Braking device for a vehicle

Abstract

A brake device for a vehicle includes a cylinder portion, a motor portion generating a rotational power, a screw shaft disposed in the cylinder portion, receiving the rotational power of the motor portion and rotating in an axial direction, a nut portion coupled with the screw shaft and reciprocating in the axial direction of the screw shaft according to the rotation of the screw shaft, a sleeve portion disposed between the cylinder portion and the screw shaft, a piston portion coupled with the nut portion and including a head portion reciprocating in the sleeve portion according to the reciprocation of the nut portion, a bearing portion disposed in the cylinder portion and coupled with the screw shaft, and a reaction force portion having a first side supported by the cylinder portion, a second side in contact with the sleeve portion, pressing the sleeve portion toward the bearing portion, and being contactable with the head portion. According to the present disclosure, assembly tolerance of the sleeve portion can be compensated for, and impact noise generated by relative movement of the sleeve portion or the bearing portion can be prevented.

Description

Technical Field

[0001] Exemplary embodiments of this disclosure relate to a braking device for a vehicle, and more particularly to a braking device for a vehicle capable of converting the rotational motion of a lead screw shaft caused by the rotational force of a motor into the linear motion of a piston. Background Technology

[0002] Typically, due to the characteristics of electric braking devices used in vehicles, a device is needed to generate brake hydraulic pressure by converting the rotational motion of an electric motor into the linear motion of a piston inside a cylinder.

[0003] As a device for converting the rotational motion of an electric motor into linear motion, a ball screw device is applied to an electric braking device. The ball screw device includes: a screw shaft that receives the rotational power of the motor and rotates; a nut that is connected to the screw shaft by balls and moves axially along the screw shaft; and a piston that is connected to the nut and pressurizes the working fluid in the cylinder.

[0004] In the past, there was no reaction structure to compensate for assembly tolerances during the assembly process between the cylinder section, sleeve section, and bearing section. This resulted in impact noise when the sleeve section and bearing section moved. Furthermore, impact noise also occurred between the piston section and cylinder section when the piston section moved towards the motor section for zero-point adjustment.

[0005] The background technology disclosed herein is disclosed in Korean Patent Publication No. 10-2021-0064367 (published on June 2, 2021, entitled "Hydraulic Unit for Hydraulic Vehicle Braking System"). Utility Model Content

[0006] Various embodiments of this disclosure relate to a braking device for a vehicle that can compensate for assembly tolerances of the sleeve portion and reduce impact noise when the piston portion returns to its initial position.

[0007] Various embodiments relate to a braking device for a vehicle that can reduce the impact or impact noise generated when the piston returns to its initial position within the cylinder.

[0008] In one embodiment of this disclosure, the braking device may include: a cylinder section; a motor section that generates rotational power; a lead screw shaft disposed within the cylinder section, receiving the rotational power from the motor section and rotating axially; a nut section coupled to the lead screw shaft and reciprocating in the axial direction of the lead screw shaft according to its rotation; a sleeve section disposed between the cylinder section and the lead screw shaft; a piston section coupled to the nut section and including a head that reciprocates within the sleeve section according to the reciprocating motion of the nut section; a bearing section disposed within the cylinder section and coupled to the lead screw shaft; and a reaction force section having a first side supported on the cylinder section and a second side in contact with the sleeve section, applying pressure to the sleeve section toward the bearing section and capable of contacting the head.

[0009] The reaction force section can be set on the path of the head moving backward within the cylinder section.

[0010] When the head moves backward and returns to the initial position, the reaction force can come into contact with the head.

[0011] The reaction force may include an elastic, deformable material.

[0012] The reaction force portion may include a reaction force body formed in an annular shape; and a reaction force protrusion that protrudes from the reaction force body toward the sleeve portion.

[0013] Multiple reaction force protrusions can be set on one side of the reaction force body and spaced apart from each other, and the working fluid can flow through the space between the multiple reaction force protrusions.

[0014] The reaction force may include rubber material.

[0015] The reaction force component may include a wave spring.

[0016] Wave springs can be wavy or corrugated.

[0017] According to this disclosure, it is possible to compensate for the assembly tolerances of the sleeve portion and to prevent impact noise caused by relative movement of the sleeve portion or the bearing portion.

[0018] Furthermore, according to this disclosure, it is possible to reduce the impact or impact noise generated when the piston returns to its initial position within the cylinder. Attached Figure Description

[0019] Figure 1 This is a cross-sectional view showing a braking device for a vehicle according to an embodiment of the present disclosure.

[0020] Figure 2 This is a perspective view of the cylinder section according to an embodiment of the present disclosure, viewed from one direction.

[0021] Figure 3 It is viewed from another direction. Figure 2 A 3D view of the cylinder section.

[0022] Figure 4 This is a cross-sectional view showing a braking device for a vehicle according to an embodiment of the present disclosure.

[0023] Figure 5 This is a perspective view showing the reaction force section according to an embodiment of the present disclosure.

[0024] Figure 6 It is shown Figure 5 A three-dimensional view of the reaction force unit in its installed state.

[0025] Figure 7 This is a perspective view showing a modified example of the reaction force section according to an embodiment of the present disclosure.

[0026] Figure 8 It is shown Figure 7 A three-dimensional view of the reaction force unit in its installed state.

[0027] Figure 9 This illustrates the working state of the piston portion advancing within the cylinder portion in a braking device for a vehicle according to an embodiment of the present disclosure.

[0028] Figure 10 This illustrates the working state of the piston portion retracting within the cylinder portion in a braking device for a vehicle according to an embodiment of the present disclosure. Detailed Implementation

[0029] The vehicle braking device of this disclosure will now be described in detail with reference to various exemplary embodiments and the accompanying drawings. It should be noted that, for clarity and convenience, the thickness of lines or the size of components in the drawings may be exaggerated. Furthermore, the terms described below are defined in consideration of their function in this disclosure, but these terms may vary depending on the intent or habit of the user or operator. Therefore, these terms should be interpreted in accordance with the overall content of this specification.

[0030] Figure 1 This is a cross-sectional view showing a braking device for a vehicle according to an embodiment of the present disclosure; Figure 2 This is a perspective view of the cylinder section according to an embodiment of the present disclosure, viewed from one direction. Figure 3 It is viewed from another direction. Figure 2 A three-dimensional view of the cylinder section; Figure 4 This is a cross-sectional view showing a braking device for a vehicle according to an embodiment of the present disclosure; Figure 5 This is a perspective view showing the reaction force section according to an embodiment of the present disclosure; Figure 6 It is shown Figure 5 A three-dimensional view of the reaction force unit in its installed state; Figure 7 This is a perspective view showing a modified example of the reaction force section according to an embodiment of the present disclosure; Figure 8It is shown Figure 7 A three-dimensional view of the reaction force unit in its installed state; Figure 9 This illustrates the working state of the piston portion advancing within the cylinder portion in a braking device for a vehicle according to an embodiment of the present disclosure; Figure 10 This illustrates the working state of the piston portion retracting within the cylinder portion in a braking device for a vehicle according to an embodiment of the present disclosure.

[0031] See Figures 1 to 4 According to an embodiment of the present disclosure, a braking device for a vehicle includes: a cylinder part 200, a motor part 300, a lead screw shaft 400, a nut part 500, a piston part 600, a sleeve part 700, and a reaction force part 1100, as detailed below.

[0032] The cylinder section 200 is disposed inside the housing section 100 and is used to support the torque generated when hydraulic pressure is formed by the reciprocating motion of the piston section 600. According to this embodiment, the housing section 100 can be formed into a hollow shape with an internal space and can be press-fitted to the cylinder section 200.

[0033] The housing portion 100 is disposed outside the cylinder portion 200. Figure 1 (Left side). The cylinder section 200 can be assembled such that the concentricity can be adjusted within the housing section 100.

[0034] The cylinder section 200 is formed in a hollow shape. Within the internal space of the cylinder section 200 (based on...) Figure 1 On the left side, a sleeve portion 700 with an internal working section is provided, so that hydraulic pressure is generated by the pressurized piston portion 600.

[0035] The motor unit 300 is connected to the cylinder unit 200, and various types of drive devices can be used within the technical concept of generating rotational power. The motor unit 300 transmits rotational power (torque) to the lead screw shaft 400.

[0036] The motor section 300 includes a fixed section 310, a motor rotating section 320, and a motor bearing section 330.

[0037] The fixing part 310 is fixed to the housing part 100, and can be formed into various shapes within the technical concept of changing the magnetic force by power supply.

[0038] The fixing part 310 includes a part fixed to one side of the housing part 100. Figure 1 The fixed frame 311 (on the right side) and the stator 312 mounted on the inner surface of the fixed frame 311 facing the motor rotating part 320, the stator 312 can generate magnetic force.

[0039] The fixed frame 311 is connected to one side of the housing 100, and the motor rotating part 320 is rotatably mounted inside the fixed frame 311.

[0040] The stator 312 is an electromagnet mounted on the inner surface of the fixed frame 311 in the circumferential direction, and the magnetic flux is changed by a control signal from the control unit (not shown), thereby causing the motor rotating part 320 to rotate.

[0041] The motor rotating part 320 is connected to the lead screw shaft 400 and rotates together with the lead screw shaft 400. It can be modified into various shapes within the scope of the technical concept of rotating according to the magnetic force change of the fixed part 310.

[0042] The motor rotating part 320 is rotatably mounted inside the fixed frame 311. The cross-section of the motor rotating part 320 is approximately formed as follows: It has a shape, and can be formed into a hollow shape.

[0043] The motor rotating part 320 includes: a rotating frame 321, which is mounted around one side of the cylinder part 200. Figure 1 (right side); and rotor 322, which is mounted on the outer surface of rotating frame 321 facing the fixed part 310 and has magnetic force.

[0044] The spline that meshes with the lead screw shaft 400 can be formed on the rotating frame 321, specifically on the inner surface of the rotating frame 321.

[0045] The motor bearing portion 330 is installed between the fixed portion 310 and the motor rotating portion 320 to reduce friction generated when the motor rotating portion 320 rotates. The rotor 322 includes a plurality of magnets, which are installed in the circumferential direction of the rotating frame 321. The rotor 322 rotates together with the rotating frame 321 by the change of the magnetic force of the stator 312.

[0046] The cover member 340 is fixed to the fixed frame 311 and is mounted around the outer end of the rotating frame 321 to prevent foreign objects from entering.

[0047] The lead screw shaft 400 is disposed inside the cylinder section 200. The lead screw shaft 400 is located along the longitudinal direction (based on...). Figure 1 The cylinder part 200 is inserted into the cylinder section 200 in the left-right direction and is axially coupled to the cylinder section 200. The central axis of the cylinder section 200 and the central axis of the lead screw shaft 400 can coincide with each other.

[0048] The lead screw shaft 400 is fixed to the bearing portion 900 via the support portion 1000. The support portion 1000 rotatably supports the lead screw shaft 400.

[0049] The lead screw shaft 400 includes a lead screw body 410, a neck 420, a power transmission part 430, and a coupling part 450.

[0050] The lead screw body 410 is rotatably mounted inside the cylinder section 200, and a helical gear can be provided in the longitudinal direction of the lead screw shaft 400. The lead screw body 410 can be located inside the rotating frame 321 of the motor section 300.

[0051] The neck 420 extends from the outer surface of the rotation center of the lead screw body 410 toward the first side (based on...). Figure 1 The right side of the screw protrudes, and its diameter is smaller than that of the main body 410.

[0052] The power transmission unit 430 extends from the free end of the neck 420 to the first side (based on...) Figure 1 It extends to the right side and its diameter is greater than the diameter of the neck (420).

[0053] A spline is formed in the circumferential direction on the outer surface of the power transmission section 430 facing the rotating frame 321. Therefore, in the absence of the cover 440 described below, the rotating frame 321 and the power transmission section 430 can engage with each other to transmit power.

[0054] The lead screw 400 also includes a cover 440. The cover 440 is configured to surround the neck 420 and the power transmission section 430. The cover 440 is located between the power transmission section 430 and the rotating frame 321 to prevent the generation of metal-on-metal noise.

[0055] A spline may be formed on the outer surface of the cover portion 440 along the circumferential direction of the cover portion 440 to engage with the rotating frame 321. The external shape of the cover portion 440 may be the same as the external shape of the power transmission portion 430.

[0056] A spline can be formed in the circumferential direction on the outer surface of the power transmission section 430 facing the cover section 440. Therefore, the cover section 440 and the power transmission section 430 engage with each other to transmit power.

[0057] The coupling part 450 extends from the outer surface of the rotation center of the lead screw body part 410 toward the second side (based on...). Figure 1 The coupling portion 450 extends from the left side and is rotatably coupled to the bearing portion 900. The coupling portion 450 is forcibly press-fitted to the bearing portion 900. The diameter of the coupling portion 450 is the same as or smaller than the diameter of the lead screw body portion 410.

[0058] The nut part 500 is located inside the rotating frame 321 of the motor part 300 and is provided inside the cylinder part 200.

[0059] The nut part 500 is coupled to the outer surface of the lead screw shaft 400 via the ball bearing component B.

[0060] The lead screw shaft 400 passes through and is coupled to the nut portion 500. Since the ball bearing member B is disposed between the helical gear formed on the inner surface of the nut portion 500 and the outer surface of the lead screw body portion 410, the rotational motion of the lead screw shaft 400 can be converted into linear motion through the nut portion 500.

[0061] The nut portion 500 may include an anti-rotation protrusion (not shown) formed on its outer surface, and a moving groove (not shown) may be formed on the inner surface of the cylinder portion 200.

[0062] When the lead screw shaft 400 rotates, the rotation of the anti-rotation protrusion of the nut part 500 is blocked by the moving groove, thereby preventing the nut part 500 from rotating. Therefore, through the anti-rotation protrusion and the moving groove, the rotational motion of the lead screw shaft 400 can be converted into the linear motion of the nut part 500.

[0063] The nut portion 500 reciprocates along the axial direction of the lead screw shaft 400 in the rotational direction of the lead screw shaft 400. For example, when the lead screw shaft 400 rotates in a first direction, the nut portion 500 can move forward; when the lead screw shaft 400 rotates in a second direction opposite to the first direction, the nut portion 500 can move backward.

[0064] The piston portion 600 is coupled to and surrounds the outside of the nut portion 500. The piston portion 600 can be linked to the reciprocating motion of the nut portion 500 and can move in the longitudinal direction of the cylinder portion 200.

[0065] The piston portion 600 includes a rod portion 610 and a head portion 620.

[0066] The rod portion 610 is hollow and is located inside the rotating frame 321 of the motor portion 300. The outer surface of the nut portion 500 is threadedly connected to the inner surface of the rod portion 610.

[0067] The head 620 and the rod 610 are integrally formed. The outer diameter of the head 620 is larger than the outer diameter of the rod 610.

[0068] The head 620 is annular and located inside the housing 100. When it reciprocates within the sleeve 700, it causes the working fluid within the sleeve 700 to move in the direction toward the port 210. Therefore, the cylinder 200 can form a double-acting hydraulic system based on the reciprocating motion of the piston 600.

[0069] The sleeve portion 700 is located inside the housing portion 100 and is disposed inside the cylinder portion 200. The sleeve portion 700 guides the movement of the piston portion 600 inserted therein.

[0070] The sleeve portion 700 is configured to surround the head 620 of the piston portion 600.

[0071] The port 210 through which the working fluid flows can be provided on the outer surface of the cylinder section 200, and the sleeve section 700 is provided inside the cylinder section 200. The port 210 can be provided at multiple points in the longitudinal direction of the cylinder section 200. The working fluid moves according to the movement of the piston section 600 and moves through the port 210, thereby achieving the required braking pressure.

[0072] A cut-off hole 710 communicating with port 210 is provided on the outer surface of the sleeve portion 700.

[0073] Multiple cut-off holes 710 can be provided at intervals between each other in the circumferential direction of the sleeve portion 700. Therefore, the working fluid in the sleeve portion 700 can be discharged in the radial direction of the piston portion 600.

[0074] See Figures 1 to 6 The first side of the reaction force part 1100 is supported by the cylinder part 200, and the second side contacts the sleeve part 700, applying pressure to the sleeve part 700 toward the bearing part 900.

[0075] The first side of the reaction force part 1100 contacts and is supported by the inner wall 260 of the cylinder part 200, and the second side opposite to the first side contacts and is supported by the end of the sleeve part 700. By providing the reaction force part 1100, the gap generated during the assembly of the sleeve part 700 to the cylinder part 200 can be filled.

[0076] Even when there is a gap between the sleeve portion 700 and the inner wall portion 260 of the cylinder portion 200, the reaction force portion 1100 is provided in this gap, allowing the sleeve portion 700 to be elastically supported and thus in close contact with the bearing portion 900. Therefore, the reaction force portion 1100 compensates for the assembly gap or assembly tolerance between the cylinder portion 200 and the sleeve portion 700, thereby preventing the generation of impact noise caused by the relative movement of the sleeve portion 700 or the bearing portion 900.

[0077] The reaction force section 1100 can contact the head 620 of the piston section 600. The piston section 600 retracts towards the motor section 300 and returns to its initial position (see...). Figure 10 During the process, the rear end 621 of the head 620 will come into contact with the reaction force part 1100 before the piston part 600 collides with the inner wall part 260 of the cylinder part 200. Therefore, when the piston part 600 returns to the initial position to adjust point O, the head 620 can be prevented from directly impacting the inner wall part 260 of the cylinder part 200, thereby avoiding impact noise or impact caused by direct collision.

[0078] The reaction force part 1100 can be provided on the path of the head 620 when it retracts. Since the reaction force part 1100 is located on the retraction path of the head 620, the reaction force part 1100 can limit the retraction movement of the head 620.

[0079] The reaction force part 1100 is provided between the sleeve part 700 and the inner wall part 260 of the cylinder part 200, and protrudes into the retraction path of the head 620.

[0080] The reaction force part 1100 may contain an elastic deformable material. Therefore, the reaction force part 1100 can elastically support the bearing part 900, so that the sleeve part 700 can be in close contact with the bearing part 900, and can buffer the impact and / or noise such as impact sound generated when the head 620 returns to the initial position and contacts the head 620.

[0081] See Figure 5 and Figure 6 The reaction force part 1100 includes a reaction force body 1110 and a reaction force protrusion 1120.

[0082] The reaction force body 1110 is arranged in a ring shape, and the reaction force protrusion 1120 protrudes towards the sleeve portion 700. The reaction force body 1110 is arranged in a ring shape along the inner circumference of the cylinder portion 200, and the reaction force body 1110 is disposed between the sleeve portion 700 and the inner wall portion 260 of the cylinder portion 200.

[0083] Multiple reaction force protrusions 1120 are provided at intervals on the surface of the reaction force body 1110. The reaction force protrusions 1120 are provided at the same rotational interval on the surface of the reaction force body 1110 facing the sleeve portion 700. The end of the sleeve portion 700 contacts the reaction force protrusions 1120, and the inner wall portion 260 of the cylinder portion 200 contacts the reaction force body 1110.

[0084] Because the multiple reaction force protrusions 1120 are spaced apart from each other, there are separation spaces between adjacent reaction force protrusions 1120. The working fluid in the sleeve portion 700 can move toward the port 210 through these separation spaces. Figure 6 The arrows indicate the movement path of the working oil. Therefore, the cylinder section 200 can form double-acting hydraulic pressure according to the reciprocating motion of the piston section 600.

[0085] The reaction force body 1110 and the reaction force protrusion 1120 may contain rubber material. The reaction force body 1110 and the reaction force protrusion 1120 may be integrally molded.

[0086] See Figure 7 and Figure 8 The reaction force part 1100 includes a wave spring 1110.

[0087] The wave spring 1110 may have a wavy or corrugated shape. Therefore, even when the wave spring 1110 is compressed and deformed, the wavy or corrugated portion of the wave spring 1110 will not fully unfold, and thus space remains around the wavy or corrugated portion of the wave spring 1110. Through the space inside the wave spring 1110, the working fluid inside the sleeve portion 700 can flow towards the port 210.

[0088] The wave spring 1110 may be composed of one or more wavy or corrugated rings, or may be formed by winding one or more wavy or corrugated rings. The wave spring 1110 may also be constructed by connecting or overlapping multiple wavy or corrugated rings.

[0089] The wave spring 1110 can be composed of one or more wavy or corrugated plates, or can be formed by winding one or more wavy or corrugated plates. The wave spring 1110 can also be constructed by connecting or overlapping multiple wavy or corrugated plates. Therefore, the shape of the wave spring 1110 is not limited to... Figure 7 The shape shown. The wave spring 1110 may contain a metallic material.

[0090] The wave spring 1110 can be arranged in a ring along the inner circumference of the cylinder portion 200 and is located between the sleeve portion 700 and the inner wall portion 260 of the cylinder portion 200.

[0091] Even when the head 620 returns to its initial position and the wave spring 1110 is compressed, there is still space inside the wave spring 1110. Therefore, the working fluid inside the sleeve 700 can flow towards the port 210 through the space inside the wave spring 1110. Figure 8 The arrows indicate the flow path of the working fluid. Therefore, the cylinder section 200 can form double-acting hydraulic pressure according to the reciprocating motion of the piston section 600.

[0092] In the sleeve portion 700, the sealing portion 750 and the O-ring portion (not shown) are respectively provided on the left and right sides of the cutting hole 710.

[0093] The sealing part 750 may be provided on the inner wall of the cylinder part 200, in the forward direction of the piston part 600 (based on...). Figure 9 The O-ring portion may be provided on the inner wall of the cylinder portion 200, in the retraction direction of the piston portion 600 (based on the leftward movement direction) and spaced apart from the cut-off hole 710; the O-ring portion may be provided on the inner wall of the cylinder portion 200, in the retraction direction of the piston portion 600 (based on the leftward movement direction) and spaced apart from the cut-off hole 710; Figure 10 (in the direction of rightward movement) spaced apart from the cutting hole 710.

[0094] A sealing portion 750 is mounted on the inner wall of the cylinder portion 200 and seals the space between the cylinder portion 200 and the sleeve portion 700. The sealing portion 750 contacts both the cylinder portion 200 and the sleeve portion 700 at multiple points to seal the space between them at multiple points. Therefore, even when the sleeve portion 700 undergoes slight axial displacement, the sealing portion 750 can still seal the space between the cylinder portion 200 and the sleeve portion 700. The sealing portion 750 may contain an elastically deformable material.

[0095] The overall cross-sectional shape of the sealing part 750 can be figure-eight or peanut-shaped. The sleeve part 700, in the longitudinal direction (based on...) Figure 1 The length in the left-right direction can be greater than that of the sleeve portion 700 in the radial direction (based on...). Figure 1 The length in the vertical direction.

[0096] The braking device for a vehicle according to this embodiment includes a damping section 800. The first side of the damping section 800 (based on...) Figure 1 The left side is supported by the lead screw 400, and the second side (based on) Figure 1 The right side of the lead screw shaft 400 is supported by the motor section 300. Therefore, when the neck 420 of the lead screw shaft 400 deviates from the central axis of the lead screw shaft 400 in the rotating frame 321 of the motor section 300, the vibration damping section 800 can suppress large-amplitude vibrations of the neck 420.

[0097] The neck 420 of the lead screw shaft 400 is indirectly in contact with the rotating frame 321 through the damping part 800. Therefore, when the vehicle's braking device is running, the relative displacement of the neck 420 of the lead screw shaft 400 with respect to the rotating frame 321 is reduced, thereby reducing the amplitude of the lead screw shaft 400.

[0098] The vibration damping unit 800 can undergo elastic deformation when supported by the lead screw shaft 400 and the motor unit 300. Therefore, when the lead screw shaft 400 shakes, the vibration damping unit 800 can undergo elastic deformation and absorb the vibration of the lead screw shaft 400 or the impact caused by the vibration.

[0099] The damping section 800 can be a helical coil. The damping section 800 can also be formed as a discontinuous ring. That is, as... Figure 2 As shown, the damping part 800 can be formed as an annular shape with an opening on one side of its outer peripheral surface.

[0100] The vibration damping section 800 includes two ends, thereby allowing the vibration of the lead screw shaft 400 to be transmitted to the vibration damping section 800 and then dispersed outward through the ends of the vibration damping section 800. The second side of the vibration damping section 800 may be configured to have a larger distance from the first side and the sleeve section 700 than the distance between the second side and the sleeve section 700.

[0101] See Figure 1The contact points between the vibration damping unit 800 and the lead screw shaft 400, as well as the contact points between the vibration damping unit 800 and the rotating frame 321 of the motor unit 300, are arranged in an inclined direction. Therefore, the vibration damping unit 800 can buffer vibrations in all directions within a 360-degree range relative to the central axis of the lead screw shaft 400.

[0102] The vibration damping part 800 may be made of steel. More specifically, the vibration damping part 800 may be made of stainless steel. The vibration damping part 800 may be a torsion spring or a deformable coil.

[0103] The first side of the vibration damping section 800 can contact and be supported by the stepped portion of the connection between the lead screw body section 410 and the neck section 420. The second side of the vibration damping section 800 can contact and be supported by the rotating frame 321 of the motor section 300. The second side of the vibration damping section 800 can contact and be supported by the tapered surface of the rotating frame 321.

[0104] Since the lead screw shaft 400 is coupled to the nut portion 500 via the ball bearing component B, a certain amount of vibration is allowed to prevent performance degradation or jamming during operation. In this embodiment, the vibration damping portion 800 is disposed within the space where the lead screw shaft 400 vibrates, thus effectively reducing vibration without restricting the vibration degrees of freedom of the lead screw shaft 400.

[0105] The vibration damping part 800 may be configured to surround the neck 420 of the lead screw shaft 400 and not interfere with the cover part 440. The vibration damping part 800 may be configured not to contact the inner peripheral surface of the neck 420.

[0106] A braking device for a vehicle according to an embodiment of the present disclosure includes a bearing portion 900. The bearing portion 900 is located inside the housing portion 100 and is disposed at the inner end of the cylinder portion 200.

[0107] The outer surfaces of the bearing portion 900 and the sleeve portion 700 are in contact with each other. The bearing portion 900 is coupled to the lead screw shaft 400 and surrounds the coupling portion 450 of the lead screw shaft 400.

[0108] The bearing section 900 includes an inner wheel section 910, bearing balls 915, and an outer wheel section 920. The inner wheel section 910 is mounted to contact the coupling section 450 of the lead screw shaft 400, and the outer wheel section 920 is mounted to contact the inner surface of the cylinder section 200.

[0109] When hydraulic pressure is generated in the cylinder section 200 by the reciprocating motion of the piston section 600 in the axial direction of the lead screw shaft 400, the bearing section 900 supports the load in the axial direction of the lead screw shaft 400.

[0110] A braking device for a vehicle according to an embodiment of the present disclosure includes a support portion 1000. The support portion 1000 is disposed inside a cylinder portion 200. The support portion 1000 is inserted into a coupling portion 450 and coupled to a lead screw shaft 400. The support portion 1000 is threadedly connected to the lead screw shaft 400. A bearing portion 900 is fixed to the support portion 1000. The support portion 1000 rotatably supports the lead screw shaft 400. The support portion 1000 may be a bolt.

[0111] The operation of a braking device for a vehicle having the above-described structure according to an embodiment of this disclosure is described below.

[0112] See Figure 9 When the motor section 300 is working, the rotational force is transmitted to the lead screw shaft 400. The lead screw shaft 400 rotates axially in the first rotation direction within the cylinder section 200, and the nut section 500 moves along the lead screw shaft 400 towards the sleeve section 700.

[0113] When the nut portion 500 moves toward the sleeve portion 700, the piston portion 600 coupled to the nut portion 500 moves forward in a straight line within the cylinder portion 200 in the same direction as the movement direction of the nut portion 500, thereby forming a braking hydraulic pressure.

[0114] See Figure 10 When the motor part 300 is working, causing the lead screw shaft 400 to rotate axially in a second rotation direction opposite to the first rotation direction, the nut part 500 moves backward along the lead screw shaft 400 in a direction away from the sleeve part 700.

[0115] When the nut portion 500 moves away from the sleeve portion 700, the piston portion 600 coupled to the nut portion 500 can retract linearly within the cylinder portion 200 in the same direction as the movement direction of the nut portion 500 and return to its initial position, thereby forming braking hydraulic pressure. Therefore, when the piston portion 600 moves linearly back and forth within the cylinder portion 200, double-acting hydraulic pressure is formed.

[0116] Although this disclosure has been described with reference to embodiments shown in the accompanying drawings, the disclosed embodiments are for illustrative purposes only, and those skilled in the art will recognize that various modifications and other equivalent embodiments can be made based on these embodiments.

Claims

1. A braking device for a vehicle, characterized in that, include: Cylinder section; The motor section generates rotational power; The lead screw shaft is disposed inside the cylinder section, receives the rotational power from the motor section, and rotates axially; The nut part is coupled to the lead screw shaft and reciprocates in the axial direction of the lead screw shaft according to the rotation of the lead screw shaft; A sleeve portion is disposed between the cylinder portion and the lead screw shaft; A piston portion, coupled to the nut portion, and including a head, which reciprocates within the sleeve portion according to the reciprocating motion of the nut portion; A bearing portion, which is disposed within the cylinder portion and coupled to the lead screw shaft; and The reaction force part has a first side supported on the cylinder part and a second side in contact with the sleeve part, applies pressure to the sleeve part toward the bearing part, and is able to contact the head.

2. The braking device for a vehicle according to claim 1, characterized in that, The reaction force unit is positioned on the path of the head moving backward within the cylinder section.

3. The braking device for a vehicle according to claim 2, characterized in that, When the head moves backward and returns to its initial position, the reaction force part comes into contact with the head.

4. The braking device for a vehicle according to claim 3, characterized in that, The reaction force component comprises an elastically deformable material.

5. The braking device for a vehicle according to claim 4, characterized in that, The reaction force component includes: The reaction force is formed in a ring shape; and The reaction force protrusion extends from the reaction force body toward the sleeve portion.

6. The braking device for a vehicle according to claim 5, characterized in that, Multiple reaction force protrusions are spaced apart from each other on one side of the reaction force body, and The working fluid flows through the space between the multiple reaction force protrusions.

7. The braking device for a vehicle according to claim 6, characterized in that, The reaction force component contains a rubber material.

8. The braking device for a vehicle according to claim 4, characterized in that, The reaction force component includes a wave spring.

9. The braking device for a vehicle according to claim 8, characterized in that, The wave spring has a wavy or corrugated shape.

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