Abstract:
Provided is a casing cover able to conform to the dimensional tolerance in a difference between levels of the casing. The casing cover has an upper level cover which covers two openings in the upper level of the casing and a lower level cover which covers an opening in a lower level of the casing. Furthermore, among the upper level cover and the lower level cover: one is formed with an insertion opening passing therethrough in the direction of the height of the difference in levels; and the other is provided with a guide fitting formed to a length in the direction of the height of the difference in levels, which is longer than the maximum allowable dimension of the height of the difference between levels plus a value, and inserted into the insertion opening. In addition, for purposes of preventing the guide fitting, which connects the upper level cover and the lower level cover, from slipping out of the insertion opening, a connection fitting is provided.

Description:
This is a 371 national phase application of PCT/JP2010/071055 filed 25 Nov. 2010, the contents of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to a casing cover. 
     BACKGROUND ART 
     In a vehicle provided with a high-voltage device and the like, the high-voltage device is contained in a casing  100  as shown in  FIG. 8 , in order to protect the high-voltage device and prevent a worker who performs maintenance and inspection, etc. of the vehicle from coming into contact with the high-voltage device. A plurality of openings are made in the walls of the casing  100 . These openings include cable insertion openings  104  into which cables  102  to be connected to an input terminal and an output terminal of the high-voltage device are inserted, and tool insertion openings  106  into which a tool is inserted in order to fix a cable terminal  103  to the input terminal or the output terminal of the high-voltage device using fastener members such as screws. 
     As shown in  FIG. 8  and Patent Literature 1, tool insertion openings  106  are covered by a protection cover which is referred to as a terminal cover  108 . The terminal cover  108  is a plate-like member having a shape corresponding to the arrangement of the tool insertion openings  106  and is fixed to a wall surface  110  by fastener members such as screws. In order to perform the operation of attaching and removing the cable terminal  103  to/from an input terminal and an output terminal of the high-voltage device, the terminal cover  108  is first removed from the casing  100  to thereby expose the tool insertion openings  106 , and the tool is then inserted into the insertion openings  106 . 
     CITATION LIST 
     Patent Literature 
     [Patent Literature 1] JP 2008-279973 A 
     SUMMARY OF INVENTION 
     Technical Problem 
     In recent years, in order to fulfill the demand for miniaturization of a casing, there has been developed a casing  122  in which the wall surface in which the tool insertion openings  106  are made is shaped in a step form having an upper step surface  118  and a lower step surface  120 , as shown in  FIG. 9 . Because the tool insertion openings  106  are provided on both the upper step surface  118  and the lower step surface  120 , both surfaces need to be covered by the terminal cover. Therefore, as shown in  FIG. 10 , it may be possible to cover the upper step surface  118  and the lower step surface  120  by a terminal cover  126  having a step portion  124  having a height equal to a design value L 0  of the step height between the upper step surface  118  and the lower step surface  120 . 
     Here, for the step height of the casing  122 , a maximum permissible size value and a minimum permissible size value having predetermined widths from the designed value L 0  are determined, and steps on individual casings  122  may have a value between a maximum permissible size value and a minimum permissible size value.  FIG. 11  shows that the terminal cover  126  is attached to the casing  122  having the step height that is the minimum permissible size value. In this case, the upper step portion  128  of the terminal cover  126  comes off the upper step surface  118  of the casing  122 . Meanwhile, as shown in  FIG. 12 , when the terminal cover  126  is attached to the casing  122  having the step height that is the maximum permissible size value, the lower step portion  130  of the terminal cover  126  comes off the lower step surface  120  of the casing  122 . As such, there are cases where, if the step height of the terminal cover is fixed, the terminal cover cannot accommodate the dimensional tolerance of the step on the casing  122 , resulting in insufficient shielding of the tool insertion openings  106 . 
     Therefore, the purpose of the present invention is to provide a casing cover that can accommodate the dimensional tolerance of the step on the casing. 
     Solution to Problem 
     The present invention relates to a cover that covers openings of a casing. A step is formed on the casing, and openings are formed in the upper step surface and the lower step surface connected to each other by the step. The cover is provided with an upper step cover for covering the opening in the upper step surface and a lower step cover for covering the openings in the lower step surface. An insertion opening penetrating in the step height direction is formed in one of the upper step cover and the lower step cover, while a guiding member configured to be inserted into the insertion opening and have a length in the step height direction longer than the maximum permissible size value of the step height is provided in another one of the upper step cover and the lower step cover. In addition, there is also provided a connecting member which connects the upper step cover to the lower step cover to thereby prevent the guiding member from falling out from the insertion opening. 
     It is also preferable in the above invention for the opening shape of the insertion opening to be noncircular, and for the guiding member to have a cross-sectional shape in a direction perpendicular to the step height direction that corresponds to the opening shape. 
     It is further preferable in the above invention for a second insertion opening penetrating in the step height direction to be formed in one of the upper step cover and the lower step cover, and for a detent pin that is to be inserted into the second insertion opening to be provided at a position on the casing corresponding to the second insertion opening. 
     Advantageous Effect of Invention 
     With a casing cover according to the present invention, it is possible to accommodate the dimensional tolerance of the step on the casing. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  shows an example of a terminal cover according to the present embodiment. 
         FIG. 2  shows the terminal cover according to the present embodiment which is attached to the casing. 
         FIG. 3  shows the terminal cover according to the present embodiment which is attached to the casing. 
         FIG. 4  shows the terminal cover according to the present embodiment which is attached to the casing. 
         FIG. 5  shows an example of a terminal cover according to another embodiment; 
         FIG. 6  shows the terminal cover according to another embodiment which is attached to the casing. 
         FIG. 7  shows the terminal cover according to another embodiment which is attached to the casing. 
         FIG. 8  shows an example of a conventional casing. 
         FIG. 9  shows an example of a miniaturized casing. 
         FIG. 10  shows an example of a step-shaped terminal cover. 
         FIG. 11  shows the step-shaped terminal cover attached to the casing. 
         FIG. 12  shows the step-shaped terminal cover attached to the casing. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     A terminal cover  10  according to the present embodiment is attached to a casing  12  as shown in  FIG. 1 . The casing  12  is a hollow housing, and a high-voltage device (not shown) is contained in the casing  12 . The casing  12  is composed of components having mechanical strength that can protect the high-voltage device, and is made of, for example, a metallic material such as aluminum. The casing  12  also supports the high-voltage device through an insulated material and has a structure that is not electrically connected to the high-voltage device even if the high-voltage device contacts with the casing  12 . The casing  12  and the high-voltage device are mounted on a vehicle having, for example, a rotating electrical machine as a drive source. The high-voltage device includes, for example, a DC/DC converter boosting DC power of a battery and an inverter converting the DC power obtained after boosting to AC power. 
     The casing  12  also has a step shape, and an upper step surface  14  is connected to a lower step surface  16  by a step surface  18 . Although, in  FIG. 1 , the step is formed on the top surface of the casing  12 , it may be formed on the side surface or the bottom surface. 
     A limit of size is determined for the step height between the upper step surface  14  and the lower step surface  16  (the length in the z direction in  FIG. 1 ). That is, assuming that a dimensional tolerance is 2d, a maximum permissible size value L 0 +d and a minimum permissible size value L 0 −d are determined with respect to a design value L 0  of the step height. If the step obtained when the casing  12  is manufactured is equal to or greater than the minimum permissible size value and equal to or smaller than the maximum permissible size value, the casing  12  is treated as an eligible article, while if the step is out of this range, the casing  12  is treated as an ineligible article. In other words, the step height of individual casings  12  may have a value between the minimum permissible size value L 0 −d and the maximum permissible size value L 0 +d. The maximum permissible size value L 0 +d and the minimum permissible size value L 0 −d may be obtained from a general tolerance. 
     On the side surface of the casing  12 , there are provided cable insertion openings  20 A to  20 D through which cable terminals are inserted into an input terminal and an output terminal of the high-voltage device (not shown) contained in the casing  12 . In the embodiment shown in  FIG. 1 , the tool insertion openings  22 A to  22 C are made in the upper step surface  14 , while the tool insertion opening  22 D is made in the lower step surface  16 . 
     The input terminal or the output terminal of the high-voltage device is fixed to the cable terminal with a fastener member such as a screw. For example, screw holes of the input terminal and the output terminal are aligned with screw holes in the cable terminals and are fastened with screws. A fastening tool such as a driver is inserted into the tool insertion openings  22 A to  22 D for fixation. 
     The terminal cover  10  according to the present embodiment is configured to close the tool insertion opening  22 A to  22 D. That is, the terminal cover  10  is configured to have an upper step cover  30  which closes the tool insertion openings  22 A to  22 C in the upper step surface  14  of the casing  12  and a lower step cover  32  which closes the tool insertion opening  22 D in the lower step surface  16  of the casing  12 . The upper step cover  30  and the lower step cover  32  are composed of components mechanically strong enough not to bend even when the operator or the like applies a load, and are made of, for example, a metallic material such as aluminum. 
     The upper step cover  30  is configured as a plate-like member having a shape corresponding to the arrangement of the tool insertion openings  22 A to  22 C, while the lower step cover  32  is configured as a plate-like member having a shape corresponding to the arrangement of the tool insertion opening  22 D. For example, in  FIG. 1 , because the tool insertion openings  22 A to  22 C are arranged in an L shape in the upper step surface  14 , the upper step cover  30  is also in an L shape. Further, fixing holes  35  are provided in the upper step cover  30  and the lower step cover  32  at positions corresponding to fixing holes  34  provided in the upper step surface  14  and the lower step surface  16  of the casing  12 . In order to fix the upper step cover  30  to the upper step surface  14  and fix the lower step cover  32  to the lower step surface  16 , the fixing holes  35  of both covers are aligned with the fixing holes  34  of the both step surfaces, and then they are fixed using fastener members such as screws. 
     Further, the lower step cover  32  is provided with an interlock key  42 . The interlock key  42  can be inserted into a key insertion opening  43  formed, in an interlocking device  41  provided in the casing  12 , at a position corresponding to the tool insertion opening  22 D. When the interlock key  42  is pulled out from the key insertion opening  43 , the interlocking device  41  cuts off power supply to the high-voltage device in the casing  12 . Specifically, a system main relay on a wire connecting the battery to the high-voltage device is switched from a connecting state to a disconnecting state. Although, in the embodiment shown in  FIG. 1 , the interlock key  42  is provided on the lower step cover  32 , this embodiment is not limiting. In short, the interlock key  42  only has to be provided at a position corresponding to the key insertion opening  43 . For example, the key insertion opening  43  may be provided in one of the tool insertion openings  22 A to  22 C, and the interlock key  42  may be provided in the upper step cover  30  at a position corresponding to the tool insertion opening in which the key insertion opening  43  is provided. 
     In addition, the upper step cover  30  is provided with an insertion opening  36  penetrating in the step height direction (Z axis direction in  FIG. 1 ). Meanwhile, the lower step cover  32  is provided with a guiding member  38  to be inserted into the insertion opening  36 . The guiding member  38  is composed of a component mechanically strong enough not to bend even when the operator or the like applies a load, and is made of, for example, a metallic material such as aluminum. Further, the guiding member  38  may be integrally formed with the upper step cover  30 . The guiding member  38  may be fixed to the upper step cover  30  as a separate component by welding, etc. 
     The guiding member  38  extends from the lower step cover  32  in the step height direction and is configured so that the length L 2  in the step height direction is greater than the maximum permissible size value L 0 +d of the step height of the casing  12  (L 2 &gt;L 0 +d), as shown in  FIG. 2 . Here, it is assumed that the height L 2  of the guiding member  38  in the step direction indicates the height from a bottom surface  33  of the lower step cover  32 . Further, a cross sectional shape of the guiding member  38  in a direction perpendicular to the step height direction (x-y plane in  FIG. 1 ) corresponds to the shape of the insertion opening  36 . In  FIG. 1 , the cross-sectional shape of the insertion opening  36  and the guiding member  38  is rectangular. 
     A narrow gap is provided between the insertion opening  36  and the guiding member  38  so that the guiding member  38  inserted into the insertion opening  36  is not fixed to the upper step cover  30 . Further, the upper step cover  30  is slidable along the guiding member  38  in the step height direction. As a result, it is possible to adjust a relative distance Δz between the upper step cover  30  and the lower step cover  32  in the step direction. Here, the relative distance Δz indicates a relative distance between the bottom surface  33  of the lower step cover  32  and a bottom surface  31  of the upper step cover  30  in the step height direction (z axis direction). 
     Further, the upper step cover  30  and the lower step cover  32  are connected by a connecting member  40 . The connecting member  40  is composed of a component that can connect the upper step cover  30  and the lower step cover  32  even if the relative distance Δz changes, and is made of a flexible material such as a resin. The connecting member  40  is fixed to the upper step cover  30  and the lower step cover  32  by, for example, fastener members such as screws. 
     As shown in  FIG. 2 , the connecting member  40  is configured so that the maximum length L 1  in the step height direction is shorter than the length L 2  of the guiding member  38  in the step height direction (L 1 &lt;L 2 ). Here, it is assumed that the maximum length L 1  of the connecting member  40  indicates the length from the bottom surface  33  of the lowest step cover  32  (surface in contact with the lower step surface  16 ) to the bottom surface  31  of the upper step cover  30  (surface in contact with the upper step surface  14 ) when the connecting member  40  is dragged in the step height direction. By making the maximum length L 1  of the connecting member  40  shorter than the height L 2  of the guiding member  38 , it is possible to prevent the guiding member  38  from falling out from the insertion opening  36 . 
     The connecting member  40  also serves to determine an upper limit of the relative distance Δz between the upper step cover  30  and the lower step cover  32 . That is, the upper step cover  30  and the lower step cover  32  cannot be separated from each other further than the maximum length L 1  of the connecting member  40 . In this regard, it is preferable that the maximum length L 1  of the connecting member  40  is equal to or longer than the length of the maximum permissible size value L 0 +d of the step height (L 1 ≧L 0 +d). In doing so, it is possible to adjust the relative distance Δz between the upper step cover  30  and the lower step cover  32 , from the minimum permissible size value L 0 −d to the maximum permissible size value L 0 +d of the step height. 
     Although, in  FIGS. 1 and 2 , the upper step cover  30  is provided with the insertion opening  36  and the lower step cover  32  is provided with the guiding member  38 , this embodiment is not limiting. In short, the configuration only has to be able to adjust the relative distance Δz between the upper step cover  30  and the lower step cover  32 . For example, the upper step cover  30  may be provided with the guiding member  38 , and the lower step cover  32  may be provided with the insertion opening  36 . In this case, the height L 2  of the guiding member  38  indicates the height from the bottom surface  31  of the upper step cover, while the maximum length L 1  of the connecting member  40  indicates the height from the bottom surface  31  of the upper step cover  30  to the bottom surface  33  of the lower step cover  32 . 
     Next, attachment of the terminal cover  10  according to the present embodiment to the casing  12  will be described. As shown in  FIG. 2 , when the step height of the casing  12  is the maximum permissible size value L 0 +d, the relative distance Δz between the upper step cover  30  and the lower step cover  32  is adjusted to be the maximum permissible size value L 0 +d of the step height. In doing so, it is possible to fix the upper step cover  30  to the upper step surface  14  of the casing  12  and fix the lower step cover  32  to the lower step surface  16  of the casing  12 . Similarly, as shown in  FIG. 3 , when the step height of the casing  12  is the minimum permissible size value L 0 −d, the relative distance Δz between the upper step cover  30  and the lower step cover  32  is adjusted to the minimum permissible size value L 0 −d of the step height. In doing so, it is possible to fix the upper step cover  30  to the upper step surface  14  of the casing  12  and fix the lower step cover  32  to the lower step surface  16  of the casing  12 . As such, because the terminal cover  10  of the present embodiment can change the relative distance in the step height direction between the upper step cover  30  and the lower step cover  32 , it is possible to accommodate the dimensional tolerance of the casing  12  in the step height to thereby cover the upper step surface  14  and the lower step surface  16  of the casing  12 . 
     Further, the terminal cover  10  according to the present embodiment has a configuration for preventing one of the tool insertion openings  22 A to  22 D from being exposed when the interlocking device  41  does not work. This configuration will be described below. In the following description, it is assumed that the interlock key  42  is provided on the lower step cover  32 . As shown in  FIG. 4 , the lower step cover  32  is fixed to the lower step surface  16  by fastener members  44  such as screws, while the fastener members  44  are removed from the upper step cover  30 . In this case, it is impossible to lift the upper step cover  30  higher than the maximum length L 1  of the connecting member  40  in the step height direction (z direction in  FIG. 4 ). Meanwhile, the length L 2  in the step height direction of the guiding member  38  is equal to or greater than the maximum length L 1  of the connecting member  40 . As a result, it is impossible to take off the upper step cover  30  from the guiding member  38 . In addition, because the insertion opening  36  and the guiding member  38  have a rectangular shape, it is impossible to expose the tool insertion openings  22 A to  22 C by rotationally moving the upper step cover  30  on the x-y plane. Further, because, as described above, the mechanical strength of the guiding member  38  is determined so that the guiding member  38  does not bend even when the operator or the like applies a load, it is impossible to bend the guiding member  38  to flip over the upper step cover  30  with respect to the upper step surface  14  of the casing  12 . Ultimately, none of the tool insertion openings  22 A to  22 D are exposed unless the fastener members  44  connected to the lower step cover  32  are removed and the upper step cover  30  and the lower step cover  32  are removed together. When the lower step cover  32  is removed, the interlock key  42  provided on the lower step cover  32  is pulled off from the key insertion opening  43  of the interlocking device  41 , thereby activating the interlocking device. As such, with the terminal cover  10  according to the present embodiment, when one of the tool insertion openings  22 A to  22 D is exposed, the interlocking device  41  is activated to thereby cut off power supply to the high-voltage device. With this, it is possible to ensure safety of the worker who inserts the tool into the tool insertion openings  22 A to  22 D to perform maintenance and inspection, etc. 
     Although, in the above-described embodiment, the cross-sectional shape of the insertion opening  36  and the guiding member  38  is rectangular, this shape is not limiting. In short, the configuration only has to be able to prevent the upper step cover  30  from rotationally moving on the x-y plane. A desired noncircular shape may be adopted in place of the rectangular shape. Further, a plurality of insertion openings  36  may be provided in order to prevent the upper step cover  30  from rotationally moving. In the latter case, the cross-sectional shape of the insertion openings  36  and the guiding members  38  may be circular or noncircular. 
       FIG. 5  shows an embodiment in which a plurality of insertion openings  36  are provided. The upper step cover  30  of the terminal cover  10  is provided with a first insertion opening  50  and a second insertion opening  52 . The guiding member  38  is inserted into the first insertion opening  50 . In addition, a detent pin  54  is provided on the upper step surface  14  of the casing  12  at a position corresponding to the second insertion opening  52 , and as shown in  FIG. 6 , the detent pin  54  is inserted into the second insertion opening  52 . Although, in the embodiment shown in  FIGS. 5 and 6 , the second insertion opening  52  is provided in the upper step cover  30 , this configuration is not limiting. In short, the second insertion opening  52  and the detent pin  54  only have to be provided on the side on which the interlock key  42  and the key insertion opening  43  are not provided. For, example, it is also possible to provide the key insertion opening  43  in one of the tool insertion openings  22 A to  22 C in the upper step surface  14  and the interlock key  42  on the upper step cover  30 , while providing the second insertion opening  52  in the lower step cover  32  and the detent pin  54  on the lower step surface  16 . 
     The detent pin  54  extends from the upper step surface  14  of the casing  12  in the step height direction (z axis direction in  FIGS. 5 and 6 ), and the length L 3  of the detent pin  54  in the step height direction is determined so that the detent pin  54  does not fall out from the second insertion opening  52  even when the relative distance Δz between the upper step cover  30  and the lower step cover  32  is maximum. Specifically, as shown in  FIG. 7 , the length L 3  of the detent pin  54  in the step height direction is determined so as to be greater than a difference between the maximum length L 1  of the connecting member  40  and the minimum permissible size value L 0 −d of the step height of the casing  12  (L 3 &gt;L 1 −(L 0 −d)). 
     The upper step cover  30  is prevented from rotationally moving by cooperation between the detent pin  54  and the guiding member  38 . Like  FIG. 4 ,  FIG. 6  and  FIG. 7  show that the fastener members  44  of the upper step cover  30  are removed, while the lower step cover  32  is fixed on the lower step surface  16  by the fastener members  44 . As shown in  FIG. 7 , as the relative distance Δz between the upper step cover  30  and the lower step cover  32  is limited by the connecting member  40 , it is impossible to separate the upper step cover  30  from the lower step cover  32  further than L 1 . Meanwhile, the sum of the length L 3  of the detent pin  54  and the minimum permissible size value L 0 −d of the step height of the casing  12  is designed to be greater than the maximum length L 1  of the connecting member  40 . Therefore, it is impossible to pull out the detent pin  54  from the second insertion opening  52 . As described above, it is also impossible to pull out the guiding member  38  from the first insertion opening  50 . As a result, rotational movement of the upper step cover  30  is limited by the guiding member  38  and the detent pin  54 . 
     REFERENCE SIGN LIST 
       10  terminal cover,  12  casing,  14  casing upper step surface,  16  casing lower step surface,  18  step surface,  20  cable insertion opening,  22  tool insertion opening,  30  upper step cover,  31  upper step cover bottom surface,  32  lower step cover,  33  lower step cover bottom surface,  34  casing side fixing hole,  35  terminal cover side fixing hole,  36  insertion opening,  38  guiding member,  40  connecting member,  41  interlocking device,  42  interlock key,  43  key insertion opening,  44  fastener member,  50  first insertion opening,  52  second insertion opening,  54  detent pin.