Abstract:
A built-in step is conducted by building a drive part which generates a rotation drive power, a rotation shaft to be rotated by the rotation drive power of the drive part through a gear mechanism, a lock stopper to be screwed with the rotation shaft to move axially by rotating of the rotation shaft, a lock bar which moves between a lock position for locking a steering shaft by movement of the lock stopper and an unlock position for unlocking the steering shaft, and a first spring interposed between the lock stopper and the lock bar for giving a bias load, into a lock body to be installed in a mounting hole part of a steering column post of a vehicle from the same direction. Thereafter, a screwing step for screwing the rotation shaft and the lock stopper after the built-in step is conducted to assemble an electric steering lock device.

Description:
[0001]    The present application is based on Japanese Patent Application No. 2007-019749 filed on Jan. 30, 2007, the entire contents of which are incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to an assembling method of an electric steering lock device, to be applied to vehicles such as automobiles. 
         [0004]    2. Related Art 
         [0005]    As conventional electric steering lock devices, for example, JP-A-2004-231123 and JP-A-2006-36107 disclose, respectively, an electric steering lock device comprising a warm gear which rotates by a rotary motor, a helical gear which rotates by rotation of the warm gear, a lock arm and a cam which operate in association with rotation of this helical gear, a lock stopper which moves between a lock position and an unlock position with respect to a steering shaft, a lock bar, and a lock body housing these parts has been known. 
         [0006]    This electric steering lock device has a configuration, in which the lock bar is moved between the lock position and the unlock position with respect to the steering shaft by mutually rotating the rotary motor in opposite directions. 
         [0007]    However, according to the electric steering lock device of JP-A-2004-231123 etc., when assembling the electric steering lock device, it was necessary to build, for example, the lock bar, the helical gear and the lock stopper etc. into the lock body from different directions. Accordingly, it was impossible to assemble these parts from the same direction. Therefore, there is a disadvantage in that it was difficult to realize the automatic assembling of the electric steering lock device, and there was a limit to reduce the cost of manufacturing by shortening the assembling time. 
       THE SUMMARY OF THE INVENTION 
       [0008]    It is an object of the invention to provide an assembling method of an electric steering lock device, in which various components can be built into the lock body from the same direction when assembling the electric steering lock device, thereby realizing the automatic assembling. 
         [0009]    [1] According to one aspect of the invention, an assembling method of an electric steering lock device comprises: 
         [0010]    a built-in step of building a drive part which generates a rotation drive power, a rotation shaft to be rotated by the rotation drive power of the drive part through a gear mechanism, a lock stopper to be screwed with the rotation shaft to move axially by rotating of the rotation shaft, a lock bar which moves between a lock position for locking a steering shaft by movement of the lock stopper and an unlock position for unlocking the steering shaft, and a first spring interposed between the lock stopper and the lock bar for giving a bias load, into a lock body to be installed in a mounting hole part of a steering column post of a vehicle from the same direction; and 
         [0011]    a screwing step for screwing the rotation shaft and the lock stopper after the built-in step. 
         [0012]    [2] In the assembling method of an electric steering lock device described in above-mentioned [1], the built-in step may comprise a step of previously building the lock bar, the first spring, and the lock stopper into the lock body from the same direction in a temporary assembled state as a sub-assay. 
         [0013]    [3] In the assembling method of an electric steering lock device described in above-mentioned [1], the screwing step may comprises a step of applying a load on the lock stopper in a direction to screw with the rotation shaft through the first spring by applying a load on the lock bar from outside, and rotating the rotation shaft, to screw the lock bar with the rotation shaft. 
         [0014]    [4] The assembling method of the electric steering lock device described in above-mentioned [1] may further comprise a bush insertion step of press fitting a bush to each of holes of the lock body and a lock body lid until a middle of each of the holes in a temporally assembled state, prior to the built-in step. 
         [0015]    [5] In the assembling method of the electric steering lock device described in above-mentioned [1], it is preferable that a male screw part of the rotation shaft and a female screw part of the lock stopper are not screwed with each other yet as a spinning state, prior to the screwing step. 
         [0016]    [6] In the assembling method of the electric steering lock device described in above-mentioned [4], the built-in step may be conducted in a state that no clearance is provided between an edge of the rotation shaft and a load receiving part of the bush. 
         [0017]    [7] In the assembling method of the electric steering lock device described in above-mentioned [1], the built-in step and the screwing step may be conducted by an automatic assembling. 
       EFFECT OF THE INVENTION  
       [0018]    According to embodiments of the present invention, it is possible to provide the assembling method of the electric steering lock device, in which various components can be built into the lock body from the same direction when assembling the electric steering lock device, thereby realizing the automatic assembling. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    Next, the present invention will be explained in more detail in conjunction with appended drawings, wherein: 
           [0020]      FIG. 1  is an exploded perspective view showing an assembly relation of each components of an electric steering lock device  10  to be installed in a steering column post  1  of a vehicle such as an automobile in a preferred embodiment according to the present invention; 
           [0021]      FIG. 2  is a cross section of the steering lock device  10  installed in the steering column post  1 , which shows a cross section including a centerline of a rotation shaft  30  etc. in which the steering lock device  10  is assembled as shown in  FIG. 1 ; 
           [0022]      FIGS. 3A to 3E  are diagrams of a bush  40 , wherein  FIG. 3A  is a plan view thereof,  FIG. 3B  is a side view thereof,  FIG. 3C  is a cross sectional view thereof along A-A line in  FIG. 3A ,  FIG. 3D ) is an enlarged view of a part A in  FIG. 3B , and  FIG. 3E  is a plan view showing a state in which the bush  40  is press fitted into holes  21   a,    22   a  of a main lock body  21  or a lock body lid  22 ; 
           [0023]      FIGS. 4A and 4B  are cross sectional views of the electric steering lock device  10  in the preferred embodiment according to the present invention, wherein  FIG. 4A  shows a state in which each components are built in from the same direction and the lock body lid  22  is not connected or fixed to the main lock body  21 , and  FIG. 4B  shows a state in which the main lock body  21  and the lock body lid  22  are pushed from both sides to have a predetermined positional relation and assembled by fixing with springs etc. in the state in which each components are built in as shown in  FIG. 4A ; and 
           [0024]      FIG. 5  is a cross sectional view of the electric steering lock device  10  in the preferred embodiment according to the present invention showing a non-connecting state, in which a lock bar  60  is not connected with a groove part  5   a  of a steering shaft  5 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiment of this Invention 
       [0025]      FIG. 1  is an exploded perspective view showing an assembly relation of each components of an electric steering lock device  10  to be installed in a steering column post  1  of a vehicle such as an automobile in a preferred embodiment according to the present invention. 
         [0026]      FIG. 2  is a cross section of the steering lock device  10  installed in the steering column post  1 , which shows a cross section including a centerline of a rotation shaft  30  etc. in which the steering lock device  10  is assembled as shown in  FIG. 1 . 
         [0027]    The steering lock device  10  comprises a lock body  20 , a rotation shaft  30 , a warm wheel  31 , a bush  40 , a lock stopper  50 , a lock bar  60 , a motor  70  and a warm gear  71  etc. 
         [0028]    The lock body  20  comprises a main lock body  21  and a lock body lid  22 . The main lock body  21  and the lock body lid  22  comprise a predetermined material, for instance, magnesium die-cast or aluminum die-cast. The main lock body  21  is installed in a predetermined position of the steering column post  1 . In the state that this main lock body  21  is installed in the steering column post  1 , a lock bar  60  (to be described later) projected from a substantial central part of the main lock body  21  moves between a lock position for locking a rotation of a steering shaft  5  and an unlock position for unlocking the steering shaft  5 , to switch a connecting state and a non-connecting state with a groove part  5   a  of the steering shaft  5 . 
         [0029]    Holes  21   a  and  22   a  to which the bush  40  (to be described later) is fitted respectively by press fitting are formed on the main lock body  21  and the lock body lid  22 . These holes  21   a  and  22   a  are formed deeply enough so that a load receiving part  40   a  of the bush  40  does not reach to a bottom of the holes  21   a  and  22   a  at the time of completion of assembly. 
         [0030]    In the rotation shaft  30 , an external screw part  30   a,  which is screwed with a female screw part  50   a  formed on the lock stopper  50  (to be described later), is formed in an intermediate part, and the warm wheel  31  on which a gear is formed is installed. An edge  30   b  is supported to be slidably rotatable by each of the main lock body  21  and the lock body lid  22  at both sides through the bush  40 . 
         [0031]      FIGS. 3A to 3E  are diagrams of the bush  40 , wherein  FIG. 3A  is a plan view thereof,  FIG. 3B  is a side view thereof,  FIG. 3C  is a cross sectional view thereof along A-A line in  FIG. 3A ,  FIG. 3D  is an enlarged view of a part A in  FIG. 3B , and  FIG. 3E  is a plan view showing a state in which the bush  40  is press fitted into holes  21   a,    22   a  of a main lock body  21  or a lock body lid  22 . 
         [0032]    The bush  40  comprises a material having a spring property such as stainless steel, and is installed by fitting the main lock body  21  and the lock body lid  22  into the holes  21   a  and  22   a  with a predetermined fit. The bush  40  is provided with the load receiving part  40   a,  an installation claw part  40   b,  and a bearing claw part  40   c.  The load receiving part  40   a  functions as a contact face with the edge  30   b  of the rotation shaft  30 , and three installation claw parts  40   b  and three bearing claw parts  40   c  are respectively provided to protrude alternately in a substantially vertical direction from this contact face side. 
         [0033]    The installation claw part  40   b  is configured to be opened from the load receiving part  40   a  to a top of an installation claw part  40   d,  so that the installation claw part  40   b  can be fixed to the holes  21   a  and  22   a  formed on the main lock body  21  or the lock body lid  22  by press fitting. For instance, each of the top of installation claw parts  40   d  is inclined by only 0.2 mm outward with respect to a dimension in the load receiving part  40   a.  Furthermore, as shown in  FIG. 3D , the installation claw part  40   b  is such configured that a surface press fitted to the holes  21   a  and  22   a  functions as a burr side by adjusting a draft direction to a direction indicated by an arrow at the time of press work, and a sharp edge part  40   e  is embedded into the holes  21   a  and  22   a,  not to be dropped off easily. 
         [0034]    The bearing claw part  40   c  is configured to be narrowed from the load receiving part  40   a  to a top of a bearing claw part  40   f,  in order to support the rotation shaft  30  to be slidably rotatable. The bearing claw part  40   c  supports an outer circumference of the rotation shaft  30  by three claws. For instance, each of the top of bearing claw parts  40   f  is inclined by only 0.1 mm inward with respect to a dimension of the load receiving part  40   a.  For facilitating an assembly work with the rotation shaft  30 , each of the top of bearing claw parts  40   f  is inclined by, for instance, only 0.2 mm outward. 
         [0035]    In the rotation shaft  30 , the outer circumference of the rotation shaft  30  is supported to be slidably rotatable by the three bearing claw parts  40   c  without any clearance, and the edge  30   b  contacts to the load receiving part  40   a  of the bush  40  to be slidably rotatable without any clearance by the main lock body  21  and the lock body lid  22  through the bush  40  respectively. As a result, the rotation shaft  30  is supported to be slidably rotatable without any clearance in both radial and thrust directions. 
         [0036]    The lock stopper  50  is screwed with an external screw part  30   a  of the rotation shaft  30  at the female screw part  50   a,  and is movable in an axial direction of the rotation shaft  30  by the rotation of the rotation shaft  30 . The lock stopper  50  is connected to the lock bar  60  (to be described later) through the first spring  80 . Furthermore, a controller case  84  is provided with a second spring  81 , so as to give a bias load to the lock stopper  50  in a direction opposite to the bias load given by the first spring  80 , so that the external screw part  30   a  of the rotation shaft  30  can be screwed with the female screw part  50   a  of the lock stopper  50 , even if the lock stopper  50  moves too much in the non-connecting direction (the unlock direction) between the lock bar  60  and the steering shaft  5 . A magnet  83  is installed under the lock stopper  50  to detect the position of the lock stopper  50  by a hole IC  82 . 
         [0037]    The lock bar  60  is connected with the lock stopper  50  through the first spring  80  and is movable between the lock position and the unlock position, so as to switch the connecting or non-connecting state with the groove part  5   a  of the steering shaft  5  by the rotation of the rotation shaft  30 . 
         [0038]    The motor  70  as a driving actuator is installed in the main lock body  21  through the controller case  84  and a spacer  85 , and the warm gear  71  is installed around an axis of the motor  70 . The warm gear  71  is screwed with a warm wheel  31  installed around the rotation shaft  30 . As a result, the rotation of the motor  70  is transmitted to the rotation shaft  30  through the warm gear  71  and the warm wheel  31 . 
         [0039]    (Assembling Method of the Electric Steering Lock Device in the Preferred Embodiment of the Present Invention) 
         [0040]    The bush  40 , the lock bar  60 , the first spring  80 , the lock stopper  50 , the rotation shaft  30 , the controller case  84 , the second spring  81 , the motor  70 , the spacer  85 , the bush  40 , and the lock body lid  22  are built into the main lock body  21  from the same direction (from a right side in  FIG. 1 ). 
         [0041]    Here, the warm wheel  31  is previously installed around the rotation shaft  30 . Furthermore, it is preferable to provide a bush insertion process, in which the bush  40  is press fitted into the main lock body  21  and the holes  21   a,    22   a  of the lock body lid  22  until a halfway of the installation claw part  40   b,  as a temporary assembled state. Furthermore, it is preferable to previously prepare a temporary assembly of the lock bar  60 , the first spring  80  and the lock stopper  50 , as a sub-assay. 
         [0042]      FIGS. 4A and 4B  are cross sectional views of the electric steering lock device  10  in the preferred embodiment according to the present invention. 
         [0043]      FIG. 4A  shows a state in which each components are built in from the same direction and the lock body lid  22  is not connected or fixed to the main lock body  21 , and  FIG. 4B  shows a state in which the main lock body  21  and the lock body lid  22  are pushed from both sides to have a predetermined positional relation and assembled by fixing with springs etc. in the state in which each components are built in as shown in  FIG. 4A . 
         [0044]    According to this step, the edge  30   b  of the rotation shaft  30  is press fitted to the holes  21   a,    22   a  while pushing the load receiving part  40   a,  and assembled without any clearance (thrust) between the edge  30   b  of the rotation shaft  30  and the load receiving part  40   a  of the bush  40  (the rotation shaft built-in step). Even after this rotation shaft built-in step, the load receiving part  40   a  of the bush  40  does not reach to the bottom of the holes  21   a  and  22   a.    
         [0045]    In the above-mentioned step ( FIG. 4B ), the external screw part  30   a  of the rotation shaft  30  and the female screw part  50   a  of the lock stopper  50  are not screwed with each other yet, i.e. in a spinning state. Here, by applying a load on a front edge of the lock bar  60  from the outside, a load is applied to the lock stopper  50  in a direction to screw with the rotation shaft  30  through the first spring  80 . By rotating the motor  70  so as to move the lock bar  60  in the direction to be the non-connecting state with the groove part  5   a  of the steering shaft  5  under this condition, the external screw part  30   a  of the rotation shaft  30  and the female screw part  50   a  of the lock stopper  50  are screwed with each other to be an assembled state as shown in  FIG. 2  (the screw step). 
         [0046]    According to the respective steps mentioned above, the assembling of the electric steering lock device  10  is completed, and it is possible to install the electric steering lock device  10  to the steering column post  1  in this state. 
         [0047]    (Function of the Electric Steering Lock Device in the Preferred Embodiment of the Present Invention) 
         [0048]    In the state that the lock bar  60  is connected with the groove part  5   a  of the steering shaft  5  ( FIG. 2 ), when operating a switch of the vehicle to a position such as “ACC”, “ON” and “START”, the motor  70  rotates in a predetermined rotational direction, the lock bar  60  is activated through the warm wheel  31 , the rotation shaft  30  and the lock stopper  50 , and the connection of the lock bar  60  and the steering shaft  5  are unlocked, to provide the non-connecting state. In a process of this operation, the motor  70  rotates at high speed (for instance, 9600 rpm). As a result, the rotation shaft  30  receives a strong force between the edge  30   b  and the load receiving part  40   a  of the bush  40  as a reaction. However, the edge  30   b  and the load receiving part  40   a  contact with each other in a state of being sidably rotatable without clearance and without backlash, abnormal noise such as impact sound etc. is not generated in the operation as mentioned above. Furthermore, it is similar in the radial direction. Furthermore, since the bush  40  comprises, for instance, the stainless steel, problems of scraping or abrasion by the rotation of the rotation shaft  30  do not occur in a long-term use. 
         [0049]      FIG. 5  is a cross sectional view of the electric steering lock device  10  in the preferred embodiment according to the present invention showing a non-connecting state, in which a lock bar  60  is not connected with a groove part  5   a  of a steering shaft  5 . 
         [0050]    In the state that the lock bar  60  is not connected with the groove part  5   a  of the steering shaft  5 , when operating the switch of the vehicle to a position of “LOCK”, the motor  70  rotates in a rotational direction opposite to the rotational direction in the operation as mentioned above, the lock bar  60  is activated through the warm wheel  31 , the rotation shaft  30 , the lock stopper  50  and the first spring  80 , and the lock bar  60  and the groove part  5   a  of the steering shaft  5  are unlocked, to provide the connecting state. In this case, similarly to the above, the rotation shaft  30  receives the strong force between the edge  30   b  and the load receiving part  40   a  of the bush  40  as a reaction. However, the edge  30   b  and the load receiving part  40   a  contact with each other in the state of being slidably rotatable without clearance and without backlash, the abnormal noise such as the impact sound etc. is not generated in the operation as mentioned above. When the position of the groove part  5   a  does not coincide with the position of the lock bar  60 , the connecting state is realized by connecting the lock bar  60  and the groove part  5   a  of the steering shaft  5  with the bias load of the first spring  80  at the stage that the position of the groove part  5   a  coincides with the position of the position of the lock bar  60  by the rotation of the steering shaft  5 . 
         [0051]    (Effect of the Preferred Embodiment According to the Present Invention) 
         [0052]    Since the moving direction of the lock bar  60 , the axial direction of the rotation shaft  30 , the moving direction by screwing with the external screw part  30   a  of the rotation shaft  30  and the female screw part  50   a  of the lock stopper  50 , the bias direction of the first spring  80  and the second spring  81 , and the press fitting direction of the bush  40  to the holes  21   a,    22   a  are determined to be the same direction, these components can be built into the lock body  20  (the main lock body  21  and the lock body lid  22 ) from the same direction. As a result, the automatic assembling of the electric steering lock device  10  can be facilitated. 
         [0053]    In the state that the rotation shaft  30  and the lock stopper  50  are built into the main lock body  21  from the same direction, the external screw part  30   a  of the rotation shaft  30  and the female screw part  50   a  of the lock stopper  50  are not screwed with each other yet, i.e. at the spinning state. However, in the state of applying the load on the front edge of the lock bar  60  and applying the load on the lock stopper  50  in the direction to screw with the rotation shaft  30  through the first spring  80 , by rotating the motor  70 , so as to move the lock bar  60  in the direction to be the non-connecting state with the groove part  5   a  of the steering shaft  5 , the external screw part  30   a  of the rotation shaft  30  and the female screw part  50   a  of the lock stopper  50  can be screwed with each other. Namely, when building the components into the main lock body  21 , it is enough to build the rotation shaft  30  and the lock stopper  50  into the main lock body  21  from the same direction, without rotating the rotation shaft  30 . It is sufficient to provide the screw step of screwing the external screw part  30   a  of the rotation shaft  30  with the female screw part  50   a  of the lock stopper  50 , after building all necessary components into the lock body  20 . As a result, it is possible to realize the automatic assembling of the electric steering lock device  10 . 
         [0054]    Although the invention has been described with respect to the specific embodiments for complete and clear disclosure, the appended claims are not to be therefore limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art which fairly fall within the basic teaching herein set forth.