Patent Publication Number: US-9407009-B2

Title: Antenna coil device

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     The present invention contains subject matter related to Japanese Patent Application 2013-119800 filed in the Japanese Patent Office on Jun. 6, 2013, the entire contents of which being incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an antenna coil device. 
     2. Description of the Related Art 
     In recent years, there has been practically used an electronic key system using an antenna coil device which is installed in a vehicle. In the electronic key system, when a driver who possesses the electronic key enters into the communication zone of the system by coming close to the vehicle, communication is carried out between the antenna coil device and the electronic key, a control circuit on the vehicle side, which is connected to this antenna coil device, is driven, and door unlocking, engine activation and the like are allowed. In addition, when the driver possessing the electronic key comes out from the communication zone of the system by going apart from the vehicle, the control circuit on the vehicle side is driven again and door locking is carried out. 
     In Patent Document 1 (Japanese unexamined patent publication No. 2009-152784) and Patent Document 2 (Japanese unexamined patent publication No. 2011-205616), there are disclosed antenna coil devices of this kind. For the antenna coil device of the Patent Document 1 (Japanese unexamined patent publication No. 2009-152784), a connector unit and a bobbin are integrally formed and a coil is wound around the cylindrical portion of the bobbin. In the inside of the connector unit, a pair of antenna terminals are exposed. The antenna terminals and the coil are connected through a circuit. The connector unit is interlinked with a connector (vehicle side connector) which is an interface of the control circuit on the vehicle side. In the antenna coil device of the Patent Document 1 (Japanese unexamined patent publication No. 2009-152784), a resin-made case is mounted by being fitted at the periphery of the connector and the bobbin. 
     Here, the shape and the dimension of the connector on the vehicle side are different generally depending on the type of vehicle. In the antenna coil device of the Patent Document 2 (Japanese unexamined patent publication No. 2011-205616), the terminal board (base unit) provided with the antenna body and the connector unit mounted with the connector on the vehicle side are separately formed by separate members. Thus, the antenna body and the base unit are fabricated by a common component and concurrently, by fabricating the connector unit with an individual shape corresponding to the connector on the vehicle side for everyone thereof, there is achieved generalization for the component of the antenna coil device. In the antenna coil device of the Patent Document 2 (Japanese unexamined patent publication No. 2011-205616), the base unit and the connector unit are indirectly combined integrally by inserting the base unit into one opening of a rubber-made annular elastic plug and by inserting the connector unit into the other opening thereof. The antenna terminal protruding from the base unit is exposed in the inside of the connector unit by passing through an elastic plug. The antenna body and the elastic plug are housed in a case. There are formed protrusions circularly in the periphery of the annular elastic plug and by engaging these protrusions with the inside of the case, the elastic plug, the base unit and the connector unit are to be fixed on the case. 
     SUMMARY OF THE INVENTION 
     When the operation accuracy of the electronic key system is low, the door will not be unlocked even if the driver possessing the electronic key comes close to the vehicle, and an inconvenience occurs for the driver. In addition, in a case in which the door will not be locked even if the driver possessing the electronic key gets off and goes apart from the vehicle, there will occur a problem in the vehicle security. The accuracy reduction in the operation of the electronic key system occurs by various causes, in which defective electrical continuity between the connector and the antenna body on the vehicle side becomes one cause thereof. 
     In the antenna coil device of the Patent Document 2 (Japanese unexamined patent publication No. 2011-205616), the base unit and the connector unit are combined through a rubber-made elastic plug. When engaging the elastic plug on the inside of the case, the elastic plug is pressed from the periphery onto the case and is distorted. For this reason, the antenna terminal inserted through the elastic plug by protruding from the base unit is displaced relatively with respect to the connector unit and the connector on the vehicle side. As a result thereof, there is fear that there may occur defective electrical continuity between the connector and the antenna body on vehicle side. 
     The present invention was invented in view of the problem as mentioned above and is to provide an antenna coil device by which it is possible to realize generalization of the base unit provided with the antenna body and by which it is possible to realize stable electric-conduction between the connector of the external circuit (for example, connector on the vehicle side) and the antenna body. 
     According to the present invention, there is provided an antenna coil device including: a connector unit mounted with a connector of an external circuit detachably by being plugged-in; and a base unit provided with an antenna body including a coil, in which the connector unit and the base unit are constituted by separate members and are used by being combined integrally each other, wherein for the connector unit and the base unit, there are formed a connector fitting portion and a base fitting portion which are formed with a concave and a convex in a direction intersecting with respect to the plug-in direction of the connector unit, and by fitting the connector fitting portion and the base fitting portion, the connector unit and the base unit are combined in a state in which the antenna body is positioned with respect to the connector unit. 
     According to an antenna coil device of the present invention, the antenna body is positioned with respect to the connector unit by fitting the connector fitting portion and the base fitting portion which are constituted by members separated from each other. Consequently, according to the antenna coil device of the present invention, it is possible to realize generalization of the base unit provided with the antenna body and concurrently, it is possible to realize stable electric-conduction between the connector of the external circuit and the antenna body. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is an exploded perspective view showing one example of an antenna coil device of the present invention; 
         FIG. 1B  is a partially enlarged view of  FIG. 1A ; 
         FIG. 2  is a perspective view showing one example of an antenna coil device of the present invention; 
         FIG. 3  is a perspective view showing a distal portion of a base unit; 
         FIG. 4  is a perspective view showing a proximal portion of a connector unit; 
         FIG. 5A  is a perspective view showing a connector fitting portion; 
         FIG. 5B  is an explanatory view showing a state in which the base fitting portion is inserted into the connector fitting portion; 
         FIG. 6  is a schematic view showing a horizontal cross section in a fitted state between the connector fitting portion and the base fitting portion; and 
         FIG. 7  is a schematic view showing a vertical cross section in a fitted state between the connector unit and the base unit. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, exemplified embodiments of the present invention will be explained based on the drawings. It should be noted in all the drawings that similar reference numerals are applied to similar constituent elements and repetitive explanations thereof will be omitted arbitrarily. 
       FIG. 1A  is an exploded perspective view showing an antenna coil device  100  relating to an exemplified embodiment of the present invention.  FIG. 1B  is a partially enlarged view of  FIG. 1A . For a base unit  30 , only a portion of on the distal side is illustrated and the illustration of other portions thereof is omitted.  FIG. 2  is a perspective view showing the antenna coil device  100  of an exemplified embodiment of the present invention. In  FIG. 1  and  FIG. 2 , the winding-axis direction of a coil  42  of an antenna body  40  is made to be Z-direction, the aligning direction of a pair of antenna terminals  44  is made to be X-direction, and the direction perpendicular to the Z axis and X axis is made to be Y axis. Within the antenna body  40 , the side on which a connector unit  10  exists is made to be (−Z)-direction and the direction apart from the connector unit  10  is made to be (+Z)-direction.  FIG. 3  is a perspective view showing a distal portion of the base unit  30 .  FIG. 4  is a perspective view showing a proximal portion of the connector unit  10 . 
     First, there will be explained an outline of the antenna coil device  100 . The antenna coil device  100  of this exemplified embodiment includes a connector unit  10  mounted with a connector of an external circuit (not shown) by being plugged-in detachably and a base unit  30  provided with an antenna body  40  which includes a coil  42 . The connector unit  10  and the base unit  30  are constituted by separate members and are used by being combined integrally with each other. For the connector unit  10  and the base unit  30 , there are formed a connector fitting portion  12  and a base fitting portion  32  which are formed with a concave and a convex respectively toward the intersecting direction with respect to the plug-in direction of the connector unit  10 . By fitting the connector fitting portion  12  and the base fitting portion  32 , the connector unit  10  and the base unit  30  are combined in a state in which the antenna body  40  is positioned with respect to the connector unit  10 . 
     The state in which the antenna body  40  is positioned with respect to the connector unit  10  means a state in which the position facing to a coupling portion  15  of the connector unit  10  within the antenna body  40 , that is, a state in which the relative position between the antenna terminal  44  and the connector unit  10  in this exemplified embodiment is fixed. 
     Next, there will be explained this exemplified embodiment in detail. 
     The antenna coil device  100  of this exemplified embodiment is a magnetic field antenna in which the coil  42  is wound around the periphery of a core  46 . The core  46  is made of a magnetic material having high magnetic permeability such as ferrite and it is formed in a bar-shape. The coil  42  is an electrical wire coated with insulator on the surface thereof. The antenna coil device  100  of this exemplified embodiment is a bar-antenna and, for example, it can be used as a transmitting antenna device on the vehicle side in the electronic key system of the vehicle. 
     In  FIG. 2 , there is illustrated a state in which the connector unit  10  and the base unit  30  are interlinked and the coil  42  is exposed, but the antenna coil device  100  is not limited by this configuration. The antenna coil device  100  may include an exterior resin (not shown) over-molded so as to coat the coil  42  which is wound around the base unit  30 . 
     The antenna body  40  constitutes a resonant circuit formed by a combination of the coil  42 , which is wound around the core  46  having an open magnetic-path structure, and a capacitor (not shown) connected in series therewith. The antenna coil device  100  is used by being connected to a connector (not shown) of an external circuit. The connector of the external circuit is inserted into the coupling portion  15  (see  FIG. 7 ) which is a concave portion on the distal side of the connector unit  10  of the antenna coil device  100 . The antenna terminal  44  of the antenna body  40  is exposed in the coupling portion  15  by penetrating from the proximal side to the distal side with respect to the connector unit  10  and the external circuit applies an AC current, which corresponds to the resonant frequency of the antenna body  40 , to the antenna terminal  44 . Thus, the antenna body  40  (antenna coil device  100 ) generates a magnetic field, propagates it into the air, and communication is carried out with respect to the electronic key (not shown) which is possessed by a user such as a vehicle driver or the like. 
     The base unit  30  is a resin-made member in which an approximately cylindrical winding-axis portion  36  which houses the core  46  and a head portion  34  which holds the antenna terminal  44  and the capacitor (not shown) are formed integrally. It should be noted that the wording of “the antenna body  40  is provided at the base unit  30 ” means that the base unit  30  constitutes the antenna body  40  together with the core  46 , the coil  42  and the like. The core  46  of this exemplified embodiment forms a bar shape which has an approximately rectangular cross section and which extends toward the Z-direction, but there is no limitation in particular for the cross-sectional shape and the whole shape of the core  46 . The base unit  30  is composed of an electrically non-conductive material and more specifically, is composed of a resin material. The base unit  30  is a unit which is formed by insert-molding a pair of antenna terminals  44  composed of a metal material and a plurality of binding terminals  48  by using a resin material. The antenna terminals  44  and the binding terminals  48  are connected separately. Both the terminals of the coil  42  are bound to the pair of binding terminals  48  respectively. 
     At the periphery of the winding-axis portion  36 , there are formed protruding portions  38  which restrict winding displacements of the coil  42  wound there-around. There are formed a plurality of protruding portions  38  by being separated at a plurality of positions toward the winding-axis direction (Z-direction) of the winding-axis portion  36 . The coil  42  is bound to the binding terminals  48  under the condition of being wound-around in multi layers at the periphery of the winding-axis portion  36  and between the protruding portions  38  each other. 
     The connector unit  10  is composed of a resin material and is used by being mounted on the head portion  34  of the base unit  30 . In case of using the antenna coil device  100  for a vehicle electronic key system, there sometimes exists a case in which the configuration of the connector in the external circuit becomes different for every vehicle type. The connector unit  10  is exclusively designed &amp; fabricated to have a configuration in conformity with each vehicle type. On the other hand, the base unit  30  and the antenna characteristic &amp; configuration of the antenna body  40  can be designed &amp; fabricated in common regardless of the vehicle type. 
     At the base unit  30 , there are provided a pair of antenna terminals  44  connected to the coil  42  by being protruded toward the plug-in direction of the connector unit  10 . The plug-in direction of the connector unit  10  of this exemplified embodiment is Z-direction. As shown in  FIG. 3  and  FIG. 6  (mentioned later), the base fitting portion  32  is formed on an extended line of the aligning direction (X-direction in this exemplified embodiment) of the pair of antenna terminals  44 . The antenna body  40  is positioned toward the intersecting direction of this aligning direction with respect to the connector unit  10 . 
     Here, the wording of “the base fitting portion  32  is formed on an extended line of the aligning direction of the pair of antenna terminals  44 ” means that the plane containing the respective center lines of the pair of antenna terminals  44  intersects with at least a portion of the base fitting portion  32 . In addition, the wording of the antenna body  40  is positioned toward a certain direction with respect to the connector unit  10 ″ means that the coupling portion (antenna terminal  44  in this exemplified embodiment) between the antenna body  40  and the connector unit  10  is restricted for the movement thereof toward the aforesaid direction with respect to the connector unit  10  without backlash or looseness and also without being displaced flexibly. In this exemplified embodiment, the antenna terminals  44  are fixed on the head portion  34  of the base unit  30 , and the base unit  30  is fitted with &amp; fixed to the connector unit  10  through the base fitting portion  32  and the connector fitting portion  12 . Consequently, the antenna terminal  44  is positioned with respect to the connector unit  10 . 
     The base fitting portion  32  has a rectangular parallelepiped shape and is chamfered smoothly for the distal side (−Z side) thereof. The protruding directions (±X-directions) of the base fitting portions  32  are referred to as thickness directions and the orthogonal directions (±Y-directions) thereof are referred to as width directions. The width dimension of the base fitting portion  32  is larger than the thickness dimension thereof. 
     As shown in  FIG. 6  (which is mentioned later), the base fitting portions  32  are formed on the both sides of the extended line in the aligning direction of the pair of antenna terminals  44 . On the inside of the plane (XY plane) perpendicular to the winding axis, a linear line (X-direction linear line), which connects the centers of the pair of antenna terminals  44  each other, passes the centers of the width dimensions of the pair of base fitting portions  32 . In addition, the width dimension (Y dimension) of the base fitting portion  32  is larger than the Y dimension of the antenna terminal  44 . More specifically, the antenna terminals  44  of this exemplified embodiment are contained in the inside of a belt-shaped area which connects the formation areas of the pair of base fitting portions  32  each other and which extends in the X-direction. Thus, by fitting the pair of base fitting portions  32  with the connector fitting portions  12  and by positioning the base unit  30  with respect to the connector unit  10 , it becomes a state in which also the antenna terminals  44  positioned in the inside thereof will be positioned with high positioning accuracy with respect to the connector unit  10 . 
     The head portion  34  of this exemplified embodiment forms a rectangular-plate shape extending within the XY plane which is perpendicular to the plug-in direction (Z-direction) of the connector unit  10 . For the head portion  34 , the antenna terminals  44  are protruded by passing there-through toward the direction perpendicular to the surface. At the periphery of the rectangular head portion  34 , the base fitting portions  32  are formed by being protruded outward from both the side edges in the aligning direction (X-direction) of the pair of antenna terminals  44 . At the periphery of the head portion  34 , there are additionally formed second fitting portions  35  ( 35   a ,  35   b ) by being protruded outward from both the side edges in the intersecting direction (orthogonal direction “±Y-directions” in this exemplified embodiment) with respect to the aligning direction (X-direction) of the pair of antenna terminals  44 . The second fitting portions  35  are positions for positioning the head portion  34  with respect to the connector unit  10  in the aligning direction of the pair of antenna terminals  44 . 
     As shown in  FIG. 4 , for the connector unit  10  of this exemplified embodiment, a cylindrical connector-acceptor  20  which is opened toward the distal side (−Z side) and a base-acceptor  22  which is opened toward the rear end side (+Z side) are formed integrally. Into the connector-acceptor  20 , there will be inserted the connector of the external circuit. Into the base-acceptor  22 , there will be inserted the head portion  34  of the base unit  30 . 
     The connector unit  10  is provided with a bottomed opening portion  14  for mounting the base unit  30 . Through-holes  18  through which the antenna terminals  44  are inserted are formed at the bottom portion  16  of the opening portion  14 . The connector (not shown) of the external circuit is plugged-in on the −Z side for the connector unit  10 . The opening portion  14  is formed with openings on the opposite side hereof (+Z side). 
     For the connector unit  10 , there are formed the connector fitting portions  12  for being fitted with the base fitting portions  32  of the base unit  30  in a concave and convex fashion. In this exemplified embodiment, there is illustrated a case in which the base fitting portions  32  are convex sides and the connector fitting portions  12  are concave sides, but it is not limited by this configuration. 
     By inserting and mounting the base unit  30  toward the depth direction of the opening portion  14 , the connector fitting portions  12  and the base fitting portions  32  are fitted with each other. 
     The opening portion  14  has a rectangular concave-shape corresponding to the rectangular head portion  34  of the base unit  30 . At the periphery of the opening portion  14 , the pair of connector fitting portions  12  are formed integrally with the through-holes  18  by being projected respectively toward the aligning direction (X-direction) of the through-holes  18 . In addition, at the periphery of the opening portion  14 , the second fitting portions  24  ( 24   a ,  24   b ) are formed integrally so as to be projected toward both the sides of the intersecting direction (orthogonal directions “±Y-directions” in this exemplified embodiment) with respect to the aligning direction of the through-holes  18 . 
     The base fitting portions  32  are formed integrally with the base unit  30  (see  FIG. 3 ) and also, the connector fitting portions  12  are formed integrally with the connector unit  10  (see  FIG. 4 ). 
       FIG. 5A  is a perspective view showing the connector fitting portion  12  and this is a partially enlarged view of the connector unit  10  shown in  FIG. 4 .  FIG. 5B  is an explanatory view showing a state in which the base fitting portion  32  is inserted into the connector fitting portion  12 . 
     At least one of the connector fitting portion  12  and the base fitting portion  32  is constituted to have symmetric taper shapes on both sides thereof, each of which is reduced in diameter or enlarged in diameter toward the depth direction of the opening portion  14 . Then, the taper ratios of the connector fitting portion  12  and the base fitting portion  32  are different from each other. Here, the wording of “the taper ratio is different” includes a configuration in which the taper ratio of one of the connector fitting portion  12  and the base fitting portion  32  is zero. In addition, the above wording includes a configuration in which the taper directions of the connector fitting portion  12  and the base fitting portion  32  are opposite to each other, that is, a configuration in which one is reduced in diameter toward the depth direction and the other is enlarged in diameter toward the depth direction. 
     In this exemplified embodiment, there is illustrated a case in which the base fitting portion  32  is the convex portion and the connector fitting portion  12  is the concave portion. The connector fitting portion  12  of this exemplified embodiment is constituted to have taper shapes in each of which the width dimension (Y dimension) decreases toward the depth direction ((−Z)-direction) of the opening portion  14 . On the other hand, with regard to the base fitting portion  32 , the width dimensions thereof are constituted to have uniform and straight shapes (taper ratio is zero). As shown in  FIG. 5 , by maintaining the operation of inserting the base fitting portion  32  with respect to the connector fitting portion  12 , the distal portion (end portion on the −Z side) of the base fitting portion  32  is pressure-contacted to the inner wall surface of the connector fitting portion  12 . The connector fitting portion  12  is constituted to have symmetric taper shapes on both sides toward the width direction. In other words, inclinations of the inner wall surfaces of the connector fitting portion  12  are symmetric with respect to the width center. For this reason, even if a machining error occurs for the width dimension of the base fitting portion  32  or even if individual differences of productions occur for the insertion depths of the base fitting portion  32  with respect to the connector fitting portion  12 , it is possible, by merely inserting the base fitting portion  32  into the connector fitting portion  12 , to obtain a configuration in which the base fitting portion  32  and the connector fitting portion  12  will be centered automatically toward the width direction (Y-direction). Therefore, it is possible to heighten the positioning accuracy relating to the Y-direction of the protruded position of the antenna terminal  44  with respect to the connector unit  10 . 
     The opening dimension of the through-hole  18  is larger than the cross-sectional dimension of the antenna terminal  44  and the antenna terminal  44  is loosely inserted with respect to the through-hole  18 . By a configuration in which the periphery (bottom portion  16 ) of the through-hole  18  does not interfere with the antenna terminal  44 , a phenomenon in which the positioning accuracy of the antenna terminal  44  will be reduced is prevented depending on the machining accuracy of the through-hole  18 . 
       FIG. 6  is a schematic view showing a horizontal cross section in a fitted state between the connector fitting portion  12  and the base fitting portion  32 . The cross section of the antenna coil device  100  which is obtained by being cut along the XY plane is referred to as a horizontal cross section. 
     The connector unit  10  and the base unit  30  are provided with second fitting portions  24  ( 24   a ,  24   b ) and  35  ( 35   a ,  35   b ) respectively which are formed by concaves and convexes toward the intersecting direction with respect to the aligning direction of the pair of antenna terminals  44  and which are fitted with each other. By fitting the second fitting portions  24  and  35  each other, the antenna body  40  is positioned in the aligning direction with respect to the connector unit  10 . Thus, in the antenna coil device  100  of this exemplified embodiment, the antenna terminals  44  of the antenna body  40  are positioned in both of the aligning direction of the antenna terminals  44  and the intersecting direction thereof with respect to the connector unit  10 . Consequently, the external circuit (not shown) and the antenna terminals  44  are connected electrically and mechanically in a very stable state through the connector unit  10 . 
     In the antenna coil device  100  of this exemplified embodiment, there is illustrated a case in which the second fitting portions  24  ( 24   a ,  24   b ) of the connector unit  10  are concave portions and the second fitting portions  35  ( 35   a ,  35   b ) of the base unit  30  are convex portions. 
     There is no limitation in particular for the number of the second fitting portions  24  and  35 . It is allowed to employ one piece for each and it is also allowed to employ a plurality of pieces for each. It is also allowed to employ a configuration in which a plurality of convex portions are fitted with a single concave portion. In this exemplified embodiment, there is illustrated an embodiment in which two respective pieces of second fitting portions  24  and  35  are formed on both sides of the ±Y-directions by sandwiching the antenna terminals  44 . 
     As shown in  FIG. 6 , for the base unit  30 , there are arranged two sets of second fitting portions  35  ( 35   a - 35   a ,  35   b - 35   b ) along the aligning direction (X-direction) of the pair of antenna terminals  44 . Each of the two sets of second fitting portions  35  ( 35   a - 35   a ,  35   b - 35   b ) are arranged by being separated from each other with wider distance than that of the pair of antenna terminals  44 . 
     For the base unit  30 , there are formed the second fitting portions  35  by two pairs of pieces respectively on both sides of the intersecting direction by sandwiching the antenna terminals  44 . More specifically, the distance W 1  between the second fitting portions  35   a - 35   a  is wider than the distance W 0  between the pair of antenna terminals  44 . In addition, the distance W 2  between the second fitting portions  35   b - 35   b  is also wider than the distance W 0  between the pair of antenna terminals  44 . It should be noted that the distance between the pair of second fitting portions  35  each other or between the pair of antenna terminals  44  each other means the distance between the adjacent edges with respect to the aligning direction (X-direction) of the antenna terminals  44 . In a case in which the second fitting portions  35  are provided by a plurality of sets ( 35   a - 35   a ,  35   b - 35   b ) as in the case of this exemplified embodiment, the wording of “the pair of second fitting portions  35  are arranged by being separated from each other with wider distance than that of the pair of antenna terminals  44 ” means that at least the distance between the pair of second fitting portions  35  ( 35   a  or  35   b ) is wider than the distance between the antenna terminals  44  each other. 
     In this exemplified embodiment, the distance W 1  between the second fitting portions  35   a - 35   a  and the distance W 2  between the second fitting portions  35   b - 35   b  are equal to each other. Based on the configuration as this exemplified embodiment in which each of the two sets of the second fitting portions  35  are disposed by being separated from each other with wider distance than that of the pair of antenna terminals  44 , it is possible to form the pair of antenna terminals  44  by a still higher machining accuracy than that of the second fitting portions  35 . 
       FIG. 7  is a schematic view showing a vertical cross section in a fitted state between the connector unit  10  and the base unit  30 . The cross section of the antenna coil device  100  which is obtained by being cut along the Z-axis is referred to as a vertical cross section. 
     The antenna coil device  100  is provided with lock mechanisms  50  for engaging the connector unit  10  and the base unit  30  by being deformed in a protruding and retracting fashion toward the intersecting direction (Y-direction) with respect to the aligning direction (X-direction) of the pair of antenna terminals  44 . 
     As shown in  FIG. 2  and  FIG. 7 , the lock mechanisms  50  are constituted by stopper claws  52  formed on the head portion  34  of the base unit  30  and restricting pieces  54  formed on the base-acceptor  22  of the connector unit  10 . The stopper claws  52  are formed by being protruded toward the outward in the circumferential direction (in the ±Y-directions for this exemplified embodiment) from the head portion  34 . With regard to the stopper claw  52 , the front end side thereof (−Z side) is inclined and the rear end side thereof (+Z side) forms a stood-up fold-back portion. 
     The restricting pieces  54  are the positions which are elastically deformed toward the same direction (Y-direction) in a freely protruding and retracting fashion. The restricting pieces  54  have tongue-piece shapes extending toward the depth direction ((−Z)-direction) of the opening portion  14  of the connector unit  10  and they are formed integrally with the base-acceptor  22 . When inserting the head portion  34  into the base-acceptor  22 , the stopper claws  52  proceed into the opening portion  14  while pushing up the restricting pieces  54 . When the head portions  34  are sufficiently inserted as far as the depth at which the stopper claws  52  go beyond the restricting pieces  54 , the restricting pieces  54  are engaged with the rear end sides of the stopper claws  52  by being restored elastically. Thus, the returns of the stopper claws  52  are restricted and the head portion  34  (the base unit  30 ) is prevented from being dropped out from the opening portion  14  of the connector unit  10 . 
     It is allowed for the lock mechanism  50  (the stopper claw  52  and the restricting piece  54 ) to be provided at one place or to be provided at a plurality of places. In this exemplified embodiment, the lock mechanisms are provided at two places facing to each other (on the ±Y sides) within the antenna coil device  100 . Thus, the antenna body  40  is stably fixed with respect to the connector unit  10 . 
     It should be noted that the present invention is not to be limited by the exemplified embodiment mentioned above and that the present invention also includes any embodiments of various modifications, improvements and the like so long as achieving the object of the present invention. 
     In the abovementioned exemplified embodiment, there was illustrated a configuration in which the antenna terminals  44  are formed in bar shapes having uniform thicknesses and are loosely inserted into the through-holes  18 , but the shapes are not limited to these configurations. It is allowed for the antenna terminal  44  to be provided with a thick diameter portion thereon and to be fitted with the bottom portion  16  (the through-hole  18 ) of the connector unit  10 . 
     In addition, in the abovementioned exemplified embodiment, there was illustrated an embodiment in which the connector fitting portion  12  and the base fitting portion  32  are formed in taper shapes which are reduced in diameter merely toward the width direction (Y-direction), but instead of this configuration, it is allowed to employ taper shapes in which the protruded thickness and the depth are reduced gradually in the depth direction (Z-direction). 
     It is not necessary for the various constituent elements of the antenna coil device of the present invention to be individually separated entities, wherein except a case of clearly specifying a single member or a separate member, it is allowed to employ a configuration in which a plurality of constituent elements are to be formed as one piece of member, to employ a configuration in which one constituent element is formed by a plurality of members, to employ a configuration in which a certain constituent element is a portion of another constituent element, to employ a configuration in which a portion of a certain constituent element and a portion of another constituent element are overlapped, and the like. 
     The abovementioned exemplified embodiment of the present invention covers the following technical ideas. 
     (1) An antenna coil device including: a connector unit mounted with a connector of an external circuit detachably by being plugged-in; and a base unit provided with an antenna body including a coil, in which the connector unit and the base unit are constituted by separate members and are used by being combined integrally each other, wherein for the connector unit and the base unit, there are formed a connector fitting portion and a base fitting portion which are formed with a concave and a convex in a direction intersecting with respect to the plug-in direction of the connector unit, and by fitting the connector fitting portion and the base fitting portion, the connector unit and the base unit are combined in a state in which the antenna body is positioned with respect to the connector unit.
 
(2) The antenna coil device described in the abovementioned item (1), wherein in the base unit, there are provided a pair of antenna terminals connected to the coil by protruding toward the plug-in direction, and the base fitting portion is formed on an extended line in the aligning direction of the pair of antenna terminals in which the antenna body is positioned toward the intersecting direction of the aligning direction with respect to the connector unit.
 
(3) The antenna coil device described in the abovementioned item (2), wherein the connector unit includes a bottomed opening portion for mounting the base unit and there is formed a through-hole for inserting the antenna terminal at the bottom portion of the opening portion.
 
(4) The antenna coil device described in the abovementioned item (3), wherein the connector fitting portion and the base fitting portion are fitted by inserting and mounting the base unit in the depth direction of the opening portion.
 
(5) The antenna coil device described in the abovementioned item (4), wherein at least one of the connector fitting portion and the base fitting portion has symmetric taper shapes on both sides, which are reduced in diameters or enlarged in diameters toward the depth direction, and also, the taper ratios thereof are different from each other.
 
(6) The antenna coil device described in any one of the abovementioned items (2) to (5), wherein the connector unit and the base unit respectively include second fitting portions each of which is formed with a concave and a convex in the intersecting direction with respect to the aligning direction of the pair of antenna terminals and which are fitted with each other, and the antenna body is positioned in the aligning direction with respect to the connector unit by fitting the second fitting portions with each other.
 
(7) The antenna coil device described in the abovementioned item (6), wherein in the base unit, the pair of second fitting portions are disposed by being apart with wider width than that of the pair of antenna terminals along the aligning direction of the pair of antenna terminals.
 
(8) The antenna coil device described in the abovementioned item (7), wherein in the base unit, the second fitting portion is formed with a pair of pieces respectively on both sides of the intersecting direction by sandwiching the antenna terminal.
 
(9) The antenna coil device described in any one of the abovementioned items (2) to (8), wherein there is provided with a lock mechanism for engaging the connector unit and the base unit by being deformed in a protruding and retracting fashion toward the intersecting direction with respect to the aligning direction of the pair of antenna terminals.
 
(10) The antenna coil device described in any one of the abovementioned items (1) to (9), wherein the base fitting portion is formed integrally with the base unit, and the connector fitting portion is formed integrally with the connector unit.
 
     INDUSTRIAL ADVANTAGE 
     According to the antenna coil device  100  explained above, it is possible to heighten the electric coupling-reliability between the connector unit  10  and the antenna terminals  44 . For this reason, in a case in which the antenna coil device  100  is used for a vehicle electronic key system, there occurs no inoperative or malfunction. In a case in which malfunction once occurs, it becomes a situation in which the door of the vehicle will be opened and a risk of robbery or the like will occur, but according to the antenna coil device  100 , it is possible to reduce the risk thereof. 
     Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments and that various changes and modifications could be effected therein by one skilled in the art without departing from the spirit or scope of the invention as defined in the appended claims.