased.

[0095] The contact diameter of the head extension part 422, which is in contact with the piston head 220, is further increased when the outer diameter of the head extension part 422 is larger than the outer diameter of the head connection part 421, rather than when the outer diameter of the head extension part 422, which is in contact with the piston head 220, is equal to the outer diameter of the head connection part 421. Accordingly, it is possible to improve the efficiency of the load transfer to the piston part 200 by the piston head 420. Furthermore, the load transfer to the piston part 200 becomes more stable when the contact diameter of the head extension part 422, which is in contact with the piston head 220, is increased.

[0096] The cylinder head extension part 422 has a curved surface area 422a on its outer circumference facing the piston head 220. The curved surface area 422a is a curved surface area with a convex shape, which faces the piston head 220 and extends over the entire outer circumference of the cylinder head extension part 422. The cylinder head extension part 422 can come into contact with the piston head 220 at the curved surface area 422a.

[0097] The head extension part 422 can be in rolling contact with the piston head 220 on the curved surface region 422a. That is, the head extension part 422 can perform a rolling movement on the curved surface region 422a with respect to the piston head 220.

[0098] The piston head 220 has a flat surface area 220a in a region that comes into contact with the curved surface area 422a. When the head extension part 422 comes into contact with the piston head 220 due to movement of the bolt screw part 400 in the first direction, the head extension part 422 with the convex curved surface area 422a and the piston head 220 with the flat surface area 220a can remain in contact with each other, even if the head extension part 422 rolls relative to the piston head 220.

[0099] When the brake disc 20 rubs against the brake pads 30 due to the movement of the piston 200 and a braking force is generated, the shape of the brake caliper body 100 can partially deform in response to the braking force. As a result, the cylinder 130 and piston part 200 may be slightly inclined relative to the central axis compared to the non-braking state. That is, when braking, the cylinder 130 and / or the piston part 200 may be inclined at a slight angle relative to their respective central axis.

[0100] If the cylinder 130 and / or the piston section 200 are inclined about their respective central axes, the head extension part 422 can come into rolling contact with the piston head 220 on the curved surface area 422a. That is, if the cylinder 130 and / or the piston section 200 are inclined about their respective central axes, the head extension part 422 can roll on the curved surface area 422a with respect to the piston head 220.

[0101] When the cylinder 130 and / or the piston part 200 are tilted about their respective central axes, the head extension part 422 rolls in relation to the piston head 220, so that the bolt body 410 coupled to the bolt head 420 is also tilted by the angle by which the bolt head 420 is tilted by the rolling motion.

[0102] In this way, if the cylinder 130 and / or the piston 200 are inclined with respect to their respective central axes, the bolt head 420 and the bolt body 410 are also inclined, thus preventing the load from concentrating on only one specific spherical element B from the plurality of spherical elements B arranged longitudinally in the bolt body 410. Accordingly, it is possible to ensure the robustness of the bolt screw part 400 against an inclination of the cylinder 130 and / or the piston part 200, thereby improving the durability of the vehicle braking system.

[0103] The bearing part 500 is arranged between the cylinder 130 and the nut screw part 300 and supports the nut screw part 300 so that the nut screw part 300 can rotate in the cylinder 130.

[0104] If the cylinder 130 and / or the piston part 200 are inclined about their respective central axes, the nut and bolt part 300 can come into rolling contact with the bearing part 500. That is, if the cylinder 130 and / or the piston 200 are inclined about their respective central axes, the nut and bolt part 300 can roll relative to the bearing part 500.

[0105] In this way, if the cylinder 130 and / or the piston 200 are inclined with respect to their respective central axes, the nut bolt part 300 is also inclined, thus preventing the load of the nut bolt part 300 from concentrating on only one specific spherical element B from the plurality of spherical elements B arranged in the longitudinal direction of the bolt body 410. Accordingly, it is possible to ensure the robustness of the bolt bolt part 400 against an inclination of the cylinder 130 and / or the piston part 200, thereby improving the durability of the vehicle braking system.

[0106] The bearing part 500 comprises an outer ring part 510 and a bearing ball 520.

[0107] The outer ring 510 is in contact with the inner surface of the cylinder 130. The outer ring 510 is pressed onto the cylinder 130, for example, via a mounting projection 135, and firmly fixed in its position. Due to the press fit with the cylinder 130, the load acting on the bearing ball 520 can be distributed via the outer ring 510 in the axial direction and / or the outer radial direction.

[0108] The bearing ball 520 is arranged between the outer wheel part 510 and the nut screw body 310. Since, in this embodiment, the nut screw body 310 takes on the role of the inner wheel part of the bearing part 500, the outer diameter of the bearing part 500 can be reduced, allowing the vehicle brake system to be manufactured more compactly and reducing the number of assembly parts, thereby lowering costs.

[0109] The outer ring part 510 comprises a bearing ball contact part 515, an outer ring step part 516 and an outer ring bottom part 517.

[0110] The outer ring part 510 comprises the outer ring base part 517, which is formed on the side of the piston head 220 with respect to the bearing ball contact part 515, and the outer ring step part 516, which is formed on the side of the nut screw end 320. The outer ring step part 516 projects further inwards towards the nut screw part 300 compared to the outer ring base part 517, and the bearing ball contact part 515 is arranged between the outer ring step part 516 and the outer ring base part 517.

[0111] The bearing ball contact part 515 is designed as a curved surface area with a concave inner shape and extends over the entire inner circumference of the outer ring 510. The bearing ball 520 is in direct contact with the bearing ball contact part 515 or is indirectly connected to the bearing ball contact part 515 via another element. In the present embodiment, the bearing ball 520 sits on the bearing ball contact part 515.

[0112] The bearing ball 520, arranged between the outer ring part 510 and the nut screw body 310, has an outermost region 520A and an innermost region 520B. The outermost region 520A is located furthest from the center of the bolt screw part 400 on the outer circumferential surface of the bearing ball 520, and the innermost region 520B is located closest to the center of the bolt screw part 400 on the outer circumferential surface of the bearing ball 520.

[0113] The outer ring step part 516 and the outer ring base part 517 project towards the nut screw part 300 in order to be positioned further inwards than the outermost region 520A of the bearing ball 520. Accordingly, the outer ring step part 516 and the outer ring base part 517 are arranged such that they surround the outermost region 520A of the bearing ball 520.

[0114] The bearing ball contact part 515 comprises a first outer contact area 515A and a second outer contact area 515B. The first outer contact area 515A is located on the side of the outer ring step part 516 with respect to the outermost area 520A of the bearing ball 520, and the second outer contact area 515B is located on the side of the outer ring base part 517 with respect to the outermost area 520A of the bearing ball 520. The bearing ball 520 can come into contact with the inner surface of the bearing ball contact part 515 at both the first outer contact area 515A and the second outer contact area 515B.

[0115] The nut screw body 310 comprises a rolling contact part 315, a nut step part 316 and a nut base part 317.

[0116] Since the nut-bolt body 310 functions as an inner ring section that is a rotating part of the bearing part 500, the nut-bolt body 310 rotates relative to the outer ring part 510. Furthermore, since the nut-bolt body 310 is provided with the rolling contact part 315 in a region facing the bearing ball 520, the nut-bolt body 310 can roll relative to the bearing ball 520. Because the nut-bolt body 310 rolls relative to the bearing ball 520, the angle between the nut-bolt body 310 and the outer ring part 510 can be changed.

[0117] The nut screw body 310 has a nut step part 316, which is arranged on the side of the piston head 220 with respect to the rolling contact part 315, and a nut base part 317, which is arranged on the side of the nut screw end 320. The nut step part 316 projects further outwards towards the outer ring part 510 compared to the nut base part 317, and the rolling contact part 315 is arranged between the nut step part 316 and the nut base part 317.

[0118] The rolling contact part 315 is arranged as a curved surface part with an inwardly concave shape and extends over the entire outer circumference of the nut screw body 310. The bearing ball 520 is in direct contact with the rolling contact part 315 or contacts the rolling contact part 315 indirectly via another element.

[0119] Since the rolling contact part 315 has the curved surface, the nut screw body 310 rolls on the rolling contact part 315 with respect to the bearing ball 520 or the outer ring part 510.

[0120] The nut step part 316 and the nut base part 317 can project further outwards than the innermost region 520B of the bearing ball 520. Accordingly, the nut step part 316 and the nut base part 317 can be arranged such that they surround the innermost region 520B of the bearing ball 520.

[0121] The rolling contact part 315 comprises a first inner contact area 315A and a second inner contact area 315B. The first inner contact area 315A is located on the side of the nut step part 316 with respect to the innermost area 520B of the bearing ball 520, and the second inner contact area 315B is located on the side of the nut base part 317 with respect to the innermost area 520B of the bearing ball 520. The bearing ball 520 is in contact with the inner surface of the rolling contact part 315 in both the first inner contact area 315A and the second inner contact area 315B.

[0122] The nut-bolt part 300 rotates in one direction to generate a braking force in the vehicle braking system, and accordingly, the bolt-bolt part 400 moves in the direction of the piston part 200. During the process of generating the braking force in the vehicle braking system, the bearing ball 520 comes into contact with the first inner contact area 315A of the rolling contact part 315 and the first outer contact area 515A of the bearing ball contact part 515 to stably bear the load of the nut-bolt part 300, which is exerted in the opposite direction to the direction of movement of the bolt-bolt part 400. The first inner contact area 315A and the first outer contact area 515A are arranged so that they face each other diagonally with respect to the bearing ball 520.

[0123] When the braking force of the vehicle braking system is released, the nut-bolt part 300 rotates in the opposite direction, causing the bolt-bolt part 400 to move to the opposite side of the piston part 200. Upon release of the braking force of the vehicle braking system, the bearing ball 520 comes into contact with the second inner contact area 315B of the rolling contact part 315 and the second outer contact area 515B of the bearing ball contact part 515, and can stably bear the load exerted by the nut-bolt part 300, which is opposite to the direction of movement of the bolt-bolt part 400. Furthermore, forward-backward displacement can be suppressed, even as the nut-bolt part 300 rotates, and zero resistance can be achieved upon separation from the piston part 200. The second inner contact area 315B and the second outer contact area 515B are arranged so that they face each other diagonally towards the bearing ball 520.

[0124] During braking of the vehicle's braking system, the piston part 200 may be inclined relative to the central axis, or the cylinder 130 may be inclined relative to the central axis due to a braking torque or the opening of the brake caliper body 100. Since, according to the present embodiment, the bolt head 420 performs a rolling motion relative to the piston part 200, it is possible to prevent a load from concentrating on only one specific spherical element B from among the plurality of spherical elements B arranged on the outer surface of the bolt part 400. Furthermore, since, according to the present embodiment, the nut part 300 moves in a rolling motion against the bearing part 500, it is possible to prevent the load from concentrating on only one specific spherical element B from among the plurality of spherical elements B arranged on the inner surface of the nut part 300.

[0125] The vehicle braking system according to the present embodiment can roll in front of the bolt-screw part 400, on the outside of the nut-screw part 300, or in front of the bolt-screw part 400 and on the outside of the nut-screw part 300. This prevents a specific ball element B from bearing a concentrated load, even if the piston part 200 or the cylinder 130 is inclined relative to the central axis. Thus, the vehicle braking system according to the present embodiment can improve the durability of the device while simultaneously ensuring robustness against inclination.

[0126] The vehicle braking system according to an embodiment of the present disclosure further comprises an actuator part 600.

[0127] The actuator part 600 receives energy from the motor part 660 to supply a rotational force to the nut screw part 300.

[0128] The actuator part 600 includes a force transmission element. The force transmission element can engage with the nut and bolt part 300 and transmit the rotational force to the nut and bolt part 300. While the nut and bolt part 300 is rotated by the rotational force provided by the actuator part 600, the bolt and bolt part 400 can be displaced.

[0129] The present embodiment provides a nut-screw-driven vehicle braking system in which the nut-screw part 300 is initially rotated by absorbing the rotational force of the actuator 600, and the nut-screw part 300 and the bolt-screw part 400, which are force-coupled via the balls B, rotate continuously. Therefore, according to the present embodiment, the axial length can be reduced compared to the bolt-screw-driven vehicle braking system.

[0130] The power transmission element can comprise a plurality of gears that engage and are coupled sequentially between a motor part 660 and the nut-bolt part 300. The power transmission element is not limited to such a configuration, and the design can be modified to incorporate various types of power transmission means capable of rotating the nut-bolt part 300 by receiving the rotational force from the motor part 660.

[0131] The power transmission part includes a power transmission groove 620, which is arranged inside an actuator housing 610.

[0132] The power transmission groove 620 is arranged so that it surrounds a rotation-prevention projection 630, and the nut screw end 320 of the nut screw part 300 can be inserted therein.

[0133] The power transmission groove 620 has a shape that corresponds to and engages with the nut end 320. The power transmission groove 620 can be a non-circular groove. A non-circular groove is a shape that does not correspond to a regular circle and includes a shape such as an ellipse, a polygon, etc. In the present embodiment, the power transmission groove 620 is a polygonal groove, more precisely an approximately hexagonal groove.

[0134] Since the nut end 320 and the power transmission groove 620 are not circular but identical or similarly shaped, the nut end 320 and the power transmission groove 620 interlock when the nut end 320 is inserted into the power transmission groove 620. If the power transmission groove 620 is rotated during operation of the actuator part 600, the nut end 320 engaging in the power transmission groove 620 also rotates in the same direction. This allows the torque of the actuator part 600 to be transmitted to the nut end 300 in a stable and lossless manner.

[0135] The actuator part 600 can include a rotation-prevention element. The rotation-prevention element can restrict the rotation of the bolt-screw part 400 by engaging with the bolt-screw part 400. While the nut-screw part 300 is rotated by the rotational force provided by the actuator part 600, the bolt-screw part 400 is displaced.

[0136] Since the nut screw part 300 and the bolt screw part 400 are force-coupled via the ball elements B, the rotation of the bolt screw part 400 is blocked by the rotation prevention part, so that the rotation of the nut screw part 300 is converted into a translational movement of the bolt screw part 400.

[0137] The anti-rotation element comprises the anti-rotation projection 630. The anti-rotation projection 630 is located inside the actuator housing 610 and protrudes outwards from the actuator housing 610. The anti-rotation projection 630 is located inside the power transmission groove 620.

[0138] When the nut end 320 is inserted into the power transmission groove 620 and engages with it, the anti-rotation projection 630 is inserted into an anti-rotation groove 411 of the bolt body 410 and engages with it. In this way, according to the present embodiment, the power transmission to the nut part 300 and the anti-rotation to the bolt part 400 can be carried out in one assembly, thereby significantly improving assembly.

[0139] The anti-rotation projection 630 can have a non-circular column shape. Non-circular refers to a shape that does not correspond to a regular circle and includes shapes such as an oval or a polygon. In the present embodiment, the anti-rotation projection 630 has a polygonal column shape, more precisely an approximately hexagonal column shape.

[0140] The anti-rotation groove 411 is arranged in the bolt body 410 in a form that corresponds to and engages with the anti-rotation projection 630. The anti-rotation groove 411 can be configured as a non-circular groove section. A non-circular shape is defined as a shape that does not correspond to a regular circle and includes, for example, a shape such as an ellipse or a polygon. In the present embodiment, the anti-rotation groove 411 is configured as a polygonal groove, more precisely as an approximately hexagonal groove.

[0141] Since the anti-rotation projection 630 and the anti-rotation groove 411 are not circular but identical or similarly shaped, the anti-rotation projection 630 and the anti-rotation groove 411 interlock when the anti-rotation projection 630 is inserted into the anti-rotation groove 411. When the power transmission groove 620 is rotated during operation of the actuator part 600, the nut end 320 connected to the power transmission groove 620 rotates in the same direction, but the rotation of the bolt body 410 is blocked. This allows the torque of the actuator part 600 to be converted into the translational movement of the bolt part 400 in a stable and lossless manner.

[0142] The anti-rotation projection 630 and the anti-rotation groove 411 are in surface contact with each other, thus reducing friction losses and ensuring the centering of the bolt body 410 under axial forward loading. Since the anti-rotation groove 411 can be formed integrally with the bolt body 410, the separate manufacturing of an anti-rotation structure is eliminated, which optimizes space utilization.

[0143] The anti-rotation groove 411 has an extended inclined surface 411a that widens outwards to facilitate the insertion of the anti-rotation projection 630. The anti-rotation projection 630 has an inclined surface area 630a that tapers outside its front end to facilitate insertion into the anti-rotation groove 411.

[0144] The length to which the anti-rotation projection 630 is inserted into the bolt body 410 can be greater than the maximum stroke of the piston part 200. The maximum stroke of the piston part 200 denotes the distance the piston part 200 travels from its starting point to its foremost point. The stroke of the piston part 200 can increase by the wear of the brake lining 30. Therefore, the length to which the anti-rotation projection 630 is inserted into the bolt body 410 is greater than the maximum stroke of the piston part 200. As a result, the anti-rotation projection 630 always engages in the anti-rotation groove 411 of the bolt body 410, and the rotation of the bolt screw part 400 can always be blocked.

[0145] Fig. Figure 7 is a cross-sectional view schematically representing a vehicle braking system according to the second embodiment of the present disclosure, Fig. 8 is a view that schematically represents a return path of a ball element in the vehicle braking system according to the second embodiment of the present disclosure, Fig. Image 9 is a partially enlarged view of Fig. 7 and Fig. 10 is a partially enlarged view of Fig. 9.

[0146] With reference to Fig. 7 to Fig. 10 together with Fig. 1 and Fig. 6. The vehicle braking system according to the second embodiment of the present disclosure comprises a brake caliper body 100, a piston part 200, a nut and bolt part 300, and a stud and bolt part 400. The vehicle braking system according to the second embodiment of the present disclosure differs from the vehicle braking system according to the first embodiment only in some configurations. Fig. 1 to Fig. 6. Therefore, the following description refers to the same configurations as in the vehicle braking system according to the first embodiment in Fig. 1 to Fig. 6 waived.

[0147] The brake caliper body 100 comprises a bridge 110, a finger 120 and a cylinder 130.

[0148] The piston part 200 comprises a piston body 210 and a piston head 220.

[0149] The nut screw part 300 comprises a nut screw body 310 and a nut screw end 320.

[0150] An outer ball rail R1, arranged on an inner circumferential surface of the nut bolt part 300, and an inner ball rail R2, formed on an outer circumferential surface of the bolt body 410, are arranged facing each other. Each of the ball elements B has an outer section, which is guided by the outer ball rail R1, and an inner section, which is guided by the inner ball rail R2, so that it moves in a spiral shape along the outer ball rail R1 and the inner ball rail R2.

[0151] The nut-bolt part 300 comprises a return path that moves the ball elements B from a first side of the outer ball rail R1 and the inner ball rail R2 to a second side of the outer ball rail R1 and the inner ball rail R2. The return path of the nut-bolt part 300 comprises a first return bore unit 350, a return channel 353, and a second return bore unit 355.

[0152] The first return bore unit 350 has an inner diameter larger than the outer diameter of each ball element B, allowing the ball elements B running on the outer ball rail R1 and the inner ball rail R2 to enter and exit. The first return bore unit 350 is arranged to communicate with the outer ball rail R1 and the inner ball rail R2, enabling the ball elements B to enter and exit.

[0153] The inner diameter of the second return bore unit 355 is larger than the outer diameter of the ball element B, allowing the ball elements B, which run on the outer ball rail R1 and the inner ball rail R2, to enter and exit. The second return bore unit 355 is arranged to communicate with the outer ball rail R1 and the inner ball rail R2, enabling the ball elements B to enter and exit. The second return bore unit 355 is located at a different position than the first return bore unit 350. In the present embodiment, the first return bore unit 350 can be arranged closer to the piston part 200 than the second return bore unit 355.

[0154] The return channel 353 is connected on one side to the first return bore unit 350 and on the other side to the second return bore unit 355, thus connecting the first return bore unit 350 to the second return bore unit 355. Therefore, the balls B entering the first return bore unit 350 are guided through the return channel 353 to the second return bore unit 355 and return to the outer ball rail R1 and the inner ball rail R2. The balls B entering the second return bore unit 355 are guided through the return channel 353 to the first return bore unit 350 and return to the outer ball rail R1 and the inner ball rail R2.

[0155] The first return bore 350 and the second return bore 355 allow the ball elements B to enter and exit. For example, when a braking force is built up in the vehicle braking system, i.e., when the bolt screw part 400 moves towards the piston part 200, the ball elements B can enter the first return bore 350 and exit the second return bore 355. Conversely, when the braking force is released in the vehicle braking system, i.e., when the bolt screw part 400 moves to the opposite side of the piston part 200, the ball elements B can enter the second return bore 355 and exit the first return bore 350.

[0156] Based on the process for generating the braking force in the vehicle braking system, when the bolt-type screw part 400 is moved towards the piston 200 by the rotation of the nut-type screw part 300 and reaches a defined point, which in the present embodiment is the first return bore 350, the balls B are drawn into the first return bore 350 by continuous rotation of the nut-type screw part 300. The balls B are then guided through the return channel 353 to the second return bore 355, exit it, and land back on the outer ball rail R1 and the inner ball rail R2. With continued rotation of the nut-type screw part 300, the balls B travel from the second return bore 355 along the outer ball rail R1 and the inner ball rail R2, reach the first return bore 350, and then return to the first return bore 350. Accordingly, the return of the ball elements B can be continued.

[0157] Based on the process for releasing the braking force of the vehicle braking system, when the bolt-screw part 400 moves to the side opposite the piston part 200 due to the rotation of the nut-screw part 300, and the ball elements B reach the point where the second return bore unit 355 is located, the ball elements B enter the second return bore unit 355 due to the rotation of the nut-screw part 300. Subsequently, the ball elements B are guided through the return channel 353 to the first return bore 350, exit the first return bore 350, and again rest on the outer ball rail R1 and the inner ball rail R2. With continued rotation of the nut-screw part 300, the ball elements B migrate from the first return bore 350 along the outer ball rail R1 and the inner ball rail R2, reach the second return bore 355, and again enter the second return bore 355.Accordingly, the return of the spherical elements B can be continued.

[0158] Since, according to the present embodiment, the return path is provided separately in the nut-bolt part 300, the ball elements B can repeatedly circulate and be actuated on the outer ball rail R1 and the inner ball rail R2. This improves the durability between the nut-bolt part 300 and the bolt-bolt part 400, and the torque can be stably converted and transmitted to the shaft during the braking or releasing process of the vehicle brake system.

[0159] The bolt screw part 400 comprises a bolt body 410 and a bolt head 420, and the bolt head 420 comprises a head connecting part 421 and a head extension part 422.

[0160] The bearing part 500 comprises an outer ring part 510 and a bearing ball 520. The outer ring part 510 comprises a bearing ball contact part 515, an outer ring step part 516 and an outer ring bottom part 517.

[0161] The outer ring part 510 comprises the outer ring base part 517, which is formed on the side of the piston head 220 with respect to the bearing ball contact part 515, and the outer ring step part 516, which is formed on the side of the nut screw end 320. The outer ring step part 516 projects further inwards towards the nut screw part 300 than the outer ring base part 517, and the bearing ball contact part 515 is arranged between the outer ring step part 516 and the outer ring base part 517.

[0162] The bearing ball contact part 515 has an inwardly concave surface area and extends over the entire inner circumference of the outer ring part 510. The bearing ball 520 is in direct contact with the bearing ball contact part 515 or is in indirect contact with the bearing ball contact part 515 via another element. In the present embodiment, the bearing ball 520 can be seated on the bearing ball contact part 515.

[0163] The bearing ball 520, arranged between the outer ring part 510 and the nut screw body 310, comprises an outermost region 520A and an innermost region 520B. The outermost region 520A is the region of the outer circumferential surface where the bearing ball 520 is furthest from the center of the bolt screw part 400, and the innermost region 520B is the region of the outer circumferential surface where the bearing ball 520 is closest to the center of the bolt screw part 400.

[0164] The outer wheel lower part 517 has the same height as a region of the bearing ball contact part 515 that touches the outermost region 520A of the bearing ball 520.

[0165] The bearing ball contact part 515 can have an outer contact area 515A. The outer contact area 515A is located closer to the outermost area 520A of the bearing ball 520, nearer the outer wheel step part 516 than the outer wheel base part 517. The bearing ball 520 can be in contact with the inner surface of the bearing ball contact part 515 in the outer contact area 515A.

[0166] The bearing part 500 further comprises a bearing cover 511. A first side of the bearing cover 511 is pressed into the inner surface of the outer ring 510, while a second side of the bearing cover 511 extends towards the nut screw body 310. The bearing cover 511 is positioned in front of the nut step part 316, so that the nut screw body 310 prevents movement beyond a defined range. Since the bearing cover 511 has a defined distance from the front of the nut step part 316, further movement of the nut step part 316 can be blocked by the bearing cover 511 when the nut screw body 310 is moved relative to the outer ring 510 by a defined range. This prevents the relative movement between the nut screw part 300 and the cylinder 130 from exceeding a defined range.

[0167] The nut body 310 comprises a rolling contact part 315, a nut step part 316, and a nut base part 317. The rolling contact part 315 is designed as a curved, inwardly concave surface area and extends over the entire outer circumference of the nut body 310. The bearing ball 520 can be in contact with the rolling contact part 315 directly or indirectly via another element. In the present embodiment, the bearing ball 520 can be seated on the rolling contact part 315.

[0168] Since the rolling contact part 315 has a curved section, the nut screw body 310 can perform a rolling movement with respect to the bearing ball 520 or the outer ring part 510 on the rolling contact part 315.

[0169] The nut step portion 316 projects further outwards than the innermost region 520B of the bearing ball 520. Accordingly, the nut step portion 316 is arranged such that it surrounds the innermost region 520B of the bearing ball 520. The nut base portion 317 has the same height as the area of ​​the rolling contact portion 315 that contacts either the innermost region 520B or the outermost region 520A of the bearing ball 520.

[0170] The rolling contact part 315 has an inner contact area 315A. With respect to the innermost area 520B of the bearing ball 520, the inner contact area 315A is located closer to the nut step part 316 than to the nut base part 317. The bearing ball 520 can be in contact with the inner surface of the rolling contact part 315 in the inner contact area 315A.

[0171] The nut-bolt part 300 rotates in one direction to generate a braking force in the vehicle braking system, and accordingly, the bolt-bolt part 400 moves in the direction of the piston part 200. When generating the braking force in the vehicle braking system, the bearing ball 520 comes into contact with the inner contact area 315A of the rolling contact part 315 and the outer contact area 515A of the bearing ball contact part 515 to stably bear the load of the nut-bolt part 300, which is exerted in the opposite direction to the direction of movement of the bolt-bolt part 400.

[0172] According to the present embodiment, the bearing ball 520 of the bearing part 500 can be configured as a two-point bearing, which, when the braking force of the vehicle braking system is generated or released, comes into contact with the inner contact area 315A of the rolling contact part 315 and the outer contact area 515A of the bearing ball contact part 515. The two-point bearing is easier to assemble than the four-point bearing, and the ball size can be reduced, thereby reducing the outer diameter of the assembly consisting of the bolt screw part 400 and the nut screw part 300.

[0173] When the vehicle's braking system is applied, the piston part 200 can tilt relative to the central axis due to the braking torque or the opening of the brake caliper body 100 or the cylinders 130. Since, according to the present embodiment, the bolt head 420 can perform a rolling movement relative to the piston part 200, it is possible to prevent the load from concentrating on only one specific spherical element B of the plurality of spherical elements B on the outer surface of the bolt part 400. Since, according to the present embodiment, the nut part 300 can also perform a rolling movement relative to the bearing part 500, it is possible to prevent the load from concentrating on only one specific spherical element B of the plurality of spherical elements B on the inner surface of the nut part 300.

[0174] Since the vehicle braking system according to the present embodiment can perform a rolling movement in front of the bolt screw part 400, on the outside of the nut screw part 300, or in front of the bolt screw part 400 and on the outside of the nut screw part 300, the absorption of a concentrated load on a specific spherical element B can be prevented even when the piston part 200 or the cylinder 130 is inclined relative to the central axis. Thus, the vehicle braking system according to the present embodiment can improve the durability of the system while simultaneously ensuring robustness against inclination.

[0175] Fig. Figure 11 is a cross-sectional view schematically representing a vehicle braking system according to the third embodiment of the present disclosure, Fig. Figure 12 is a cross-sectional view showing a nut screw part and a bolt screw part of the vehicle brake system according to the third embodiment of the present disclosure, Fig. Figure 13 is a perspective cross-sectional view showing the nut screw part and the bolt screw part of the vehicle brake system according to the third embodiment of the present disclosure, Fig. 14 is a partially enlarged view of Fig. 11 and Fig. 15 is a partially enlarged view of Fig. 14.

[0176] With reference to Fig. 11 to Fig. 15 together with Fig. 1 and Fig. 6. The vehicle braking system according to the third embodiment of the present disclosure comprises a brake caliper body 100, a piston part 200, a nut and bolt part 300, and a stud and bolt part 400. The vehicle braking system according to the third embodiment of the present disclosure differs from the vehicle braking system according to the first embodiment only in some configurations. Fig. 1. A description of the same configurations as in the vehicle braking system according to the first embodiment in Fig. Number 1 will be omitted in the following.

[0177] The brake caliper body 100 comprises a bridge 110, a finger 120 and a cylinder 130.

[0178] The piston part 200 comprises a piston body 210 and a piston head 220.

[0179] The nut screw part 300 comprises a nut screw body 310 and a nut screw end 320.

[0180] The inner circumferential surface of the nut-bolt part 300 can be provided with a rail bore part and a through bore part 325. In the rail bore part, an outer ball rail R1, on which the ball elements B are seated, is arranged in a spiral shape in the longitudinal direction. The through bore part 325 is an inner circumferential surface part of the nut-bolt part 300 on which the outer ball rail R1 is not arranged.

[0181] The through-bore section 325 is arranged along an inner circumferential surface of a nut bolt end 320. The inner diameter of the through-bore section 325 is larger than the maximum outer diameter of the bolt body 410. Accordingly, the bolt body 410 can move within the through-bore section 325 during rotation of the nut bolt section 300.

[0182] A stop 326 is provided in the through-bore section 325. The stop 326 can be formed during the machining of the inner circumferential surface of the nut-bolt section 300. The stop 326 is arranged separately from the nut-bolt section 300 and can be pressed or screwed into the nut-bolt section 300 to be integrated with it.

[0183] The stop 326 projects inwards from the inner circumferential surface of the through-bore 325 and lies on the path of travel of a stop projection 416. When the bolt body 410 is moved towards the piston part 200 by the rotation of the nut screw part 300, the stop projection 416 at the end of the bolt body 410 also moves in the same direction. Since the stop 326 lies on the path of travel of the stop projection 416, the stop projection 416 is blocked by the stop 326 after a certain distance traveled by the bolt body 410 and can no longer move. The defined travel distance of the bolt body 410 can be within the maximum permissible stroke range of the vehicle braking system.

[0184] The maximum permissible stroke of the bolt screw part 400 can be adjusted differently depending on the thickness of a brake pad 30 required for the brake caliper. Depending on the degree of wear of the brake pad 30, the bolt screw part 400 can be moved further in the first direction, and the zero setting can be reset in the further moved position.

[0185] When the bolt body 410 is moved a defined distance towards the piston part 200, the bolt body 410 is prevented from moving towards the piston part 200 by the nut screw part 300. According to another embodiment, the stop projection 416 of the bolt screw part 400 comes into contact with the stop 326 of the nut screw part 300 when the bolt screw part 400 reaches the maximum permissible stroke, thus blocking the movement of the bolt screw part 400 in the first direction.

[0186] The maximum distance by which the bolt body 410 can move within the nut screw part 300 can be the maximum permissible stroke of the bolt screw part 400. If the bolt screw part 400 is moved within the maximum permissible stroke, malfunctions or failures of the vehicle braking system can be prevented in advance.

[0187] By limiting the piston stroke of the vehicle brake system, as in another embodiment of the present disclosure, it is possible to prevent malfunctions or failures due to various reasons, including improper manual handling, when the brake pad 30 is replaced due to complete wear of the brake pad 30.

[0188] The nut end 320 has a non-circular column shape. A non-circular shape is defined as a shape that does not correspond to a regular circle and includes shapes such as an ellipse and a polygon. In the present embodiment, the nut end 320 has a polygonal column shape, more precisely an approximately hexagonal column shape.

[0189] The bolt screw part 400 comprises the bolt body 410 and the bolt head 420, and the bolt head 420 comprises a head connecting part 421 and a head extension part 422.

[0190] The bolt body 410 is provided with the stop projection 416, particularly at its end opposite the bolt head 420. The stop projection 416 is press-fitted or screwed to the bolt body 410 and forms a single unit with it. The stop projection 416 extends beyond the outer circumferential surface of the bolt body 410 and contacts the stop 326 of the nut-bolt part 300 when the bolt body 410 is moved a certain distance. As soon as the stop projection 416 contacts the stop 326, the movement of the bolt body 410 in the first direction is blocked.

[0191] The bearing part 500 comprises an outer ring 510 and a bearing ball 520. The outer ring 510 rests against the inner surface of the cylinder 130. The outer ring 510 is pressed onto the cylinder 130 to ensure it is firmly fixed in its position. The bearing ball 520 is arranged between the outer ring 510 and the nut screw body 310. In the present embodiment, the nut screw body 310 serves as the inner ring part; however, the inner ring part can be formed integrally with the nut screw body 310, as in this embodiment, or separately from it.

[0192] The nut screw body 310 comprises a rolling contact part 315, an upper nut step part 316 and a lower nut base part 317.

[0193] The nut bolt body 310 has an upper nut step part 316, which is arranged on the side of the piston head 220 with respect to the rolling contact part 315, and a lower nut base part 317, which is arranged on the side of the nut bolt end 320. The upper nut step part 316 projects outwards compared to the lower nut base part 317, and the rolling contact part 315 is arranged between the upper nut step part 316 and the lower nut base part 317.

[0194] The rolling contact element 315 is designed as a curved, inwardly concave section and is arranged over the entire outer circumference of the nut screw body 310. The bearing ball 520 is in direct contact with the rolling contact element 315 or contacts the rolling contact element 315 indirectly via another element.

[0195] Since the rolling contact part 315 has a curved section, the nut screw body 310 can perform a rolling movement with respect to the bearing ball 520 or the outer ring part 510 on the rolling contact part 315.

[0196] When the vehicle's braking system is applied, the piston part 200 can be inclined due to the braking torque or the opening of the brake caliper body 100, or the cylinder 130 can be inclined relative to the central axis. Since, according to the present embodiment, the bolt head 420 can perform a rolling movement relative to the piston part 200, it is possible to prevent the load from concentrating on only one specific spherical element B or the plurality of spherical elements B on the outer surface of the bolt part 400. Since, according to the present embodiment, the nut part 300 can also perform a rolling movement relative to the bearing part 500, it is possible to prevent the load from concentrating on only one specific spherical element B or the plurality of spherical elements B on the inner surface of the nut part 300.

[0197] Since the vehicle braking system according to the present embodiment can perform a rolling movement in front of the bolt screw part 400, on the outside of the nut screw part 300, or in front of the bolt screw part 400 and on the outside of the nut screw part 300, the absorption of a concentrated load on a specific spherical element B can be prevented even when the piston part 200 or the cylinder 130 is inclined relative to the central axis. Thus, the vehicle braking system according to the present embodiment can improve the durability of the system while simultaneously ensuring robustness against inclination.

[0198] Although exemplary embodiments of the disclosure have been disclosed for illustrative purposes, it is apparent to the person skilled in the art that various modifications, additions, and substitutions are possible without deviating from the scope of protection and the spirit of the disclosure as defined in the appended claims. The true technical scope of the disclosure should therefore be defined by the following claims. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] KR 10-2024-0054695

[0005]

Claims

[1] Vehicle braking system, comprising: a brake caliper body with a cylinder; a piston part that is movably arranged in the cylinder and is arranged so that it faces a brake pad; a nut screw part that is arranged in the piston part and rotates by receiving a rotational force from an actuator; a bolt screw part comprising a bolt body coupled to the nut screw part and receiving the rotational force from the nut screw part, and a bolt head provided separately from the bolt body, coupled to the bolt body and arranged to face the piston part; and a bearing part comprising an outer ring part that is in contact with an inner surface of the cylinder and a bearing ball that is arranged between the outer ring part and the nut screw part. [2] Vehicle braking system according to claim 1, wherein the outer ring part comprises: a bearing ball contact part on which the bearing ball sits; an outer ring base part connected to a first side of the bearing ball contact part; and an outer ring step part that is connected to a second side of the bearing ball contact part and projects further towards the nut screw part than the outer ring bottom part. [3] Vehicle brake system according to claim 2, wherein the outer ring base part projects towards the nut screw part in order to be arranged further inwards than an outermost area of ​​the bearing ball. [4] Vehicle braking system according to claim 3, wherein the nut screw part comprises: a rolling contact part on which the bearing ball sits; a nut base part that is connected to a first side of the rolling contact part; and a nut step part that is connected to a second side of the rolling contact part and projects further towards the outer ring part than the nut base part. [5] Vehicle brake system according to claim 4, wherein the nut base part projects towards the outer ring part in order to be arranged further outwards than an innermost area of ​​the bearing ball. [6] Vehicle braking system according to claim 5, wherein the bearing ball contact part comprises a first outer contact area arranged on one side of the outer ring step part in relation to the outermost area of ​​the bearing ball, and a second outer contact area arranged on one side of the outer ring bottom part, and wherein the rolling contact part comprises a first inner contact area located on one side of the nut step part in relation to the innermost area of ​​the bearing ball, and a second inner contact area located on one side of the nut base part. [7] Vehicle brake system according to claim 6, wherein the first outer contact area and the first inner contact area are arranged such that they are diagonally opposite each other with respect to the bearing ball, and the bearing ball is supported by contact with the first outer contact area and the first inner contact area when the bolt screw part moves in the direction of the piston part. [8] Vehicle brake system according to claim 6 or 7, wherein the second outer contact area and the second inner contact area are arranged such that they are opposite each other in a diagonal direction with respect to the bearing ball, and the bearing ball is supported by contact with the second outer contact area and the second inner contact area when the bolt screw part moves in the direction of the opposite side of the piston part. [9] Vehicle braking system according to any one of claims 1 to 8, wherein the bolt head comprises: a head connecting part that is coupled to the bolt body and has a larger diameter than the outer diameter of the bolt body; and a head extension part that extends from the head connection part towards the piston part and has an outer diameter that is larger than the outer diameter of the head connection part. [10] Vehicle braking system according to claim 9, wherein the head extension part has a curved surface area around an outer circumference in the direction of the piston part, and the head extension part is in rolling contact with the piston part on the curved surface area. [11] Vehicle braking system, comprising: a brake caliper body with a cylinder; a piston part that is movably arranged in the cylinder and is arranged so that it faces a brake pad; a nut-and-screw part arranged in the piston part, which rotates by receiving a rotational force from an actuator and includes an outer ball rail that forms a circular path of ball elements on an inner circumferential surface; and a bolt screw part comprising a bolt body coupled to the nut screw part and receiving the rotational force from the nut screw part, and a bolt head provided separately from the bolt body, coupled to the bolt body and arranged to face the piston part, wherein an inner ball rail is provided on an outer circumferential surface of the bolt body, such that it faces the outer ball rail and forms a circumferential path of the ball elements, wherein the nut screw part comprises a first return bore unit through which the ball elements enter and exit, a return channel which is connected to the first return bore unit, and a second return bore unit which is connected to the return channel and through which the ball elements enter and exit. [12] Vehicle braking system according to claim 11, wherein the ball elements entering the first return bore unit are guided through the return channel to the second return bore unit and the ball elements entering the second return bore unit are guided through the return channel to the first return bore unit. [13] Vehicle brake system according to claim 12, wherein the first return bore unit is arranged closer to the piston part than the second return bore unit. [14] Vehicle brake system according to claim 13, further comprising a bearing part with an outer ring part in contact with an inner surface of the cylinder and a bearing ball arranged between the outer ring part and the nut screw part. [15] Vehicle braking system according to claim 14, wherein the outer ring part comprises: a bearing ball contact part on which the bearing ball sits; an outer ring base part that is connected to a first side of the bearing ball contact part and has the same height as a region of the bearing ball contact part that contacts an outermost region of the bearing ball; and an outer ring step part that is connected to a second side of the bearing ball contact part and projects further towards the nut screw part than the outer ring bottom part. [16] Vehicle braking system, comprising: a brake caliper body with a cylinder; a piston part that is movably arranged in the cylinder and is arranged so that it faces a brake pad; a nut and screw component located in the piston part, which rotates by receiving a rotational force from an actuator; and a bolt screw part comprising a bolt body coupled to the nut screw part to receive the rotational force from the nut screw part, and a bolt head provided separately from the bolt body to be coupled to the bolt body, and arranged to face the piston part, wherein when the bolt body is moved by a specified distance in the direction of the piston part, movement in the direction of the piston part is blocked by the nut screw part. [17] Vehicle braking system according to claim 16, wherein the bolt body is provided with a stop projection and a stop is provided on an inner circumferential surface of the nut screw part, and where, when the stop projection is in contact with the stop, the bolt body is prevented from moving within the nut bolt part. [18] Vehicle braking system according to claim 17, wherein the stop projection extends further outwards than an outer circumferential surface of the bolt body and the stop extends further inwards than an inner circumferential surface of the nut screw part. [19] Vehicle braking system according to claim 17 or 18, wherein the stop projection is pressed or screwed to form a single unit with the bolt body, and where the stop is pressed or screwed together with the nut and bolt part to form a single unit. [20] Vehicle braking system according to any one of claims 16 to 19, further comprising a bearing part that is arranged between the cylinder and the nut screw part and supports the nut screw part in such a way that the nut screw part rotates in the cylinder, where, if the piston part is inclined with respect to a central axis, the nut screw part rolls with respect to the bearing part.

Images