Braking device for a vehicle

Abstract

A brake device for a vehicle includes a cylinder provided with a port through which a working fluid moves, a motor configured to generate rotational power, a screw shaft located inside the cylinder and configured to receive the rotational power from the motor and rotate about an axis, a nut coupled to the screw shaft and configured to reciprocate in an axial direction of the screw shaft in response to the rotation of the screw shaft, a sleeve located inside the cylinder and including an inner diameter portion facing the screw shaft and an outer diameter portion facing the cylinder, the outer diameter portion including a first outer diameter portion and a second outer diameter portion coupled to the first outer diameter portion, and a piston coupled to the nut and configured to reciprocate inside the sleeve in response to the reciprocation of the nut. According to the present disclosure, the sleeve can be manufactured in a manner in which a plurality of sleeve portions are connected together, thereby reducing a degree of difficulty in processing and improving a mass production efficiency of the brake device for a vehicle.

Description

Technical Field

[0001] Exemplary embodiments of this disclosure relate to braking devices for vehicles, and more specifically, to braking devices for vehicles that can convert the rotational motion of a screw shaft generated by the rotational force of an electric motor into the linear motion of a piston. Background Technology

[0002] Typically, due to the characteristics of a vehicle's electric braking system, a mechanism is needed that can convert the rotational motion of an electric motor into the linear motion of a piston in a cylinder to generate hydraulic braking pressure.

[0003] Ball screw devices are used in electric braking systems as mechanisms that convert the rotary motion of a motor into linear motion. A ball screw device includes: a screw shaft that receives rotational force from a motor and rotates about its axis; a nut connected to the screw shaft via balls and configured to move axially along the screw shaft; and a piston connected to the nut and configured to pressurize working fluid in a cylinder.

[0004] In related technologies, machining centers require machining both the inner and outer diameters of the sleeve simultaneously, resulting in extremely high machining difficulty. In particular, the overall length increases further in large-capacity braking devices, further increasing the machining complexity.

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

[0006] Various embodiments are intended to provide braking devices for vehicles, wherein the sleeve is manufactured by joining multiple sleeve portions, thereby reducing manufacturing difficulty and increasing mass production rate.

[0007] A braking device for a vehicle according to an embodiment of the present disclosure may include: a cylinder having a port through which working fluid moves; a motor configured to generate rotational power; a screw shaft located within the cylinder and configured to receive rotational power from the motor and rotate about an axis; a nut coupled to the screw shaft and configured to reciprocate in the axial direction of the screw shaft in response to rotation of the screw shaft; a sleeve located within the cylinder including an inner diameter portion toward the screw shaft and an outer diameter portion toward the cylinder, the outer diameter portion including a first outer diameter portion and a second outer diameter portion coupled to the first outer diameter portion; and a piston coupled to the nut and configured to reciprocate within the sleeve in response to the reciprocating motion of the nut.

[0008] The first outer diameter section and the second outer diameter section can be connected to each other by spot welding.

[0009] The connection area between the first outer diameter portion and the second outer diameter portion can face the port.

[0010] The working fluid in the sleeve can be discharged to the outside of the sleeve through the non-spot welded area in the connection region between the first outer diameter section and the second outer diameter section.

[0011] The connection area between the first outer diameter portion and the second outer diameter portion can be located between the first overflow plate and the second overflow plate mounted on the inner wall of the cylinder.

[0012] The sleeve may also include a connecting portion that connects the inner diameter portion and the first outer diameter portion. The inner diameter portion, the connecting portion, and the first outer diameter portion may be integrally formed.

[0013] The first outer diameter portion and the second outer diameter portion may include steel material. Attached Figure Description

[0014] Figure 1 This is a cross-sectional view of a braking device for a vehicle according to an embodiment of the present disclosure.

[0015] Figure 2 This is a perspective view of a cylinder viewed from one direction, according to an embodiment of the present disclosure.

[0016] Figure 3 yes Figure 2 A three-dimensional view of the cylinder from another perspective.

[0017] Figure 4 This is a cross-sectional view of a braking device for a vehicle according to an embodiment of the present disclosure.

[0018] Figure 5 This is a perspective view of a sleeve according to an embodiment of the present disclosure.

[0019] Figure 6 This is an exploded perspective view of the sleeve according to an embodiment of the present disclosure.

[0020] Figure 7 This is an example of an embodiment of the present disclosure showing the operating state of a piston moving forward within a cylinder in a braking device for a vehicle.

[0021] Figure 8 The diagram illustrates the operating state of a piston moving rearward within a cylinder in a braking device for a vehicle according to an embodiment of the present disclosure. Detailed Implementation

[0022] Hereinafter, embodiments of the braking device for a vehicle according to the present disclosure will be described with reference to the accompanying drawings. It should be noted that the drawings are not drawn to exact scale, and the thickness of lines or the dimensions of components may be exaggerated for ease of description and clarity only. Furthermore, the terminology used herein is defined with consideration of the function of the present disclosure and may be changed according to the user's or operator's habits or purpose. Therefore, the definitions of terminology should be based on the overall disclosure set forth herein.

[0023] Figure 1 This is a cross-sectional view of a braking device for a vehicle according to an embodiment of the present disclosure. Figure 2 This is a perspective view of a cylinder viewed from one direction, according to an embodiment of the present disclosure. Figure 3 yes Figure 2 A three-dimensional view of the cylinder from another perspective. Figure 4 This is a cross-sectional view of a braking device for a vehicle according to an embodiment of the present disclosure. Figure 5 This is a perspective view of a sleeve according to an embodiment of the present disclosure. Figure 6 This is an exploded perspective view of the sleeve according to an embodiment of the present disclosure. Figure 7 This is an example of an embodiment of the present disclosure showing the operating state of a piston moving forward within a cylinder in a braking device for a vehicle. Figure 8 The diagram illustrates the operating state of a piston moving rearward within a cylinder in a braking device for a vehicle according to an embodiment of the present disclosure.

[0024] refer to Figures 1 to 6 A braking device for a vehicle according to an embodiment of the present disclosure may include a cylinder 200, a motor 300, a screw shaft 400, a nut 500, a piston 600, and a sleeve 700, as described in detail below.

[0025] The cylinder 200 can be located inside the housing 100 and can withstand the torque generated by the hydraulic pressure formed by the reciprocating motion of the piston 600. According to an embodiment of the present disclosure, the housing 100 can have a hollow shape with an internal space in which the cylinder 200 can be press-fitted.

[0026] The housing 100 can be disposed on the outside of the cylinder 200 (based on...). Figure 1 (Left side). Cylinder 200 can be assembled to housing 100 with controllable concentricity.

[0027] Cylinder 200 may have a hollow shape. Sleeve 700 may be located within one side of the space of cylinder 200 (based on...). Figure 1 (On the left side), an operating section is provided in the sleeve 700 to allow hydraulic pressure to be generated by pressing the piston 600.

[0028] The motor 300 can be connected to the cylinder 200, and various types of drive devices can be used within the technical concept of generating rotational power. The motor 300 can transmit rotational power (torque) to the screw shaft 400.

[0029] The motor 300 may include a stationary component 310, a rotating component 320, and a motor bearing 330.

[0030] The stationary component 310 can be fixed to the housing 100 and can be formed into various shapes within the technical concept of changing the magnetic force by power supply.

[0031] The stationary component 310 may include: fixed to one side of the housing 100 (based on...) Figure 1 The fixed frame 311 (on the right side) and the stator 312 are mounted on the inner surface of the fixed frame 311 facing the rotating member 320 and are configured to generate magnetic force.

[0032] The fixed frame 311 can be connected to one side of the housing 100. The rotating component 320 can be rotatably mounted inside the fixed frame 311.

[0033] The stator 312 is an electromagnet that can be mounted on the inner surface of the fixed frame 311 in a circumferential direction and can rotate the rotating component 320 by changing the magnetic flux in response to a control signal from a controller (not shown).

[0034] The rotating component 320 can be connected to the screw shaft 400 and can rotate together with the screw shaft 400. The rotating component 320 can be modified into various shapes within the following technical concept: the rotating component 320 can rotate according to the magnetic force change of the stationary component 310.

[0035] The rotating component 320 can be rotatably mounted inside the fixed frame 311. The rotating component 320 can have an approximately "C" shaped cross-section and can be formed into a hollow shape.

[0036] Rotating component 320 may include surrounding one side of cylinder 200 (based on...) Figure 1 A rotating frame 321 (on the right side) is mounted in a shape, and a rotor 322 with magnetic force is disposed on the outer surface of the rotating frame 321 facing the stationary member 310.

[0037] A spline that meshes with the screw shaft 400 can be formed in the rotating frame 321, specifically on the inner surface of the rotating frame 321.

[0038] The motor bearing 330 can be disposed between the stationary component 310 and the rotating component 320 to reduce friction generated during the rotation of the rotating component 320. The rotor 322 consists of a plurality of magnets mounted along the circumferential direction of the rotating frame 321, and can rotate together with the rotating frame 321 under the action of the magnetic force change of the stator 312.

[0039] The frame cover 340 fixed to the fixed frame 311 can be installed in a shape that surrounds the outer surface of the end of the rotating frame 321 to prevent foreign objects from entering.

[0040] The screw shaft 400 can be disposed inside the cylinder 200. The screw shaft 400 can be positioned along the longitudinal direction of the cylinder 200 (based on...). Figure 1 It can be inserted in the left and right directions and can be axially connected to the cylinder 200. The central axis of the cylinder 200 and the central axis of the screw shaft 400 can coincide with each other.

[0041] The screw shaft 400 can be fixed to the bearing 900 by the support member 1000. The support member 1000 can rotatably support the screw shaft 400.

[0042] The screw shaft 400 may include a screw body 410, a neck portion 420, a power transmission portion 430, and a connecting portion 450.

[0043] The screw body 410 can be rotatably mounted within the cylinder 200 and may include a helical thread formed along the longitudinal direction of the screw shaft 400. The screw body 410 may be located inside the rotating frame 321 of the motor 300.

[0044] The neck portion 420 can be oriented from the outer surface of the screw body 410 around the center of rotation towards the first side (based on...). Figure 1 The right side protrudes and can be formed with a diameter smaller than that of the screw body 410.

[0045] The power transmission section 430 can be directed from the free end of the neck section 420 toward the first side (based on...). Figure 1 (extends to the right) and can be formed with a diameter greater than the diameter of the neck portion 420.

[0046] Splines can be formed along the circumferential direction on the outer surface of the power transmission section 430 facing the rotating frame 321. Therefore, without the shaft cover 440 described below, the rotating frame 321 and the power transmission section 430 can mesh with each other to transmit power.

[0047] The screw shaft 400 may also include a shaft cover 440. The shaft cover 440 may be configured to surround the neck portion 420 and the power transmission portion 430. The shaft cover 440 may be inserted between the power transmission portion 430 and the rotating frame 321 to prevent the generation of metallic rattling noise.

[0048] A spline can be formed on the outer surface of the shaft cover 440 along the circumferential direction, and the spline can engage with the rotating frame 321. The outer shape of the shaft cover 440 can correspond to the outer shape of the power transmission section 430.

[0049] A spline can be formed circumferentially on the outer surface of the power transmission section 430 facing the shaft cover 440. Therefore, the shaft cover 440 and the power transmission section 430 can mesh with each other to transmit power.

[0050] The connecting portion 450 can be directed from the outer surface of the screw body 410 around the center of rotation towards the second side (based on...). Figure 1 The connecting portion 450 extends from the left side and can be rotatably connected to the bearing 900. The connecting portion 450 can also be press-fitted to the bearing 900. The connecting portion 450 can be formed with a diameter equal to or smaller than the diameter of the screw body 410.

[0051] Nut 500 can be located inside the rotating frame 321 of motor 300 and inside cylinder 200.

[0052] Nut 500 can be connected to the outer surface of screw shaft 400 via ball bearing B.

[0053] The screw shaft 400 can be connected by a nut 500. Since the ball B is located between the helical thread formed on the inner surface of the nut 500 and the helical thread formed on the outer surface of the screw body 410, the rotational motion of the screw shaft 400 can be converted into linear motion by the nut 500.

[0054] An anti-rotation protrusion (not shown) may be formed on the outer surface of the nut 500, and a motion groove (not shown) may be formed in the inner surface of the cylinder 200.

[0055] When the screw shaft 400 rotates, the nut 500 does not rotate because the rotation of the anti-rotation protrusion of the nut 500 is blocked by the motion groove. Therefore, the rotational motion of the screw shaft 400 can be converted into the linear motion of the nut 500 through the anti-rotation protrusion and the motion groove.

[0056] The nut 500 can reciprocate along the axial direction of the screw shaft 400 according to the rotation direction of the screw shaft 400. For example, when the screw shaft 400 rotates in a first direction, the nut 500 moves forward, and when the screw shaft 400 rotates in a second direction opposite to the first direction, the nut 500 can move backward.

[0057] The piston 600 can be connected in a manner that surrounds the outside of the nut 500. The piston 600 can move in the longitudinal direction of the cylinder 200 together with the reciprocating motion of the nut 500.

[0058] The piston 600 may include a rod 610 and a head 620.

[0059] The rod 610 can be formed into a hollow shape and can be located inside the rotating frame 321 of the motor 300. The outer surface of the nut 500 and the inner surface of the rod 610 can be threaded together.

[0060] The head 620 can be integrally formed with the rod 610. The outer diameter of the head 620 can be larger than the outer diameter of the rod 610.

[0061] The head 620 can be formed as an annular shape, located inside the housing 100, and can reciprocate within the sleeve 700 to allow the working fluid inside the sleeve 700 to flow toward the port 210. Therefore, the cylinder 200 can generate double-acting hydraulic pressure based on the reciprocating motion of the piston 600.

[0062] The sleeve 700 can be located inside the housing 100 and can be disposed inside the cylinder 200. The sleeve 700 can guide the movement of the piston 600 inserted therein. The sleeve 700 can be formed to surround the head 620 of the piston 600.

[0063] Port 210 through which the working fluid flows can be formed on the outer surface of the area where the sleeve 700 of the cylinder 200 is located. Port 210 can be respectively provided at multiple points along the longitudinal direction of the cylinder 200. The working fluid that flows according to the movement of the piston 600 can flow through port 210 to generate the required braking pressure.

[0064] The sleeve 700 may include an inner diameter portion 711, a connecting portion 712, and an outer diameter portion.

[0065] The inner diameter portion 711 can form the inner circumference of the sleeve 700 and can face the screw shaft 400. The inner diameter portion 711 can be formed as a hollow cylinder. The screw shaft 400 can be located inside the inner diameter portion 711.

[0066] The outer diameter portion can form the outer circumference of the sleeve 700 and can face the inner wall of the cylinder 200. The outer diameter portion can be formed as a hollow cylinder and can surround the inner diameter portion 711.

[0067] The connecting portion 712 can connect the inner diameter portion 711 and the first outer diameter portion 713 of the outer diameter portion. The connecting portion 712 can be formed in a ring shape, with its inner circumference connected to the inner diameter portion 711 and its outer circumference connected to the first outer diameter portion 713. The inner diameter portion 711 and the outer diameter portion can be spaced apart from each other by the width of the connecting portion 712.

[0068] The inner diameter portion 711 and the outer diameter portion can be connected to each other at their respective ends facing the bearing 900 via a connecting portion 712, but not at their respective ends facing the nut 500. Therefore, the sleeve 700 can have a closed surface at its end facing the bearing 900 and can be open at its other end facing the nut 500. The piston 600 can be inserted into the sleeve 700 through the open other end of the sleeve 700.

[0069] The outer diameter portion may include a first outer diameter portion 713 and a second outer diameter portion 720 connected to the first outer diameter portion 713. The first outer diameter portion 713 and the second outer diameter portion 720 may be integrally connected to each other by spot welding.

[0070] The first outer diameter portion 713 and the second outer diameter portion 720 may comprise metallic materials. In this embodiment, the first outer diameter portion 713 and the second outer diameter portion 720 may be made of steel, or they may be made of other metallic materials of the same kind.

[0071] The end face 715 of the first outer diameter portion 713 and the end face 725 of the second outer diameter portion 720 can face each other and can be spot-welded together. The end face 715 of the first outer diameter portion 713 can be the end face opposite to the connecting portion 712. The end face 725 of the second outer diameter portion 720 can be the end face facing the bearing 900.

[0072] Welding points 730 formed by spot welding can be disposed on the end face 715 of the first outer diameter portion 713 and the end face 725 of the second outer diameter portion 720. Multiple welding points 730 can be formed along the respective circumferences of the end face 715 of the first outer diameter portion 713 and the end face 725 of the second outer diameter portion 720. The multiple welding points 730 can be spaced apart from each other by a predetermined distance.

[0073] The end face 715 of the first outer diameter portion 713 and the end face 725 of the second outer diameter portion 720 can be integrated by welding point 730. In the area outside welding point 730, there may be a gap between the end face 715 of the first outer diameter portion 713 and the end face 725 of the second outer diameter portion 720.

[0074] Since the first outer diameter portion 713 and the second outer diameter portion 720 are connected by spot welding, there is a gap between the first outer diameter portion 713 and the second outer diameter portion 720 in the area other than the welding point 730, thereby allowing the working fluid to flow through the gap between the first outer diameter portion 713 and the second outer diameter portion 720.

[0075] In the area where the first outer diameter portion 713 and the second outer diameter portion 720 are joined, at the welding point 730, which is a spot welding area, the flow of working fluid is blocked, but the flow of working fluid is allowed through the area outside the spot welding area.

[0076] The area where the first outer diameter portion 713 and the second outer diameter portion 720 meet, i.e., the area where spot welding is performed, can face the port 210 of the cylinder 200. Therefore, the working fluid inside the sleeve 700 can be discharged to the outside of the sleeve 700 through the gap between the first outer diameter portion 713 and the second outer diameter portion 720, such as... Figure 5 As indicated by the arrow, it can flow through port 210.

[0077] The inner diameter portion 711, the connecting portion 712, and the first outer diameter portion 713 can be integrally formed with each other. In this embodiment, the sleeve 700 may include: a first sleeve portion 710, which forms the inner diameter portion 711, the connecting portion 712, and the first outer diameter portion 713; and a second sleeve portion 720, which corresponds to the second outer diameter portion 720. The first sleeve portion 710 and the second sleeve portion 720 can be integrally formed with each other by spot welding.

[0078] The first sleeve portion 710 and the second sleeve portion 720 can be manufactured using separate processes, thus reducing the difficulty of machining the sleeve 700. Therefore, the mass production rate of braking devices for vehicles can be increased.

[0079] The connection area between the first outer diameter portion 713 and the second outer diameter portion 720 can be located between the first overflow plate 220 and the second overflow plate 221. The first overflow plate 220 can be located on one side of the inner wall of the cylinder 200, and the second overflow plate 221 can be located on the other side of the inner wall of the cylinder 200. The first overflow plate 220 and the second overflow plate 221 can be spaced apart from each other by a predetermined distance, and the corresponding port 210 can be located between the first overflow plate 220 and the second overflow plate 221. The connection area between the first outer diameter portion 713 and the second outer diameter portion 720 can be configured to face the port 210 located between the first overflow plate 220 and the second overflow plate 221. Therefore, leakage of working fluid discharged through the gap in the connection area between the first outer diameter portion 713 and the second outer diameter portion 720 can be prevented by the sealing effect of the first overflow plate 220 and the second overflow plate 221, and the working fluid can be discharged to the outside through the port 210.

[0080] A braking device for a vehicle according to an embodiment of the present disclosure may include a bearing 900. The bearing 900 may be located inside a housing 100 and may be disposed at one end inside a cylinder 200.

[0081] The outer surfaces of the bearing 900 and the sleeve 700 can be mounted in contact with each other. The bearing 900 can be connected to the screw shaft 400 in a shape that surrounds the connecting portion 450 of the screw shaft 400.

[0082] The bearing 900 may include an inner ring 910, bearing balls 915, and an outer ring 920. The inner ring 910 may contact the connecting portion 450 of the screw shaft 400, and the outer ring 920 may be mounted in contact with the inner surface of the cylinder 200.

[0083] The bearing 900 can bear the axial load when the piston 600, which reciprocates along the axial direction of the screw shaft 400, generates hydraulic pressure within the cylinder 200.

[0084] A braking device for a vehicle according to an embodiment of the present disclosure may include a support member 1000. The support member 1000 may be disposed inside a cylinder 200. The support member 1000 may be inserted into a connecting portion 450 and may be connected to a screw shaft 400. The support member 1000 may be threadedly connected to the screw shaft 400. A bearing 900 may be fixed to the support member 1000. The support member 1000 may rotatably support the screw shaft 400. The support member 1000 may be a bolt.

[0085] A braking device for a vehicle according to an embodiment of the present disclosure may include a reaction force member 1100. A first side of the reaction force member 1100 may be supported by a cylinder 200, and a second side of the reaction force member 1100 may contact a sleeve 700 to press the sleeve 700 against a bearing 900. The reaction force member 1100 may be a wave spring.

[0086] The operation of a braking device for a vehicle having the above configuration according to an embodiment of the present disclosure will now be described.

[0087] refer to Figure 7 When the motor 300 is running to transmit rotational force to the screw shaft 400, the screw shaft 400 can rotate along its axis within the cylinder 200 in a first rotational direction, and the nut 500 can move forward along the screw shaft 400 toward the sleeve 700.

[0088] In response to the movement of the nut 500 toward the sleeve 700, the piston 600 connected to the nut 500 can move linearly forward in the cylinder 200 in the same direction as the movement of the nut 500, thereby generating hydraulic braking pressure.

[0089] refer to Figure 8 When the motor 300 is running, causing the screw shaft 400 to rotate along its axis within the cylinder 200 in a second rotation direction opposite to the first rotation direction, the nut 500 can move backward along the screw shaft 400 in a direction opposite to the sleeve 700.

[0090] In response to the movement of the nut 500 in the opposite direction to that of the sleeve 700, the piston 600 connected to the nut 500 can move linearly backward within the cylinder 200 in the same direction as the movement of the nut 500, thereby generating hydraulic braking pressure. Therefore, when the piston 600 moves linearly forward and backward within the cylinder 200, double-acting hydraulic pressure can be generated.

[0091] According to this disclosure, a sleeve can be manufactured by joining multiple sleeve portions, thereby reducing the difficulty of processing and increasing the mass production rate of braking devices for vehicles.

[0092] Although this disclosure has been described with reference to embodiments shown in the accompanying drawings, the embodiments of this disclosure are for illustrative purposes only, and those skilled in the art will understand that various modifications and other equivalent embodiments can be made from the described embodiments.

Claims

1. A braking device for a vehicle, characterized in that, include: A cylinder is provided with a port through which working fluid moves; The motor is configured to generate rotational power; The screw shaft is located inside the cylinder and is configured to receive rotational power from the motor and rotate about an axis; A nut is connected to the screw shaft and configured to reciprocate in the axial direction of the screw shaft in response to rotation of the screw shaft; A sleeve, located inside the cylinder, includes an inner diameter portion facing the screw shaft and an outer diameter portion facing the cylinder. The outer diameter portion includes a first outer diameter portion and a second outer diameter portion connected to the first outer diameter portion. The piston, connected to the nut, is configured to reciprocate within the sleeve in response to the reciprocating motion of the nut.

2. The braking device for a vehicle according to claim 1, characterized in that, The first outer diameter portion and the second outer diameter portion can be connected to each other by spot welding.

3. The braking device for a vehicle according to claim 2, characterized in that, The connection area between the first outer diameter portion and the second outer diameter portion faces the port.

4. The braking device for a vehicle according to claim 3, characterized in that, The working fluid in the sleeve is discharged to the outside of the sleeve through a non-spot welded area in the connection region between the first outer diameter portion and the second outer diameter portion.

5. The braking device for a vehicle according to claim 3, characterized in that, The connection area between the first outer diameter portion and the second outer diameter portion is located between the first overflow plate and the second overflow plate, which are mounted on the inner wall of the cylinder.

6. The braking device for a vehicle according to claim 1, characterized in that, The sleeve further includes a connecting portion that connects the inner diameter portion and the first outer diameter portion; and The inner diameter portion, the connecting portion, and the first outer diameter portion are integrally formed.

7. The braking device for a vehicle according to claim 6, characterized in that, The first outer diameter portion and the second outer diameter portion each comprise steel.

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