Abstract:
A vehicle disc brake device for preventing snow, ice, and mud from adhering to a caliper includes a body-anchoring part provided in a cylinder of a caliper, the body-anchoring part for securing a wire guide used to support a brake wire. The body-anchoring part has a first surface oriented along the longitudinal direction of the brake wire, and a second surface located on the side opposite the first surface. A wire-guide-anchoring part is secured to the second surface. The first surface is a flat, inclined surface.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a vehicle disc brake device having a brake wire for a parking brake. 
     BACKGROUND OF THE INVENTION 
     Disc brake devices apply hydraulic pressure to clamp a disc rotor that rotates with the wheels, and thereby applies a braking action on the wheels. Disc brake devices used on rear wheels are generally provided with a parking brake device, and a wire guide of the parking brake device is bolted securely in place (e.g., Japanese Utility Model Application Laid-Open Publication No. H06-28376). 
     There are known in the art parking brake devices such as the device disclosed in Japanese Patent Application Laid-Open No. 2003-294068, in which a wire guide for supporting a brake wire of the device is integrally formed with a caliper body. 
     However, a drawback with the prior art is that in cold weather conditions, snow and ice tend to adhere to the wire guide after having been kicked up from the road surface. Once a large enough amount thereof has accumulated, the snow and ice may then start to adhere to the wire, making the parking brake harder to operate. 
     In particular, snow, ice and mud may adhere to the bolt head and the outer surface of the caliper near the bolt in the disc brake device disclosed in the H06-28376 publication, increasing the likelihood that it will then adhere to the wire guide and impair the function of the brake wire. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a vehicle disc brake device that can prevent snow, ice, and mud from adhering to the surface of the caliper facing the brake wire. 
     According to the present invention, there is provided a vehicle disc brake device which comprises: a pivoting lever secured to a rotary shaft for operating a mechanical brake mechanism to restrict rotation of a wheel of a vehicle, the rotary shaft being supported in a caliper having a cylinder; a brake wire attached to the pivoting lever; a body-anchoring part protruding, upon attachment of the disc brake device to the vehicle, from a side of a downwardly-directed bottom of the caliper cylinder outwardly in a radial direction of the cylinder; and a wire guide secured to the body-anchoring part, for supporting the brake wire, wherein the wire guide has a wire-guide-anchoring part secured to the body-anchoring part and a wire-supporting part connected to the wire-guide-anchoring part, for supporting the brake wire, the body-anchoring part has a first surface positioned to face a length of the brake wire and a second surface positioned on a reverse side of the first surface, at least the first surface comprises a flat surface and is inclined toward the second surface relative a line passing over a radial center of the cylinder and a center of a proximal end of the body-anchoring part, and the wire-guide-anchoring part is secured to the second surface. 
     With this arrangement, the region between the outer surface of the caliper and the protruding body-anchoring part can be made substantially flat, and devoid of any narrow-angled regions. Moreover, since the outer surface of the caliper facing the direction of the brake wire will not have a step provided for the wire guide, the substantially flat shape will not be compromised. As a result, snow, ice, and mud can be prevented from adhering to the caliper surface facing the brake wire. 
     Preferably, the wire-guide-anchoring part and the body-anchoring part are secured together via a bolt that is threadedly engaged therewith while the bolt has a distal end facing a same direction as the first surface. Therefore, the head part of the bolt is not disposed facing the brake wire; no large step is formed on the first surface by the protruding head part of the bolt; and snow, ice, and mud kicked up by the wheels can be reliably prevented from adhering to the first surface. 
     Desirably, the bolt has a length selected such that the distal end protrudes from the flat surface of the first surface of the body-anchoring part. Thus, even when snow, ice, or mud passes over the first surface, it will move to the distal end of the bolt from the flat first surface and readily fall off. As a result, any snow, ice, or mud adhering to the flat surface can be readily removed. 
     In a preferred form, a length of protrusion of the distal end of the bolt is set to be smaller than a length of protrusion of a head part of the bolt. 
     A wide angle is preferably formed by the first surface of the body-anchoring part and a substantially horizontal outer peripheral surface of the cylinder bottom. Consequently, the area between the outer peripheral surface of the cylinder bottom and the first surface is not recessed but substantially flat, and snow, ice or mud will not readily accumulate in that area. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A preferred embodiment of the present invention will be described in detail below, by way of example only, with reference to the accompanying drawings, in which: 
         FIG. 1  is a rear view showing a vehicle disc brake device according to an embodiment of the present invention; 
         FIG. 2  is a sectional view taken along line  2 - 2  of  FIG. 1 ; 
         FIG. 3  is a perspective view showing the disc-brake device of  FIG. 1 ; 
         FIG. 4  is a cross-sectional view taken along line  4 - 4  of  FIG. 1 ; and 
         FIG. 5  is a perspective view showing a vicinity of a body-anchoring part of the disc brake device of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As shown in  FIGS. 1 and 2 , the vehicle disc brake device  11  is used on a rear wheel  12  of a vehicle, and presses both surfaces of a disc rotor  13  that rotates with the rear wheel  12 , whereby a braking action is applied to the rear wheel  12 . The disc brake device  11  has a parking brake device  14 , which is a mechanical brake mechanism. When the vehicle is moving forward, the disc rotor  13  will rotate in the direction shown by arrow a 1 . 
     As shown in  FIGS. 1 through 3 , the disc brake device  11  has a connecting member  22  that is connected to a rear suspension device  21 ; a caliper  23  that is attached to the connecting member  22 ; a hydraulic brake mechanism  25  that is provided to the caliper  23 ; and pads  27  for applying pressure to both surfaces of the disc rotor  13  An operating fluid is supplied to the hydraulic brake mechanism  25  by a hydraulic hose  28 . 
     The hydraulic brake mechanism  25  and the parking brake device  14  shown in  FIGS. 1 through 5  will now be described. 
     The hydraulic brake mechanism  25  has a cylinder  31  associated with the caliper  23 , and a piston  32  slidably fitted within the cylinder  31 , as shown in  FIGS. 3 and 4 . 
     The cylinder  31  opens toward the disc rotor  13  (opening  33 ), and has its length extending in the direction of the axial line Cr of the disc rotor  13  (the direction indicated by arrow a 2 ). A shaft-insertion hole  36  is formed in a rear end part  35  facing the opening  33 . A pad  27  is disposed on the piston  32 . 
     The parking brake device  14  is provided with a parking brake cable  38  that is connected to a parking brake lever (not shown) disposed inside a vehicle compartment (not shown); a wire guide  42  for supporting the parking brake cable  38  at a distal end (first end)  41  thereof; and a body-anchoring part  46  formed on an outer peripheral surface  45  of the cylinder  31 , there being a anchoring part (second end)  43  of the wire guide  42  fastened to the body-anchoring part  46 . In a broad sense, the outer peripheral surface  45  of the cylinder  31  is part of the outer surface  47  of the caliper  23 . 
     As shown in  FIG. 3 , the parking brake device  14  is provided with a pivoting lever  52  to which a connecting end  51  of the parking brake cable  38  is hooked; a rotating cam shaft  55  ( FIG. 4 ) integrally fitted to the pivoting lever  52  and secured in place by a nut  54 ; a return spring  56  fitted on the outer surface of the nut  54 ; and a push-rod mechanism  57  ( FIG. 4 ) that is in contact with the cam shaft  55 . The piston  32  is connected to the push-rod mechanism  57 . 
     As shown in  FIG. 4 , the cam shaft  55  is attached, via a bearing  58 , in the shaft-insertion hole  36  formed in the cylinder  31 . When the cam shaft  55  is made to rotate by the pulling force of the parking brake cable  38  shown in  FIG. 3  (in the direction indicated by arrow a 3 ), the piston  32  advances toward the disc rotor  13  and presses the pad  27  against it. 
     A fulcrum end part  62  of the pivoting lever  52  is securely fitted onto an end part  61  ( FIG. 3 ) of the cam shaft  55 , the end part  61  protruding from the shaft-insertion hole  36  (by a length corresponding to the height of the nut  54 ). 
     As illustrated in  FIGS. 1 through 5 , the pivoting lever  52  is anchored to a rotary shaft (cam shaft  55 ) that operates a mechanical brake mechanism (parking brake device  14 ) for restricting the rotation of wheels  71  (in the direction of arrow a 4 ). A brake wire (parking brake cable  38 ) is attached to the pivoting lever  52 . The rotary shaft (cam shaft  55 ) is supported by the cylinder  31  of the caliper body (caliper  23 ). The body-anchoring part  46  protrudes outwardly in the radial direction of the cylinder  31  (in the direction of arrow a 5  of  FIG. 2 ) from a side of the cylinder bottom  72  that faces the underside of the cylinder  31 . The brake wire (parking brake cable  38 ) is supported by the wire guide  42  that is secured to the body-anchoring part  46  and turns the pivoting lever  52  (in the direction of arrow a 6  of  FIG. 4 ). 
     As shown in  FIG. 2 , the wire guide  42  has a wire-guide-anchoring part  43  for securing the wire guide to the body-anchoring part  46 , and a wire-supporting part  73  which is connected to the wire-guide-anchoring part  43  and faces the pivoting lever  52 . The body-anchoring part  46  has a first surface (bottom surface)  76  that faces the parking brake cable  38 , and a second surface (upper surface)  77  disposed on the other side of the first surface  76  and lying on of the wire-guide-anchoring part  43 . At least the first surface  76  is a flat surface. The first surface  76  is inclined toward the second surface  77  side with respect to line B (at angle a). Line B connects the radial center S 1  of the cylinder  31  as viewed in cross-section and the center S 2  of a proximal end  81  of the body-anchoring part  46 . The wire-supporting part  73  is part of the first end  41  of the wire guide  42 . 
     A bolt  83  is used to screw the wire-guide-anchoring part  43  to the body-anchoring part  46 , the distal end  84  of the bolt  83  being parallel to the first surface  76 . 
     The length L ( FIG. 2 ) of the bolt  83  is set so that the distal end  84  thereof protrudes from the flat surface of the first surface  76  of the body-anchoring part  46 . The length to which the distal end  84  of the bolt  83  protrudes is set so as to be less than the length to which the head part  85  protrudes (height of the head). 
     Next, an operation the disc brake device  11  will be described. 
     As shown in  FIG. 2 , snow S lying on a road surface in cold weather conditions, is kicked up by the rotation of the wheels (in the direction of arrow a 1 ) and by air currents formed underneath the vehicle as it moves. The snow S scatters onto the disc brake device  11  used for the rear wheels. Even if the snow S might adhere to the wire guide  42  and the body-anchoring part  46  as shown by arrow b 1 , it will readily fall off the flat surface of the first surface  76  of the body-anchoring part  46 . As a result, snow, ice, and mud kicked up by the wheels can be prevented from adhering between the body-anchoring part  46  and the parking brake cable  38 . 
     In the disc brake device  11  according to the present embodiment, the distal end  84  of the bolt  83  is parallel to the first surface  76  of the body-anchoring part  46 . Therefore, a large step caused by the protruding head part  85  of the bolt  83  is not formed on the first surface  76 ; and snow, ice, and mud thrown up by the wheels can be more reliably prevented from adhering to the disc brake device. 
     Since the distal end  84  of the bolt  83  protrudes from the flat inclined surface of the first surface of the body-anchoring part  46 , snow, ice, and mud will pass onto the distal end  84  of the bolt  83  from the flat part of the first surface  76  and readily fall in the direction indicated by arrow b 2 . Even if snow, ice, or mud does adhere to the flat surface, it can be readily removed. Furthermore, melted snow and ice will accumulate on the distal end  84  and fall off in drops without spreading over the flat surface of the first surface  76 , whereby it can be removed. 
     As shown in  FIG. 2 , the body-anchoring part  46  is inclined toward the second surface  77  side (angle α) with respect to the line B connecting the radial center S 1  of the cylinder  31  and the center S 2  (relative to the thickness direction) of the proximal end  81  of the body-anchoring part  46 . Accordingly, there is no narrow angle formed between the first surface  76  and the (substantially horizontal) outer peripheral surface  45  of the downward-facing cylinder bottom  72  of the cylinder  31  associated with the caliper  23 . Specifically, a boundary region  87  formed between these two surfaces is substantially flat and devoid of any large recesses, which is beneficial in that and snow, ice, and mud will not readily accumulate in the region  87 . 
     An example of the disc brake device of the present invention was given in an embodiment in which the device was used in a rear wheel, but the disc brake device can also be used in a front wheel. 
     The disc brake device of the present embodiment illustrated an example in which the disc brake device is provided with a hydraulic brake mechanism and a mechanical brake mechanism, but the device may be provided solely with a mechanical brake mechanism. 
     The disc brake device of the present embodiment is not limited to use in automobiles; it may also be applied to a variety of vehicles including, e.g., two-wheeled automotive vehicles and all-terrain vehicles (ATVs). 
     Obviously, various minor changes and modifications of the present invention are possible in light of the above teaching. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.