Vehicle braking system

Abstract

A vehicle braking device includes a cylinder, an electric motor connected to the cylinder and configured to generate rotational power, a screw shaft mounted within the cylinder and configured to receive rotational power from the electric motor and rotate about its axis, a nut connected to the screw shaft via balls and configured to reciprocate in the axial direction of the screw shaft according to the rotation of the screw shaft, a piston connected to the nut and configured to move with the nut, a sleeve disposed within the cylinder and configured to guide the movement of the piston inserted into the sleeve, and a damper connected to the screw shaft and elastically deformable. This disclosure provides an effect in which, when the screw shaft oscillates, the elastically deformable damper, installed in the gap between the screw shaft journal and the bearing cap, can compensate for the oscillation and reduce resonance of the screw shaft, thereby improving the connection force between the screw shaft and the electric motor.

Description

Technical Field

[0001] Exemplary embodiments of this disclosure relate to a vehicle braking device, and more specifically, to a vehicle braking device that can convert the rotational motion of a screw shaft into the linear motion of a piston, wherein the screw shaft rotates by receiving a rotational force from a motor. Background Technology

[0002] Typically, due to the characteristics of vehicle electric braking systems, a mechanism is required that is configured to convert the rotational motion of an electric motor into the linear motion of a piston within a cylinder to generate hydraulic braking pressure.

[0003] The electric braking device uses a ball screw mechanism to convert the rotational motion of the motor into linear motion. The ball screw mechanism includes a screw shaft that receives the rotational force of the motor and rotates about its axis, a nut that is connected to the screw shaft via balls and moves axially along the screw shaft, and a piston that is connected to the nut and configured to pressurize the working fluid in the cylinder.

[0004] In existing technologies, resonance occurring in the ball screw mechanism during the generation of hydraulic braking pressure can lead to problems such as damage to the motor connection, degraded system performance, and vibration and noise. Therefore, improvements are urgently needed to address these issues.

[0005] The background technology disclosed herein is disclosed in Korean Patent Publication 10-2021-0064367 (published on June 2, 2021, entitled "Hydraulic Unit of Hydraulic Vehicle Braking System"). Utility Model Content

[0006] To address the technical problem that resonance occurring in the ball screw assembly during the generation of hydraulic braking pressure can lead to damage to the motor connection, degraded system performance, and vibration and noise, several embodiments aim to provide a vehicle braking device that can reduce resonance generated by the screw shaft.

[0007] Several embodiments aim to provide a vehicle braking device that can convert the rotational motion of a screw shaft into the linear motion of a piston, wherein the screw shaft rotates by receiving rotational force from a motor.

[0008] To achieve the above objectives, a vehicle braking device according to an embodiment of the present disclosure may include: a cylinder; a motor connected to the cylinder and configured to generate rotational power; a screw shaft mounted in the cylinder and configured to receive rotational power from the motor and rotate about its axis; a nut connected to the screw shaft via balls and configured to reciprocate in the axial direction of the screw shaft according to the rotation of the screw shaft; a piston connected to the nut and configured to move together with the nut; a sleeve disposed in the cylinder and configured to guide the movement of the piston inserted into the sleeve; and a damper connected to the screw shaft and elastically deformable.

[0009] The piston may include: a rod threadedly engaged with the outer surface of the nut; and a head integrally formed with the rod, configured to reciprocate within the sleeve in the longitudinal direction of the sleeve.

[0010] The braking device may further include a shaft bearing disposed within the cylinder and connected to the screw shaft, the bearing being configured to support axial loads within the cylinder during the generation of hydraulic pressure.

[0011] The screw shaft may include: a screw body rotatably disposed within the cylinder about its axis; a neck protruding from the screw body; a power transmission portion extending from the neck and configured to receive rotational power from the motor; and a shaft cover enclosing the neck and the power transmission portion.

[0012] The damper may be made of metal. The bushing may be made of plastic.

[0013] The diameter of the power transmission section can be larger than the diameter of the neck.

[0014] A gap may be provided between the neck and the shaft cover.

[0015] The damper may include: a damper body inserted between the bearing cap and the neck, configured to enclose the neck; and an elastic portion protruding convexly from the damper body, configured to elastically support the bearing cap.

[0016] The elastic portion can protrude from the outer peripheral surface of the damper body along the radial direction of the damper body, and can be formed in the circumferential direction of the damper body.

[0017] The damper body can be annular in structure, with an opening on one side of its outer peripheral surface.

[0018] A vehicle braking device according to an embodiment of the present disclosure may include: a cylinder; a motor configured to generate rotational power; a screw shaft disposed within the cylinder, configured to receive rotational power from the motor and rotate about its axis; a nut connected to the screw shaft, configured to reciprocate in the axial direction of the screw shaft according to the rotation of the screw shaft; a sleeve disposed between the cylinder and the screw shaft; a piston connected to the nut, the piston including a head reciprocating within the sleeve according to the reciprocating motion of the nut; and a damper including a first side supported on the screw shaft and a second side supported on the motor, the damper being elastically deformable.

[0019] The damper may include a helical coil.

[0020] The spiral coil may have a discontinuous ring structure.

[0021] The spiral coil may include a metallic material.

[0022] The damper may include a torsion spring.

[0023] The screw shaft may include: a screw body rotatably disposed within the cylinder about its axis; a neck protruding from the screw body; and a power transmission section extending from the neck, configured to receive rotational power from the motor. A first side of the damper may be supported by contact with a stepped portion in the connection region between the screw body and the neck.

[0024] The second side of the damper can be supported by contacting a tapered surface on the motor.

[0025] The second side of the damper can be set to be further away from the sleeve than the first side of the damper.

[0026] The piston may include: a rod connected to the outer surface of the nut; and a head integrally formed with the rod, configured to reciprocate within the sleeve in the longitudinal direction of the sleeve.

[0027] The braking device may further include a bearing disposed within the cylinder, the bearing being connected to the screw shaft and configured to support axial loads within the cylinder during the generation of hydraulic pressure.

[0028] According to the vehicle braking device disclosed herein, the following technical effects are achieved: When the screw shaft oscillates, a damper that is elastically deformable and installed in the gap formed between the screw shaft journal and the shaft cover can compensate for the oscillation and reduce the resonance of the screw shaft, thereby improving the connection force between the screw shaft and the motor. Furthermore, the axial load caused by the reaction force during the formation of hydraulic pressure can be supported in both directions by a bearing connected to the cylinder, thereby preventing the axial load caused by the hydraulic pressure from being transmitted to the motor. Furthermore, since the damper is elastically deformable, it can absorb the vibration of the screw shaft or the impact caused by such vibration. Attached Figure Description

[0029] Figure 1 This is a cross-sectional view showing a vehicle braking device according to an embodiment of the present disclosure.

[0030] Figure 2 This is a perspective view of a cylinder as seen from one direction according to an embodiment of the present disclosure.

[0031] Figure 3 It shows the view from another direction. Figure 2 A perspective view of the cylinder.

[0032] Figure 4 It is shown Figure 2 An exploded perspective view of the cylinder.

[0033] Figure 5 It is shown Figure 3 An exploded perspective view of the cylinder.

[0034] Figure 6 This is a cross-sectional view showing a cylinder according to an embodiment of the present disclosure.

[0035] Figure 7 It is shown Figure 6 A magnified view of the middle section.

[0036] Figure 8 This is a perspective view showing a damper according to an embodiment of the present disclosure.

[0037] Figure 9 This is a cross-sectional view showing the operating state of a vehicle braking device according to an embodiment of the present disclosure, in which the piston moves forward and enters the cylinder.

[0038] Figure 10 This is a cross-sectional view showing the operating state of a piston moving rearward within a cylinder in a vehicle braking device according to an embodiment of the present disclosure.

[0039] Figure 11 This is a cross-sectional view showing a vehicle braking device according to another embodiment of the present disclosure.

[0040] Figure 12 This is a perspective view of a cylinder viewed from one direction according to another embodiment of the present disclosure.

[0041] Figure 13 It shows the view from another direction. Figure 12 A perspective view of the cylinder.

[0042] Figure 14 This is a schematic cross-sectional view of a vehicle braking device according to another embodiment of the present disclosure.

[0043] Figure 15 This is an enlarged cross-sectional view of the area surrounding the damper according to another embodiment of the present disclosure.

[0044] Figure 16 This is a view showing the operating state of a piston moving forward within a cylinder in a vehicle braking device according to another embodiment of the present disclosure.

[0045] Figure 17 This is a view showing the operating state of a piston moving backward within a cylinder in a vehicle braking device according to another embodiment of the present disclosure. Detailed Implementation

[0046] Embodiments of the vehicle braking device of this disclosure will now be described with reference to the accompanying drawings. It should be noted that the drawings are not drawn to exact scale, and for ease of description and clarity, line thickness or component dimensions may be exaggerated. Furthermore, the terminology used herein is defined with regard to its function in this disclosure and may be changed according to the user's or operator's habits or intentions. Therefore, the definitions of terminology should be based on the overall disclosure described herein.

[0047] Figure 1 This is a cross-sectional view showing a vehicle braking device according to an embodiment of the present disclosure. Figure 2 This is a perspective view of a cylinder as seen from one direction according to an embodiment of the present disclosure. Figure 3 It shows the view from another direction. Figure 2 A perspective view of the cylinder. Figure 4 It is shown Figure 2 An exploded perspective view of the cylinder. Figure 5 It is shown Figure 3 An exploded perspective view of the cylinder. Figure 6 This is a cross-sectional view showing a cylinder according to an embodiment of the present disclosure.

[0048] Reference Figures 1 to 6 According to one embodiment of the present disclosure, a vehicle braking device may include a cylinder 200, a motor 300, a screw shaft 400, a nut 500, a piston 600, a sleeve 700, and a damper 800, which will be described in detail below.

[0049] The cylinder 200 can be installed in the housing 100 by press-fitting and can withstand the torque generated by the hydraulic pressure formed by the reciprocating motion of the piston 600. In one embodiment of this disclosure, the housing 100 may have a hollow shape and have an internal space.

[0050] The housing 100 may be disposed on the outside of the cylinder 200 (based on...). Figure 1 (Left side). The cylinder 200 can be assembled onto the housing 100 with controlled concentricity.

[0051] The cylinder 200 may have a hollow shape. The sleeve 700 may be disposed in one side space inside the cylinder 200 (based on...). Figure 1 (on the left side), an operating part is provided in the sleeve 700 to allow hydraulic pressure to be generated by squeezing the piston 600.

[0052] The motor 300 can be connected to the cylinder 200, and various types of drive devices can be used within the technical concept of generating rotational power. The motor 300 can transmit rotational power (torque) to the screw shaft 400.

[0053] The motor 300 may include a stationary component 310, a rotating component 320, and a motor bearing 330.

[0054] The fixing component 310 can be fixed to the housing 100, and can be formed into various shapes based on the technical concept of changing the magnetic force by power supply. The fixing component 310 may include fixing to one side of the housing 100 (based on...) Figure 1 The fixed frame 311 (on the right side) and the stator 312 mounted on the inner surface of the rotating assembly 320 facing the fixed frame 311 and configured to generate magnetic force.

[0055] The fixed frame 311 can be connected to one side of the housing 100. The rotating assembly 320 is rotatably mounted inside the fixed frame 311.

[0056] The stator 312, acting as an electromagnet, can be mounted on the inner surface of the fixed frame 311 in the circumferential direction and can rotate the rotating assembly 320 by changing the magnetic flux in response to a control signal from a controller (not shown).

[0057] The rotating component 320 can be connected to the screw shaft 400 and can rotate together with the screw shaft 400. The rotating component 320 can be modified into various shapes within the scope of technical concept, and the rotating component 320 can rotate according to the magnetic force change of the fixed component 310.

[0058] The rotating component 320 is rotatably mounted within the fixed frame 311. The rotating component 320 may have an approximately "C" shaped cross-section and may be hollow.

[0059] Rotating assembly 320 may include one side of cylinder 200 (based on) Figure 1 The rotating frame 321 is mounted in the shape of the right side of the rotating frame 321, and the rotor 322, which is mounted on the outer surface of the rotating frame 321 facing the fixed component 310 and has magnetic force, is also mounted on the right side of the rotating frame 321.

[0060] A spline that engages with the screw shaft 400 (described in detail below) may be formed in the rotating frame 321.

[0061] The motor bearing 330 can be installed between the stationary component 310 and the rotating component 320 to reduce friction generated during the rotation of the rotating component 320. The rotor 322 consists of a plurality of magnets mounted circumferentially along the rotating frame 321 and can rotate together with the rotating frame 321 by changes in the magnetic force of the stator 312.

[0062] The frame cover 340, which is fixed to the fixed frame 311, can be installed in a shape that encloses the outer surface of one end of the rotating frame 321 to prevent foreign objects from entering.

[0063] The screw shaft 400 can be disposed inside the cylinder 200. The screw shaft 400 can be inserted along the longitudinal direction of the cylinder 200 and can be axially connected to the cylinder 200.

[0064] The central axis of cylinder 200 can coincide with the central axis of screw shaft 400. Screw shaft 400 can be fixed on bearing 900 (described below) by support assembly 1000.

[0065] The screw shaft 400 may include a screw body 410, a neck 420, a power transmission part 430, a shaft cover 440, and a coupling portion 450.

[0066] The screw body 410 is rotatably mounted within the cylinder 200 and may include a helical thread formed along the longitudinal direction of the screw shaft 400. The screw body 410 may be located within a rotating frame 321 disposed in the motor 300.

[0067] The neck 420 can be positioned on the first side from the outer surface of the screw body 410's rotation center (based on...). Figure 1 The right side protrudes and can be formed to have a diameter smaller than that of the screw body 410.

[0068] The power transmission unit 430 can be directed from the free end of the neck 420 toward the first side (based on...) Figure 1(Extends to the right) and can be formed with a diameter greater than that of the neck (420).

[0069] A spline can be formed along the circumferential direction on the outer surface of the power transmission unit 430 facing the rotating frame 321. Therefore, the rotating frame 321 and the power transmission unit 430 can be engaged with each other to realize power transmission.

[0070] The shaft cover 440 can be configured to enclose the neck 420 and the power transmission section 430. A gap G can be formed between the neck 420 and the shaft cover 440. As described below, the damper 800 can be installed within the gap G.

[0071] The shaft cover 440 can be inserted between the power transmission section 430 and the rotating frame 321 to prevent the generation of metallic rattle noise.

[0072] A spline can be formed on the outer surface of the shaft cover 440 along the circumferential direction, and the spline can engage with the rotating frame 321. The shape of the shaft cover 440 can correspond to the shape of the power transmission unit 430.

[0073] The connecting part 450 can be directed from the outer surface of the screw body 410 around the center of rotation towards the second side (based on...). Figure 1 (The left side) extends and can be formed to have a diameter smaller than that of the screw body 410.

[0074] The connecting part 450 can be rotatably connected via the bearing 900 (described below).

[0075] The nut 500 can be located in the rotating frame 321 located in the motor 300, and can also be located in the cylinder 200.

[0076] Nut 500 can be connected to the outer surface of screw shaft 400 via ball B.

[0077] The screw shaft 400 can be connected to the nut 500 by passing through it. The ball B is located between the helical thread formed on the inner surface of the nut 500 and the helical thread formed on the outer surface of the screw body 410, so that the rotational motion of the screw shaft 400 can be converted into linear motion through the nut 500.

[0078] Nut 500 can reciprocate in the axial direction of screw shaft 400 according to the rotation direction of screw shaft 400.

[0079] The piston 600 can be connected to the nut 500 by enclosing the outside of the nut 500. The piston 600 can move in the longitudinal direction of the cylinder 200 as the nut 500 moves.

[0080] The piston 600 may include a rod 610 and a head 620.

[0081] The rod 610 may be hollow and may be located within the rotating frame 321 disposed in the motor 300. The outer surface of the nut 500 and the inner surface of the rod 610 may be threaded together.

[0082] The head 620 can be integrally formed with the rod 610. The diameter of the head 620 can be larger than the diameter of the rod 610.

[0083] The head 620 may be annular, positioned within the housing 100, and reciprocate within the sleeve 700 to push the working fluid within the sleeve 700 toward the port 210. Thus, the cylinder 200 can generate dual-acting hydraulic pressure according to the reciprocating motion of the piston 600.

[0084] The sleeve 700 may be located inside the housing 100 and may be disposed inside the cylinder 200. The sleeve 700 may guide the movement of the piston 600 inserted therein.

[0085] The sleeve 700 can be formed into the head 620 of the piston 600.

[0086] The port 210 through which the working fluid flows can be located on the outer surface of the cylinder 200 corresponding to the sleeve 700. The port 210 can be located on both longitudinal sides of the cylinder 200. The working fluid driven by the movement of the piston 600 can be transmitted through the port 210 to achieve the required braking pressure.

[0087] A stop hole 710 communicating with port 210 may be formed on the outer surface of sleeve 700.

[0088] Multiple shut-off holes 710 can be arranged to be spaced apart along the circumferential direction of the sleeve 700. Therefore, the working fluid inside the sleeve 700 can be discharged in the radial direction of the piston 600.

[0089] Figure 7 It is shown Figure 6 A magnified view of the middle section. Figure 8 This is a perspective view showing a damper according to an embodiment of the present disclosure.

[0090] Reference Figures 1 to 8 According to one embodiment of the present disclosure, a damper 800 can be connected to a screw shaft 400. The damper 800 can be mounted to enclose a neck 420.

[0091] The damper 800 can be installed in the gap G formed between the neck 420 and the bushing 440. The damper 800 can be made of metal.

[0092] The damper 800 can elastically deform to reduce resonance that may occur in the screw shaft 400.

[0093] The central axis of the screw shaft 400 may tilt due to the load generated by the hydraulic pressure during the forward movement of the piston 600 and clearance tolerances. The oscillation of the screw shaft 400 can occur with the connecting part 450 as a reference point. The degree of oscillation of the screw shaft 400 is greatest at the neck 420, which is furthest from the connecting part 450.

[0094] When the screw shaft 400 resonates, the maximum oscillation (vibration) can occur at the neck 420, which may lead to damage to the shaft cover 440, degraded system performance, and quality problems caused by noise and vibration.

[0095] When the screw shaft 400 oscillates, the shaft cover 440 may deform, and resonance may occur at the gap G. A resilient damper 800 may be installed in the space where resonance may occur to reduce resonance when it occurs.

[0096] The damper 800 may include a damper body 810 and an elastic part 820.

[0097] The central portion of the damper body 810 may be formed as an opening along the axial direction of the screw shaft 400, and the damper body 810 may have a circular or elliptical ring shape with a set length. The damper body 810 may be formed into an approximately "C" shape with an opening on one side of its outer peripheral surface.

[0098] The damper body 810 can be configured to enclose the neck 420. The damper body 810 can be located between the shaft cover 440 and the neck 420.

[0099] The elastic portion 820 can protrude convexly from the damper body 810. The elastic portion 820 can protrude from the outer peripheral surface of the damper body 810 in the radial direction. The elastic portion 820 can be formed in the circumferential direction of the damper body 810.

[0100] The elastic portion 820 can elastically support the shaft cover 440. The inner peripheral surface of the elastic portion 820 may not contact the outer peripheral surface of the neck 420, while the outer peripheral surface of the elastic portion 820 may be in close contact with the inner peripheral surface of the shaft cover 440 to elastically support the shaft cover 440.

[0101] A vehicle braking device according to one embodiment of the present disclosure may include a bearing 900.

[0102] The bearing 900 can be located inside the housing 100 and at the inner end of the cylinder 200.

[0103] The outer surface of the bearing 900 and the outer surface of the sleeve 700 can be mounted to contact each other. The bearing 900 can enclose the connecting part 450 of the screw shaft 400 and be connected to the screw shaft 400 in shape.

[0104] The bearing 900 may include an inner ring 910 that is mounted in contact with the connection portion 450 of the screw shaft 400, and an outer ring 920 that is mounted in contact with the inner surface of the cylinder 200.

[0105] During the process of hydraulic pressure being generated in the cylinder 200 by the piston 600 reciprocating along the screw shaft 400, the bearing 900 can support the axial load.

[0106] The vehicle braking device according to embodiments of the present disclosure may include a support assembly 1000.

[0107] The support assembly 1000 can be disposed inside the cylinder 200. The end of the connecting portion 450 can be received inside the support assembly 1000. The bearing 900 can be fixed to the outer peripheral surface of the support assembly 1000. The support assembly 1000 can rotatably support the screw shaft 400.

[0108] The operation process of a vehicle braking device having the above structure according to an embodiment of the present disclosure will now be described.

[0109] Figure 9 This is a cross-sectional view showing the operating state of a vehicle braking device according to an embodiment of the present disclosure, in which the piston moves forward and enters the cylinder.

[0110] Reference Figure 9 When the motor 300 operates to transmit rotational force to the screw shaft 400, the screw shaft 400 can rotate around its axis in the cylinder 200 in the first rotational direction, and the nut 500 can move forward along the screw shaft 400 toward the sleeve 700.

[0111] When the nut 500 moves toward the sleeve 700, the piston 600 connected to the nut 500 moves together with the nut 500 and moves linearly forward within the cylinder 200, thereby generating hydraulic braking pressure.

[0112] Figure 10 This is a cross-sectional view showing the operating state of a piston moving rearward within a cylinder in a vehicle braking device according to an embodiment of the present disclosure.

[0113] Reference Figure 10 When the motor 300 operates, causing the screw shaft 400 to rotate along its axis within the cylinder 200 in a second rotation direction opposite to the first rotation direction, the nut 500 can move backward along the screw shaft 400 in a direction opposite to that of the sleeve 700.

[0114] When the nut 500 moves in the opposite direction to the sleeve 700, the piston 600 connected to the nut 500 moves together with the nut 500 and moves linearly backward within the cylinder 200, thereby generating hydraulic braking pressure. Therefore, when the piston 600 moves linearly back and forth within the cylinder 200, a dual-acting hydraulic pressure is formed.

[0115] In the vehicle braking device according to an embodiment of the present disclosure, when the screw shaft 400 oscillates, a damper 800, which is elastically deformable and installed in the gap G formed between the neck 420 of the screw shaft 400 and the axle cover 440, can reduce the resonance of the screw shaft 400 and compensate for the oscillation of the screw shaft 400. Therefore, the connection force between the screw shaft 400 and the motor 300 can be improved.

[0116] In the vehicle braking device according to an embodiment of the present disclosure, the bearing 900 connected to the cylinder 200 can withstand the axial load caused by the reaction force during the hydraulic pressure formation process in both directions, thereby preventing the axial load caused by the hydraulic pressure from being transmitted to the motor 300.

[0117] In the vehicle braking device according to an embodiment of the present disclosure, since the motor 300 does not bear axial load, the weight and size of the housing 100 and the bearing 900 can be reduced.

[0118] In the vehicle braking device according to an embodiment of the present disclosure, perpendicularity and concentricity can be compensated by utilizing the inherent clearance of the bearing 900, thereby eliminating the need for existing separate components for shaft alignment, reducing manufacturing costs, and shortening the overall axial length.

[0119] Figure 11 This is a cross-sectional view showing a vehicle braking device according to another embodiment of the present disclosure. Figure 12 This is a perspective view of a cylinder viewed from one direction according to another embodiment of the present disclosure. Figure 13 It shows the view from another direction. Figure 12 A perspective view of the cylinder. Figure 14 This is a schematic cross-sectional view of a vehicle braking device according to another embodiment of the present disclosure. Figure 15 This is an enlarged cross-sectional view of the area surrounding the damper according to another embodiment of the present disclosure. Figure 16 This is a view showing the operating state of a piston moving forward within a cylinder in a vehicle braking device according to another embodiment of the present disclosure. Figure 17 This is a view showing the operating state of a piston moving backward within a cylinder in a vehicle braking device according to another embodiment of the present disclosure.

[0120] Reference Figures 11 to 17 According to another embodiment of the present disclosure, the vehicle braking device may include: a cylinder 200, a motor 300, a screw shaft 400, a nut 500, a piston 600, a sleeve 700, and a damper 800, which will be described in detail below.

[0121] The cylinder 200 may be located inside the housing 100 and may withstand the torque generated by the hydraulic pressure formed by the reciprocating motion of the piston 600. According to this embodiment, the housing 100 may have a hollow shape, in which an internal space is provided, and the cylinder 200 may be press-fitted into the housing 100.

[0122] The housing 100 may be disposed on the outside of the cylinder 200 (based on...). Figure 11 (Left side). The cylinder 200 can be assembled onto the housing 100 with controlled concentricity.

[0123] The cylinder 200 may have a hollow shape. The sleeve 700 may be disposed in one side space inside the cylinder 200 (based on...). Figure 11 (on the left side), an operating part is provided in the sleeve 700 to allow hydraulic pressure to be generated by squeezing the piston 600.

[0124] The motor 300 can be connected to the cylinder 200, and various types of drive devices can be used within the technical concept of generating rotational power. The motor 300 can transmit rotational power (torque) to the screw shaft 400.

[0125] The motor 300 may include a fixed component 310, a rotating component 320, and a motor bearing 330.

[0126] The fixing component 310 can be fixed to the housing 100, and can be formed into various shapes based on the technical concept of changing the magnetic force by power supply.

[0127] The fixing component 310 may include a fixing to one side of the housing 100 (based on...) Figure 11 The fixed frame 311 (on the right side) and the stator 312 mounted on the inner surface of the rotating assembly 320 facing the fixed frame 311 and configured to generate magnetic force.

[0128] The fixed frame 311 can be connected to one side of the housing 100. The rotating assembly 320 is rotatably mounted inside the fixed frame 311.

[0129] The stator 312, acting as an electromagnet, can be mounted on the inner surface of the fixed frame 311 in the circumferential direction and can rotate the rotating assembly 320 by changing the magnetic flux in response to a control signal from a controller (not shown).

[0130] The rotating component 320 can be connected to the screw shaft 400 and can rotate together with the screw shaft 400. The rotating component 320 can be modified into various shapes within the scope of the technical concept, wherein the rotating component 320 can rotate according to the magnetic force change of the fixed component 310.

[0131] The rotating component 320 is rotatably mounted within the fixed frame 311. The rotating component 320 may have an approximately "C" shaped cross-section and may be hollow.

[0132] Rotating assembly 320 may include one side of cylinder 200 (based on) Figure 11 The rotating frame 321 is mounted in the shape of the right side of the rotating frame 321, and the rotor 322, which is mounted on the outer surface of the rotating frame 321 facing the fixed component 310 and has magnetic force, is also mounted on the right side of the rotating frame 321.

[0133] The spline that meshes with the screw shaft 400 can be formed on the rotating frame 321, specifically on the inner surface of the rotating frame 321.

[0134] The motor bearing 330 can be disposed between the stationary component 310 and the rotating component 320 to reduce friction generated during the rotation of the rotating component 320. The rotor 322 is composed of a plurality of magnets mounted along the circumferential direction of the rotating frame 321, and can rotate together with the rotating frame 321 by the magnetic force change of the stator 312.

[0135] The frame cover 340, which is fixed to the fixed frame 311, can be installed in a shape that encloses the outer surface of one end of the rotating frame 321 to prevent foreign objects from entering.

[0136] The screw shaft 400 can be disposed inside the cylinder 200. The screw shaft 400 can be positioned along the longitudinal direction of the cylinder 200 (based on...). Figure 11 It can be inserted in the left or right direction and can be axially connected to the cylinder 200. The central axis of the cylinder 200 and the central axis of the screw shaft 400 can coincide with each other.

[0137] The screw shaft 400 can be fixed to the bearing 900 by the support assembly 1000. The support assembly 1000 can rotatably support the screw shaft 400.

[0138] The screw shaft 400 may include a screw body 410, a neck 420, a power transmission part 430, and a connecting part 450.

[0139] The screw body 410 is rotatably mounted within the cylinder 200 and may include a helical thread formed along the longitudinal direction of the screw shaft 400. The screw body 410 may be located within the rotating frame 321 of the motor 300.

[0140] The neck 420 can be positioned on the first side from the outer surface of the screw body 410's rotation center (based on...). Figure 11 The right side protrudes, and its diameter can be smaller than that of the screw body 410.

[0141] The power transmission unit 430 can be directed from the free end of the neck 420 toward the first side (based on...) Figure 11 (Extends to the right) and can be formed with a diameter greater than that of the neck (420).

[0142] A spline can be formed in the circumferential direction on the outer surface of the power transmission section 430 facing the rotating frame 321. Therefore, without the shaft cover 440 (described later), the rotating frame 321 and the power transmission section 430 can be engaged to transmit power.

[0143] The screw shaft 400 may also include a shaft cover 440. The shaft cover 440 may be configured to enclose the neck 420 and the power transmission section 430. The shaft cover 440 may be inserted between the power transmission section 430 and the rotating frame 321 to prevent metallic clicking noise.

[0144] A spline can be formed on the outer surface of the shaft cover 440 along the circumferential direction, and the spline can engage with the rotating frame 321. The shape of the shaft cover 440 can correspond to the shape of the power transmission unit 430.

[0145] A spline can be formed along the circumferential direction on the outer surface of the power transmission section 430 facing the bearing cover 440. Therefore, the bearing cover 440 and the power transmission section 430 can be engaged with each other to transmit power.

[0146] The connecting part 450 can be directed from the outer surface of the screw body 410 around the center of rotation towards the second side (based on...). Figure 11 The connecting part 450 extends to the left side and can be rotatably connected to the bearing 900. The connecting part 450 can be connected to the bearing 900 by press fitting. The connecting part 450 can be formed so that its diameter is equal to or smaller than the diameter of the screw body 410.

[0147] Nut 500 may be located inside the rotating frame 321 of motor 300 and inside cylinder 200.

[0148] Nut 500 can be connected to the outer surface of screw shaft 400 via ball B.

[0149] The screw shaft 400 can be connected via the nut 500. Since the ball B is located between the helical thread formed on the inner surface of the nut 500 and the helical thread formed on the outer surface of the screw body 410, the rotational motion of the screw shaft 400 can be converted into linear motion by the nut 500.

[0150] An anti-rotation protrusion (not shown) may be formed on the outer surface of the nut 500, while a motion groove (not shown) may be formed on the inner surface of the cylinder 200.

[0151] When the screw shaft 400 rotates, the nut 500 does not rotate because the rotation of the anti-rotation protrusion of the nut 500 is blocked by the motion groove. Therefore, the rotational motion of the screw shaft 400 can be converted into the linear motion of the nut 500 through the anti-rotation protrusion and the motion groove.

[0152] The nut 500 can reciprocate along the axial direction of the screw shaft 400 according to the rotation direction of the screw shaft 400. For example, if the nut 500 moves forward when the screw shaft 400 rotates in a first direction, then the nut 500 can move backward when the screw shaft 400 rotates in a second direction opposite to the first direction.

[0153] The piston 600 can be connected by enclosing the outside of the nut 500. The piston 600 can move along the longitudinal direction of the cylinder 200 together with the reciprocating motion of the nut 500.

[0154] The piston 600 may include a rod 610 and a head 620.

[0155] The rod 610 can be formed into a hollow shape and can be positioned within the rotating frame 321 of the motor 300. The outer surface of the nut 500 and the inner surface of the rod 610 can be threaded together.

[0156] The head 620 can be integrally formed with the rod 610. The outer diameter of the head 620 can be larger than the outer diameter of the rod 610.

[0157] The head 620 may be annular, located inside the housing 100, and reciprocate within the sleeve 700 to push the working fluid within the sleeve 700 toward the port 210. Thus, the cylinder 200 can generate dual-acting hydraulic pressure according to the reciprocating motion of the piston 600.

[0158] The sleeve 700 may be located inside the housing 100 and may be arranged inside the cylinder 200. The sleeve 700 may guide the movement of the piston 600 inserted therein.

[0159] The sleeve 700 can be formed into the head 620 of the piston 600.

[0160] The port 210 through which the working fluid flows can be located on the outer surface of the area where the sleeve 700 is located on the cylinder 200. The port 210 can be located at multiple points in the longitudinal direction of the cylinder 200. The working fluid that moves according to the movement of the piston 600 can be transmitted through the port 210 to achieve the required braking pressure.

[0161] A stop hole 710 communicating with port 210 may be formed on the outer surface of sleeve 700.

[0162] Multiple shut-off holes 710 can be arranged to be spaced apart from each other in the circumferential direction of the sleeve 700. Therefore, the working fluid inside the sleeve 700 can be discharged in the radial direction of the piston 600.

[0163] The screw shaft 400 may tilt or oscillate on its central axis due to the load generated by the hydraulic pressure during the forward movement of the piston 600 or due to clearance tolerance. The tilting or oscillation of the screw shaft 400 can occur with the connection area between the connecting part 450 and the support assembly 1000 as the reference point (center point).

[0164] When the screw shaft 400 oscillates, the amplitude of the screw shaft 400 gradually increases with the distance from the oscillation reference point, and reaches its maximum value at the neck 420, which is furthest from the oscillation reference point.

[0165] In this embodiment, the damper 800 prevents the amplitude of the screw shaft 400 from increasing significantly or from resonating prematurely. Therefore, it prevents damage to the power transmission section 430 or the shaft cover 440, thereby avoiding malfunctions in the normal power transmission from the motor 300 to the screw shaft 400, or quality problems caused by noise and vibration.

[0166] In this embodiment, the damper 800 may have a first side supported by the screw shaft 400. Figure 15 (left side) and the second side supported by motor 300 Figure 15 (Right side of the middle). Therefore, the damper 800 can suppress excessive vibration of the neck 420 of the screw shaft 400 within the rotating frame 321 of the motor 300, which deviates from the central axis of the screw shaft 400.

[0167] The neck 420 of the screw shaft 400 is in indirect contact with the rotating frame 321 via a damper 800. Therefore, during the operation of the vehicle braking device, the relative displacement between the neck 420 of the screw shaft 400 and the rotating frame 321 can be reduced, thereby reducing the amplitude of the screw shaft 400.

[0168] The damper 800 is elastically deformable under the support of the screw shaft 400 and the motor 300. Therefore, when the screw shaft 400 shakes, the damper 800 will undergo elastic deformation, thereby absorbing the vibration of the screw shaft 400 or the impact caused by the vibration.

[0169] The damper 800 can be a helical coil.

[0170] The damper 800 can be formed into a discontinuous ring shape. That is, as... Figure 12 As shown, the damper 800 can be formed into a ring shape with an opening on one side of its outer peripheral surface.

[0171] Since the damper 800 has two ends, the vibration of the screw shaft 400 can be transmitted to the damper 800 and dispersed outward through each end of the damper 800.

[0172] The second side of the damper 800 can be set to be further away from the sleeve 700 than the first side of the damper 800.

[0173] according to Figure 15 The points where the damper 800 contacts the screw shaft 400 and the points where the damper 800 contacts the rotating frame 321 of the motor 300 are arranged diagonally. Therefore, the damper 800 can absorb vibrations in all directions (360 degrees) around the central axis of the screw shaft 400.

[0174] The damper 800 may include steel. More specifically, the damper 800 may be made of stainless steel.

[0175] The damper 800 can be a torsion spring or a torsion coil.

[0176] The first side of the damper 800 can contact and be supported by the stepped portion 411 in the connection area between the screw body 410 and the neck 420. Since the stepped portion 411 is planar, the first side of the damper 800 can be stably and elastically supported on the stepped portion 411.

[0177] The second side of the damper 800 can contact and be supported by the rotating frame 321 of the motor 300. The second side of the damper 800 can contact and be supported by the conical surface 325 of the rotating frame 321. Since the conical surface 325 is planar, the second side of the damper 800 can be stably and elastically supported on the conical surface 325.

[0178] Since the screw shaft 400 is connected to the nut 500 via ball bearings B, a certain amount of vibration is required during operation to prevent performance degradation or jamming. In this embodiment, the damper 800 is disposed within the space where the screw shaft 400 vibrates. Therefore, when vibration occurs, it can be effectively reduced without restricting the degree of freedom of the screw shaft 400.

[0179] The damper 800 can be arranged to enclose the neck 420 of the screw shaft 400 without interfering with the shaft cover 440. The damper 800 can also be arranged not to contact the inner circumferential surface of the neck 420.

[0180] According to another embodiment of this disclosure, the vehicle braking device may further include a bearing 900.

[0181] The bearing 900 can be located inside the housing 100 and at the inner end of the cylinder 200.

[0182] The outer surface of the bearing 900 and the outer surface of the sleeve 700 can be mounted to contact each other. The bearing 900 can be connected to the screw shaft 400 in a shape that encloses the connecting portion 450 of the screw shaft 400.

[0183] The bearing 900 may include an inner ring 910, a bearing ball 915, and an outer ring 920. The inner ring 910 may be installed in contact with the connecting portion 450 of the screw shaft 400, and the outer ring 920 may be installed in contact with the inner surface of the cylinder 200.

[0184] The bearing 900 can withstand axial loads within the cylinder 200 during the period when hydraulic pressure is generated by the piston 600 reciprocating along the screw shaft 400.

[0185] According to another embodiment of the present disclosure, a vehicle braking device may include a support assembly 1000.

[0186] The support assembly 1000 can be disposed inside the cylinder 200. The support assembly 1000 can be inserted into the connecting portion 450 and connected to the screw shaft 400. The support assembly 1000 can be threadedly engaged with the screw shaft 400. The bearing 900 can be fixed to the support assembly 1000. The support assembly 1000 rotatably supports the screw shaft 400. The support assembly 1000 can be a bolt.

[0187] According to another embodiment of this disclosure, the vehicle braking device may include a reaction force assembly 1100.

[0188] The first side of the reaction force assembly 1100 can be supported by the cylinder 200, and the second side of the reaction force assembly 1100 can contact the sleeve 700 to press the sleeve 700 against the bearing 900. The reaction force assembly 1100 can be a wave spring.

[0189] The operation of a vehicle braking device having the above configuration according to another embodiment of the present disclosure will now be described.

[0190] Reference Figure 16 When the motor 300 is running to transmit rotational force to the screw shaft 400, the screw shaft 400 can rotate around its axis in the cylinder 200 in the first rotational direction, and the nut 500 can move forward along the screw shaft 400 toward the sleeve 700.

[0191] In response to the movement of the nut 500 toward the sleeve 700, the piston 600 connected to the nut 500 can move linearly forward in the cylinder 200 in the same direction as the movement of the nut 500, thereby generating hydraulic braking pressure.

[0192] Reference Figure 17 When the motor 300 operates, causing the screw shaft 400 to rotate around its axis within the cylinder 200 in a second rotation direction opposite to the first rotation direction, the nut 500 can move backward along the screw shaft 400 in a direction opposite to the sleeve 700.

[0193] In response to the movement of the nut 500 in the opposite direction to that of the sleeve 700, the piston 600 connected to the nut 500 can move linearly backward within the cylinder 200 in the same direction as the movement of the nut 500, thereby generating hydraulic braking pressure. Therefore, when the piston 600 moves linearly back and forth within the cylinder 200, a dual-acting hydraulic pressure can be generated.

[0194] In a vehicle braking device according to another embodiment of the present disclosure, when the screw shaft 400 swings, the swing amplitude of the screw shaft 400 can be reduced by a damper 800 that is elastically deformable and disposed between the screw shaft 400 and the motor 300, and the connection force between the screw shaft 400 and the motor 300 can be improved.

[0195] This disclosure provides an effect in which, when the screw shaft oscillates, a damper that is elastically deformable and installed in the gap formed between the screw shaft journal and the shaft cover can compensate for the oscillation and reduce the resonance of the screw shaft, thereby improving the connection force between the screw shaft and the motor.

[0196] This disclosure provides an effect in which the axial load caused by the reaction force during the formation of hydraulic pressure can be supported in both directions by a bearing connected to the cylinder, thereby preventing the axial load caused by the hydraulic pressure from being transmitted to the motor.

[0197] In this disclosure, since the motor does not bear axial load, the weight and size of the housing and bearings can be reduced.

[0198] In this disclosure, perpendicularity and concentricity can be compensated by utilizing the inherent clearance of the bearing, thereby eliminating the need for existing separate components for shaft alignment, reducing manufacturing costs, and shortening the overall axial length.

[0199] In this disclosure, the damper can suppress vibrations of the screw shaft that deviate from the central axis.

[0200] In this disclosure, since the damper is elastically deformable, it can absorb the vibration of the screw shaft or the impact caused by the vibration.

[0201] Although this disclosure has been described with reference to the embodiments shown in the accompanying drawings, the embodiments of this disclosure are for illustrative purposes only, and those skilled in the art will understand that various modifications and other equivalent embodiments can be derived from these embodiments.

Claims

1. A vehicle braking device, characterized in that, include: cylinder; An electric motor is connected to the cylinder and configured to generate rotational power; A screw shaft is mounted inside the cylinder and configured to receive rotational power from the motor and rotate about its axis; The nut is connected to the screw shaft via balls and is configured to reciprocate in the axial direction of the screw shaft according to the rotation of the screw shaft; A piston, connected to the nut, and configured to move together with the nut; A sleeve, disposed within the cylinder and configured to guide the movement of a piston inserted into the sleeve, and A damper is connected to the screw shaft and is elastically deformable.

2. The vehicle braking device according to claim 1, characterized in that, The piston includes: The rod is threadedly engaged with the outer surface of the nut; and The head is integrally formed with the rod and configured to reciprocate within the sleeve in the longitudinal direction of the sleeve.

3. The vehicle braking device according to claim 1, characterized in that, Also includes: A bearing, disposed within the cylinder and connected to the screw shaft, is configured to support axial loads during the formation of hydraulic pressure within the cylinder.

4. The vehicle braking device according to claim 1, characterized in that, The screw shaft includes: The screw body is rotatably mounted inside the cylinder about its axis; The neck protrudes from the screw body; A power transmission unit extends from the neck and is configured to receive rotational power from the motor; and A shaft cover that encloses the neck and the power transmission section.

5. The vehicle braking device according to claim 4, characterized in that, The damper comprises a metallic material, and the bushing comprises a plastic material.

6. The vehicle braking device according to claim 4, characterized in that, The diameter of the power transmission section is larger than the diameter of the neck.

7. The vehicle braking device according to claim 6, characterized in that, A gap is provided between the neck and the shaft cover.

8. The vehicle braking device according to claim 7, characterized in that, The damper includes: A damper body, inserted between the shaft cap and the neck, and configured to enclose the neck; and An elastic portion protrudes convexly from the damper body and is disposed to elastically support the shaft cover.

9. The vehicle braking device according to claim 8, characterized in that, The elastic portion protrudes from the outer peripheral surface of the damper body along the radial direction of the damper body and is formed in the circumferential direction of the damper body.

10. The vehicle braking device according to claim 8, characterized in that, The damper body is annular in shape, with an opening on one side of its outer peripheral surface.

11. A vehicle braking device, characterized in that, include: cylinder; An electric motor, configured to generate rotational power; A screw shaft is disposed within the cylinder and configured to receive rotational power from the motor and rotate about its axis; A nut, connected to the screw shaft, and configured to reciprocate in the axial direction of the screw shaft according to the rotation of the screw shaft; A sleeve is disposed between the cylinder and the screw shaft; A piston, connected to the nut, and including a head that reciprocates within the sleeve according to the reciprocating motion of the nut; as well as The damper includes a first side supported on the screw shaft and a second side supported on the motor, and the damper is elastically deformable.

12. The vehicle braking device according to claim 11, characterized in that, The damper includes a helical coil.

13. The vehicle braking device according to claim 12, characterized in that, The spiral coil has a discontinuous loop shape.

14. The vehicle braking device according to claim 13, characterized in that, The spiral coil is made of metallic material.

15. The vehicle braking device according to claim 11, characterized in that, The damper includes a torsion spring.

16. The vehicle braking device according to claim 11, characterized in that, The screw shaft includes: The screw body is rotatably mounted inside the cylinder about its axis; The neck protrudes from the screw body; and A power transmission unit extends from the neck and is configured to receive rotational power from the motor. The first side of the damper is supported by contact with a stepped portion in the connection area between the screw body and the neck.

17. The vehicle braking device according to claim 11, characterized in that, The second side of the damper is supported by contact with a tapered surface on the motor.

18. The vehicle braking device according to claim 11, characterized in that, The second side of the damper is positioned further away from the sleeve than the first side of the damper.

19. The vehicle braking device according to claim 11, characterized in that, The piston includes: The rod is connected to the outer surface of the nut; The head is integrally formed with the rod and is configured to reciprocate within the sleeve in the longitudinal direction of the sleeve.

20. The vehicle braking device according to claim 11, characterized in that, It also includes a bearing disposed within the cylinder and connected to the screw shaft, the bearing being configured to withstand axial loads during the formation of hydraulic pressure within the cylinder.

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