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 and absorbs the rotational force of the engine part in order to be 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 a rotation of the screw shaft; a sleeve part that is arranged between the cylinder part and the screw shaft; a piston part coupled to the nut part and comprising a head section which moves back and forth within the sleeve part in accordance with the back-and-forth movement of the nut part; a bearing component that is located inside the cylinder part and is coupled to the screw shaft; and a support part that is screwed to the screw shaft, comes into contact with the bearing part and supports the screw shaft in order to be axially rotatable.

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 the rotary motion of a screw shaft, which is rotated by receiving a rotary force from a motor, into a linear motion of a piston. 2. State of the art

[0002] Due to the characteristics of an electronic braking device for a vehicle, a device is generally required that converts the rotary motion of the engine into the linear motion of the piston in a cylinder in order to generate brake fluid pressure.

[0003] As a device that converts the rotary motion of a motor into a linear motion, a ball screw drive device is used in the electric brake device, which includes a screw shaft that receives the rotational force of the motor and rotates, a nut that is connected to the screw shaft via a ball and moves in the axial direction of the screw shaft, and a piston that is connected to the nut and pressurizes the working fluid inside the cylinder.

[0004] In the past, problems such as damage to the connection with the engine, loss of performance, vibrations, and noise have occurred due to resonance in the ball screw drive during brake fluid pressure generation. Furthermore, a bearing component can come into contact with a sleeve component during the alignment process, leading to impact noise and insufficient shaft alignment compensation. This can result in reduced efficiency of the vehicle's braking system and cause vibrations and noise. Therefore, there is a need to resolve these issues.

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

[0006] Various embodiments relate to a braking device for a vehicle that is able to ensure a fastening force between a support part and a screw shaft by screwing the support part to the screw shaft.

[0007] Various embodiments relate to a braking device for a vehicle that is able to increase the contact surface between the support part and the screw shaft.

[0008] Various embodiments relate to a braking device for a vehicle that is able to prevent the screw connection between the support part and the screw shaft from loosening when the piston part moves in the main operating direction.

[0009] Various embodiments relate to a braking device for a vehicle that prevents friction between the sleeve part and the bearing during rotation, thereby reducing vibrations and noise.

[0010] In one embodiment of the present disclosure, a braking device for a vehicle may comprise a cylinder part, a motor part that generates a rotational force, a screw shaft arranged within the cylinder part and which receives the rotational force of the motor part in order to be rotated axially, a nut part that is coupled to the screw shaft and moves back and forth in an axial direction in accordance with a 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 within the sleeve part in accordance with the reciprocating movement of the nut part, a bearing part that is arranged within the cylinder part and coupled to the screw shaft, and a support part that is screwed to the screw shaft, comes into contact with the bearing part and supports the screw shaft.to be axially rotatable.

[0011] The support part can include a support bolt, and the support bolt can be inserted into a coupling part of the screw shaft and screwed to an inner surface of the coupling part.

[0012] When the support bolt is screwed to the coupling part, a front end of the support bolt can be spaced away from an innermost bottom surface of the coupling part.

[0013] When the screw shaft rotates and the piston part moves forward towards the sleeve part, the support part can rotate in a direction in which the support part is attached to the screw shaft.

[0014] If the screw shaft rotates in a left-hand thread direction and the piston part moves forward towards the sleeve part, the support part can rotate in the left-hand thread direction and be screwed to the screw shaft, and if the screw shaft rotates in the right-hand thread direction and the piston part moves forward towards the sleeve part, the support part can rotate in a right-hand thread direction and be screwed to the screw shaft.

[0015] The bearing part can comprise an outer ring part that is in contact with an inner surface of the cylinder part and with the sleeve part, and an inner ring part that is rotatable on an inner surface of the outer ring part, is in contact with the screw shaft and is spaced apart from the sleeve part.

[0016] The sleeve part can comprise a first facing section that is directed towards and in contact with the outer ring part, and a second facing section that is directed towards and spaced apart from the inner ring part.

[0017] The first facing section and the second facing section can be formed in stages.

[0018] The sleeve part can connect the first facing section and the second facing section and include a transition section arranged so that it gradually separates from the bearing part when transitioning from the first facing section to the second facing section.

[0019] The braking device for a vehicle may further comprise a reaction force part that pushes the sleeve part towards the bearing part, with a first side supported by the cylinder part and a second side in contact with the sleeve part.

[0020] Since the support part is screwed to the screw shaft according to the present disclosure, the fastening force between the support part and the screw shaft can be ensured.

[0021] Since the support part according to the present disclosure comprises a support bolt which is screwed to a coupling part, the fastening area between the support part and the screw shaft can be increased, thereby achieving a higher fastening strength.

[0022] According to the present disclosure, it is possible to prevent the screw connection between the support part and the screw shaft from loosening when the piston part moves in the main operating direction.

[0023] Since, according to the present disclosure, the rotating part of the bearing part and the sleeve part are arranged at a distance from each other, friction with the sleeve part can be prevented when the bearing part rotates, and vibrations, noise, etc. caused by this 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 an enlarged cross-sectional view of the circumference of a vibration damping element according to an embodiment of the present disclosure. Fig. Figure 6 is an enlarged cross-sectional view of the circumference of a support part and a screw shaft according to an embodiment of the present disclosure. Fig. Figure 7 illustrates an operating condition in which a piston part moves forward in a cylinder part in a brake device for a vehicle according to an embodiment of the present disclosure. Fig. Figure 8 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

[0024] A braking device for a vehicle according to the present disclosure is described in detail below with reference to the accompanying drawings and 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 to simplify the description.

[0025] Furthermore, the terms described below have been defined in light of their functions in this disclosure and may vary depending on the user's or operator's intent or approach. Accordingly, these terms should be interpreted based on the overall context of this description.

[0026] Fig. Figure 1 is a cross-sectional view of a vehicle braking device 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 vehicle braking device according to one embodiment of the present disclosure. Fig. Figure 5 is an enlarged cross-sectional view of the periphery of a vibration damping element according to an embodiment of the present disclosure. Fig. Figure 6 is an enlarged cross-sectional view of the circumference of a support part and a screw shaft according to an embodiment of the present disclosure. Fig. Figure 7 shows an operating condition in which the piston part moves forward within the cylinder part of the vehicle brake device according to an embodiment of the present disclosure. Fig. Figure 8 shows an operating condition in which the piston part retracts within the cylinder part of the vehicle brake device according to an embodiment of the present disclosure.

[0027] With reference to Fig. 1 to Fig. 8 The brake 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, a bearing part 900 and a support part 1000, which are described in detail below.

[0028] The cylinder part 200 is arranged in a housing part 100 and supports the torque generated when hydraulic pressure arises due to the reciprocating movement of the piston part 600. According to the present embodiment, the housing part 100 can be arranged in a hollow form with an interior space and can be pressed together with the cylinder part 200.

[0029] The housing part 100 can be attached to the outside (left side of the Fig. 1) of the cylinder part 200. The cylinder part 200 can be assembled with the housing part 100 so that the concentricity is regulated.

[0030] The cylinder part 200 is formed in a hollow shape. The sleeve part 700 with the actuating section provided therein is in a space (left side based on Fig. 1) arranged within the cylinder part 200, so that hydraulic pressure is generated by pressurizing the piston part 600.

[0031] The motor part 300 is connected to the cylinder part 200, and various drive devices can be used within the framework of the technical concept for generating torque. The motor part 300 transmits torque to the screw shaft 400.

[0032] The motor part 300 comprises a mounting part 310, a motor rotating part 320 and a motor bearing part 330.

[0033] The fastening part 310 is attached to the housing part 100 and can have different shapes within the framework of the technical concept for changing the magnetic force by supplying current.

[0034] The fastening part 310 comprises a fastening frame 311, which is attached to one side (right side in 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.

[0035] The mounting frame 311 is connected to one side of the housing part 100 and the motor rotating part 320 is rotatably installed on the inside of the mounting frame 311.

[0036] The stator 312, which is an electromagnet, is mounted circumferentially on the inner surface of the mounting frame 311, and the magnetic flux changes by a control signal from a control unit (not shown), thereby rotating the motor rotating part 320.

[0037] The motor rotating part 320 is connected to the screw shaft 400 in order to rotate together with the screw shaft 400, and can be modified into different shapes within the framework of the technical turning concept according to the change in the magnetic force of the fastening part 310.

[0038] The motor rotating part 320 is rotatably installed on the inside of the mounting frame 311. The cross-section of the motor rotating part 320 can be approximately C- or U-shaped, or it can be hollow.

[0039] The motor rotating part 320 comprises a rotating frame 321, which is installed in a form that has one side (right side in Fig. 1) surrounds the cylinder part 200, and a rotor 322 which is installed on the outer surface of the rotating frame 321 opposite the mounting part 310 and has a magnetic force.

[0040] A splined toothing that meshes with the screw shaft 400 can be arranged in the rotary frame 321, in particular on an inner surface of the rotary frame 321.

[0041] The motor bearing part 330 is installed between the mounting part 310 and the motor rotating part 320 to reduce friction that occurs when the motor rotating part 320 rotates. The rotor 322, which consists of a plurality of magnets installed circumferentially around the rotating frame 321, rotates together with the rotating frame 321 by changing the magnetic force of the stator 312.

[0042] A cover element 340, attached to the mounting frame 311, is installed in a form that surrounds the outside of the end of the rotating frame 321 and blocks the ingress of foreign substances.

[0043] The screw shaft 400 is provided within the cylinder part 200. The screw shaft 400 can be installed in the longitudinal direction (left-right direction based on...). Fig. 1) of the cylinder part 200 and can be axially coupled to the cylinder part 200. A central axis of the cylinder part 200 and a central axis of the screw shaft 400 can coincide.

[0044] The screw shaft 400 is attached to the bearing part 900 by the support part 1000. The support part 1000 allows the screw shaft 400 to rotate. The screw shaft 400 comprises a screw body section 410, a neck section 420, a power transmission section 430, and a coupling section 450.

[0045] The screw body section 410 is rotatably installed within the cylinder part 200, and one thread can be arranged in the longitudinal direction of the screw shaft 400. The screw body section 410 is arranged within the rotating frame 321 of the motor part 300.

[0046] The neck section 420 extends from the outer surface of the center of rotation of the screw body section 410 to a first side (right side, as shown in Fig. 1 shown) and has a smaller diameter than the screw body section 410.

[0047] The force transmission section 430 extends from the free end of the neck section 420 to the first side (right side, as shown in Fig. 1 shown) and has a larger diameter than the neck section 420.

[0048] A splined connection can be formed along the circumferential direction on the outer surface of the power transmission section 430 facing the rotary frame 321. If no cover section 440, described later, is present, the rotary frame 321 and the power transmission section 430 can engage to transmit force.

[0049] The screw shaft 400 further comprises the cover section 440. The cover section 440 is arranged to surround the neck section 420 and the power transmission section 430. The cover section 440 can be positioned between the power transmission section 430 and the rotating frame 321 to prevent metallic rattling noises.

[0050] A splined connection can be formed on the outer surface of the cover section 440 along its circumferential direction, so that the cover section 440 can engage with the rotary frame 321. The outer shape of the cover section 440 can be the same as the outer shape of the power transmission section 430.

[0051] A splined connection can be formed along the circumferential direction on the outer surface of the power transmission section 430 facing the cover section 440. Accordingly, the cover section 440 and the power transmission section 430 can be engaged to achieve power transmission.

[0052] The coupling section 450 extends from the outer surface of the center of rotation of the screw body section 410 to a second side (left side in Fig. 1) and is rotatably coupled to the bearing part 900. The coupling section 450 can be pressed into and coupled to the bearing part 900. The coupling section 450 has the same or a smaller diameter than the screw body section 410.

[0053] The nut part 500 is arranged within the rotating frame 321 of the motor part 300 and is located within the cylinder part 200. The nut part 500 can be connected to the outer surface of the screw shaft 400 via ball elements B.

[0054] The screw shaft 400 can be coupled by passing through the nut part 500. Since the ball elements B are arranged between the inner surface of the nut part 500 and the thread formed 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.

[0055] The nut part 500 can have an anti-rotation projection (not shown) formed on the outer surface, and the cylinder part 200 can have a movement groove (not shown) formed on the inner surface.

[0056] When the screw shaft 400 rotates, the anti-rotation projection of the nut part 500 is prevented from rotating by the groove, thus preventing the nut part 500 from rotating. Accordingly, 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 groove.

[0057] Depending on the direction of rotation of the screw shaft 400, the nut part 500 can move back and forth in the axial direction of the screw shaft 400. For example, if the screw shaft 400 rotates in a first direction, the screw shaft 400 moves forward, and if the screw shaft 400 rotates in a second direction opposite to the first, the screw shaft 400 moves backward.

[0058] The piston part 600 is coupled in such a way that it surrounds the outer surface of the nut part 500. The piston part 600 moves longitudinally along the cylinder part 200 in conjunction with the reciprocating movement of the nut part 500.

[0059] The piston part 600 comprises a rod section 610 and a head section 620.

[0060] The rod section 610 is hollow and is arranged within 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.

[0061] The head section 620 can be integrally formed with the rod section 610. The outer diameter of the head section 620 can be larger than the outer diameter of the rod section 610.

[0062] The head section 620 is designed in a ring shape, is located inside the housing part 100, and moves the working fluid within the sleeve part 700 towards the ports 210 while reciprocating within 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.

[0063] The sleeve part 700 is located inside the housing part 100 and is arranged inside the cylinder part 200. The sleeve part 700 can cause movement of the piston part 600 inserted therein.

[0064] The sleeve section 700 encloses the head region 620 of the piston section 600. The ports 210, through which the working fluid flows, are located in areas where the sleeve section 700 rests on an outer surface of the cylinder section 200. The ports 210 can be provided at several locations along the longitudinal direction of the cylinder section 200. The working fluid, moved by the movement of the piston section 600, flows through the ports 210 and can build up the required brake pressure.

[0065] Through-holes 710 are arranged on the outer surface of the sleeve part 700, which communicate with the ports 210. A plurality of through-holes 710 are arranged along the circumference of the sleeve part 700, spaced apart from one another. This allows the working fluid to drain from the sleeve part 700 in the radial direction of the piston part 600.

[0066] The sleeve part 700 can extend in the longitudinal direction of the screw shaft 400. A front end 750 (left end based on Fig. 6) The sleeve part 700 is arranged on the side of the bearing part 900. The front end 750 of the sleeve part 700 comprises a first facing section 751 and a second facing section 752.

[0067] The first facing section 751 faces an outer ring part 920 of the bearing part 900 and contacts the outer ring part 920. The second facing section 752 faces an inner ring part 910 of the bearing part 900 and is spaced from the inner ring part 910 by a predetermined distance D. Since the first facing section 751 is in surface contact with the outer ring part 920, relative movement between the bearing 900 and the sleeve part 700 can be restricted.

[0068] Since the inner ring part 910, which is the rotating part of the bearing part 900, and the second facing section 752 of the sleeve part 700 are arranged so that they are spaced apart from each other, the friction with the sleeve part 700 and the vibrations, noise, etc. caused by the friction can be reduced when the bearing part 900 rotates.

[0069] The first facing section 751 and the second facing section 752 can be formed in stages.

[0070] The front end 750 of the sleeve part 700 further comprises a transition section 752a which connects the first facing section 751 and the second facing section 752.

[0071] The transition section 752a can be arranged such that it gradually moves away from the bearing part 900 from the first facing section 751 to the second facing section 752. With reference to Fig. 6 the transition section 752a is arranged such that it is inclined to the right from the end of the first facing section 751 and is connected to the end of the second facing section 752.

[0072] The first facing section 751 and the second facing section 752 can be arranged in a horizontal surface shape with respect to the bearing part 900, and the transition section 752a can be arranged in an inclined surface shape with respect to the bearing part 900, thereby optimizing the stroke of the piston part 600.

[0073] The second facing section 752 is arranged horizontally with respect to the bearing part 900, so that the interior space of the sleeve part 700 cannot be reduced. Accordingly, the stroke of the piston part 600, which moves within the interior of the sleeve part 700, can be maximized, thus preventing any loss of stroke of the piston part 600 when the brake fluid pressure builds up.

[0074] The maximum outer diameter of the second facing section 752 can be equal to or greater than the maximum outer diameter of the inner ring part 910. In other words, the outermost point of the second facing section 752 can be located at the same position in the outer direction as an outermost point 910a of the inner ring part 910, or further outwards in the outer direction.

[0075] In Fig. 6. The diameter at the outermost point of the second facing section 752 is larger than the diameter at the outermost point 910a of the inner ring part 910. Consequently, the second facing section 752 can be spaced a predetermined distance D from the inner ring part 910 over its entire area.

[0076] The screw shaft 400 can tilt or wobble about a central axis due to a load caused by hydraulic pressure or play tolerance when the piston part 600 moves forward. The tilting or wobbling of the screw shaft 400 can occur with the connecting section of the coupling part 450 and the support part 1000 as the origin (center point).

[0077] When the screw shaft 400 wobbles, the amplitude of the screw shaft 400 gradually increases as the screw shaft 400 moves away from the origin of the wobbling motion, and may be greatest on the side of the neck section 420 that is furthest from the origin of the wobbling motion.

[0078] The braking device for a vehicle according to an embodiment of the present disclosure further comprises a vibration damping element 800.

[0079] In this embodiment, it is possible to prevent a significant increase in the amplitude of the screw shaft 400 or the occurrence of resonance through the vibration damping element 800. As a result, damage to the power transmission section 430 or the cover section 440 can be prevented, thus preventing the normal transmission of power from the motor part 300 to the screw shaft 400 and avoiding quality problems caused by noise and vibration.

[0080] A first page (left side, as in Fig. 5) of the vibration damping part 800 according to the present embodiment can be supported by the screw shaft 400 and a second side (right side, as in Fig. (5 shown) of the vibration damping part 800 can be supported by the motor part 300. Accordingly, the vibration damping part 800 can prevent the neck section 420 of the screw shaft 400 from vibrating significantly outside the central axis of the screw shaft 400 within the rotating frame 321 of the motor part 300.

[0081] The neck section 420 of the screw shaft 400 indirectly contacts the rotating frame 321 via the vibration damping element 800. Therefore, when the brake device for a vehicle is actuated, the relative displacement of the neck section 420 of the screw shaft 400 with respect to the rotating frame 321 is reduced, thereby reducing the amplitude of the screw shaft 400.

[0082] The vibration damping element 800 is elastically deformable while being supported by the screw shaft 400 and the motor part 300. Therefore, if the screw shaft 400 wobbles, the vibration damping element 800 can deform elastically and absorb the vibration or shock caused by the vibration of the screw shaft 400.

[0083] The vibration damping element 800 can be a spiral coil. The vibration damping element 800 can have an interrupted ring shape. That is, the vibration damping element 800 can be designed in a ring shape with one side of the outer circumference open, as shown in Fig. 2 shown.

[0084] 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 dissipated outwards through each end 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.

[0085] With reference to Fig. Point 5 is a point where the vibration damping element 800 comes into contact with the screw shaft 400, and a point where the vibration damping element 800 comes into contact with the rotating frame 321 of the motor part 300, arranged at an angle. Accordingly, the vibration damping element 800 can dampen vibrations in all directions of 360 degrees with respect to the central axis of the screw shaft 400.

[0086] The vibration damping component 800 may contain a steel material. 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 spiral spring.

[0087] The first side of the vibration damping element 800 is in contact with and supported by the stepped section 411 at the connection between the screw body section 410 and the neck section 420. Since the stepped section 411 has the form of a flat surface, the first side of the vibration damping element 800 can be supported stably and elastically on the stepped section 411.

[0088] The second side of the vibration damping element 800 is in contact with and supported by the rotating frame 321 of the motor part 300. The second side of the vibration damping element 800 is in contact with and supported by a conical surface 325 of the rotating frame 321. Since the conical surface 325 has the shape of a flat surface, the second side of the vibration damping element 800 can be supported stably and elastically on the conical surface 325.

[0089] Since the screw shaft 400 is coupled to the nut section 500 via the ball elements B, a certain degree of vibration occurs, preventing power loss or jamming during operation. Because, in the present embodiment, the vibration damping element 800 is located in the space where the vibration of the screw shaft 400 occurs, it is possible to effectively reduce the vibration of the screw shaft 400 when it occurs, without restricting the degrees of freedom.

[0090] The vibration damping element 800 can be arranged so that it surrounds the neck section 420 of the screw shaft 400 and does not collide with the cover section 440. The vibration damping element 800 can be arranged so that it does not come into contact with the inner surface of the neck section 420.

[0091] The bearing part 900 is located on the inside of the housing part 100 and is provided at the inner end of the cylinder part 200.

[0092] The bearing part 900 is installed while its outer surface and the outer surface of the sleeve part 700 are in contact. The bearing part 900 is coupled to the screw shaft 400 in a form that surrounds the coupling part 450 of the screw shaft 400.

[0093] The bearing part 900 is in contact with the sleeve part 700, but the rotating part of the bearing part 900 does not touch the sleeve part 700. When the rotating part of the bearing part 900 turns, it prevents the rotating part of the bearing part 900 and the sleeve part 700 from rubbing against each other. This avoids impact noise when the vehicle brakes are applied and compensates for shaft misalignment, thereby reducing the NVH (Noise, Vibration and Harshness) phenomenon.

[0094] The bearing part 900 comprises the inner ring part 910, a bearing ball 915 and the outer ring part 920.

[0095] The outer ring part 920 is in contact with the inner surface of the cylinder part 200 and is in contact with the sleeve part 700.

[0096] The inner ring part 910 is a rotating part of the bearing part 900 and is rotatably arranged on the inside of the outer ring part 920. The inner ring part 910 comes into contact with the coupling section 450 of the screw shaft 400 and is arranged such that it is spaced apart from the second facing section 752 of the sleeve part 700. The coupling section 450 can be forcibly pressed into the inside of the inner ring part 910 and coupled to the inner ring part 910.

[0097] The bearing part 900 can carry a load in an axial direction if hydraulic pressure is built up in the cylinder part 200 by the reciprocating movement of the piston part 600 in the axial direction of the screw shaft 400.

[0098] The braking device for a vehicle according to an embodiment of the present disclosure further comprises a reaction force part 1100.

[0099] 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.

[0100] The reaction force element 1100 can include an elastically deformable spring. The reaction force element 1100 exerts pressure on the sleeve element 700 by means of an elastic restoring force after compression, while being supported by the cylinder element 200. The front end 750 of the sleeve element 700 can always be in close contact with the bearing element 900 by the reaction force element 1100.

[0101] The reaction force component 1100 can be located in a brake fluid flow path and arranged in such a way that it does not impede the flow of the brake fluid. The reaction force component 1100 can be a wave spring.

[0102] The support part 1000 is located inside the cylinder part 200. The support part 1000 is inserted into the coupling part 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 can support the screw shaft 400 so that it rotates axially about the central axis.

[0103] The support part 1000 comprises a support bolt 1000A in the form of a bolt. The support bolt 1000A comprises a bolt head 1010 and a bolt body 1020.

[0104] The bolt body 1020 of the support bolt 1000A is inserted into the coupling groove 451 of the coupling section 450 of the screw shaft 400 and screwed to the inner surface of the coupling section 450. A front end (a right end based on Fig. 6) The bolt body 1020 can be positioned deeper in the coupling groove 451 than one end (a right end based on Fig. 6) of the bearing part 900.

[0105] Since the bolt body 1020 is inserted into the coupling section 450 beyond the area of ​​the bearing part 900 (see Fig. 6) A large screw fastening area can be ensured between the bolt body 1020 and the coupling section 450. This results in a fastening strength between the support part 1000 and the screw shaft 400.

[0106] The bolt head 1010 of the support bolt 1000A can be positioned so that it comes into contact with the bearing part 900. As a result, the height of the bolt head 1010 is adjusted to limit the distance between the parts, and sufficient space can be provided to reduce the size of the device and system or to modify the design of adjacent parts.

[0107] When the bolt body 1020 is screwed into the coupling groove 451 of the coupling part 450, the front end (right end, as shown in Fig. 6 shown) of the bolt body 1020 from the innermost bottom surface (outermost right side, as in Fig. 6 shown) of the coupling section 450.

[0108] This means that the depth of the coupling groove 451 of the coupling section 450 can be greater than the length of the bolt body 1020 inserted into the coupling groove 451. Accordingly, the fastening force between the support part 1000 and the coupling section 450 can be further increased.

[0109] When the screw shaft 400 rotates, the piston part 600 moves forward in the main operating direction to build up brake pressure (see Fig. 7) The support part 1000 can rotate in the direction in which it is locked to the screw shaft 400. That is, when the screw shaft 400 rotates and the piston part 600 moves forward toward the sleeve part 700, the support part 1000 can rotate in the direction in which it is secured to the screw shaft 400. Therefore, the securing force between the support part 1000 and the screw shaft 400 can be ensured even when the piston part 600 moves in the main operating direction.

[0110] Even if the support part 1000 rotates in the main operating direction with respect to the screw shaft 400 during the forward movement of the piston part 600, the direction of rotation of the support part 1000 becomes the direction in which the support part 1000 is further locked to the screw shaft 400 (a direction in which the support part 1000 is fixed).

[0111] Accordingly, it is possible to prevent the support part 1000 from detaching from the screw shaft 400 when the piston part 600 moves forward in the main operating direction due to the rotation of the motor 300. This allows malfunctions such as control errors and a reduction in system efficiency to be avoided in advance. Furthermore, the discrepancy between the rotational speed of the motor part 300 and the forward speed of the piston part 600 can be managed and controlled.

[0112] The forward movement of the piston part 600 in the main operating direction means that the head section 620 of the piston part 600 is moved forward towards the front end 750 of the sleeve part 700. When the driver presses a brake pedal, the piston part 600 is moved forward in the main operating direction.

[0113] If the screw shaft 400 rotates in a left-hand thread direction and the piston part 600 moves forward in the direction of the sleeve part 700, the support part 1000 can rotate in the left-hand thread direction and be screwed to the screw shaft 400.

[0114] In other words, the support part 1000 rotates in the left-hand thread direction and is screwed to the screw shaft 400. When the screw shaft 400 rotates in a left-hand thread direction and the piston part 600 moves forward toward the sleeve part 700, the support part 1000 rotates relative to the screw shaft 400 in the left-hand thread direction. Even if the support part 1000 rotates relative to the screw shaft 400 in the main operating direction during the forward movement of the piston part 600, the direction of rotation of the support part 1000 therefore becomes the direction in which the support part 1000 is more securely locked to the screw shaft 400 (the direction in which the support part 1000 is fixed).

[0115] When the screw shaft 400 rotates in the right-hand thread direction and the piston part 600 moves forward in the direction of the sleeve part 700, the support part 1000 can rotate in the right-hand thread direction and be screwed to the screw shaft 400.

[0116] In other words, since the support part 1000 rotates in the right-hand thread direction and is screwed to the screw shaft 400, the relative direction of rotation of the support part 1000 with respect to the screw shaft 400 becomes the tightening thread direction when the screw shaft 400 rotates in the right-hand thread direction and the piston part 600 moves forward toward the sleeve part 700. Therefore, even if the support part 1000 rotates in the main operating direction relative to the screw shaft 400 during the forward movement of the piston part 600, the direction of rotation of the support part 1000 becomes the direction in which the support part 1000 is more firmly locked in the screw shaft 400 (the direction in which it is secured).

[0117] An operating procedure of a braking device for a vehicle according to an embodiment of the present disclosure with the configuration described above is described as follows.

[0118] With reference to Fig. 7, 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 a first direction of rotation within 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.

[0119] When the nut part 500 is moved in the direction of the sleeve part 700, the piston part 600 coupled to the nut part 500 is moved forward in a straight line in the same direction as the direction of movement of the nut part 500, generating a hydraulic brake pressure.

[0120] With reference to Fig.8, when the motor part 300 is operated in such a way that the screw shaft 400 is rotated axially in a second direction of rotation which is the opposite direction to the first direction of rotation, the nut part 500 is moved backwards along the screw shaft 400 in the opposite direction to the sleeve part 700.

[0121] When the nut part 500 is moved in a direction opposite to that of the sleeve part 700, the piston part 600 connected to the nut part 500 can generate the hydraulic brake pressure as it moves back in a straight line within the cylinder part 200 in the same direction as the direction of movement of the nut part 500. Accordingly, when the piston part 600 moves back and forth in a straight line within the cylinder part 200, the double-acting hydraulic pressure is generated.

[0122] According to the brake device for a vehicle as described in one embodiment of the present disclosure, the support part 1000 is screwed to the screw shaft 400, thus ensuring a secure fastening force between the support part 1000 and the screw shaft 400. The support part 1000 includes a support bolt screwed to the coupling section 450, thereby increasing the fastening area between the support part 1000 and the screw shaft 400 and enhancing the fastening stability. Furthermore, this prevents the screw connection between the support part 1000 and the screw shaft 400 from loosening when the piston part 600 is moved in the main operating direction.

[0123] 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 the disclosure should therefore be defined by the following claims. QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] KR 10-2021-0064367

[0005] Cited non-patent literature

[0000] June 2, 2021 entitled “Hydraulic unit 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 and absorbs the rotational force of the engine part in order to be 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 a rotation of the screw shaft; a sleeve part that is arranged between the cylinder part and the screw shaft; a piston part coupled to the nut part and comprising a head section which moves back and forth within the sleeve part in accordance with the back-and-forth movement of the nut part; a bearing component that is located inside the cylinder part and is coupled to the screw shaft; and a support part that is screwed to the screw shaft, comes into contact with the bearing part and supports the screw shaft in order to be axially rotatable. [2] Braking device for a vehicle according to claim 1, wherein the support part includes a support bolt and wherein the support bolt is inserted into a coupling part of the screw shaft and is screwed to an inner surface of the coupling part. [3] Braking device for a vehicle according to claim 2, wherein, when the support bolt is screwed to the coupling part, a front end of the support bolt is spaced apart from an innermost bottom surface of the coupling part. [4] Brake device for a vehicle according to one of claims 1 to 3, wherein, when the screw shaft rotates and the piston part moves forward in the direction of the sleeve part, the support part is rotatable in a direction in which the support part is attached to the screw shaft. [5] Braking device for a vehicle according to any one of claims 1 to 4, wherein, if the screw shaft rotates in a left-hand thread direction and the piston part moves forward in the direction of the sleeve part, the support part rotates in the left-hand thread direction and is screwed to the screw shaft, and wherein, if the screw shaft rotates in a right-hand thread direction and the piston part moves forward in the direction of the sleeve part, the support part rotates in a right-hand thread direction and is screwed to the screw shaft. [6] Brake device for a vehicle according to any one of claims 1 to 5, wherein the bearing part comprises: an outer ring part that is in contact with an inner surface of the cylinder part and with the sleeve part; and an inner ring part that is rotatable on an inner side of the outer ring part, is in contact with the screw shaft and is spaced apart from the sleeve part. [7] Brake device for a vehicle according to claim 6, wherein the sleeve part comprises: a first facing section that is facing the outer ring part and is in contact with the outer ring part; and a second facing section that faces the inner ring part and is spaced apart from the inner ring part. [8] Braking device for a vehicle according to claim 7, wherein the first facing section and the second facing section are formed in steps. [9] Brake device for a vehicle according to claim 7 or 8, wherein the sleeve part connects the first facing section and the second facing section and comprises a transition section arranged such that it gradually separates from the bearing part when transitioning from the first facing section to the second facing section. [10] Braking device for a vehicle according to any one of claims 1 to 9, further comprising a reaction force part which pushes the sleeve part towards the bearing part, with a first side which is supported by the cylinder part and a second side which is in contact with the sleeve part.

Images