Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to Korean Patent Application Number 10-2009-0084300 filed Sept. 8, 2009, the entire contents of which application is incorporated herein for all purposes by this reference. 
     BACKGROUND OF THE INVENTION 
     1. Field 
     The present disclosure relates to an electronic wedge brake apparatus, in more detail, an electronic wedge brake apparatus for ensuring stable operability of an electronic wedge brake and improving durability. 
     2. Description of Related Art 
     In order to brake a front wheel of a vehicle at relatively low voltage of 12V, as shown in  FIGS. 1 and 2 , an electronic wedge brake apparatus using a self-servo effect has been proposed. 
     In this apparatus, with a fixed lower wedge  500  as a base, when a connecting spring  504  moves an upper wedge  506  along an inclined surface supported to a roller  508  by converting rotational force of a motor  502  into straight movement force, a brake disc  512  is pressed between an inner pad  510  and an outer pad  514  and rotational force of brake disc  512  is applied to upper wedge  506  to be further rotated, in which the rotational force further moves upper wedge  506  along the inclined surface supported to roller  508 , such that a self-servo effect pressing brake disc  512  is generated. 
     When braking in the front direction, the self-servo effect is achieved by moving upper wedge  506  to the right along the inclined surface in  FIG. 1 , and when braking in the rear direction, the self-servo effect is achieved by moving upper wedge  506  to the left along the inclined surface. In this configuration, connecting spring  504  necessarily bends for the braking in the rear direction. As such, the connecting spring  504  needs to be flexible like a leaf spring and also stiff enough to endure the pressing force in the axial direction of motor  502 . 
     However, as the stiffness of connecting spring  504  increases, the spring function becomes less effective. Also, if the spring is too flexible, the spring may not be stiff enough. Therefore, rear braking may be difficult or connecting spring  504  may be broken by buckling in front braking. 
     The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information constitutes prior art. 
     SUMMARY 
     Various aspects of the present invention are directed to provide an electronic wedge brake apparatus that makes it possible to increase safety of parts and ensure durability and smooth operability in braking, by increasing axial stiffness of a motor while keeping the spring effect of connecting springs driving an upper wedge with force from the motor. 
     An aspect of the present invention provides an electronic wedge brake apparatus, which includes a connector converting rotational force of a motor into straight movement force; connecting springs having an end connected to an upper wedge and the other end connected to the connector; and support members extending from the connector toward the upper wedge to support the opposite surface to the surface facing the upper wedge of the connecting springs. 
     The moving angle of the upper wedge may be larger than the mounting angle of the motor and the difference is set within 10°. 
     The moving angle of the upper wedge may be set to be the same as the mounting angle of the motor, and the upper wedge may be further provided with additional support members extending toward the connector to support the surfaces facing the upper wedge of the connecting springs. 
     In this configuration, the support members and the additional support members may be formed in a size to overlap each other, with the connecting springs therebetween. 
     The present invention makes it possible to increase safety of parts and ensure durability and smooth operability in braking by increasing axial stiffness of a motor while keeping the spring effect of connecting springs driving an upper wedge with force from the motor. 
     The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1 and 2  are views illustrating an electronic wedge brake apparatus. 
         FIG. 3  is a view showing an electronic wedge brake apparatus according to an embodiment of the present invention. 
         FIG. 4  is a view illustrating relationship in angle of the apparatus shown in  FIG. 3 . 
         FIG. 5  is a view illustrating another embodiment of the present invention. 
         FIG. 6  is a view illustrating the operation of the embodiment shown in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. 
     Referring to  FIG. 3 , an embodiment of the present invention includes a connector  3  converting rotational force of a motor  1  into straight movement force; connecting springs  7  having an end connected to an upper wedge  5  and the other end connected to connector  3 ; and support members  9  extending from connector  3  toward upper wedge  5 . The connecting springs  7  are bolted to the upper wedge  5 . 
     In the embodiment of  FIG. 3 , two connection springs  7  are provided. Each connecting spring  7  includes an elongated strip portion having two opposite surfaces. As illustrated, one of the surfaces faces the upper wedge  5 , and the other surface  13  faces away from the upper wedge  5 . One support member  9  is provided on the surface  13  to support the spring  7 . 
     According to embodiments, the moving angle of upper wedge  5  is larger than the mounting angle of motor  1  and the difference is set within 10°. In the foregoing configuration, the upper wedge  5  is configured to move along its inclined surface  15  whereas the connecting spring  7  moves along the axial direction of the motor  1 , which has to do with mounting angle of the motor  1 . As such, with reference to a reference plane or line, the moving angle of upper wedge  5  is the same as the angle of the inclined surface supported by a roller  11 ; and the mounting angle of motor  1  is the same as the angle of the straight movement by connector  3  and the moving angle of the spring  7 . 
     Referring to  FIG. 4 , “X” is the reference plane or line, the moving angle of upper wedge  5  relative to the brake disc is A, and the mounting angle of motor  1  is B. According to embodiments, the difference between A and B is within 10°. In this configuration, if the moving angle of upper wedge  5  is set too much larger than the mounting angle of motor  1 , the effect that connecting spring  7  is supported by support member  9 ; therefore, it is preferable that the difference is within 10°. 
     In the foregoing configuration, the motor  1  operates and the connecting springs  7  apply pressing force to upper wedge  5  at the angle B, which moves the upper wedge  5  at the angle A to perform front braking. Then, the connecting spring  7  may be forced in the opposite direction from the upper wedge  5 , which could cause buckling of the spring  7  but for the support members  9 . However, the support members  9  prevents such buckling from occurring. Thus, the connecting springs  7  can smoothly push upper wedge  5  with sufficient stiffness. 
     Further, as the possibility of buckling of connecting spring  7  is reduced, as described above, connecting springs  7  can be made of a more flexible material to flexibly bend in the rear braking, as described above, and smoothly pull upper wedge  5  by making connecting springs more flexible, and accordingly, it is possible to implement stable and smooth rear braking. 
       FIG. 5  is a view showing another embodiment of the present invention, the moving angle of upper wedge  5  is set to be the same as the mounting angle of motor  1 , and other than support members  9  provided to connector  3 , upper wedge  5  is further provided with additional support members  13  extending toward connector  3  to support the surfaces facing upper wedge  5  of connecting springs  7 . 
     In this embodiment, since support members  9  and additional support members  13  are formed in a size to overlap each other, with connecting springs  7  therebetween, there is no section at any one side over the entire length which is not supported by support members  9  or additional support members  13  in connecting spring  7 . 
     As described above, when the moving angle of upper wedge  5  is set to be the same as the mounting angle of motor  1 , connecting springs  7  may buckle toward upper wedge  5 . Accordingly, connecting springs  7  are supported by additional support members  13  to prevent the buckling. 
       FIG. 6  illustrates bending of a connecting spring  7  while being supported by the support members  9  and additional support members  13 . The support members  9  and additional support members  13  appropriately support connecting springs  7  to prevent them from buckling in the front braking, and connecting springs  7  smoothly deform and upper wedge  5  smoothly moves in the rear braking, such that it is possible to achieve smooth and stable operability in the rear braking. 
     The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.

Technology Category: 2