MASTER BRAKE CYLINDER OF A VEHICLE BRAKE

Abstract

A vehicle brake master cylinder includes a housing, a motor, a screw, a moving piston, a guide, and a pressurizing member. The housing has a port configured to move hydraulic fluid. The motor is connected to the housing and configured to provide rotational power. The screw is rotatably mounted in the motor and configured to rotate in response to rotational power from the motor. The moving piston is engaged with an outer surface of the screw and configured to move in a longitudinal direction of the housing in response to rotation of the screw. The guide is blocked by the housing and prevented from rotating and is configured to prevent rotation of the moving piston and guide linear movement of the moving piston in the longitudinal direction.The pressurizing part is installed between the housing and the guide and is configured to pressurize the guide via a clamping force.

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2019-0069350, filed on June 12, 2019, which is incorporated by reference into this application for all purposes as if fully set forth herein. BACKGROUND AREA

[0002] Exemplary embodiments relate generally to a master cylinder of a vehicle brake, and more particularly to a master cylinder of a vehicle brake that can easily control preload and tolerance between assembled parts through an elastic body and thereby improve operational reliability. DISCUSSION

[0003] Generally, a master cylinder of a vehicle brake generates braking force to restrict the movement of a vehicle's wheels using hydraulic pressure generated in response to a piston moving within the master cylinder. When a driver steps on a pedal, the braking pressure is determined. The master cylinder is thus operated to implement the braking pressure, and the hydraulic pressure generated by the master cylinder is transmitted to each of the wheels. Since the master cylinder is typically operated by hydraulic pressure, difficulties arise in precisely moving the piston to implement the braking pressure. To address (or solve) such a problem, a method for moving a piston using rotational power from an engine has been proposed, as in Korean Patent Application No. 10-2016-0095486, published on August 11, 2016, entitled "Master Cylinder for Brake of Vehicle."However, since the tolerance between assembled parts is typically not controlled, friction and interference between the parts can occur. Therefore, there is a need for a structure capable of solving such problems.

[0004] The aforementioned information disclosed in the Background section is provided solely for the purpose of providing a better understanding of the background of the inventive concepts and may therefore include information that is not prior art. OVERVIEW

[0005] Some exemplary embodiments relate to a master cylinder of a vehicle brake capable of controlling preload and tolerance between assembled parts through an elastic body, thereby improving operational reliability.

[0006] Additional aspects will be set forth in the detailed description which follows, and in part will be apparent from the disclosure or may be learned by practice of the inventive concepts.

[0007] According to some exemplary embodiments, a master cylinder of a vehicle brake includes a housing, a motor, a screw, a moving piston, a guide, and a pressurizing member. The housing includes a port configured to move hydraulic fluid. The motor is connected to the housing and configured to provide rotational power. The screw is rotatably installed in the motor and configured to rotate in response to rotational power from the motor. The moving piston engages an outer surface of the screw and is configured to move in a longitudinal direction of the housing in response to rotation of the screw. The guide is blocked by the housing and prevented from rotating and is configured to prevent rotation of the moving piston and guide linear movement of the moving piston in the longitudinal direction.The pressurizing part is installed between the housing and the guide and is configured to pressurize the guide via a clamping force.

[0008] In some exemplary embodiments, the motor may include a fixed part, a motor rotating part, and a motor bearing part. The fixed part may be fixed to the housing and configured to change magnetism in response to supplied power. The motor rotating part may be connected to the screw. The motor rotating part may be configured to rotate with the screw and rotate according to the change in magnetism of the fixed part. The motor bearing part may be installed between the fixed part and the motor rotating part. The motor bearing part may be configured to reduce friction associated with the rotation of the motor rotating part.

[0009] In some exemplary embodiments, the motor rotating part may include a rotating frame and a rotor. The rotating frame may be rotatably installed in the fixed part. One shape of the rotating frame may cover one end of the moving piston. The rotor may be installed outside the rotating frame and face the fixed part. The rotor may include magnetism. In some exemplary embodiments, the screw may include a screw body and a screw rotating shaft. The screw body may be rotatably installed in the rotating frame. The screw may have spiral gearing formed on the outside of the screw. The screw rotating shaft may extend from the screw body and be splined to the rotating frame.

[0010] In some exemplary embodiments, a compensation play may be provided between the rotating frame and the screw driving shaft.

[0011] In some exemplary embodiments, the pressurizing member may be a disc spring having a curved cross-section and may be configured to pressurize the guide in a direction away from the moving piston.

[0012] According to some exemplary embodiments, a master cylinder of a vehicle brake includes a housing, a motor, a screw, a ball member, and a support member. The housing includes a port configured to transmit hydraulic fluid. The motor is connected to the housing and configured to provide rotational power. The screw is rotatably installed in the motor and configured to rotate in response to the rotational power of the motor. The ball member is connected to a screw rotation shaft of the screw and includes a curved surface. The support member is positioned on opposite sides of the ball member and rotatably supports the ball member.

[0013] In some exemplary embodiments, the support member may include a first support element and a second support element. The first support element may be positioned within the motor, and the screw driver shaft may include a portion extending through the first support element. The second support element may be installed at a position facing the first support element.

[0014] In some exemplary embodiments, the first and second support members may be configured to rotate together with the screw driving shaft.

[0015] In some exemplary embodiments, the master cylinder of a vehicle may further include a thrust bearing member installed at a position facing the second support member. The thrust bearing member may be configured to reduce friction associated with rotation of the second support member.

[0016] According to various exemplary embodiments, a pressurizing member implemented as an elastic body can elastically pressurize a guide body in a direction in which a support member is installed in a master cylinder, and as such can apply a preload between assembled parts of the master cylinder. In this way, tolerance control can be easily performed and friction and interference between parts can be reduced.

[0017] The foregoing general description and the following detailed description are exemplary and explanatory and serve to further explain the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are included to provide a further understanding of the inventive concept and are incorporated in and constitute a part of the specification, illustrate exemplary embodiments of the inventive concept and, together with the description, serve to explain the principles of the inventive concept. Fig. 1 is a cross-sectional view schematically illustrating a structure of a master cylinder of a vehicle brake according to some exemplary embodiments. Fig. Figure 2 shows a cross-sectional view showing a screw in the structure of Fig. 1 configured to compensate for a deflection angle while being rotated about a ball element, according to some exemplary embodiments. Fig. Figure 3 shows a cross-sectional view showing a screw in the structure of Fig. 1 configured to compensate for eccentricity while being rotated about a ball member, according to some exemplary embodiments. Fig. 4 is a diagram illustrating that a compensation clearance is formed between a side projection and a pivot frame, according to some exemplary embodiments. Fig. 5 shows a cross-sectional view illustrating hydraulic pressure being generated at one side of a piston member, according to some exemplary embodiments. Fig. 6 is a cross-sectional view illustrating hydraulic pressure being generated on both sides of a piston member, according to some exemplary embodiments. Fig. 7 shows a cross-sectional view illustrating hydraulic pressure being generated on the other side of a piston member, according to some exemplary embodiments. DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0019] In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of various exemplary embodiments. As used herein, the terms "embodiments" and "implementations" are used interchangeably and are non-limiting examples employing one or more of the inventive concepts disclosed herein. However, it will be understood that various exemplary embodiments may be practiced without these specific details or with one or more equivalent arrangements. In other instances, well-known structures and devices are shown in block diagram form in order not to unnecessarily obscure various exemplary embodiments. Further, various exemplary embodiments may differ from one another but are not necessarily mutually exclusive.For example, specific shapes, configurations, and characteristics of one exemplary embodiment may be used or implemented in another exemplary embodiment without departing from the inventive concepts.

[0020] Unless otherwise indicated, the illustrated exemplary embodiments are to be understood as providing exemplary features with varying detail of some exemplary embodiments. Therefore, unless otherwise indicated, the features, components, modules, layers, films, panels, regions, aspects, etc. (hereinafter referred to individually or collectively as "element" or "elements") of the various figures may be differently combined, separated, interchanged, and / or rearranged without departing from the inventive concepts.

[0021] The use of cross-hatching and / or shading in the accompanying drawings is generally intended to clarify boundaries between adjacent elements. As such, neither the presence nor the absence of cross-hatching or shading conveys or indicates, unless specifically stated, a preference or requirement for particular materials, material properties, dimensions, proportions, commonalities between depicted elements, and / or any other characteristic, attribute, property, etc. of the element. Furthermore, in the accompanying drawings, the size and relative sizes of elements may be exaggerated for clarity and descriptive purposes. As such, the sizes and relative sizes of the respective elements are not necessarily to be limited to those shown in the drawings.If an exemplary embodiment can be implemented differently, a specific process sequence may be performed differently than the described sequence. For example, two processes described sequentially may be performed substantially concurrently or in an order reverse to the described sequence. Furthermore, like reference numerals indicate like elements.

[0022] When an element, such as a layer, is referred to as being "on," "connected to," or "coupled to" another element, it may be immediately on, connected to, or coupled to the other element, or there may be intervening elements. However, when an element is referred to as being "immediately on," "immediately connected to," or "immediately coupled to," no intervening elements are present. Other terms and / or phrases used to describe a relationship between elements should be interpreted in the same way, e.g., "between" versus "immediately between," "adjacent" versus "immediately adjacent," "on" versus "immediately upon," etc. Furthermore, the terms "connected" may refer to physical, electrical, and / or fluidic connections.Furthermore, the X-axis, Y-axis, and Z-axis are not limited to three axes of a rectangular coordinate system and can be interpreted in a broader sense. For the purposes of the present disclosure, "at least one of X, Y, and Z" and "at least one selected from the group formed by X, Y, and Z" can be understood as only X, only Y, only Z, or any combination of two or more of X, Y, and Z, such as XYZ, XYY, YZ, and ZZ. As used herein, the term "and / or" encompasses any and all combinations of one or more of the aforementioned elements.

[0023] While the terms "first," "second," etc., are used herein to describe various elements, these elements should not be limited by these terms. These terms serve to distinguish one element from another. Thus, a first element discussed below may be referred to as a second element without departing from the scope of the teachings of the present disclosure.

[0024] Spatial referents such as "beneath," "under," "deeper," "above," "upper," "over," "higher," "lateral" (e.g., as in "sidewall"), and the like may be used herein for descriptive purposes to describe the relationship of one element to one or more other elements as shown in the drawings. Spatial referents are intended to encompass, in addition to the orientation shown in the drawings, different orientations of a device during use, operation, and / or manufacture. For example, if a device is inverted in the drawings, elements described as being located "below" or "below" other elements or features would then be located "above" the other elements or features. Thus, the exemplary term "below" can encompass both an arrangement above and below an element or feature.Furthermore, the device may also be oriented differently (for example, rotated by 90 degrees or have a different orientation) and thus the spatial reference descriptors used here must be interpreted accordingly.

[0025] The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" also include the plural forms unless the context clearly indicates otherwise. Furthermore, the terms "having," "comprising," "comprising," and / or "comprising," when used in the description, indicate the presence of specified devices, integers, steps, operations, elements, and / or groups thereof, without precluding the presence or addition of one or more other devices, integers, steps, operations, elements, and / or groups thereof.It should also be noted that the terms "substantially" and "approximately" or other similar expressions, when used herein, are used as terms of approximation rather than of degree and are used to account for inherent variations in measured, calculated and / or provided values ​​that would be recognized by a person skilled in the art.

[0026] Various exemplary embodiments are described herein with reference to sectional views, isometric views, perspective views, plan views, and / or exploded views, which are schematic representations of idealized exemplary embodiments and / or intermediate structures. Deviations from the shapes shown in the figures due to, for example, manufacturing processes and / or tolerances are thus to be expected. Therefore, exemplary embodiments disclosed herein should not be limited to the particular shapes of regions shown, but should be considered to encompass variations in shapes caused, for example, by manufacturing.As such, the regions illustrated in the drawings are schematic in nature and shapes of these regions are not intended to represent the actual shapes of regions of a device and should not be considered limiting.

[0027] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as one of ordinary skill in the art to which this disclosure pertains. Terms such as those defined in commonly used dictionaries should be interpreted to have a meaning consistent with their meaning in the context of the relevant field and should not be interpreted in an idealized or overly formal sense unless expressly stated herein.

[0028] Various exemplary embodiments of a master brake cylinder of a vehicle brake are described below with reference to the accompanying drawings.

[0029] Fig. 1 is a cross-sectional view schematically illustrating a structure of a master cylinder of a vehicle brake according to some exemplary embodiments. Fig. Figure 2 shows a cross-sectional view showing a screw in the structure of Fig. 1 configured to compensate for a deflection angle while being rotated about a ball element, according to some exemplary embodiments. Fig. Figure 3 shows a cross-sectional view showing a screw in the structure of Fig. 1 configured to compensate for eccentricity while being rotated about a ball member, according to some exemplary embodiments. Fig. 4 is a diagram illustrating that a compensation clearance is formed between a side projection and a pivot frame, according to some exemplary embodiments. Fig. 5 shows a cross-sectional view illustrating hydraulic pressure being generated at one side of a piston member, according to some exemplary embodiments. Fig. 6 is a cross-sectional view illustrating hydraulic pressure being generated on both sides of a piston member, according to some exemplary embodiments. Fig. 7 shows a cross-sectional view illustrating hydraulic pressure being generated on the other side of a piston member, according to some exemplary embodiments.

[0030] Referring to Fig. 1, a master cylinder 1 of a vehicle brake according to some exemplary embodiments comprises a housing 10, a motor 20, a screw 30, a moving piston 50, a guide 90, and a pressurizing part 80. The housing 10 has a port 12 through which a fluid (e.g., a gas, oil, or the like) is moved. For simplicity of description, the fluid will be referred to as oil below. The motor 20 is connected to the housing 10 and provides rotational power. The screw 30 is rotatably installed in the motor 20 and is rotated by the rotational power received from the motor 20. The moving piston 50 engages the outer side of the screw 30 and moves in the longitudinal direction D of the housing 10 due to the rotation of the screw 30.The guide 90 is blocked and prevented from rotating by the housing 10 and guides the moving piston 50 to move in the longitudinal direction D, while the guide prevents the rotation of the moving piston 50. The pressurizing part 80 is installed between the housing 10 and the guide 90 and pressurizes the guide 90 using a clamping force.

[0031] A driver's action by depressing a pedal determines (e.g., determines, regulates, etc.) the brake pressure. Consequently, the master cylinder 1 of a vehicle brake is operated to implement the brake pressure, and the generated hydraulic pressure is transmitted to each wheel of a vehicle.

[0032] The vehicle brake master cylinder 1 according to some exemplary embodiments provides a pre-pressure control mounting structure among the assembled parts of the motor 20, the screw 30, the moving piston 50, and the guide 90. Thus, the vehicle brake master cylinder 1 can reduce the tolerance between the mounting parts while improving the degree of design freedom and thereby reducing manufacturing costs. Furthermore, when the vehicle brake master cylinder 1 is driven, active shaft alignment compensation and wear gap compensation can be achieved to improve durability and system efficiency and reduce noise and vibration.

[0033] The port 12 of the housing 10 through which the oil is moved is formed on both sides of the housing 10 in the longitudinal direction D, and the housing 10 has an internal working space in which a piston element 54 of the moving piston 50 is moved. The oil moved by the movement of the piston element 54 implements the brake pressure associated with the operation of the pedal while being moved through the port 12.

[0034] As long as the motor 20 is connected to the housing 10 and provides rotational power, various types of drive devices can be used as the motor 20. The motor 20 according to some exemplary embodiments includes a motor support part 21, a fixed part 22, and a motor rotating part 26.

[0035] The fixed part 22 can be formed in various shapes, as long as the fixed part 22 is fixed to the housing 10 and the magnetism is changed by power supply. The fixed part 22 according to some exemplary embodiments includes a fixed frame 23 fixed to one side of the housing 10, and a stator 24 installed in the fixed frame 23 facing the motor rotating part 26 and configured to generate magnetism.

[0036] The fixed frame 23 is connected to one side of the housing 10, and the motor rotating part 26 is rotatably installed in the fixed frame 23. Furthermore, the stator 24 is configured as an electromagnet and installed in the fixed frame 23 in a circumferential direction. The stator 24 rotates the motor rotating part 26 while changing magnetic fluxes by a control signal from a control unit (not shown).

[0037] The motor rotating part 26 can be modified in various forms, as long as the motor rotating part 26 is connected to the screw 30, rotates with the screw 30, and rotates according to a change in the magnetism of the fixed part 22. The motor rotating part 26 according to some exemplary embodiments includes a rotating frame 27 and a rotor 28. The rotating frame 27 is rotatably installed in the fixed frame 23 and installed in such a way that one end of the moving piston 50 is covered. The rotor 28 is installed outside the rotating frame 27, facing the fixed part 22, and has magnetism.

[0038] The motor rotating member 26 according to some exemplary embodiments has a U-shaped cross-section and is formed in a hollow shape. In some exemplary embodiments, the motor rotating member 26 is shaped like a fixed core and is splined to the outside of a separate shaft, the rotation of which is restricted by the motor rotating member 26. When the fixed core-like motor rotating member 26 is rotated, the shaft, while moving linearly, can consequently move the piston element 54, thereby generating hydraulic pressure.

[0039] The motor bearing part 21 is installed between the fixed part 22 and the motor rotating part 26 and reduces friction that occurs when the motor rotating part 26 rotates. The rotor 28, which has a plurality of magnets in the circumferential direction of the rotating frame 27, is rotated by the change in magnetism of the stator 24 in the rotating frame 27.

[0040] A cover member 29 is fixed to the fixed frame 23 and installed in such a way that the outer side of one end of the rotating frame 27 is covered. As such, the cover member 29 blocks the intrusion of foreign matter.

[0041] The screw 30 can be formed in various shapes, as long as the screw 30 is rotatably installed in the motor 20 and rotated by the rotational power received from the motor 20. The screw 30 according to some exemplary embodiments includes a screw body 32 and a screw rotation shaft 34. The screw body 32 is rotatably installed in the rotating frame 27 and has spiral gearing formed on its outer surface. The screw rotation shaft 34 extends from the screw body 32 and is splined to the rotating frame 27.

[0042] The screw shaft 34, which extends outward from the rotation center of the screw body 32, has a smaller diameter than the screw body 32. As shown in Fig. As shown in Figure 4, a plurality of side projections 35 protrude from the outer side of the screw driving shaft 34, which faces the rotating frame 27. Thus, the rotating frame 27 and the screw 30 are splined to transmit power.

[0043] Furthermore, a compensation clearance 40 is provided between the rotating frame 27 and the screw shaft 34. The side projections 35 formed on the screw 30 and the rotating frame 27 are spaced apart by a predetermined distance, thereby forming the compensation clearance 40. Thus, a degree of freedom is ensured so that the screw 30 and a compensator 70 can move in an up-down direction, as shown in Fig. 3. Therefore, it is possible to compensate for coaxiality among the housing 10, the screw 30 and the motor 20 when assembling the master cylinder 1 of a vehicle brake.

[0044] Further referring to Fig. 1, the moving piston 50 can be configured in various shapes, as long as the moving piston 50 engages the outer surface of the screw 30 and is moved in the longitudinal direction D of the housing 10 by the rotation of the screw 30. The moving piston 50 according to some exemplary embodiments includes a moving body 52, the piston element 54, and a sealing element 56.

[0045] The moving body 52 is installed in such a way that the outer side of the screw body 32 is covered and is moved linearly by the rotation of the screw body 32. One side of the moving body 52 is installed in the motor rotating part 26, and the other side is positioned in the housing 10.

[0046] The piston element 54 is connected to the moving body 52, extending into the housing 10, and moves oil between the housing 10 and a fixed piston 60 toward the port 12. The piston element 54 is annular and fixed to the outside of the other end of the moving body 52. ​​The piston element 54 and the moving body 52 can be formed as a single body or manufactured separately and then assembled together.

[0047] When the piston member 54 and the moving body 52 are formed as one body, a process for assembling the piston member 54 and the moving body 52 is eliminated, and the axial length of the vehicle brake master cylinder 1 can be reduced. Therefore, reducing the number of parts, reducing the number of assembly processes, and reducing the axial length of the vehicle brake master cylinder 1 can improve system packaging efficiency. The sealing member 56 is installed on a side surface of the moving body 52 and on a side surface of the piston member 54 and is moved with the moving body 52.

[0048] The fixed piston 60 can be formed in various shapes, as long as the fixed piston 60 is fixed to the inside of the housing 10 and the moving piston 50 is positioned outside the fixed piston 60. The fixed piston 60 according to some exemplary embodiments is positioned on the same axial line as the screw 30, and one side of the fixed piston 60 is positioned inside the moving piston 50 and the other side is fixed to the housing 10. The fixed piston 60 according to some exemplary embodiments is cylindrical, and the rotation centers of the fixed piston 60, the screw 30, and the motor rotating part 26 are positioned on the same axial line.

[0049] The compensator 70 can be configured in various shapes, as long as the compensator 70 is installed in the rotating frame 27 and compensates for the coaxiality of the rotating frame 27 and the screw 30. The compensator 70 according to some exemplary embodiments includes a ball element 72 and a support part 74.

[0050] The ball element 72 is connected to the screw shaft 34 of the screw 30 positioned in the rotating frame 27 and has a spherical surface. The support member 74 is positioned on both sides of the ball element 72 and rotatably supports the ball element 72. The support member 74 according to some exemplary embodiments includes a first support member 76 and a second support member 78. The first support member 76 is positioned in the rotating frame 27 so that the screw shaft 34 is disposed therethrough, and the second support member 78 is installed at a position facing the first support member 76.

[0051] The ball element 72 can be hemispherical or spherical. Furthermore, various spherical elements can be used as the ball element 72. Two or more positions of the ball element 72 are supported by the support member 74. Both sides of the ball element 72 are supported by the first support member 76 and the second support member 78 according to some exemplary embodiments.

[0052] The first support member 76 is positioned between the ball member 72 and the side projections 35 and is installed such that it contacts the inner surface of the rotating frame 27 facing the ball member 72. Since the first support member 76 facing the ball member 72 has a concave groove, the first support member 76 can rotatably support the ball member 72 with the second support member 78.

[0053] The second support member 78 is installed at a position facing the first support member 76 with the ball member 72 interposed therebetween, and is rotatably installed by the thrust bearing part 110. Since the second support member 78 facing the ball member 72 also has a concave groove, the second support member 78 can rotatably support the ball member 72 with the first support member 76. The first support member 76 and the second support member 78 according to some exemplary embodiments can be rotated with the screw driving shaft 34.

[0054] The pressurizing member 80 is installed between the housing 10 and the guide 90 and applies pressure to the guide 90 using a clamping force to apply a preload. According to some exemplary embodiments, the pressurizing member 80 is a Belleville spring with a curved cross-section and applies pressure to the guide 90 in the direction in which the first support member 76 is installed. Because the pressurizing member 80 applies pressure to the guide 90 in a direction away from the moving piston 50, a preload can be applied during assembly of parts.

[0055] Two or more positions of the ball element 72 are supported by the support part 74, and the ball element 72 in contact with the support part 74 forms a curved surface at one or more positions. Since the ball element 72 has an alignment structure positioned between the first support member 76 and the second support member 78, a load transmitted from the pressurizing part 80 to the ball element 72 can be reduced, simplifying operation of the alignment and assembly parts.

[0056] The pressurizing part 80 is installed on a side wall of the housing 10 facing the guide 90 and pressurizes the guide 90 towards the other side (right in Fig. 1) of the housing 10 elastically with pressure.

[0057] The pressurizing member 80 implemented with a disc spring may include a disc ring. The pressurizing member 80 may be modified in various forms. For example, the pressurizing member 80 may be implemented as an elastic member with a curved cross-section. The spring ring is a washer that combines the functions of a flat washer and a spring washer, and serves to prevent relaxation during surface pressure distribution. Further, a rubber O-ring may be used as the pressurizing member 80, and the pressurizing member 80 may be modified in various ways. For example, a member including at least one of silicone, synthetic resin, and rubber may be used as the pressurizing member 80.

[0058] The guide 90 may be formed in various shapes as long as the guide 90 is blocked by the housing 10 and prevented from rotating, prevents the rotation of the moving piston 50, and guides the moving piston 50 to move linearly in the longitudinal direction D. In some exemplary embodiments, the guide 90 includes a guide body 92, a wing member 94, and a fixed projection 96.

[0059] The guide body 92 has a groove into which the vane member 94 is inserted to move in the longitudinal direction D. The guide body 92 is positioned outside the moving piston 50, and the fixed projection 96 extending from the guide body 92 is fixedly installed on the housing 10. Since the fixed projection 96 is installed at a position facing the pressurizing part 80, the fixed projection 96 is pressed by the pressurizing part 80 and pressurized toward the other sides of the housing 10.

[0060] The vane element 94 is fixed to the outside of the moving body 52, formed in a shape such that it protrudes from the outside of the moving body 52, and is moved with the moving body 52. ​​One side of the vane element 94 is fixed to the moving body 52, and the other side is inserted into the guide body 92.

[0061] The rotation of the vane member 94, which is fixed to the moving body 52 of the moving piston 50, is restricted by the guide body 92 when the screw 30 is rotated. Thus, the moving body 52 serves to determine the position of the piston member 54 while moving linearly. That is, to implement a driver's braking pressure, the motor 20 rotates the screw 30, and thus the moving body 52 is moved linearly to determine the position of the piston member 54. Consequently, the braking pressure level of the master cylinder 1 of a vehicle brake is controlled, and the sealing member 56, the fixed piston 60, and the housing 10, which are mounted on the respective components, seal the space in which the braking pressure is generated.

[0062] The thrust bearing part 110 is installed between the second support element 78 and the guide 90 and serves to reduce friction that occurs during rotation of the second support element 78.

[0063] In the following, an exemplary operation of the master brake cylinder 1 of a vehicle brake according to some exemplary embodiments will be described in more detail with reference to the accompanying drawings.

[0064] When the magnetism of the stator 24 is changed to implement a driver's braking pressure, the motor rotating part 26 is rotated with the rotor 28. The motor rotating part 26 rotates the wedge-coupled screw 30, and the rotation of the screw 30 linearly moves the moving piston 50 in the longitudinal direction D of the housing 10.

[0065] In addition to the coupling structure in which the screw driving shaft 34 is splined to the rotating frame 27, the screw driving shaft 34 may be connected to the rotating frame 27 by connecting a power transmission member. Various types of connecting members, including a spline, a key, and a coupler, may be used as the power transmission member to connect the screw driving shaft 34 to the rotating frame 27.

[0066] The movement piston 50 facing the screw 30 is only allowed to move linearly, since the wing element 94 projecting towards the outside of the movement piston 50 is inserted into the guide body 92 and is prevented from rotating.

[0067] The brake pressure is formed by the movement of the moving piston 50 having the piston element 54 and the oil for forming the brake pressure is moved through the port 12.

[0068] The master brake cylinder 1 of a vehicle brake according to various exemplary embodiments is configured to compensate for an axial alignment under the center axis of the motor 20, the center axis of the screw 30, and the center axis of the moving piston 50. If compensation of the axial alignment under the center axes of the respective parts is desired, the parts can be rotated about the ball element 72, as shown in Fig. 2, which allows compensation of a deflection angle between the assembled parts. As shown in Fig. 3, the screw 30 can also be moved in the up-to-down direction to compensate for eccentricity.

[0069] Furthermore, a preload of a part mounted between the pressurizing part 80 and the first support member 76 can be controlled by the pressurizing part 80 and the guide body 92 implemented as a slidable structure. Since the preload value can be controlled by the pressurizing part 80 implemented as an elastic body, a tolerance between the mounted parts can be reduced and a degree of design freedom can be achieved. Furthermore, design values ​​for compensating the deflection angle and eccentricity can be verified and effectively controlled.

[0070] As in Fig. 5, a first valve 102 connected to the port 12 formed on one side of the housing 10 may be open, and a second valve 104 connected to the port 12 formed on the other side of the housing 10 may be closed. In this state, hydraulic pressure is applied only to one side (e.g., left side in Fig. 5) of the piston element 54 and transmitted to a wheel brake 100.

[0071] Accordingly, the pressure generated by the hydraulic pressure forms a first force F1, while the force is sequentially transmitted to the piston member 54, the moving body 52, the screw body 32, the ball member 72, and the first support member 76. Furthermore, the clamping force of the pressurizing member 80 forms a second force F2, while the force is sequentially transmitted to the fixed projection 96, the guide body 92, the thrust bearing member 110, the ball member 72, and the first support member 76. Since the respective parts are pressed against each other by the first and second forces F1 and F2, it is possible to prevent noise or vibration generation due to a tolerance between the parts.

[0072] As in Fig. 6, the valve 102, which is connected to the port 12 formed on one side of the housing 10, may be open, and the second valve 104, which is connected to the port 12 formed on the other side of the housing 10, may also be open. In this state, hydraulic pressure is generated on both sides of the piston element 54 and transmitted to the wheel brake 100.

[0073] At this time, pressure generated by the hydraulic pressure forms a first force F1, while the force is transmitted sequentially to the piston member 54, the moving body 52, the screw body 32, the ball member 72, and the first support member 76. In addition, the clamping force of the pressurizing part 80 forms a second force F2, while the force is transmitted sequentially to the fixed projection 96, the guide body 92, the thrust bearing part 110, the ball member 72, and the first support member 76. In addition, hydraulic pressure generated by the force generated on the other side (e.g., the right side in Fig. 6) of the piston element 54, a third force F3 is generated to pressurize the guide body 92 towards the other side of the piston element 54.

[0074] Since the respective parts are pressed against each other by the first to third forces F1 to F3, it is consequently possible to prevent the generation of noise and vibration by a tolerance between the parts.

[0075] As in Fig. As shown in Figure 7, the first valve 102, which is connected to the port 12 formed on one side of the housing 10, may be closed, and the second valve 104, which is connected to the port 12 formed on the other side of the housing 10, may be opened. In this state, hydraulic pressure is only applied to the other side (e.g., right side in Fig. 7) of the piston element 54 and transmitted to the wheel brake 100.

[0076] Accordingly, pressure formed by the hydraulic pressure forms a first force F1 to move the piston element 54 to one side (e.g., the left side in Fig. 7) of the housing 10, and the clamping force of the pressing part 80 forms a second force F2 for pressing the guide 90 to the other side of the housing 10, while the force is transmitted in turn to the fixed projection 96, the guide body 92, the thrust bearing part 110, the ball member 72 and the first support member 76.

[0077] The hydraulic pressure of the chamber positioned on the other side of the piston member 54 forms a third force F3 to push the guide 90 toward the other side of the housing 10. Thus, a total force Ftot applied to the parts positioned between the pressurizing part 80 and the first support member 76 is a positive value obtained by subtracting the first force F1 from the sum of the second and third forces F2 and F3. Thus, a constant force is transmitted from the pressurizing part 80 to the first support member 76. Consequently, since the parts are pressed against each other by the pre-pressure, it is possible to prevent (or at least reduce) the generation of noise or vibration due to a tolerance between the parts.

[0078] That is, the master cylinder 1 of a vehicle brake according to various exemplary embodiments is configured to apply a unidirectional load to the assembled parts, although the distribution of the hydraulic pressure within both chambers is changed in various ways based on the sealing element 56 of the piston element 54.

[0079] The pressurizing member 80 can continuously compensate for the clearance created by wear of the parts during use of the master cylinder 1 of a vehicle brake. Furthermore, the structure in which an axial load caused by the hydraulic pressure within the chamber of the housing 10 is not applied to the pressurizing member 80 can ensure a degree of design freedom and the durability of the pressurizing member 80 to apply a preload.

[0080] Furthermore, the position of the screw 30 can be corrected such that the screw rotation shaft 34 of the screw 30 becomes coaxial with the rotation center of the motor rotating part 26 and the fixed piston 60. Since the rotatable ball element 72 and the compensation clearance 40 provide a structure capable of actively performing axial compensation between the respective parts when the brake master cylinder 1 for the vehicle is operated, the system efficiency can be improved.

[0081] Since the sealing area of ​​the guide 90 is larger than the sealing area of ​​the piston element 54, as in Fig. 1, a load may be generated to the right side of the piston member 54 even though hydraulic pressure is generated on the right side of the piston member 54.

[0082] That is, a first sealing length A, which corresponds to a distance between the outer side of the moving body 52 and the inner wall surface of the housing 10, is proportional to the area sealed by the piston member 54, and a second sealing length B, which corresponds to a distance between the outer side of the moving body 52 and the outer surface of the guide 90, is proportional to the area sealed by the guide 90. The second sealing length B is greater than the first sealing length A. Thus, although hydraulic pressure is generated on the right side of the piston member 54, more hydraulic pressure can be applied in a direction toward the guide 90, which has a sealing area proportional to the second sealing length B, than in a direction toward the piston member 54, which has a sealing area proportional to the first sealing length A.Since the guide 90 is forced into another structure and is thus not fixed but slides, the guide 90 also serves to generate the same load in one direction.

[0083] According to various exemplary embodiments, the pressurizing part 80 implemented as an elastic body elastically pressurizes the guide body 92 in the direction in which the support part 74 is installed, thus applying a preload between the assembled parts. In this way, tolerance control can be easily performed, and friction and interference between parts can be reduced. Furthermore, when the master cylinder 1 of a vehicle brake is operated, system efficiency can be improved by preload control between the respective parts. The active shaft compensation efficiency between the power transmission shafts can also be improved. In addition, the tolerance of a single part can be reduced to increase a degree of design freedom. Furthermore, durability can be improved, and operating noise can be reduced by the preload operation state.In addition, the ball member 72 and the compensation clearance 40 can compensate the coaxiality and the degree of right angle between the moving piston 50 and the screw 30, which are positioned on the same axis as the rotation center axis of the motor rotating part 26, and thereby the operation reliability can be improved.

Claims

[1] Master brake cylinder (1) of a vehicle brake with: a housing (10) having a port (12) configured to move a hydraulic fluid; a motor (20) connected to the housing (10) and configured to provide rotational power; a screw (30) rotatably installed in the motor (20) and configured to rotate in response to the rotational power of the motor (20); a moving piston (50) engaged with an outer side of the screw (30) and configured to move in a longitudinal direction (D) of the housing (10) in response to rotation of the screw (30); a guide (90) blocked by the housing (10) and prevented from rotating, the guide (90) being configured to prevent rotation of the moving piston (50) and guide linear movement of the moving piston (50) in the longitudinal direction; and a pressurizing part (80) installed between the housing (10) and the guide (90) and configured to pressurize the guide (90) via a clamping force. [2] Master cylinder according to claim 1, wherein the motor (20) comprises: a fixed part (22) fixed to the housing (10) and configured to change its magnetism in response to an applied power; a motor rotating part (26) connected to the screw (30), the motor rotating part (26) being configured to rotate with the screw (30) and to rotate in accordance with the change in magnetism of the fixed part (22); and a motor support member (21) installed between the fixed member (22) and the motor rotating member (26), the motor support member (21) being configured to reduce friction associated with rotation of the motor rotating member (26). [3] Master brake cylinder according to claim 2, wherein the motor rotating part (26) comprises: a rotating frame (27) rotatably installed in the fixed part (22), wherein a shape of the rotating frame (27) covers one end of the moving piston (50); and a rotor (28) installed outside the rotating frame (27) and facing the fixed part (22), the rotor (28) having magnetism. [4] Master brake cylinder according to claim 3, wherein the screw (30) comprises: a screw body (32) rotatably installed in the rotating frame (27), the screw (30) having a spiral toothing formed on the outside of the screw (30); and a screw driving shaft (34) extending from the screw body (32), the screw driving shaft (34) being wedge-coupled to the rotating frame (27). [5] Master brake cylinder according to claim 4, wherein a compensation play is provided between the rotating frame (27) and the screw rotating shaft (34). [6] Master brake cylinder according to claim 1, wherein: the pressure-applying member (80) is a disc spring with a curved cross-section; and the pressurizing member (80) is configured to pressurize the guide (90) in a direction away from the moving piston (50). [7] Master brake cylinder of a vehicle brake with: a housing (10) having a port (12) configured to transmit hydraulic fluid; a motor (20) connected to the housing (10) and configured to provide rotational power; a screw (30) rotatably installed in the motor (20) and configured to rotate in response to the rotational power of the motor (20); a ball element (72) connected to a screw shaft (34) of the screw (30), the ball element (72) having a curved surface; and a support member (74) positioned on opposite sides of the ball member (72), the support member (74) rotatably supporting the ball member (72). [8] Master brake cylinder according to claim 7, wherein the support member (74) comprises: a first support member (76) positioned in the motor (20), the screw driving shaft (34) having a portion extending through the first support member (76); and a second support member (78) installed at a position facing the first support member (76). [9] A master cylinder according to claim 8, wherein the first and second support members (76, 78) are configured to rotate together with the screw driving shaft (34). [10] Master brake cylinder according to claim 8, further comprising: a thrust bearing part (110) installed at a position facing the second support member (78), the thrust bearing part (110) being configured to reduce friction associated with rotation of the second support member (78).

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