Abstract:
Disclosed is an electro-mechanical brake device, including: a disk; a pair of brake pads respectively disposed at both sides of the disk; a caliper respectively disposed inside the pair of brake pads; a brake module portion disposed at one side of the caliper; and a parking brake portion that is disposed to be perpendicular to a motor shaft of the brake module portion and is connected to a parking brake switch that is operated by a driver, and selectively controls a rotation of the motor shaft depending on the operation of the parking brake switch.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to and the benefit of Korean Patent Application No. 10-2015-0149528 filed in the Korean Intellectual Property Office on Oct. 27, 2015, the entire contents of which are incorporated herein by reference. 
       BACKGROUND 
       [0002]    The present invention relates to electro-mechanical brake device. More particularly, the present invention relates to an electro-mechanical brake device that enables it to sustain braking force in a power-off condition and can realize a parking brake in a power-off condition, that is, a parking mode. 
         [0003]    Generally, a brake device of a vehicle decelerates or stops a running vehicle, and further it is a braking device that enables the vehicle to be a parking condition. 
         [0004]    In general, there is a friction type of a brake device that transforms a moving energy to heat energy that is radiated to the atmosphere, wherein hydraulic pressure presses a pair of brake pads of both sides toward a brake disk that rotates with a wheel to make it perform a braking function. 
         [0005]    However, because the hydraulic type brake device uses a hydraulic pressure that presses brake pads toward a disk side, and therefore there is a drawback that a device configuration is complicated. 
         [0006]    That is to say, a conventional hydraulic type brake device needs a master cylinder that is operated by a booster that increases a pedal operation force to generated hydraulic pressure, and a hydraulic pressure line that is connected to a wheel cylinder as well as various complicated devices that controls and assists them, and thus there is a weakness that a predetermined limitation exists on improving reliability and stability of braking performance from the crowdedness and the hydraulic usage. 
         [0007]    Recently, due to the above problem, an electro-mechanical brake device (EMB) has been being mainly used to pursue a simplification of a device configuration that a conventional hydraulic type brake cannot have and can improve braking performance reliability and can realize a parking brake function. 
         [0008]    The said electro-mechanical brake device uses a motor as a power source, uses a gear speed reducer to amplify torque of the motor, and includes a structure that transforms a rotation movement to a line motion by using a ball screw, and so on. 
         [0009]    An electro parking brake (EPB) function is necessary for a parking brake of the electro-mechanical brake device (EMB), and a structure such as a solenoid and a ratchet is mainly used to realize the electro parking brake (EPB) function, due to a characteristic that using a power transmission device such as a ball-screw that power transmission efficiency is high and a friction coefficient is low to realize a braking. 
         [0010]    As a conventional art having the above structure, Patent Laid-Open Publication No. 10-2010-0030285 (2010 Mar. 18) is disclosed, in particularly, an electro-mechanical brake (EMB) presses a brake pad more than a press force that is necessary for a parking brake and a power of a solenoid is turned on or turned off, and an instrument of a ratchet shape is operated to maintain the braking force. 
         [0011]    However, the conventional art has to a size larger than a conventional hydraulic type caliper, because of this, the size and the weight of an electro-mechanical brake device becomes more larger, a solenoid, a latch and a gear are used together with a gear inside a gear reducer, thus there is a drawback that the structure configuration becomes complicated and the volume thereof becomes larger, and further there is a problem in an aspect of an assembly characteristics and vehicle packaging layout. 
         [0012]    Meanwhile, there is a push type and a pull type in a solenoid, and the type is divided by conditions that an operation direction is push direction and an operation direction is pull direction when a power is turned on. When a push type is applied to a parking brake mechanism, a solenoid power is continuously maintained during a parking brake condition to have a vehicle battery exhausted. 
         [0013]    On the contrary, when a pull type is applied to a parking brake mechanism, a solenoid power is continuously maintained during a running condition to have a parking brake condition. 
         [0014]    In this condition, when a solenoid is turned off by a condition that cannot be predicted such as short cut of a power line of a vehicle, the solenoid is moved to an opposite direction by a compression spring, and there is a danger that a ratchet or an operating portion can be damaged. 
         [0015]    The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
       SUMMARY 
       [0016]    The present invention has been made in an effort to provide an electro-mechanical brake device having a solenoid that is operated by a parking brake switch of a user and a parking brake portion having a toggle that is inserted or drawn out by one-touch method, when the solenoid is operated once (ON-OFF), a parking brake is performed, when the solenoid is operated once more (ON-OFF), a parking brake is released, and further when a parking brake is performed or released, it does not needs a continuous power so as to maintain one condition (parking brake condition or parking brake release condition), and a safe braking condition of a wheel is maintained when a power is not supplied. 
         [0017]    An electro-mechanical brake device according to the present invention may include a disk that is disposed at one side of a wheel of a vehicle and is rotated together with the wheel, a pair of brake pads that are respectively disposed at an outer side and an inner side of the disk and brakes the rotating disk through a friction force proportional to a rate that contacts the disk, a caliper that is respectively disposed inside the pair of brake pads, a brake module portion that is disposed at one side of the caliper, a motor shaft of a motor rotates depending on an operation of a brake pedal of a user, a torque of the motor shaft offers a contact rate that presses the brake pad to an inner surface of a disk, and a repulsive force that is generated when an inner side brake pad contacts the disk moves the caliper to an inner side direction of the disk, and offers a contact rate that has an outer side brake pad contact an outer side surface of the disk, and a parking brake portion that is disposed to be perpendicular to the motor shaft of the brake module portion and is connected to a parking brake switch that is operated by a driver, and selectively controls a rotation of the motor shaft depending on the operation of the parking brake switch. 
         [0018]    The brake module portion may include a gear box that is connected to a motor gear of the motor shaft through a gear, and reduces a rotation speed of a motor shaft torque to increase an output torque, and a press portion that offers a press pressure to push the brake pad to the inner side of the disk through a length extension that is generated while a rotation movement of a torque outputted from the gearbox is transformed to a line motion. 
         [0019]    The parking brake portion may include a solenoid that applies a physical force downwards through an electrical signal from a parking brake switch that is operated by a driver, and a toggle that is disposed at a lower portion of the solenoid, and pushes or draws a stopper that is engaged with a motor gear by using a physical force of the solenoid to selectively regulate a rotation of the motor shaft. 
         [0020]    The toggle may include a housing of which an upper surface is opened to have a cylindrical shape and a closed portion of a lower surface has an inlet-outlet hole that is formed on a center thereof, a plunger that is disposed in the housing, selectively moves up and down, and a stopper is formed downwards at a center of a lower surface and moves up and down through the inlet-outlet hole of the housing, a spring that is disposed between a lower surface of the housing and a lower surface of the plunger and offers an elastic force to the plunger such that the plunger is supported to be returned to an return position, a rotation motion element that is disposed on a plane surface of the plunger in the housing and a plurality of flanges are upwards formed on an upper surface to be radially disposed based on a center, an vertical movement guide that is fixed on an upper side of an inner portion of the housing, locking jaws that are slanted in one side direction are formed along a circumference direction of a lower end, and a guide groove that is cut upwards from an end of one of the locking jaws is formed to have a predetermined interval. 
         [0021]    An electro-mechanical brake device according to the present invention has following effects. 
         [0022]    First, a solenoid that is operated by a parking brake switch of a user and a parking brake portion having a toggle that is inserted or drawn out by one-touch method are disposed, when the solenoid is operated once (ON-OFF), a parking brake is performed, when the solenoid is operated once more (ON-OFF), a parking brake is released, and further when a parking brake is performed or released, and thus there is an effect that it does not need continuous power so as to maintain one condition (parking brake condition or parking brake release condition) and a safe braking condition of a wheel is maintained when a power is not supplied. 
         [0023]    Second, a parking brake portion is disposed at a side of a motor shaft of a motor and a rotation of a motor shaft and a motor gear that generates minimum torque before a torque is increased by a gear box is controlled, and thus there is an effect that minimum force can realize a parking brake. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]      FIG. 1  is an illustration showing an electro-mechanical brake device in according to a first embodiment of the present invention. 
           [0025]      FIG. 2  is an exploded perspective view showing a toggle of a parking brake portion according to a first embodiment of the present invention. 
           [0026]      FIG. 3  is an illustration showing an installation condition of a parking brake portion according to a first embodiment of the present invention. 
           [0027]      FIG. 4  is an illustration showing an implementation condition of a toggle of a parking brake portion according to a first embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0028]    Hereinafter, referring to the drawings, a desirable exemplary embodiment will be described in detail according to the present invention. 
         [0029]    Prior to making the description, the terms or words used in the specification and claims of the present invention are not interpreted using typical or dictionary limited meanings, and are constructed as meanings and concepts conforming to the technical spirit of the present invention based on the principle that the inventors can appropriately define the concepts of the terms to explain the present invention in the best manner. 
         [0030]    Therefore, configurations illustrated in the embodiments and the drawings described in the present specification are only the most preferred embodiment of the present invention and do not represent all of the technical spirit of the present invention, and thus it is to be understood that various equivalents and modified examples, which may replace the configurations, are possible when filing the present application. 
         [0031]    The present invention relates to an electro-mechanical brake device having a solenoid that is operated by a parking brake switch of a user and a parking brake portion having a toggle that is inserted or drawn out by one-touch method, when the solenoid is operated solitarily (ON-OFF), a parking brake is performed, when the solenoid is operated one more solitarily (ON-OFF), a parking brake is released, and further when a parking brake is performed or released, it does not needs a continuous power so as to maintain one condition (parking brake condition or parking brake release condition), and a safe braking condition of a wheel is maintained when a power is not supplied, and will be described with reference to the drawings as follows. 
         [0032]    Referring to  FIG. 1  to  FIG. 3 , an electro mechanical brake device according to the present invention includes a disk  100 , a pair of brake pads  201  and  202 , a caliper  300 , a brake module portion  400 , and a parking brake portion  500 , and firstly a disk  100  is disposed at one side of a wheel of a vehicle and rotates together with the wheel. 
         [0033]    In this condition, the disk  100  has a circular plate shape such as a conventional brake disk, and the detailed description of a structure and a function of the conventional brake disk will be omitted. 
         [0034]    And, brake pads  201  and  202  are disposed at an outer side and an inner side of the disk  100  and they brake the disk  100  through a friction force that is proportional to a contact force between the pair of brake pads  201  and  202  and the disk  100 . 
         [0035]    In this condition, a brake pad that is disposed at an outer surface of the disk  100 , which a brake module portion  400  and a parking brake portion  500  are not disposed, is called an outer brake pad  201  and a brake pad that is at an inner surface of the disk  100 , which the brake module portion  400  and the parking brake portion  500  are disposed, is called as an inner brake pad  202  in the present invention. 
         [0036]    It is desirable that the above brake pads  201  and  202  generate a friction force that is proportional to a surface contact force with the disk  100 , and the friction force that is generated thereby brakes the disk  100 . 
         [0037]    Also, the brake pads  201  and  202  are fixed by a caliper  300 , and a pair of brake pads  201  and  202  is disposed across the disk  100 . 
         [0038]    In this condition, a brake module portion  400  is disposed at one side of the caliper  300 , the brake module portion  400  rotates a motor shaft  411  of a motor  410  depending a brake pedal operation force of an user to press an inner brake pad  202  toward a disk  100  through a torque of a motor shaft  411 , a repulsive force that is formed by a contact force of the inner brake pad  202  and the disk  100  moves the caliper  300  toward an inner side direction of the disk  100 , and an outer brake pad  201  is pressed to an outer side of the disk  100  such that a wheel is braked. 
         [0039]    Here, a motor  410  is disposed in the brake module portion  400  and uses a power that is supplied from an outside to rotate a motor shaft  411 , a motor gear  412  is engaged with a motor shaft  411  of the motor  410 , a gear box  420  is gear-connected to the motor gear  412  to receive a torque of the motor shaft  411  through a motor gear  412 , and the gear box  420  outputs increased torque by reducing a rotation speed of a motor torque. 
         [0040]    And, a torque that is outputted from an output side of the gearbox  420  is outputted to a press portion  430 , and the press portion  430  presses the inner brake pad  202  toward the disk  100  through a length increment that is formed by transforming a rotation movement to a straight movement. 
         [0041]    In more detail, the press portion  430  includes a ball screw shaft  431 , a ball screw nut  433 , a nut cap  434 , and a head  432 , a screw groove that a steel ball can moved in an axial direction is formed on an external circumferential surface of the ball screw shaft  431 , one side thereof is connected to an output side of the gear box  420  to be rotated in one side direction or the other side direction by a torque outputted from an output side of the gear box  420 . 
         [0042]    In this condition, a ball screw nut  433  having steel balls is disposed on an external circumference of the ball screw shaft  431 , when the ball screw shaft  431  is rotated in one direction or the other direction, the nut  433  moves forward or reward along an axial direction of the ball screw shaft  431  to transform a rotation movement to a straight movement. 
         [0043]    And, a nut cap  434  is screw-engaged on an external circumference of the ball screw nut  433 , a screw that is formed on external circumferential surface of the ball screw nut  433  and a screw that is formed on an interior circumference of the nut cap  434  have an opposite direction to a screw of the ball screw shaft  431 , for example, a screw of the ball screw shaft  431  has a right-handed, and a screw of an external circumferential surface of the ball screw nut  433  and a screw of an interior circumference of the nut cap  434  has a left-handed. 
         [0044]    In the above configuration, if the ball screw shaft  431  is rotated by one direction, the ball screw nut  433  moves backward along an axial direction (to a gear box side), the nut cap  434  moves forward along an axial direction (to a disk side), an engagement length the ball screw nut  433  and the nut cap  434  is increased, a head  432  that is formed at an end of the nut cap  434  presses an inner brake pad  202  to a disk  100 , a repulsive force is generated in an opposite direction to a movement direction of the nut cap  434  due to an engagement length increment of the ball screw nut  433  and the nut cap  434 , the caliper  300  is moved to a gear box  420  by the repulsive force, and an outer brake pad  201  is pressed to a disk  100 . 
         [0045]    And, if the ball screw shaft  431  is rotated in the other direction, the ball screw nut  433  moves forward along an axial direction (to a disk side), the nut cap  434  moves back along an axial direction (to a gear box side), an engagement length of the ball screw nut  433  and the nut cap  434  is decreased, and the pressure that is applied to brake pads  201  and  202  is eliminated to release the braking of the disk  100 . 
         [0046]    Here, it is desirable the nut cap  434  is fixed to one side of the caliper  300  such that it does not perform a rotation movement but perform a straight movement. 
         [0047]    Accordingly, when an engagement length of the ball screw nut  433  and the nut cap  434  is extended or contracted, the disk is braked or released. 
         [0048]    Thus, in accordance with a brake pedal operation of an user, if a motor shaft  411  of a motor  410  is rotated, a torque of the motor shaft  411  is transmitted to a gear box  429  through a motor gear  412 , and the gearbox  420  reduces a rotation speed transmitted from the motor gear  412  to output the increased torque to a press portion  430  through an output side. 
         [0049]    In this moment, a ball screw shaft  431  of the press portion  430  is rotated one direction or the other direction by a torque outputted from the gear box  420 , a head  432  that is formed at one side end of the nut cap  434  is moved to an inner side of a disk  100 , the head  432  presses an inner brake pad  202  to the disk  100 , the inner brake pad  202  contacts an inner surface of the disk  100 , a repulsive force that is generated by an engagement length increment of the ball screw nut  433  and the nut cap  434  moves a caliper  300  to an inner side direction, an outer brake pad  201  contact an outer surface of a disk  100 , and the disk  100  is braked. 
         [0050]    Also, a parking brake portion  500  is disposed perpendicularly to a motor shaft  411  of the brake module portion  400 , and is connected to a parking brake switch that is operated by a driver, when the parking brake switch is operated by a driver, a rotation of the motor shaft  411  of the motor  410  is controlled, and the parking brake portion  500  has a one-touch toggle method. 
         [0051]    In more detail for the parking brake portion  500 , a solenoid  510  is disposed to apply physical force to a lower direction of a parking brake switch that is operated by a driver, a toggle  520  is disposed at a lower portion of the solenoid  510 , and when the solenoid  510  applies physical force, a stopper  523  that is engaged with a motor gear  412  of the motor shaft  411  is drawn out to control a rotation of the motor shaft  411 . 
         [0052]    In this moment, the solenoid  510  is electrically connected to a parking brake switch that is operated by a driver to be operated by an electric signal, but it is not limited thereto, the solenoid can be connected thereto to be operated by a physical signal. 
         [0053]    Accordingly, the parking brake portion  500  is disposed at a motor shaft  411  of a motor  410 , and a parking brake is realized by controlling a rotation of a motor shaft  411  and a motor gear  412  that generates minimum torque before a torque is increased by a gear box  420 . 
         [0054]    In this condition, the solenoid  510  that is operated by an electric signal, a physical force that is applied to a toggle  520  is generated at one time such as cam movement, if the solenoid  510  applies physical force once, the toggle  520  draws out a stopper  523  to be engaged with a motor gear  412  and a rotation of the motor shaft  411  and the motor gear  412  is limited, and if the solenoid  510  again applies physic force, the toggle  520  inserts or receives a stopper  523  to separate the stopper  523  from the motor gear  412 , and simultaneously release the rotation limitation of the motor shaft  411  and the motor gear  412  such that the parking brake portion  500  is realized by one-touch method. 
         [0055]    A housing  521  of which the upper is opened is disposed at the toggle  520 , a lower surface of the housing  521  has a closed surface unlike an upper surface, and an inlet/outlet hole is formed at a center of a lower surface such that the toggle  520  performs the above function. 
         [0056]    And, a plunger  522  is disposed at an inner portion of the housing  521 , the plunger  522  has a circular plate type and moves up and down direction in the housing  521 , and a wedge type stopper  523  is downwardly formed at a center of a lower surface of the circular plate type plunger  522  to be drawn out or inserted through the inlet/outlet hole of the housing  521 . 
         [0057]    Accordingly, when the plunger  522  moves up or down in the housing  521 , a stopper  523  is protruded or inserted through the inlet/outlet hole of the housing  521 . 
         [0058]    And, a spring  524  is disposed between a lower surface of the housing  521  and a lower surface of a plunger  522 , an elastic force is applied to the plunger  522 , a rotation motion element  525  is disposed on a plane surface of the plunger  522  in the housing  521 , and a plurality of flanges  526  that is extended upward are disposed in a radial direction on an upper surface of the rotation motion element  525 . 
         [0059]    It is desirable that the spring  524  has a coil spring type, and a slant surface that is slant to one side is formed at each upper end of a plurality of flanges  526  that is disposed in a radial direction at an upper surface of the rotation motion element  524 . 
         [0060]    Also, an up/down movement guide  527  is fixed inside an upper side of the housing  521 , the up/down movement guide  527  has a locking jaws  528  that is slant corresponding to a slant surface that is formed along a circumference of a lower end of the flange  526 , and a guide groove  529  that is cut out from an end to an upper side of a locking jaw is formed at one locking jaw  528  of the above locking jaws  528 . 
         [0061]    A vertical motion element  530  is disposed at an upper portion of the rotation motion element  525  in the housing  521  to move up and down direction in the housing  521 , a crown  30  such as a gear corresponding to an upper end of flanges  526  of the rotation motion element  525  is formed at an lower end of the vertical motion element  530 , and a plurality of protrusion  531  is formed to sequentially correspond to a locking jaw  528  and a guide groove  529  while it moves along a lower end of the vertical motion guide  527  along an external circumferential surface. 
         [0062]    An exemplary embodiment of a toggle  520  according to the above configuration will be described hereinafter, (d) to (d) of  FIG. 4  shows a condition that a stopper of a parking brake portion is engaged with a motor gear, (d) to (f) of  FIG. 4  shows a condition that a stopper of a parking brake portion is separated from a motor gear, if a press force (solitary physical force) that is generated by a solenoid  510  is applied to a vertical motion element  530  that is disposed at an uppermost of a toggle  520 , the vertical motion element  530  moves in a straight line along an vertical motion guide  527  to sequentially press the rotation motion element  525  and the plunger  522  downward. 
         [0063]    And, a repulsive force is formed between a vertical motion element  530  and a rotation motion element  525  by a spring  524  between a housing  521  and a plunger  522 , a protrusion  532  of the vertical motion element  530  separated from a lower end of the vertical motion guide  527 , slant surfaces of a rotation motion element  525  and a vertical motion element  530  face from each other, and a rotation motion element  525  rotates along a slant surface, if a press force of the vertical motion element  530  is eliminated, a protrusion  532  of a rotation motion element  525  is positioned in a locking jaw  528  or a guide groove  529  that are sequentially formed on the vertical motion guide  527 . 
         [0064]    Accordingly, a parking brake is realized by a following step, after a disk  100  is braked by a brake module portion  400 , a parking brake portion  500  is operated, a rotation of a motor shaft  411  and a motor gear  412  of a brake module portion  400  is controlled, a braking condition is maintained, and thus it does not a separate power to maintain a braking and a minimum energy is used to realize a parking brake, because a rotation is controlled at an initial torque generation point before a torque is increased. 
         [0065]    While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.