Patent Publication Number: US-11661135-B2

Title: Hydraulic pressure control unit, braking system, and bicycle

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a hydraulic pressure control unit of a braking system capable of executing an antilock braking control, a braking system including the hydraulic pressure control unit, and a bicycle including the braking system. 
     There is a conventional bicycle which includes a braking system capable of executing an antilock braking control. The braking system includes a hydraulic pressure control unit for changing the hydraulic pressure of brake fluid in a wheel braking part. The hydraulic pressure control unit has a base body in which an internal flow path is formed, and an inlet valve and an outlet valve which are attached to the base body and opened and closed when the antilock braking control is executed (e.g., see WO 2017/115171). 
     In the conventional bicycle, first, one end of an adapter is joined to a bicycle and a hydraulic pressure control unit is joined to the other end of the adapter, so that the hydraulic pressure control unit is joined to the bicycle. In such a case, due to the intervention of the adapter, the protruding amount of the hydraulic pressure control unit from the bicycle increases. Further, it may be difficult to connect the hydraulic pressure control unit to the bicycle while securing protection and design. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in view of the above-described problem, and an object thereof is to provide a hydraulic pressure control unit where a degree of freedom in connection to a bicycle is improved. Further, an object of the present invention is to provide a braking system including such a hydraulic pressure control unit. Further, an object of the present invention is to provide a bicycle including such a braking system. 
     The present invention is directed to a hydraulic pressure control unit of a braking system mounted on a bicycle and capable of executing an antilock braking control. The hydraulic pressure control unit includes a base body in which an internal flow path through which brake liquid flows is formed; an inlet valve which is attached to the base body, is opened and closed when the antilock braking control is executed, and is driven by a first coil; an outlet valve which is attached to the base body, is opened and closed when the antilock braking control is executed, and is driven by a second coil; a coil casing in which the first coil and the second coil are accommodated; and a fixing member. The fixing member is joined to the coil casing in a state where a columnar space with both ends opened is formed between a partial region of an outer surface of the coil casing and a partial region of an outer surface of the fixing member, or the fixing member is joined to the base body in a state where a columnar space with both ends opened is formed between a partial region of an outer surface of the base body and the partial region of the outer surface of the fixing member. 
     The present invention is also directed to a braking system including the hydraulic pressure control unit defined above. 
     The present invention is also directed to a bicycle including the braking system defined above. 
     In the hydraulic pressure control unit, the braking system, and the bicycle according to the present invention, the fixing member is joined to the coil casing in a state where a columnar space with both ends opened is formed between a partial region of an outer surface of the coil casing and a partial region of an outer surface of the fixing member, or the fixing member is joined to the base body in a state where a columnar space with both ends opened is formed between a partial region of an outer surface of the base body and the partial region of the outer surface of the fixing member. That is, in a state where the fixing member is joined to the coil casing or the base body, the columnar space with both ends opened is formed between a partial region of an outer surface of the coil casing or the base body and a partial region of an outer surface of the fixing member. The hydraulic pressure control unit is joined to the bicycle by using the columnar space. Therefore, as compared with the case where one end of an adapter is joined to a bicycle and a hydraulic pressure control unit is joined to the other end of the adapter, it is possible to suppress the hydraulic pressure control unit from protruding from the bicycle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a view showing a schematic configuration of a bicycle on which a braking system according to an embodiment of the present invention is mounted; 
         FIG.  2    is a view showing a schematic configuration of the braking system according to the embodiment of the present invention; 
         FIG.  3    is a perspective view of a hydraulic pressure control unit of the braking system according to the embodiment of the present invention; 
         FIG.  4    is a front view of the hydraulic pressure control unit of the braking system according to the embodiment of the present invention in a state where a fifth surface of a base body is viewed from the front; 
         FIG.  5    is a perspective view of the base body of the hydraulic pressure control unit of the braking system according to the embodiment of the present invention; 
         FIG.  6    is a perspective view of the base body of the hydraulic pressure control unit of the braking system according to the embodiment of the present invention; 
         FIG.  7    is a perspective view showing a connection state of the hydraulic pressure control unit of the braking system according to the embodiment of the present invention to the bicycle; and 
         FIG.  8    is a perspective view showing a modification of the hydraulic pressure control unit of the braking system according to the embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, a hydraulic pressure control unit, a braking system, and a bicycle according to the present invention will be described with reference to the drawings. 
     Meanwhile, in the following, the case where a braking system according to the present invention is mounted on a normal bicycle is described. However, the braking system according to the present invention may be mounted on another bicycle such as an electric-assisted bicycle or an electric bicycle. Meanwhile, a bicycle means a general vehicle in which a propulsion force can be generated by a user providing a pedal effort to a pedal. Further, the normal bicycle means a bicycle in which a propulsion force is obtained by only a pedal effort provided by a user. Further, the electric-assisted bicycle means a bicycle which has a function of assisting a pedal effort provided by a user with an electric motor. Further, the electric bicycle means a bicycle which has a function of obtaining a propulsion force by only an electric motor. 
     Further, the configuration, operation, and the like described below are examples, and a hydraulic pressure control unit, a braking system, and a bicycle according to the present invention are not limited to the case of such configuration, operation, and the like. For example, in the following, the case where the hydraulic pressure control unit according to the present invention is a pump-less type is described. However, the hydraulic pressure control unit according to the present invention may have a pump to assist the flow of brake fluid. Further, in the following, the case where a braking system according to the present invention executes an antilock braking control for only a braking force generated in a front wheel is described. However, the braking system according to the present invention may execute an antilock braking control for only a braking force generated in a rear wheel or may execute an antilock braking control for both a braking force generated in a front wheel and a braking force generated in a rear wheel. 
     Further, in each of the drawings, the same or similar members or parts are denoted by the same reference numerals or the reference numerals thereof are omitted. Further, for the detailed structure, illustration is simplified or omitted as appropriate. Further, duplicated explanations are simplified or omitted as appropriate. 
     Embodiments 
     Hereinafter, a braking system according to an embodiment will be described. 
     &lt;Mounting of Braking System onto Bicycle&gt; 
     Mounting of a braking system according to an embodiment onto a bicycle will be described. 
       FIG.  1    is a view showing a schematic configuration of a bicycle on which a braking system according to an embodiment of the present invention is mounted. Meanwhile, although  FIG.  1    shows a case where a bicycle  200  is a two-wheeled vehicle, the bicycle  200  may be another bicycle such as a three-wheeled vehicle. 
     As shown in  FIG.  1   , the bicycle  200  includes a frame  1 , a turning part  10 , a saddle  21 , a pedal  22 , a rear wheel  23 , and a rear wheel braking part  24 . 
     For example, the frame  1  has a head tube  1 A pivotally supporting a steering column  11  of the turning part  10 , a top tube  1 B and a down tube  1 C joined to the head tube  1 A, a seat tube  1 D joined to the top tube  1 B and the down tube  1 C and holding the saddle  21 , and a stay  1 E joined to upper and lower ends of the seat tube  1 D and holding the rear wheel  23  and the rear wheel braking part  24 . 
     The turning part  10  includes the steering column  11 , a handle stem  12  held by the steering column  11 , a handle bar  13  held by the handle stem  12 , a braking operation part  14  attached to the handle bar  13 , a front fork  15  joined to the steering column  11 , a front wheel  16  rotatably held by the front fork  15 , and a front wheel braking part  17 . The front fork  15  is a member that has one end joined to the steering column  11  and the other end extending on both sides of the front wheel  16  and reaching the rotation center of the front wheel  16 . 
     The braking operation part  14  includes a mechanism used as an operation part of the front wheel braking part  17  and a mechanism used as an operation part of the rear wheel braking part  24 . For example, the mechanism used as an operation part of the front wheel braking part  17  is disposed on the right end side of the handle bar  13 , and the mechanism used as an operation part of the rear wheel braking part  24  is disposed on the left end side of the handle bar  13 . 
     A hydraulic pressure control unit  110  is joined to the front fork  15  of the turning part  10 . The hydraulic pressure control unit  110  is a unit responsible for controlling the hydraulic pressure of brake fluid in the front wheel braking part  17 . Meanwhile, the rear wheel braking part  24  may be a type of a braking part that generates a braking force by increasing the hydraulic pressure of brake fluid or may be a type of a braking part that mechanically generates a braking force (for example, a type of a braking part that generates a braking force by generating a tension on a wire, etc.). 
     For example, a power supply unit  180  serving as a power supply of the hydraulic pressure control unit  110  is attached to the down tube  1 C of the frame  1 . The power supply unit  180  may be a battery or a generator. For example, the generator includes those (for example, a hub dynamo that generates power by the rotation of the front wheel  16  or the rear wheel  23 , one that serves as an electric motor of a driving source of the front wheel  16  or the rear wheel  23  and generates regenerative electric power, etc.) that generate power by the running of the bicycle  200 , those that generate power with sunlight, and the like. 
     That is, the bicycle  200  is equipped with a braking system  100 . The braking system  100  includes at least the braking operation part  14 , the front wheel braking part  17 , the hydraulic pressure control unit  110 , and the power supply unit  180 . The braking system  100  is capable of executing an antilock braking control by controlling the hydraulic pressure of brake fluid in the front wheel braking part  17  with the hydraulic pressure control unit  110 . 
     &lt;Configuration of Braking System&gt; 
     A configuration of a braking system according to an embodiment will be described. 
       FIG.  2    is a view showing a schematic configuration of a braking system according to the embodiment of the present invention. 
     As shown in  FIG.  2   , the hydraulic pressure control unit  110  has a base body  120  which will be described later in detail. A master cylinder port  121 , a wheel cylinder port  122 , and an internal flow path  123  for communicating the master cylinder port  121  and the wheel cylinder port  122  with each other are formed in the base body  120 . 
     The internal flow path  123  has a partial flow path  123 A, a partial flow path  123 B, a partial flow path  123 C, and a partial flow path  123 D. The master cylinder port  121  and the wheel cylinder port  122  communicate with each other via the partial flow path  123 A and the partial flow path  123 B. Further, the portion between an intermediate portion of the partial flow path  123 B and an intermediate portion of the partial flow path  123 A is bypassed via the partial flow path  123 C and the partial flow path  123 D. 
     The braking operation part  14  is connected to the master cylinder port  121  via a liquid pipe  18 . The braking operation part  14  has a brake lever  14 A, a master cylinder  14 B, and a reservoir  14 C. The master cylinder  14 B has a piston part (not shown) which moves in conjunction with the operation of the brake lever  14 A by a user. The master cylinder  14 B is connected to an inlet side of the partial flow path  123 A via the liquid pipe  18  and the master cylinder port  121 . With the movement of the piston part, the hydraulic pressure of brake fluid in the partial flow path  123 A increases or decreases. Further, the brake fluid for the master cylinder  14 B is accumulated in the reservoir  14 C. 
     The front wheel braking part  17  is connected to the wheel cylinder port  122  via a liquid pipe  19 . The front wheel braking part  17  has a wheel cylinder  17 A and a rotor  17 B. The wheel cylinder  17 A is attached to a lower end portion of the front fork  15  (that is, a portion far from the steering column  11  than the portion to which the hydraulic pressure control unit  110  is attached). The wheel cylinder  17 A has a piston part (not shown) which moves in conjunction with the hydraulic pressure of the liquid pipe  19 . The wheel cylinder  17 A is connected to an outlet side of the partial flow path  123 B via the liquid pipe  19  and the wheel cylinder port  122 . The rotor  17 B is held by the front wheel  16  and rotates together with the front wheel  16 . With the movement of the piston part, a brake pad (not shown) is pressed against the rotor  17 B, thereby braking the front wheel  16 . 
     Further, the hydraulic pressure control unit  110  has an inlet valve  131  and an outlet valve  132 . The inlet valve  131  is provided between an outlet side of the partial flow path  123 A and an inlet side of the partial flow path  123 B, and opens and closes the flow of brake fluid between the partial flow path  123 A and the partial flow path  123 B. The outlet valve  132  is provided between an outlet side of the partial flow path  123 C and an inlet side of the partial flow path  123 D, and opens and closes the flow of brake fluid between the partial flow path  123 C and the partial flow path  123 D. The hydraulic pressure of brake fluid is controlled by the opening and closing operations of the inlet valve  131  and the outlet valve  132 . 
     The inlet valve  131  is, for example, an electromagnetic valve which is opened when de-energized. When a first coil  131 A as a driving source is in a de-energized state, the inlet valve  131  releases the flow of brake fluid in both directions. Further, when the first coil  131 A is energized, the inlet valve  131  is brought into a closed state to block the flow of brake fluid. 
     The outlet valve  132  is, for example, an electromagnetic valve which is closed when de-energized. When a second coil  132 A as a driving source is in a de-energized state, the outlet valve  132  blocks the flow of brake fluid. Further, when the second coil  132 A is energized, the outlet valve  132  is brought into an opened state to release the flow of brake fluid. 
     Further, the hydraulic pressure control unit  110  has an accumulator  133 . The accumulator  133  is connected to an intermediate portion of the partial flow path  123 D. The brake fluid that has passed through the outlet valve  132  is stored in the accumulator  133 . 
     Further, the hydraulic pressure control unit  110  has a hydraulic pressure sensor  134  for detecting the hydraulic pressure of brake fluid in the wheel cylinder  17 A. The hydraulic pressure sensor  134  is provided in the partial flow path  123 B or the partial flow path  123 C. 
     Further, the hydraulic pressure control unit  110  has a control unit  135 . Signals from various sensors such as the hydraulic pressure sensor  134  and a wheel speed sensor (not shown) for detecting the rotational speed of the front wheel  16  are inputted to the control unit  135 . Meanwhile, the respective parts of the control unit  135  may be arranged in a bundled manner or may be arranged in a distributed manner. For example, the control unit  135  may be configured to include a microcomputer, a microprocessor unit and the like, or may be configured to include an updatable firmware or the like, or may be configured to include a program module or the like which is executed by a command from a CPU or the like. 
     The control unit  135  controls the hydraulic pressure of brake fluid in the wheel cylinder  17 A, i.e., the braking force of the front wheel  16  by controlling the opening and closing operations of the inlet valve  131  and the outlet valve  132 . 
     For example, when a user brakes the front wheel  16  by operating the brake lever  14 A, the control unit  135  starts an antilock braking control when it is determined from a signal of a wheel speed sensor (not shown) that the front wheel  16  is locked or may be locked. 
     When the antilock braking control is started, the control unit  135  brings the first coil  131 A into an energized state to close the inlet valve  131  and blocks the flow of brake fluid from the master cylinder  14 B to the wheel cylinder  17 A, thereby suppressing the pressure increase of brake fluid in the wheel cylinder  17 A. On the other hand, the control unit  135  brings the second coil  132 A into an energized state to open the outlet valve  132  and allows the flow of brake fluid from the wheel cylinder  17 A to the accumulator  133 , thereby decreasing the pressure of brake fluid in the wheel cylinder  17 A. In this way, the locking of the front wheel  16  is released or avoided. When it is determined from a signal of the hydraulic pressure sensor  134  that the pressure of brake fluid in the wheel cylinder  17 A decreases to a predetermined value, the control unit  135  brings the second coil  132 A into a de-energized state to close the outlet valve  132  and, for a short time, brings the first coil  131 A into a de-energized state to open the inlet valve  131 , thereby increasing the pressure of brake fluid in the wheel cylinder  17 A. The control unit  135  may increase or decrease the pressure of the wheel cylinder  17 A only once or may repeat the same multiple times. 
     When the antilock braking control is ended and the brake lever  14 A is returned, the inside of the master cylinder  14 B is brought into an atmospheric pressure state and the brake fluid in the wheel cylinder  17 A is returned. Further, due to the occurrence of such atmospheric pressure state, the brake fluid in the accumulator  133  is returned to the partial flow path  123 A. 
     &lt;Configuration of Hydraulic Pressure Control Unit&gt; 
     A configuration of a hydraulic pressure control unit of the braking system according to the embodiment will be described. 
       FIG.  3    is a perspective view of a hydraulic pressure control unit of the braking system according to the embodiment of the present invention.  FIG.  4    is a front view of the hydraulic pressure control unit of the braking system according to the embodiment of the present invention in a state where a fifth surface of a base body is viewed from the front.  FIGS.  5  and  6    are perspective views of the base body of the hydraulic pressure control unit of the braking system according to the embodiment of the present invention. Meanwhile,  FIG.  4    shows a state in which an outer surface of only coil casing  136  is partially broken. Further, in  FIGS.  5  and  6   , an internal structure of the base body  120  is drawn so as to overlap with the outer shape of the hydraulic pressure control unit  110 . 
     As shown in  FIGS.  3  and  4   , the hydraulic pressure control unit  110  includes the base body  120 , the coil casing  136 , a connector  137 , and a casing cover  138 . 
     The base body  120  is a substantially rectangular parallelepiped member made of, for example, an aluminum alloy. The base body  120  has a first surface  120   a  serving as an upper surface in a state where the bicycle  200  stands upright, a second surface  120   b  facing the first surface  120   a  and serving as a lower surface in a state where the bicycle  200  stands upright, a third surface  120   c  having both ends reaching the first surface  120   a  and the second surface  120   b  and serving as one side surface in a state where the bicycle  200  standing upright is viewed from the front, a fourth surface  120   d  facing the third surface  120   c  and serving as the other side surface in a state where the bicycle  200  standing upright is viewed from the front, a fifth surface  120   e  having both ends reaching the first surface  120   a  and the second surface  120   b  and serving as a back surface in a state where the bicycle  200  standing upright is viewed from the front, and a sixth surface  120   f  facing the fifth surface  120   e  and serving as a front surface in a state where the bicycle  200  standing upright is viewed from the front. Meanwhile, each surface may be flat, or may have a curved portion, or may have a step. 
     The master cylinder port  121  is formed in the first surface  120   a  of the base body  120  and the wheel cylinder port  122  is formed in the second surface  120   b  of the base body  120  (see  FIGS.  5  and  6   ). That is, the master cylinder port  121  and the wheel cylinder port  122  are formed on separate surfaces of the base body  120  facing each other. 
     An inlet valve hole  124  to which the inlet valve  131  is attached and an outlet valve hole  125  to which the outlet valve  132  is attached are formed in the third surface  120   c  of the base body  120  (see  FIGS.  5  and  6   ). Valve bodies (not shown) of the inlet valve  131  and the outlet valve  132  are located in the internal flow path  123  of the base body  120 . Further, the first coil  131 A serving as a driving source of the inlet valve  131  and the second coil  132 A serving as a driving source of the outlet valve  132  are attached in a state where their axial directions face the valve bodies (not shown). The first coil  131 A and the second coil  132 A are held in a state where one ends thereof are in contact with the base body  120  and the other ends protrude from the third surface  120   c  of the base body  120 . That is, the first coil  131 A and the second coil  132 A are erected on the third surface  120   c . A connecting terminal (plus terminal and minus terminal)  131 At is erected on an end portion of the first coil  131 A on the side protruding from the third surface  120   c . A connecting terminal (plus terminal and minus terminal)  132 At is erected on an end portion of the second coil  132 A on the side protruding from the third surface  120   c . The connecting terminal  131 At and the connecting terminal  132 At are inserted into through-holes formed in a circuit board  135 A constituting at least a part of the control unit  135  and are electrically connected to the circuit board  135 A. 
     Further, an accumulator hole  126  is formed in the second surface  120   b  of the base body  120  (see  FIGS.  5  and  6   ). A bottom portion of the accumulator hole  126  communicates with the internal flow path  123  of the base body  120 . Respective members (for example, a plunger, a compression spring, a hole cover, etc.) constituting the accumulator  133  are attached to the inside of the accumulator hole  126  to constitute the accumulator  133 . That is, the accumulator  133  is provided on the second surface  120   b.    
     Further, a hydraulic pressure sensor hole  127  is formed in the third surface  120   c  of the base body  120  (see  FIGS.  5  and  6   ). The hydraulic pressure sensor  134  is attached to the hydraulic pressure sensor hole  127 . In this state, one end of the hydraulic pressure sensor  134  is located in the internal flow path  123  of the base body  120 . Further, the other end of the hydraulic pressure sensor  134  is electrically connected to the circuit board  135 A. 
     The coil casing  136  is made of, for example, resin. The coil casing  136  has a shape covering the third surface  120   c  and the sixth surface  120   f  of the base body  120 . The coil casing  136  has an internal space which penetrates the portion of the coil casing  136  covering at least the third surface  120   c  of the base body  120 . In a state where the coil casing  136  is attached to the base body  120 , the first coil  131 A, the second coil  132 A, the hydraulic pressure sensor  134 , and the circuit board  135 A are accommodated in the internal space. 
     In a state where the bicycle  200  stands upright, upper ends of the coil casing  136  and the circuit board  135 A extend above the first surface  120   a  of the base body  120 . The connector  137  is attached to the upper end of the coil casing  136 . A connecting terminal  137   t  of the connector  137  is inserted into a through-hole formed in the circuit board  135 A and is electrically connected to the circuit board  135 A. A cable group including signal lines (not shown) of various sensors such as the hydraulic pressure sensor  134  and a wheel speed sensor (not shown) for detecting the rotational speed of the front wheel  16  and a power supply line (not shown) extending from the power supply unit  180 , and the like is connected to the connector  137 . 
     The casing cover  138  is attached to the surface of the coil casing  136  facing the surface in contact with the third surface  120   c  of the base body  120 . In a state where the casing cover  138  is attached to the coil casing  136 , the internal space of the coil casing  136  is hermetically sealed. 
     A fixing member  139  for connecting the hydraulic pressure control unit  110  to the front fork  15  of the bicycle  200  is joined to the coil casing  136  by using a fastener  140 . For example, in a state where the bicycle  200  standing upright is viewed from the front, a recess extending substantially in an upper and lower direction is formed on a front surface  136   a  of the coil casing  136 . Further, in a state where the bicycle  200  standing upright is viewed from the front, a recess extending substantially in the upper and lower direction is formed on a back surface  139   a  of the fixing member  139 . Further, a columnar space  155  with both ends opened is formed between an inner surface of the recess that is a partial region  151  of an outer surface of the coil casing  136  and an inner surface of the recess that is a partial region  152  of an outer surface of the fixing member  139 , so that a mount part  150  of the hydraulic pressure control unit  110  to the bicycle  200  is formed. Meanwhile, although  FIG.  3    shows a case where the fixing member  139  has a block shape, the fixing member  139  may be one or more bands or the like. That is, the entire of the outer circumference of the columnar space  155  may not be closed. Further, although  FIG.  3    shows a case where the recesses are formed in both the front surface  136   a  of the coil casing  136  and the back surface  139   a  of the fixing member  139 , one or both of the front surface  136   a  of the coil casing  136  and the back surface  139   a  of the fixing member  139  may be flat. That is, the columnar space  155  may not have a columnar shape. 
     Here, a direction in which the first surface  120   a  and the second surface  120   b  of the base body  120  are arranged or a direction in which the columnar space  155  extends is defined as a direction D, and the positional relationship of respective members will be described. Meanwhile, the direction in which the first surface  120   a  and the second surface  120   b  of the base body  120  are arranged is defined as a direction parallel to a straight line intersecting with the first surface  120   a  and the second surface  120   b . Further, the direction in which the columnar space  155  extends is defined as a direction parallel to a straight line intersecting with both end surfaces of the columnar space  155 . 
     First, the first coil  131 A, the second coil  132 A, and the hydraulic pressure sensor  134  are arranged side by side along the direction D. That is, the straight line parallel to the direction D intersects with the first coil  131 A, the second coil  132 A, and the hydraulic pressure sensor  134 . In the direction D, the first coil  131 A, i.e., the inlet valve  131  is located closer to the master cylinder port  121  than the second coil  132 A, i.e., the outlet valve  132 . Further, the hydraulic pressure sensor  134  is located closer to the wheel cylinder port  122  than the first coil  131 A, i.e., the inlet valve  131  and the second coil  132 A, i.e., the outlet valve  132 . 
     Further, the circuit board  135 A is held in a state where its mounting surface  135 Am extends along the direction D. That is, in a state where the bicycle  200  stands upright, the circuit board  135 A is held in an upright state. In particular, in a state where the bicycle  200  stands upright, it is preferable that the circuit board  135 A is held in a state where the mounting surface  135 Am extends along the direction D and extends along a front and rear direction of the bicycle  200 . 
     Further, the connector  137  is erected in a direction different from the direction D. That is, the connector  137  is held in a state where the attachment and detachment direction of the cable group connected to the connector  137  is different from the direction D. In particular, in a state where the bicycle  200  standing upright is viewed from the front, it is preferable that the attachment and detachment direction is a substantially right and left direction. Further, it is preferable that the first coil  131 A, the second coil  132 A, and the connector  137  are held in a state where leading ends of the connecting terminal  131 At, the connecting terminal  132 At, and the connecting terminal  137   t  protrude from the same side with respect to the mounting surface  135 Am of the circuit board  135 A. Furthermore, in a state where the mounting surface  135 Am of the circuit board  135 A is viewed from the front, it is preferable that the connector  137  is located on the side where the first surface  120   a  is located with respect to the first coil  131 A and the second coil  132 A. 
     &lt;Connection of Hydraulic Pressure Control Unit to Bicycle&gt; 
     Connection of the hydraulic pressure control unit of the braking system according to the embodiment to a bicycle will be described.  FIG.  7    is a perspective view showing a connection state of the hydraulic pressure control unit of the braking system according to the embodiment of the present invention to a bicycle. 
     As shown in  FIG.  7   , the hydraulic pressure control unit  110  is held in a state where the front fork  15  of the bicycle  200  is located in the columnar space  155  of the mount part  150 . That is, the fixing member  139  is joined to the coil casing  136  with the front fork  15  sandwiched therebetween to form the mount part  150 . In this way, the hydraulic pressure control unit  110  is joined to the bicycle  200 . Meanwhile, in a state where the bicycle  200  standing upright is viewed from the front, the hydraulic pressure control unit  110  may be joined to a first bar  15   a , which is shown in  FIG.  7    with centerline  175 , the first bar  15   a  extending on the right side of the front wheel  16  of the front fork  15  or may be joined to a second bar  15   b  extending on the left side of the front wheel  16  of the front fork  15 . Further, the mount part  150  may be directly joined to the front fork  15  or may be joined to the front fork  15  via an adapter or the like. 
     In a state where the bicycle  200  standing upright is viewed from the front, the base body  120  and the coil casing  136  may be located on the back side of the front fork  15 . In particular, it is preferable that the hydraulic pressure control unit  110  is attached in a state where the first coil  131 A, the second coil  132 A, the hydraulic pressure sensor  134 , and the circuit board  135 A are located between the base body  120  and the front wheel  16 . That is, in a state where the bicycle  200  standing upright is viewed from the front, it is preferable that the hydraulic pressure control unit  110  is configured so that the first coil  131 A, the second coil  132 A, and the hydraulic pressure sensor  134  are erected on the third surface  120   c  that is a left surface of the base body  120  when the hydraulic pressure control unit  110  is attached to the first bar  15   a . Furthermore, it is preferable that the connector  137  is erected to the left. Further, in a state where the bicycle  200  standing upright is viewed from the front, it is preferable that the hydraulic pressure control unit  110  is configured so that the first coil  131 A, the second coil  132 A, and the hydraulic pressure sensor  134  are erected on the third surface  120   c  that is a right surface of the base body  120  when the hydraulic pressure control unit  110  is attached to the second bar  15   b . Furthermore, it is preferable that the connector  137  is erected to the right. 
     MODIFICATION 
     A modification of the hydraulic pressure control unit of the braking system according to the embodiment will be described. 
       FIG.  8    is a perspective view showing a modification of the hydraulic pressure control unit of the braking system according to the embodiment of the present invention. 
     In the foregoing, the case where the fixing member  139  for joining the hydraulic pressure control unit  110  to the front fork  15  of the bicycle  200  is joined to the coil casing  136  has been described. However, as shown in  FIG.  8   , the fixing member  139  may be joined to the base body  120 . For example, in a state where the bicycle  200  standing upright is viewed from the front, a recess extending substantially in the upper and lower direction is formed on the sixth surface  120   f  that is a front surface of the base body  120 . Further, in a state where the bicycle  200  standing upright is viewed from the front, a recess extending substantially in the upper and lower direction is formed on the back surface  139   a  of the fixing member  139 . Further, the columnar space  155  with both ends opened is formed between an inner surface of the recess that is a partial region  153  of an outer surface of the base body  120  and an inner surface of the recess that is the partial region  152  of the outer surface of the fixing member  139 , so that the mount part  150  of the hydraulic pressure control unit  110  to the bicycle  200  is formed. 
     &lt;Effect of Braking System&gt; 
     Effects of the braking system according to the embodiment will be described. 
     In the braking system  100 , the fixing member  139  is joined to the coil casing  136  in a state where the columnar space  155  with both ends opened is formed between the partial region  151  of an outer surface of the coil casing  136  and the partial region  152  of an outer surface of the fixing member  139 , or the fixing member  139  is joined to the base body  120  in a state where the columnar space  155  with both ends opened is formed between the partial region  153  of an outer surface of the base body  120  and the partial region  152  of an outer surface of the fixing member  139 . That is, in a state where the fixing member  139  is joined to the coil casing  136  or the base body  120 , the columnar space  155  with both ends opened is formed between the partial region  151  or  153  of an outer surface of the coil casing  136  or the base body  120  and the partial region  152  of an outer surface of the fixing member  139 . The hydraulic pressure control unit  110  is joined to the bicycle  200  by using the columnar space  155 . Therefore, as compared with the case where one end of an adapter is joined to the bicycle  200  and the hydraulic pressure control unit  110  is joined to the other end of the adapter, it is possible to prevent the hydraulic pressure control unit  110  from protruding from the bicycle  200 . Generally, the bicycle  200  is configured to include many rod-shaped members. Therefore, the connection using the columnar space  155  is particularly useful for the case where the braking system  100  capable of executing an antilock braking control is mounted on the bicycle  200 . 
     Preferably, in the braking system  100 , the first coil  131 A and the second coil  132 A are arranged side by side along the direction (D) in which the columnar space  155  extends. With such a configuration, the first surface  120   a  and the second surface  120   b  of the base body  120  are widened, so that an increase in the protruding amount of the hydraulic pressure control unit  110  from the bicycle  200  can be suppressed. 
     Preferably, in the braking system  100 , the circuit board  135 A is held in a state where its mounting surface  135 Am extends along the direction D in which the columnar space  155  extends. With such a configuration, an increase in the protruding amount of the hydraulic pressure control unit  110  from the bicycle  200  can be suppressed. 
     Preferably, in the braking system  100 , the connector  137  is erected in a direction different from the direction D in which the columnar space  155  extends. With such a configuration, when it is necessary to separately arrange the cables (for example, a cable extending to the power supply unit  180  and cables extending to the hydraulic pressure sensor  134  and a wheel speed sensor) of the cable group connected to the connector  137  in two directions opposite to each other along the direction D in which the columnar space  155  extends, the cable disposed in either direction is prevented from largely protruding from the bicycle  200 . In particular, when the first coil  131 A, the second coil  132 A, and the connector  137  are held in a state where leading ends of the connecting terminals  131 At,  132 At,  137   t  protrude from the same side with respect to the mounting surface  135 Am of the circuit board  135 A, the process of connecting the first coil  131 A, the second coil  132 A, and the connector  137  to the circuit board  135 A can be shortened. 
     Preferably, in the braking system  100 , the hydraulic pressure control unit  110  is a pump-less type. With such a configuration, the heavy hydraulic pressure control unit  110  is joined to the bicycle  200 , which less affects the travelling performance. 
     Preferably, the hydraulic pressure control unit  110  is joined to the front fork  15  of the bicycle  200 . With such a configuration, when mounting the braking system  100  capable of executing the antilock braking control on the bicycle  200 , other equipment that should be normally visually perceived by a user can be securely attached to the periphery of the handle. Further, when it is necessary to connect many elements disposed near the front wheel  16  of the bicycle  200  to the hydraulic pressure control unit  110 , this connection is facilitated since the hydraulic pressure control unit  110  is disposed near the front wheel  16 . 
     Although the embodiments have been described above, the present invention is not limited to the description of the embodiments. For example, only a part of the description of the embodiments may be implemented. 
     REFERENCE SIGNS LIST 
       1 : Frame,  10 : Turning part,  14 : Braking operation part,  14 A: Brake lever,  14 B: Master cylinder,  14 C: Reservoir,  15 : Front fork,  16 : Front wheel,  17 : Front wheel braking part,  17 A: Wheel cylinder,  17 B: Rotor,  18 ,  19 : Liquid pipe,  23 : Rear wheel,  24 : Rear wheel braking part,  100 : Braking system,  110 : Hydraulic pressure control unit,  120 : Base body,  120   a : First surface,  120   b : Second surface,  120   c : Third surface,  120   d : Fourth surface,  120   e : Fifth surface,  120   f : Sixth surface,  121 : Master cylinder port,  122 : Wheel cylinder port,  123 : Internal flow path,  124 : Inlet valve hole,  125 : Outlet valve hole,  126 : Accumulator hole,  127 : Hydraulic Pressure sensor hole,  131 : Inlet valve,  131 A: First coil,  131 At: Connecting terminal,  132 : Outlet valve,  132 A: Second coil,  132 At: Connecting terminal,  133 : Accumulator,  134 : Hydraulic pressure sensor,  135 : Control unit,  135 A: Circuit board,  135 Am: Mounting surface,  136 : Coil casing,  137 : Connector,  137   t : Connecting terminal,  138 : Casing cover,  139 : Fixing member,  140 : Fastener,  150 : Mount part,  151 ,  152 ,  153 : Partial region,  155 : Columnar space,  180 : Power supply unit,  200 : Bicycle.