Brake device for a vehicle

Abstract

Braking device for a vehicle, comprising: a cylinder part; a motor part that generates a rotational force; a screw shaft that is located inside the cylinder part, absorbs the rotational force of the engine part and is rotated axially; a nut part that is coupled to the screw shaft and moves back and forth in an axial direction of the screw shaft according to the rotation of the screw shaft; a sleeve part that is arranged between the cylinder part and the screw shaft; a piston part that is coupled to the nut part and includes a head section that moves back and forth in the sleeve part in accordance with the back-and-forth movement of the nut part; a bearing component that is arranged in the cylinder part and coupled to the screw shaft; and a reaction force part, the first side of which is supported on the cylinder part and the second side of which touches the sleeve part, pushes the sleeve part towards the bearing part and is able to touch the head section.

Description

Background 1. Technical field

[0001] Exemplary embodiments of the present disclosure relate to a braking device for a vehicle and in particular to a braking device for a vehicle which is capable of converting a rotary motion of a screw shaft by means of a rotary force of a motor part into a linear motion of a piston part. 2. State of the art

[0002] Due to the characteristics of an electric braking device for a vehicle, a device is generally required that generates brake fluid pressure by converting the rotary motion of a motor into the linear motion of a piston in a cylinder.

[0003] In the electric brake device, a ball screw drive is used as the device for converting the rotary motion of a motor into linear motion. This drive comprises a spindle shaft that receives and rotates the rotational force of the motor, a nut that is connected to the spindle shaft via balls and moves in an axial direction along the spindle 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 between a cylinder part, a sleeve part, and a bearing part. This caused a problem where impact noises arose from the movement of the sleeve part and the bearing part. Furthermore, an issue arose where impact noises occurred between a piston part and a cylinder part when the piston part moved towards the engine part for zeroing.

[0005] The background technology of the present disclosure is disclosed in Korean patent publication No. 10-2021-0064367 (published on June 2, 2021, entitled “Hydraulic part for hydraulic vehicle braking system”). Summary

[0006] Various embodiments relate to a braking device for a vehicle that is able to compensate for an assembly tolerance of a sleeve part and reduce impact noise when a piston part returns to a home position.

[0007] Various embodiments relate to a braking device for a vehicle that is capable of reducing shocks or impact noises that occur when a piston part in a cylinder part returns to a starting position.

[0008] In one embodiment of the present disclosure, a braking device may comprise a cylinder part, a motor part that generates a rotational force, a screw shaft arranged inside the cylinder part that receives the rotational force of the motor part and is axially rotated, a nut part that is coupled to the screw shaft and moves back and forth in an axial direction of the screw shaft in accordance with the rotation of the screw shaft, a sleeve part that is arranged between the cylinder part and the screw shaft, a piston part that is coupled to the nut part and comprises a head section that moves back and forth in the sleeve part in accordance with the reciprocating movement of the nut part, a bearing part that is arranged in the cylinder part and coupled to the screw shaft, and a reaction force part, the first side of which is supported on the cylinder part and the second side of which contacts the sleeve part.the sleeve part is pushed towards the bearing part and is able to touch the head section.

[0009] The reaction force component can be arranged in a path through which the head section moves backwards in the cylinder part.

[0010] The reaction force component can touch the head section when the head section moves backward and returns to a starting position.

[0011] The reaction force component can comprise an elastically deformable material.

[0012] The reaction force part can include a reaction force body formed in a ring shape and a reaction force projection extending from the reaction force body towards the sleeve part.

[0013] A plurality of reaction force protrusions can be arranged on one side of the reaction force body such that they are spaced apart from each other, and a working fluid can flow through spaces between the plurality of reaction force protrusions.

[0014] The reaction force component may include a rubber material.

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

[0016] The wave spring can have a wavy or ribbed shape.

[0017] According to the present disclosure, assembly tolerances of the sleeve part can be compensated for and the occurrence of impact noise due to a relative movement of the sleeve part or the bearing part can be prevented.

[0018] Furthermore, according to the present disclosure, the impact or impact noise that occurs when the piston part returns to its starting position in the cylinder part can be reduced. Brief description of the drawings Fig. Figure 1 is a cross-sectional view representing a braking device for a vehicle according to an embodiment of the present disclosure. Fig. Figure 2 is a perspective view of a cylinder part according to an embodiment of the present disclosure, viewed from one direction. Fig. Figure 3 is a perspective view of the cylinder part. Fig. 2, viewed from a different direction. Fig. Figure 4 is a cross-sectional view that schematically represents a braking device for a vehicle according to an embodiment of the present disclosure. Fig. Figure 5 is a perspective view representing a reaction force component according to an embodiment of the present disclosure. Fig. Figure 6 is a perspective view illustrating a state in which the reaction force component is made up of Fig. 5 is mounted. Fig. Figure 7 is a perspective view illustrating a modified example of the reaction force part according to an embodiment of the present disclosure. Fig. Figure 8 is a perspective view illustrating a state in which the reaction force component is made up of Fig. 7 is mounted. Fig. Figure 9 illustrates an operating condition in which a piston part advances in a cylinder part in a brake device for a vehicle according to an embodiment of the present disclosure. Fig. Figure 10 illustrates an operating condition in which a piston part retracts into a cylinder part in a brake device for a vehicle according to an embodiment of the present disclosure. Detailed description

[0019] A braking device for a vehicle according to the present disclosure is described in detail below with reference to the accompanying drawings, using various exemplary embodiments. It should be noted that the thickness of each line or the size of each component in the drawings may be exaggerated for the sake of clarity and simplification. Furthermore, terms described below have been defined in consideration of their functions in this description and may vary depending on the intention or procedure of the user or operator. Therefore, these terms should be interpreted based on the entire content of this description.

[0020] Fig. Figure 1 is a cross-sectional view representing a braking device for a vehicle according to an embodiment of the present disclosure. Fig. Figure 2 is a perspective view of a cylinder part according to an embodiment of the present disclosure, viewed from one direction. Fig. Figure 3 is a perspective view of the cylinder part of Fig. 2, viewed from a different direction. Fig. Figure 4 is a cross-sectional view that schematically represents the braking device for a vehicle according to one embodiment of the present disclosure. Fig. Figure 5 is a perspective view representing a reaction force component according to an embodiment of the present disclosure. Fig. Figure 6 is a perspective view illustrating a state in which the reaction force component is made up of Fig. 5 is mounted. Fig. Figure 7 is a perspective view illustrating a modified example of the reaction force part according to an embodiment of the present disclosure. Fig. Figure 8 is a perspective view depicting a state in which the reaction force component is made up of Fig. 7 is mounted. Fig. Figure 9 illustrates an operating condition in which a piston part advances in a cylinder part in a brake device for a vehicle according to an embodiment of the present disclosure. Fig. Figure 10 illustrates an operating condition in which a piston part retracts into the cylinder part in the brake device for a vehicle according to an embodiment of the present disclosure.

[0021] With reference to Fig. 1 to Fig. 4 The braking device for a vehicle according to an embodiment of the present disclosure comprises a cylinder part 200, a motor part 300, a screw shaft 400, a nut part 500, a piston part 600, a sleeve part 700 and a reaction force part 1100, which is described in detail below.

[0022] The cylinder part 200 is arranged inside the housing part 100 to absorb a torque generated by the reciprocating movement of the piston part 600 when hydraulic pressure is built up. According to the present embodiment, the housing part 100 can be hollow and have an internal cavity, and can be press-fitted to the cylinder part 200.

[0023] The housing part 100 is positioned outside the cylinder part 200 (left side of Fig. 1) The cylinder part 200 can be assembled in such a way that concentricity is regulated in the housing part 100.

[0024] The cylindrical part 200 is formed in a hollow shape. In a space (left side based on Fig. 1) in the cylinder part 200 the sleeve part 700 with an actuating section provided therein can be arranged in such a way that a hydraulic pressure is generated by pressing the piston part 600.

[0025] The motor part 300 is connected to the cylinder part 200, and various types of drive devices can be used within the framework of a technical concept to generate torque. The motor part 300 transmits the torque to the screw shaft 400.

[0026] The motor part 300 comprises a mounting part 310, a motor rotating part 320 and a motor bearing part 330.

[0027] The fastening part 310 is attached to the housing part 100 and can be designed in various shapes as part of a technical idea in which a magnetic force is changed by the supply of current.

[0028] The fastening part 310 comprises a fastening frame 311, which is attached to one side (right side of Fig. 1) of the housing part 100, and a stator 312 which is installed on an inner surface of the mounting frame 311 opposite the motor rotating part 320 and generates a magnetic force.

[0029] The mounting frame 311 is connected to one side of the housing part 100 and the motor rotating part 320 is rotatably installed in the mounting frame 311.

[0030] The stator 312, which is an electromagnet, is installed circumferentially on an inner surface of the mounting frame 311, and a magnetic flux is changed by a control signal from a control unit (not shown) to rotate the motor rotating part 320.

[0031] The motor rotating part 320 is connected to the screw shaft 400 in order to be rotated together with the screw shaft 400, and can be modified into different shapes within the framework of the technical idea that it rotates according to the change in the magnetic force of the fastening part 310.

[0032] The motor rotating part 320 is rotatably installed in the mounting frame 311. A cross-section of the motor rotating part 320 is approximately in a "⊂" shape and can also be in a hollow shape.

[0033] The motor rotating part 320 comprises a rotating frame 321, which is installed in a form that forms one side (right side) of Fig. 1) surrounds the cylinder part 200, and a rotor 322 which is installed on an outer surface of the rotating frame 321 which faces the mounting part 310 and has a magnetic force.

[0034] A splined connection engaging with the screw shaft 400 can be formed on the rotary frame 321, more precisely on an inner surface of the rotary frame 321.

[0035] The motor bearing part 330 is installed between the mounting part 310 and the motor rotating part 320 to reduce the friction that occurs when the motor rotating part 320 rotates. The rotor 322 comprises a plurality of magnets installed in the circumferential direction of the rotating frame 321 and is rotated by a change in the magnetic force of the stator 312 together with the rotating frame 321.

[0036] The cover element 340, attached to the mounting frame 311, is installed in a form that surrounds the outer end of the rotating frame 321 to prevent the ingress of foreign substances.

[0037] The screw shaft 400 is located inside the cylinder part 200. The screw shaft 400 is oriented longitudinally (in a left-right direction based on...). Fig. 1) inserted into the cylinder part 200 and axially coupled to the cylinder part 200. The central axis of the cylinder part 200 and the central axis of the screw shaft 400 can coincide.

[0038] The screw shaft 400 is attached to a bearing part 900 via a support part 1000. The support part 1000 rotatably supports the screw shaft 400.

[0039] The screw shaft 400 comprises a screw body section 410, a neck section 420, a power transmission section 430 and a coupling section 450.

[0040] The screw body section 410 is rotatably installed in the cylinder part 200, and a spiral gear can be arranged in the longitudinal direction of the screw shaft 400. The screw body section 410 can be arranged in the rotating frame 321 of the motor part 300.

[0041] The neck section 420 extends from an outer surface of a center of rotation of the screw body section 410 towards the first side (right side based on Fig. 1) and has a smaller diameter than that of the screw body section 410.

[0042] The power transmission section 430 extends from a free end of the neck section 420 towards the first side (right side based on Fig. 1) and has a larger diameter than that of the neck section 420.

[0043] A splined connection can be formed on an outer surface of the power transmission section 430 facing the rotary frame 321 in the circumferential direction. Therefore, the rotary frame 321 and the power transmission section 430 can also be engaged for power transmission in the absence of the cover section 440 described later.

[0044] The screw shaft 400 further comprises the cover section 440. The cover section 440 is arranged such that it surrounds the neck section 420 and the power transmission section 430. The cover section 440 is positioned between the power transmission section 430 and the rotating frame 321 to prevent the generation of metallic rattling noises.

[0045] A wedge-shaped toothing can be formed in the outer surface of the cover section 440 along the circumferential direction of the cover section 440 in order to engage with the rotating frame 321. The outer shape of the cover section 440 can correspond to the outer shape of the power transmission section 430.

[0046] A wedge-shaped toothing can be formed on an outer surface of the power transmission section 430 facing the cover section 440 in the circumferential direction. This allows the cover section 440 and the power transmission section 430 to interlock and enable power transmission.

[0047] The coupling section 450 extends from an outer surface of a rotation center of the screw body section 410 towards a second side (left side based on Fig. 1) and is rotatably coupled to the bearing part 900. The coupling section 450 is forcefully pressed into the bearing part 900. The coupling section 450 has a diameter that is equal to or smaller than that of the screw body section 410.

[0048] The mother part 500 is arranged in the rotating frame 321 of the motor part 300 and is arranged in the cylinder part 200.

[0049] The mother part 500 is coupled to the outer surface of the screw shaft 400 via ball elements B.

[0050] The screw shaft 400 passes through the nut part 500 and is coupled to it. Since the ball elements B are arranged between the inner surface of the nut part 500 and the spiral gear on the outer surface of the screw body section 410, the rotary motion of the screw shaft 400 can be converted into a linear motion by the nut part 500.

[0051] The mother part 500 can have an anti-rotation projection formed on its outer surface (not shown) and the cylinder part 200 can have a movement groove formed on its inner surface (not shown).

[0052] The rotation of the anti-rotation projection of the nut part 500 is blocked by the motion groove when the screw shaft 400 rotates, thus preventing the nut part 500 from rotating. Therefore, the rotational movement of the screw shaft 400 can be converted into a linear movement of the nut part 500 by the anti-rotation projection and the motion groove.

[0053] The nut part 500 moves back and forth in the axial direction of the screw shaft 400 along the direction of rotation of the screw shaft 400. For example, if the screw shaft 400 rotates in a first direction, the nut part 500 can be moved forward, and if the screw shaft 400 rotates in a second direction opposite to the first, the nut part 500 can be moved backward.

[0054] The piston part 600 is coupled in such a way that it surrounds the outer surface of the mother part 500. The piston part 600 can be coupled to the reciprocating movement of the mother part 500 and move in the longitudinal direction of the cylinder part 200.

[0055] The piston part 600 comprises a rod section 610 and a head section 620.

[0056] The rod section 610 has a hollow shape and is positioned inside the rotating frame 321 of the motor part 300. The outer surface of the nut part 500 and the inner surface of the rod section 610 can be screwed together.

[0057] The head section 620 is formed integrally with the rod section 610. The outer diameter of the head section 620 is larger than the outer diameter of the rod section 610.

[0058] The head section 620 has a ring shape, is arranged inside the housing part 100, and moves the working fluid in the sleeve part 700 in one direction of the port 210 while moving back and forth inside the sleeve part 700. Accordingly, the cylinder part 200 can generate a double-acting hydraulic pressure corresponding to the reciprocating movement of the piston part 600.

[0059] The sleeve part 700 is arranged in the housing part 100 and is located in the cylinder part 200. The sleeve part 700 induces a movement of the piston part 600 inserted therein.

[0060] The sleeve part 700 is arranged so that it surrounds the head section 620 of the piston part 600.

[0061] The port 210, through which the working fluid flows, can be located on an outer surface of the cylinder part 200, on which the sleeve part 700 is located. The port 210 can be provided at multiple locations along the longitudinal direction of the cylinder part 200. The working fluid, moving in accordance with the movement of the piston part 600, flows through the port 210 and can generate the required brake pressure.

[0062] Shut-off holes 710 are arranged on an outer surface of the sleeve part 700, which are connected to the port 210.

[0063] A plurality of shut-off holes 710 can be arranged such that they are spaced apart from each other in the circumferential direction of the sleeve part 700. Accordingly, the working fluid can be discharged in the sleeve part 700 in the radial direction of the piston part 600.

[0064] With reference to Fig. 1 to Fig. 6 The reaction force part 1100 has a first side which is supported by the cylinder part 200 and a second side which is in contact with the sleeve part 700 in order to push the sleeve part 700 towards the bearing part 900.

[0065] The first side of the reaction force part 1100 is in contact with and supported by an inner wall section 260 of the cylinder part 200, and the second side, opposite the first side, is in contact with and supported by an end section of the sleeve part 700. A gap that arises when assembling the sleeve part 700 with the cylinder part 200 can be filled by positioning the reaction force part 1100.

[0066] Even if a gap exists between the sleeve part 700 and the inner wall section 260 of the cylinder part 200, the sleeve part 700 can be elastically supported by the reaction force part 1100 and remain in close contact with the bearing part 900, since the reaction force part 1100 is positioned in the gap. Accordingly, the assembly gap or assembly tolerance between the cylinder part 200 and the sleeve part 700 is compensated for by the reaction force part 1100, thus preventing the occurrence of a knocking noise caused by the relative movement of the sleeve part 700 or the bearing part 900.

[0067] The reaction force part 1100 can touch the head section 620 of the piston part 600. During a process in which the piston part 600 is retracted and returned to a starting position in the direction of the motor part 300 (see Fig. 10) as the piston returns, a rear end 621 of the head section 620 touches the reaction force part 1100 before the piston section 600 collides with the inner wall section 260 of the cylinder section 200. Accordingly, the head section 620 is prevented from directly colliding with the inner wall section 260 of the cylinder section 200 when the piston section 600 returns to its initial position to set the zero point, thus preventing the knocking noise or impact caused by the direct collision.

[0068] The reaction force component 1100 can be arranged in a path along which the head section 620 retracts. Since the reaction force component 1100 is located on the retraction path of the head section 620, the retraction movement of the head section 620 can be limited by the reaction force component 1100.

[0069] The reaction force part 1100 is arranged between the sleeve part 700 and the inner wall section 260 of the cylinder part 200 and projects into the retraction movement path of the head section 620.

[0070] The reaction force part 1100 can comprise an elastically deformable material. Accordingly, the reaction force part 1100 can elastically support the bearing part 900, so that the sleeve part 700 is in close contact with the bearing part 900 and can dampen noises such as impact and / or knocking noises due to contact with the head section 620 when the head section 620 returns to its initial position.

[0071] With reference to Fig. 5 and Fig. 6 the reaction force part 1100 comprises a reaction force body 1110 and reaction force projections 1120.

[0072] The reaction force body 1110 is arranged in a ring shape, and the reaction force projections 1120 extend towards the sleeve part 700. The reaction force body 1110 is arranged in a ring shape along the inner circumference of the cylinder part 200 and is located between the sleeve part 700 and the inner wall section 260 of the cylinder part 200.

[0073] A plurality of reaction force projections 1120 are arranged on a surface of the reaction force body 1110, spaced apart from one another. The reaction force projections 1120 are arranged at the same rotational interval on the surface of the reaction force body 1110 facing the sleeve part 700. One end of the sleeve part 700 contacts the reaction force projection 1120, and the inner wall section 260 of the cylinder part 200 contacts the reaction force body 1110.

[0074] Since the majority of reaction force projections 1120 are spaced apart from each other, there are separation spaces between adjacent reaction force projections 1120. The working fluid in the sleeve part 700 can move through these separation spaces in one direction towards the connection 210. An arrow in Fig. Figure 6 indicates the movement path of the working fluid. Accordingly, the cylinder part 200 can generate a double-acting hydraulic pressure corresponding to the reciprocating movement of the piston part 600.

[0075] The reaction force body 1110 and the reaction force projections 1120 can be made of a rubber material. The reaction force body 1110 and the reaction force projections 1120 can be formed in one piece.

[0076] With reference to Fig. 7 and Fig. 8 The reaction force part 1100 includes a wave spring 1110.

[0077] The wave spring 1110 can have a corrugated or ribbed shape. Even when the wave spring 1110 is compressed and deformed, the corrugated or ribbed section of the wave spring 1110 does not fully unfold, leaving a space around it. The working fluid in the sleeve part 700 can flow through this space within the wave spring 1110 in one direction towards the connection 210.

[0078] The wave spring 1110 can be formed from one or more rings with a corrugated or ribbed shape, or in a form in which one or more rings with a corrugated or ribbed shape are wound. The wave spring 1110 can be formed by joining or overlapping a plurality of rings with a corrugated or ribbed shape.

[0079] The wave spring 1110 can consist of one or more plates with a corrugated or ribbed shape, or it can have a shape in which one or more plates with a corrugated or ribbed shape are wound. The wave spring 1110 can be formed by joining or overlapping a plurality of plates with a corrugated or ribbed shape. Therefore, the shape of the wave spring 1110 is not limited to the one described in Fig. The form shown is limited to 7. The wave spring 1110 may contain a metal material.

[0080] The wave spring 1110 can be formed in a ring shape along the inner circumference of the cylinder part 200 and arranged between the sleeve part 700 and the inner wall section 260 of the cylinder part 200.

[0081] Even when the head section 620 returns to its starting position and the wave spring 1110 is compressed, a space remains in the wave spring 1110. This allows the working fluid in the sleeve part 700 to move through the space in the wave spring 1110 towards the connection 210. An arrow in Fig. Figure 8 indicates the movement path of the working fluid. According to the reciprocating movement of the piston part 600, the cylinder part 200 can therefore generate a double-acting hydraulic pressure.

[0082] A sealing part 750 and an O-ring part (not shown) are arranged on the left and right sides of the shut-off holes 710 in the sleeve part 700, respectively.

[0083] The sealing part 750 can be arranged on the inner wall of the cylinder part 200 such that it is in the forward direction of movement of the piston part 600 (the left direction of movement based on Fig. 9) is spaced apart from the shut-off holes 710, and the O-ring part can be arranged on the inner wall of the cylinder part 200 such that it is in the reverse direction of movement of the piston part 600 (the right direction of movement based on Fig. 10) is spaced away from the shut-off hole 710.

[0084] The sealing element 750 is installed on the inner wall of the cylinder part 200 and seals the space between the cylinder part 200 and the sleeve part 700. The sealing element 750 contacts the cylinder part 200 and the sleeve part 700 at multiple points to seal the space between them. Even with axial play in the sleeve part 700, the sealing element 750 can still seal the space between the cylinder part 200 and the sleeve part 700. The sealing element 750 may contain an elastically deformable material.

[0085] The sealing part 750 can have an overall cross-sectional shape of an "8" or a peanut shape. The length of the sleeve part 700 in the longitudinal direction (left and right directions based on Fig. 1) can be longer than the length of the sleeve part 700 in the radial direction (vertical direction based on Fig. 1).

[0086] The braking device for a vehicle according to the present embodiment comprises a vibration damping element 800. The vibration damping element 800 is mounted on a first side (left side in Fig. 1) from the screw shaft 400 and on a second side (right side in Fig. 1) carried by the motor part 300. Accordingly, the vibration damping part 800 can prevent the neck section 420 of the screw shaft 400 from vibrating strongly while it deviates from the central axis of the screw shaft 400 in the rotating frame 321 of the motor part 300.

[0087] The neck section 420 of the screw shaft 400 is in indirect contact with the rotating frame 321 via the vibration damping element 800. When the brake device for a vehicle is actuated, the neck section 420 of the screw shaft 400 accordingly has a reduced relative displacement with respect to the rotating frame 321, so that the amplitude of the screw shaft 400 can be reduced.

[0088] The vibration damping element 800 can be elastically deformed while supported by the screw shaft 400 and the motor part 300. When the screw shaft 400 is shaken, the vibration damping element 800 can be elastically deformed accordingly and absorb the vibration of the screw shaft 400 or the shock caused by the vibration.

[0089] The vibration damping element 800 can be a spiral coil. The vibration damping element 800 can be designed in an interrupted ring shape. That is, as in Fig. As shown in Figure 2, the vibration damping element 800 can be designed in a ring shape, in which one side of the outer circumferential surface is open.

[0090] The vibration damping element 800 has two ends, so that the vibration of the screw shaft 400 can be transmitted to the vibration damping element 800 and then dissipated outwards through the ends of the vibration damping element 800. The second side of the vibration damping element 800 can be positioned further away from the sleeve part 700 than the first side.

[0091] As in Fig. Figure 1 shows a point where the vibration damping element 800 contacts the screw shaft 400, and a point where the vibration damping element 800 contacts the rotating frame 321 of the motor part 300, arranged at an angle. This allows the vibration damping element 800 to dampen vibrations in all directions of 360 degrees with respect to the central axis of the screw shaft 400.

[0092] The vibration damping component 800 may contain steel. In particular, the vibration damping component 800 may be made of stainless steel. The vibration damping component 800 may be a torsion spring or a deformation coil.

[0093] A first side of the vibration damping element 800 can contact and be supported by a stepped section of a connecting section between the screw body section 410 and the neck section 420. A second side of the vibration damping element 800 can contact and be supported by the rotating frame 321 of the motor part 300. The second side of the vibration damping element 800 can contact and be supported by the conical surface of the rotating frame 321.

[0094] Since the screw shaft 400 is coupled to the nut part 500 via the balls B, a certain degree of vibration is permissible to prevent power loss or jamming during operation. In the present embodiment, the vibration damping element 800 is arranged in the space where the vibration of the screw shaft 400 occurs, so that the vibration can be effectively reduced without restricting the degrees of freedom of vibration of the screw shaft 400.

[0095] The vibration damping element 800 can be arranged so that it surrounds the neck section 420 of the screw shaft 400 in order not to interfere with the cover section 440. The vibration damping element 800 can be arranged so that it does not contact an inner circumferential surface of the neck section 420.

[0096] The brake device for a vehicle according to an embodiment of the present disclosure comprises the bearing part 900. The bearing part 900 is arranged inside the housing part 100 and is provided at an inner end of the cylinder part 200.

[0097] The outer surface of the bearing part 900 and the outer surface of the sleeve part 700 can be in contact with each other. The bearing part 900 is coupled to the screw shaft 400 to enclose the coupling section 450 of the screw shaft 400.

[0098] The bearing part 900 comprises an inner wheel section 910, bearing balls 915 and an outer wheel section 920. The inner wheel section 910 is installed in contact with the coupling section 450 of the screw shaft 400 and the outer wheel section 920 is installed in contact with the inner surface of the cylinder part 200.

[0099] The bearing part 900 carries a load in an axial direction of the screw shaft 400 when hydraulic pressure is generated in the cylinder part 200 by the piston part 600, which moves back and forth in the axial direction of the screw shaft 400.

[0100] The braking device for a vehicle according to one embodiment of the present disclosure comprises the support part 1000. The support part 1000 is provided in the cylinder part 200. The support part 1000 is inserted into the coupling section 450 and coupled to the screw shaft 400. The support part 1000 is screwed to the screw shaft 400. The bearing part 900 is attached to the support part 1000. The support part 1000 rotatably supports the screw shaft 400. The support part 1000 can be a screw.

[0101] An operating procedure of the braking device for a vehicle according to an embodiment of the present disclosure with the configuration described above is described as follows.

[0102] With reference to Fig. 9, when the motor part 300 is operated and the rotational force is transferred to the screw shaft 400, the screw shaft 400 is rotated axially in the first direction of rotation in the cylinder part 200 and the nut part 500 is moved forward along the screw shaft 400 in the direction of the sleeve part 700.

[0103] When the nut part 500 is moved towards the sleeve part 700, the piston part 600 connected to the nut part 500 moves forward in a straight line in the same direction as the nut part 500 in order to build up hydraulic brake pressure.

[0104] With reference to Fig.10. The nut part 500 is moved back along the screw shaft 400 in the opposite direction to the sleeve part 700 when the motor part 300 is operated in such a way that the screw shaft 400 is axially rotated in the second direction of rotation, which is the opposite direction to the first direction of rotation.

[0105] When the nut part 500 is moved in the opposite direction to the sleeve part 700, the piston part 600 connected to the nut part 500 can retract linearly within the cylinder part 200 in the same direction as the direction of movement of the nut part 500 and return to its starting position to build up hydraulic brake pressure. When the piston part 600 moves linearly back and forth within the cylinder part 200, the double-acting hydraulic pressure is built up.

[0106] Although exemplary embodiments of the disclosure have been disclosed for illustrative purposes, it is apparent to the person skilled in the art that various modifications, additions, and substitutions are possible without departing from the scope of protection and the spirit of the disclosure as defined in the appended claims. The true technical scope of protection of the disclosure should therefore be defined by the following claims. QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] Korean patent publication no. 10-2021-0064367 (published on June 2, 2021 entitled “Hydraulic part for hydraulic vehicle braking system

[0005]

Claims

[1] Braking device for a vehicle, comprising: a cylinder part; a motor part that generates a rotational force; a screw shaft that is located inside the cylinder part, absorbs the rotational force of the engine part and is rotated axially; a nut part that is coupled to the screw shaft and moves back and forth in an axial direction of the screw shaft according to the rotation of the screw shaft; a sleeve part that is arranged between the cylinder part and the screw shaft; a piston part that is coupled to the nut part and includes a head section that moves back and forth in the sleeve part in accordance with the back-and-forth movement of the nut part; a bearing component that is arranged in the cylinder part and coupled to the screw shaft; and a reaction force part, the first side of which is supported on the cylinder part and the second side of which touches the sleeve part, pushes the sleeve part towards the bearing part and is able to touch the head section. [2] Braking device for the vehicle according to claim 1, wherein the reaction force part is arranged in a path through which the head section moves rearward in the cylinder part. [3] Braking device for the vehicle according to claim 2, wherein the reaction force part touches the head section when the head section moves backward and returns to a starting position. [4] Braking device for the vehicle according to claim 3, wherein the reaction force part comprises an elastically deformable material. [5] Braking device for the vehicle according to claim 4, wherein the reaction force part comprises: a reaction force body designed in a ring shape; and a reaction force projection that extends from the reaction force body towards the sleeve part. [6] Braking device for the vehicle according to claim 5, wherein a plurality of reaction force projections are arranged on one side of the reaction force body such that they are spaced apart from each other, and wherein a working fluid flows through spaces between the plurality of reaction force projections. [7] Braking device for the vehicle according to claim 6, wherein the reaction force part comprises a rubber material. [8] Braking device for the vehicle according to one of claims 4 to 6, wherein the reaction force part comprises a wave spring. [9] Brake device for the vehicle according to claim 8, wherein the wave spring has a corrugated shape or a ribbed shape.

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