Electronic brake device

Abstract

An electronic brake device is disclosed. An electronic brake device according to one aspect of the present invention comprises a main housing, a motor including a stator and a rotor received in the main housing, a ball screw connected to the rotor and rotating, a pump piston disposed on the radial outer side of the ball screw and translated by the rotation of the ball screw, a pump housing having one side open to form hydraulic pressure by the pump piston, a first space receiving the pump piston, and a second space partitioned from the first space, and an MPS assembly received in the second space and transmitting rotation information of the motor to an ECU, wherein the MPS assembly comprises an MPS shaft having one end coupled to the ball screw and rotating by the motor, a magnet holder coupled to the other end of the MPS shaft, and a magnet fixed to the magnet holder, and a bush supporting the MPS shaft may be press-fitted and disposed on the inner surface of the second space.

Description

Technology Field

[0001] The present invention relates to a brake device provided in an electronic brake system, and more specifically, to an electronic brake device provided with an MPS assembly and a support structure. Background Technology

[0002] An electric brake system (EBS) is a system that electronically controls the operation of the brakes in a vehicle braking system. An example of an electronic brake device equipped in an electric brake system is an integrated dynamic brake (IDB), which integrates an electronic booster and an electronic control unit.

[0003] Such IDBs allow the brakes to be engaged through a simple switch operation by the driver, and furthermore, can automatically engage or disengage the brakes based on the judgment of an electronic control unit, such as an ECU (Engine Control Unit), which oversees overall control. Therefore, IDBs are essential for autonomous vehicles.

[0004] In order for the ECU to make control decisions, multiple sensors are required to detect the vehicle's status or external information; one of these is the MPS (Motor Position Sensor), which detects the motor's rotational speed for motor control.

[0005] Generally, the MPS transmits motor rotation information to the ECU via a magnet. The MPS is connected to the motor's rotation axis inside the housing and rotates together with it; to reduce friction between the MPS and the inner chamfer surface of the housing, a bearing such as a ball bearing may be provided.

[0006] At this time, as the MPS rotates, vibrations occur between the chamfer surface and the bearing and between the bearing and the MPS, which can damage the bearing and cause problems such as vibration and collision noise. The problem to be solved

[0007] The present invention is intended to solve the above-mentioned problems, and the objective of the present invention is to provide an electronic brake device with a long lifespan by reducing damage to components.

[0008] Another objective of the present invention is to provide an electronic brake device capable of reducing vibration and noise caused by bearing members.

[0009] Another objective of the present invention is to provide an electronic brake device capable of reducing the cost of parts.

[0010] The problems of the present invention are not limited to those mentioned above, and other unmentioned problems will be clearly understood by a person skilled in the art to which the present invention pertains from the description below. means of solving the problem

[0011] According to one aspect of the present invention, an electronic brake device is provided comprising: a main housing; a motor including a stator and a rotor received in the main housing; a ball screw connected to the rotor and rotating; a pump piston disposed on the radial outer side of the ball screw and translated by the rotation of the ball screw; a pump housing having one side open to form hydraulic pressure by the pump piston, a first space receiving the pump piston, and a second space partitioned from the first space; and an MPS assembly received in the second space and transmitting rotation information of the motor to an ECU; wherein the MPS assembly comprises an MPS shaft having one end coupled to the ball screw and rotating; a magnet holder coupled to the other end of the MPS shaft; and a magnet fixed to the magnet holder; and wherein a bush supporting the MPS shaft is press-fitted into the inner surface of the second space.

[0012] At this time, an electronic brake device is provided comprising: a body portion formed to extend in the axial direction and having one end coupled to the ball screw; a support portion formed to extend from the other end of the body portion and being supported in contact with the bush; and a protrusion formed to extend from the support portion and having the magnet holder coupled thereto.

[0013] At this time, the above body part is provided with an electronic brake device that is press-fitted and fixed into a receiving groove formed at one end of the ball screw.

[0014] At this time, the MPS assembly is provided with an electronic brake device having a tolerance ring further provided between the body part and the ball screw.

[0015] At this time, an electronic brake device is provided in which the cross-section of the body portion has a first diameter, and the cross-section of the support portion has a second diameter larger than the first diameter.

[0016] At this time, an electronic brake device is provided in which the cross-section of the support portion has a second diameter, and the cross-section of the protrusion has a third diameter smaller than the second diameter.

[0017] At this time, the support member is provided with an electronic brake device including a stopper surface that supports one end of the magnet holder.

[0018] At this time, an electronic brake device is provided in which a cylindrical side wall is provided in the axial direction inside the pump housing, a first space is formed on the outer side of the cylindrical side wall, and a second space is formed on the inner side.

[0019] At this time, an electronic brake device is provided in the second space of the pump housing, comprising: a through surface extending from one open side of the pump housing and having a cross-sectional diameter larger than the diameter of the bush; a press-fit surface extending from the through surface and having a cross-sectional diameter corresponding to the outer diameter of the bush; and a stepped surface extending radially inward from one side of the press-fit surface.

[0020] At this time, an electronic brake device is provided that further includes a spacing surface in the second space of the pump housing, which is formed to extend axially from the stepped surface and has a cross-section larger than the diameter of the magnet. Effects of the invention

[0021] According to the above configuration, an electronic brake device according to one aspect of the present invention provides an electronic brake device with a long lifespan by reducing damage to the member due to friction through the press-fitting of the bush.

[0022] In addition, the electronic brake device according to one aspect of the present invention can reduce the cost of parts by providing a support structure in the MPS assembly.

[0023] In addition, an electronic brake device according to one aspect of the present invention can reduce vibration and noise by providing a support structure to the MPS assembly and press-fitting a bush.

[0024] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention. Brief explanation of the drawing

[0025] FIG. 1 is a cross-sectional view illustrating an electronic brake device according to one embodiment of the present invention. FIG. 2 is an exploded view of an MPS assembly of an electronic brake device according to one embodiment of the present invention. FIG. 3 is a cross-sectional view of a configuration in which an MPS assembly and a ball screw of an electronic brake device are combined according to one embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view of an MPS assembly of an electronic brake device according to one embodiment of the present invention. FIG. 5 is a cross-sectional view of a pump housing of an electronic brake device according to one embodiment of the present invention. Figure 6 is an enlarged view of section X in Figure 5. Specific details for implementing the invention

[0026] Hereinafter, embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein. To clearly explain the present invention, parts unrelated to the description in the drawings have been omitted, and the same reference numerals have been used throughout the specification for identical or similar components.

[0027] The words and terms used in this specification and claims are not limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention in accordance with the principles by which the inventor defines terms and concepts to best describe his invention.

[0028] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings correspond to preferred embodiments of the present invention and do not represent all technical concepts of the present invention; thus, various equivalents and modifications that may replace such configurations may exist at the time of filing the present invention.

[0029] In this specification, terms such as “comprising” or “having” are intended to describe the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should not be understood as precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0030] The statement that a component is "in front," "rear," "upper," or "lower" of another component includes, unless there are special circumstances, not only being positioned "in front," "rear," "upper," or "lower" in direct contact with the other component, but also cases where another component is positioned in between. Furthermore, the statement that a component is "connected" to another component includes, unless there are special circumstances, not only being directly connected to each other, but also being indirectly connected to each other.

[0031] Hereinafter, an electronic brake device according to an embodiment of the present invention will be described with reference to the drawings.

[0032] FIG. 1 is a cross-sectional view illustrating an electronic brake device according to an embodiment of the present invention. Hereinafter, when viewed in FIG. 1, the direction a is defined as the axial direction and the direction r is defined as the radial direction, and the direction from the main housing (100) toward the pump housing (200) is defined as the forward direction and the direction from the pump housing (200) toward the main housing (100) is defined as the rear direction for explanation.

[0033] Referring to FIG. 1, an electronic brake device (1) according to one embodiment of the present invention includes a main housing (100), a motor (110), a ball screw (120), a pump piston (130), a pump housing (200), and an MPS assembly (300).

[0034] The main housing (100) has a receiving space formed inside, and the motor (110) and ball screw (120)-pump piston (130) assembly can be received inside the main housing (100).

[0035] The motor (110) is equipped with a stator (112) and a rotor (114), and a hollow shaft (150) is coupled to the rotor (114) so ​​that it can rotate.

[0036] The hollow shaft (150) may be rotatably positioned in the main housing (100). To reduce friction between the main housing (100) and the hollow shaft (150), a bearing may be provided between the main housing (100) and the hollow shaft (150). The hollow shaft (150) may be provided as a cylindrical member with an open front and a hollow may be formed inside.

[0037] The ball screw (120) is coupled to the inside of the hollow shaft (150) and can rotate together with the hollow shaft (150) as it rotates. At this time, the ball screw (120) can be coupled to a rotation axis provided on one side of the front of the main housing (100), and a bearing can likewise be provided between the main housing (100) and the ball screw (120).

[0038] When the hollow shaft (150) rotates, the ball screw (120) can be press-fitted and fixed to the hollow shaft (150) so that the ball screw (120) does not detach or slip.

[0039] The pump piston (130) is provided with a nut fastening portion having threads formed on the inside and can be coupled to a ball screw (120) having threads formed on the outside through the nut fastening portion.

[0040] In order for the pump piston (130) to move in translational motion in the axial direction (x) without rotating together with the ball screw (120) as it rotates, a guide tube (140) that limits the rotation of the pump piston (130) may be provided radially (r) outward from the pump piston (130).

[0041] The guide tube (140) can be fixed inside the main housing (100) so as not to rotate. At this time, the guide tube (140) can be placed in the space between the hollow shaft (150) and the ball screw (120).

[0042] Meanwhile, the pump housing (200) may be positioned in the axial direction (x) in front of the main housing (100). As shown in FIG. 1, the main housing (100) and the pump housing (200) may each be connected to one side and the other side of a block (b) in which a hollow is formed. However, the main housing (100) and the pump housing (200) may be connected to each other or formed as a single unit without being separated.

[0043] By opening the front of the main housing (100) and opening the rear of the pump housing (200), a passage connecting the interior of the main housing (100) and the interior of the pump housing (200) in the axial direction (x) can be formed. At this time, the pump piston (130) can move in translation through the connected passage.

[0044] The pump housing (200) may be provided with a first space (A1) in which hydraulic pressure is formed due to the advancement of the pump piston (130) and a second space (A2) in which the MPS assembly (300) is accommodated. The first space (A1) and the second space (A2) may be separated to prevent liquid from leaking from the first space (A1) to the second space (A2). The detailed structure of the pump housing (200) is illustrated in FIG. 5, and details regarding this will be described later.

[0045] At this time, a pump tube (230) may be provided within the first space (A1). The pump tube (230) may be inserted in the form of a tube so as to be in contact with the outer surface in the radial direction (r) of the first space (A1), and the inner surface of the pump tube (230) may be formed to correspond to the outer surface of the pump piston (130).

[0046] When the pump piston (130) advances, the pump piston (130) can be received inside the pump tube (230). At this time, hydraulic pressure is formed inside the pump housing (200), and a sealing member (S1) is provided between the pump tube (230) and the pump piston (130) to prevent leakage of liquid, and likewise, a sealing member (S2) can be provided between the pump piston (130) and the pump housing (200).

[0047] A pump housing (200) according to one embodiment of the present invention is fixed to a block (b) so as not to rotate, and a rotation prevention structure corresponding to the outer surface of the pump tube (230) may be provided on the inner surface of the pump housing (200) to prevent the pump tube (230) from rotating inside the pump housing (200). Likewise, a rotation prevention structure corresponding to the outer surface of the pump piston (130) may be provided on the inner surface of the pump tube (230) to prevent the pump piston (130) from rotating inside the pump tube (230). However, this may be omitted because the rotation of the pump piston (130) is restricted by the guide tube (140) described above.

[0048] Meanwhile, referring to FIG. 1, the MPS assembly (300) can rotate together with the ball screw (120) to transmit rotation information of the motor (110) to the ECU (2). The ECU (2) receives and stores the sensed information, processes the information, and controls the vehicle as a whole.

[0049] The MPS assembly (300) can be rotatably accommodated inside the second space (A2). At this time, the bush (220) can be positioned between the pump housing (200), which is fixed by being pressed into the outer surface of the second space (A2), and the rotating MPS assembly (300).

[0050] FIG. 2 is an exploded perspective view of an MPS assembly of an electronic brake device according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of a configuration in which an MPS assembly of an electronic brake device and a ball screw are combined according to an embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view of an MPS assembly of an electronic brake device according to an embodiment of the present invention.

[0051] Referring to FIG. 2, the MPS assembly (300) may be provided as an assembly of an MPS shaft (310), a magnet holder (320) coupled to the MPS shaft (310), and a magnet (330) coupled to the magnet holder (320).

[0052] Referring to FIG. 3, the MPS shaft (310) may be provided with a body portion (312) in which a rear end is coupled to a ball screw (120).

[0053] The body portion (312) can be coupled to a receiving groove (122) provided at the front end of the ball screw (120). At this time, by pressing the ball screw (120) into the receiving groove (122), rotation information of the motor (110) can be accurately transmitted to the ECU (2) without slipping or coming off the ball screw (120).

[0054] At this time, the MPS assembly (300) may further be provided with a tolerance ring (340) that is coupled to the radial (r) circumference of the body part (312) and positioned between the body part (312) and the receiving groove (122) of the ball screw (120).

[0055] As shown in FIG. 2, the tolerance ring (340) has a small protrusion formed on its outer diameter, which can fundamentally prevent the MPS shaft (310) from slipping or coming out of the receiving groove (122) of the ball screw (120).

[0056] If the MPS shaft (310) slips or becomes dislodged, a DTC error occurs in the motor (110), the motor (110) stops operating, switches to fallback mode, and is controlled by a manual brake system.

[0057] Meanwhile, referring to FIG. 4, the MPS shaft (310) may be provided with a support member (314) that is extended from the front of the body part (312) and rotatably supported in the pump housing (200).

[0058] At this time, the cross-section of the body part (312) has a first diameter (D1) and the cross-section of the support part (314) has a second diameter (D2), but the second diameter (D2) can be formed larger than the first diameter (D1).

[0059] At this time, the second diameter (D2) is formed to correspond to the inner diameter of the bush (220), so that the support member (314) can be supported in contact with the bush (220) pressed into the pump housing (200). Since the axial (x) support of the MPS shaft (310) is omitted and the support member (314) that supports the pump housing (200) in the radial (r) direction is provided, the bearing structure is simplified and thus costs can be reduced.

[0060] In addition, by not having rolling elements in a simplified bearing structure, vibration and noise caused by the bearing can be reduced.

[0061] In addition, the bush (220) is pressed into the pump housing (200), so that damage caused by shaking or friction between the inner surface of the pump housing (200) and the bush (220) can also be prevented, and the lifespan of the device can be extended.

[0062] Meanwhile, referring to FIG. 4, the MPS shaft (310) may be provided with a protrusion (316) that extends from the front of the support member (314) and is coupled with a magnet holder (320).

[0063] At this time, the cross-section of the protrusion (316) has a third diameter (D3), and the third diameter (D3) can be formed to be smaller than the second diameter (D2).

[0064] As the third diameter (D3) is formed to be smaller than the second diameter (D2), the support portion (314) may be provided with a stopper surface (318) formed by the step difference between the support portion (314) and the protrusion (316).

[0065] A protrusion (316) can be inserted and coupled to the magnet holder (320) until the rear end of the magnet holder (320) is seated on the stopper surface (318). As the stopper surface (318) is provided, the protrusion (316) may not be inserted beyond a certain depth. As shown in FIG. 4, if the protrusion length of the protrusion (316) is shorter than the axial length (a) into which the protrusion (316) can be inserted into the magnet holder (320), the protrusion (316) may be spaced apart from the magnet (330) coupled to the front side of the magnet holder (320) and may not come into contact with each other.

[0066] The magnet holder (320) may be provided as a cylindrical member with the front and rear open to be coupled with the protrusion (316) or the magnet (320), respectively. Accordingly, the radial diameters (r) of the front and rear of the magnet holder (320) may be formed differently. The rear inner diameter of the magnet holder (320) may be provided to correspond to the third diameter (d3) of the protrusion (316), and the front inner diameter may be provided to correspond to the diameter of the magnet (330).

[0067] The magnet (330) is coupled to the front of the magnet holder (320) and can be coupled by an adhesive or the like without being pressed in due to its weak brittleness.

[0068] As the magnet (330) rotates in the same way as the ball screw (120), it transmits rotation information of the motor (110) to the ECU (2).

[0069] FIG. 5 is a cross-sectional view of a pump housing of an electronic brake device according to one embodiment of the present invention. FIG. 6 is an enlarged view of section X in FIG. 5.

[0070] Meanwhile, referring to FIG. 5, the pump housing (200) may be provided with an axially cylindrical side wall (210) inside. The internal space of the pump housing (200) may be divided into a first space (A1) formed on the outside and a second space (A2) formed on the inside based on the cylindrical side wall (210).

[0071] As described above, hydraulic pressure can be formed in the first space (A1) according to the translational movement of the pump piston (130), and the MPS assembly (300) can be accommodated in the second space (A2).

[0072] Referring to FIG. 6, a through surface (212) may be provided on the inner side of the second space (A2), extending from one open side of the pump housing (200). The through surface (212) is a portion where the bush (220) is not pressed in, and the cross-section of the through surface (212) is formed larger than the diameter of the bush (220) so that it can be easily inserted up to the portion where the bush (220) is pressed in. However, for the sake of explanation, the diameter of the cross-section of the through surface (212) in FIG. 6 is shown somewhat exaggerated.

[0073] A bush (220) inserted into the second space (A2) can be pressed into a press-fit surface (214) formed extending from the front of the penetration surface (212). To press-fit and secure the bush (220), the cross-section of the press-fit surface (214) can be formed to correspond to the outer diameter of the bush (220). Accordingly, the diameter of the cross-section of the press-fit surface (214) can be formed to be smaller than that of the penetration surface (212).

[0074] A separation surface (218) may be extended and formed in front of the press-in surface (214). At this time, the diameter of the cross-section of the separation surface (218) is formed to be smaller than that of the press-in surface (214), thereby providing a step surface (216) between the press-in surface (214) and the separation surface (218).

[0075] By providing a stepped surface (216) on the front side of the press-fit surface (214), the bush (220) is supported axially (a) on the stepped surface (216), and its position can also be fixed.

[0076] A magnet (330) can be accommodated inside the separation surface (218). The diameter of the cross-section of the separation surface (218) can be formed to be larger than the outer diameter of the magnet holder (320) to which the magnet (330) is attached. By separating the separation surface (218) and the magnet (330) by a certain distance so as not to rub against each other, damage to the magnet (330), which has weak brittleness, due to friction can be prevented.

[0077] Although embodiments of the present invention have been described, the spirit of the present invention is not limited by the embodiments presented in this specification. Those skilled in the art who understand the spirit of the present invention may easily propose other embodiments within the scope of the same spirit by adding, changing, deleting, or adding components, and such are also to be considered to fall within the scope of the spirit of the present invention. Explanation of the symbols

[0078] 1: Electronic brake system 2: ECU 100: Main housing 110: Motor 120: Ball screw 130: Pump piston 140: Guide tube 150: Hollow shaft 200: Pump housing 210: Cylindrical sidewall 212: Penetration surface 214: Press-in surface 216 : Step surface 218 : Separation surface 220 : Bush 230 : Pump tube 300: MPS Assembly 310: MPS Shaft 312 : Body part 314 : Support part 316: Protrusion 318: Stopper surface 320 : Magnet holder 330 : Magnet 340 : Tolerance Ring A1 : First Space A2 : Second space

Claims

Claim 1 A main housing; a motor including a stator and a rotor housed in the main housing; a ball screw connected to the rotor and rotating; a pump piston disposed on the radial outer side of the ball screw and translational by the rotation of the ball screw; a pump housing having one side open to form hydraulic pressure by the pump piston, a first space housed in the pump piston, and a second space partitioned from the first space; and an MPS assembly housed in the second space and transmitting rotation information of the motor to an ECU; wherein the MPS assembly comprises: an MPS shaft having one end coupled to the ball screw and rotating; a magnet holder coupled to the other end of the MPS shaft; and a magnet fixed to the magnet holder; wherein a bushing supporting the MPS shaft is press-fitted into the inner surface of the second space, and the MPS shaft comprises: a body part extending in the axial direction and having one end coupled to the ball screw; and a support part extending from the other end of the body part and being supported in contact with the bushing. An electronic brake device comprising: a protrusion formed extending from the support portion and to which the magnet holder is coupled; wherein the cross-section of the body portion has a first diameter, and the cross-section of the support portion has a second diameter larger than the first diameter, and the second diameter is formed to correspond to the inner diameter of the bush, so that the MPS shaft rotates with the support portion in contact with the inner side of the bush, and the axial length of the support portion is formed to be smaller than the axial length of the bush. Claim 2 delete Claim 3 In claim 1, the body part is an electronic brake device that is press-fitted and fixed into a receiving groove formed at one end of the ball screw. Claim 4 In claim 3, the MPS assembly is an electronic brake device further comprising a tolerance ring between the body part and the ball screw. Claim 5 delete Claim 6 An electronic brake device according to claim 1, wherein the cross-section of the support portion has a second diameter, and the cross-section of the protrusion has a third diameter smaller than the second diameter. Claim 7 In claim 6, the support member is an electronic brake device comprising a stopper surface that supports one end of the magnet holder. Claim 8 An electronic brake device according to claim 1, wherein a cylindrical side wall is provided in the axial direction inside the pump housing, a first space is formed on the outer side of the cylindrical side wall, and a second space is formed on the inner side. Claim 9 An electronic brake device according to claim 8, wherein the second space of the pump housing comprises: a through surface extending from one open side of the pump housing and having a cross-sectional diameter larger than the diameter of the bush; a press-fit surface extending from the through surface and having a cross-sectional diameter corresponding to the outer diameter of the bush; and a stepped surface extending radially inward from one side of the press-fit surface. Claim 10 An electronic brake device according to claim 9, wherein the second space of the pump housing further comprises a spaced surface formed extending axially from the stepped surface, the cross-section of which is formed to be larger than the diameter of the magnet.

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