JP6593702B2 - Grounding structure, grounding method, and free access floor - Google Patents

Description

  The present invention relates to a grounding structure and a grounding method for grounding a grounding wire drawn from the upper side of a floor portion of a free access floor, and a free access floor having the grounding structure.

  2. Description of the Related Art Conventionally, a so-called free access floor, which is a double floor structure for storing objects to be stored including electrical wiring, power supply equipment, or air conditioning equipment, is known (see, for example, Patent Document 1). Usually, the support leg which supports a floor panel is mainly comprised from the metal which is the material which was strong and excellent in workability. Therefore, the construction worker of the free access floor pays attention to the electrical conductivity of the metal and may perform the grounding work of the electrical / electronic equipment by bringing the grounding wire drawn from the upper side of the floor into contact with the support leg. is there.

JP 2009-144378 A (FIG. 3 etc.)

  However, when constructing a free access floor, if a support leg of a type that does not assume this grounding work is used, for example, it is necessary to process a part of the support leg or attach a fixing jig as a preliminary work. There is. As a result, there arises a problem that the number of parts and work man-hours required for the grounding work are greatly increased.

  As an alternative, it is conceivable to always use a support leg of a type that assumes a grounding work when constructing a free access floor. However, the types of support legs that can be used are greatly limited, which is undesirable for construction workers.

  The present invention has been made in view of the above-described problems, and a grounding structure and a grounding method that can be widely applied to many types of support legs while minimizing the number of parts and work man-hours required for grounding work. The purpose is to provide a free access floor.

  The “grounding structure” according to the present invention is a grounding structure for grounding a grounding wire routed from the upper side of the floor portion of the free access floor, and is located at a height away from the base floor of the free access floor. A support leg including a conductive support that can support the floor, and a height position that covers at least a part of a connection portion that is electrically connected to the ground wire on the outer peripheral surface of the support; A spiral spring wound around the support leg one or more times along the outer peripheral surface is provided.

  Since it comprised in this way, even after a floor part is already formed, a grounding wire can be easily fixed and hold | maintained with respect to an electroconductive support | pillar part. Specifically, the operator holds the one end (center side) of the spiral spring in a state where the outer peripheral surface of the support column is electrically connected to the ground wire after holding the spiral spring with both hands while spreading and unfolding. Press against the ground wire. After that, when the worker moves along the circumferential direction while grasping the other end (outside) of the spiral spring, the spiral spring is elastically deformed in the direction of rewinding by the restoring force generated, and One or more turns are wound around the support leg along the outer peripheral surface while covering at least a part.

Through this winding step, the ground wire is stably held by being pressed toward the outer peripheral surface of the support column. That is, since the spiral spring can be elastically deformed according to the shape of the outer peripheral surface, it is not necessary to separately process the support leg or attach a separate fixing jig. Moreover, since it is sufficient if it is long enough to be wound around the support leg one or more times, it is not necessary to change the length type of the spiral spring according to the type of the support leg or the ground wire. For the above reasons, the present invention can be widely applied to many types of support legs while minimizing the number of parts and work man-hours required for grounding work.

  In addition, a conductive plate member that is fixed while being in contact with the conductor exposed portion of the grounding wire is further provided, and the connection portion includes a portion where the plate member having a shape following the outer peripheral surface contacts the outer peripheral surface. It is preferable. Since the area of the energizing contact increases through the conductive plate material, the grounding behavior is stabilized.

  Moreover, it is preferable that the said board | plate material has a nail | claw part which can be engaged with the upper end part of the said spiral spring provided in the said main-body part and wound around the main-body part which has the shape which followed the said outer peripheral surface. When the ground wire is pulled downward, downward tension is simultaneously generated not only in the ground wire but also in the spiral spring engaged by the claw portion of the plate material. That is, since tension applied to the ground wire is dispersed, the ground wire is unlikely to come off the support leg.

  Moreover, it is preferable that the spiral spring is wound around the support leg two or more times and covers at least a part of the engaging portion by the claw portion. By covering at least a part of the engagement portion with the spiral spring, it is possible to prevent the engagement state between the claw portion and the spiral spring from being released due to rolling up or the like.

  Moreover, it is preferable that the said outer peripheral surface exists in the upper half side of the said support | pillar part. Since the work position for the worker standing on the foundation floor becomes higher, the work efficiency is improved accordingly.

  Or it is preferable that the said outer peripheral surface exists in the lower half side of the said support | pillar part. In the case of using a grounding wire laid on the foundation floor, the floating amount of the grounding wire is small, so that the possibility that the operator's foot gets caught on the grounding wire can be reduced.

  The outer peripheral surface is preferably a circumferential surface or a tapered surface. Since it has the shape of the peripheral surface close to a part of the spiral, the adhesion of the spiral spring to the outer peripheral surface is enhanced, and the grounding behavior is further stabilized correspondingly.

  The “grounding method” according to the present invention is a grounding method for grounding a grounding wire routed from the upper side of the floor portion of the free access floor, wherein the grounding method is at a height away from the base floor of the free access floor. With respect to a support leg including a conductive support column that can support the floor, at a height position that covers at least a part of a connection portion that is electrically connected to the ground wire on the outer peripheral surface of the support column. And a winding step of winding a spiral spring around the support leg one or more times along the outer peripheral surface.

  The “free access floor” according to the present invention has any one of the grounding structures described above.

  The grounding structure, the grounding method, and the free access floor according to the present invention can be widely applied to many types of support legs while minimizing the number of parts and work man-hours required for grounding work.

It is a schematic block diagram of the free access floor which has a grounding structure concerning this embodiment. It is a perspective view of the grounding structure shown in FIG. It is an expanded view of the spiral spring which shows the arrangement | positioning relationship of a grounding wire and a board | plate material. It is a perspective view of the grounding structure concerning a modification.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a grounding structure according to the present invention will be described with reference to the accompanying drawings by giving preferred embodiments in relation to a grounding method and a free access floor.

[Configuration of Free Access Floor 10]
FIG. 1 is a schematic configuration diagram of a free access floor 10 having a grounding structure 30 according to this embodiment. The free access floor 10 includes a plurality of support legs 12 two-dimensionally arranged on a foundation floor F (floor slab), and a plurality of floors arranged without gaps while being supported by the plurality of support legs 12. And a panel 14. The floor portion 16 of the free access floor 10 is formed by combining a plurality of (9 in this example) floor panels 14.

  On the upper side of the floor portion 16, one closed space (hereinafter referred to as a floor space 18) is formed by being surrounded by a ceiling and a wall (both not shown). The floor space 18 is used for various purposes including a general office room, an electronic computer room, a data center, or a factory facility. In this case, electrical / electronic devices including a computer, office equipment, network equipment, and various servers are installed in the floor space 18.

  A single closed space (hereinafter referred to as an underfloor space 20) is formed below the floor portion 16 by being surrounded by the foundation floor F, the floor portion 16, and a wall (not shown). A storage object including electrical wiring, power supply equipment, or air conditioning equipment can be stored in the underfloor space 20. In addition to the power cable and the network cable, the electrical wiring includes a ground line W for performing “equipment grounding” for the electric / electronic device.

  In the illustrated example, the ground wire W is routed from the floor space 18 toward the floor space 20 through the hole 22 provided in the floor panel 14. In the underfloor space 20, a grounding structure 30 for electrically connecting the grounding wire W to the ground (hereinafter referred to as “earth connection”) is constructed. The ground structure 30 can electrically protect the grounded device and can prevent malfunction caused by electrical noise.

[Configuration of Grounding Structure 30]
FIG. 2 is a perspective view of the grounding structure 30 shown in FIG. The grounding structure 30 is provided at a specific location in the underfloor space 20. For example, the four ground wires W are respectively routed toward the four corners of the underfloor space 20 and are grounded to the support legs 12 disposed at the respective corners.

  The support leg 12 is integrally formed with a plate-like base 32 fixed on the foundation floor F, a support portion 34 erected along the normal direction of the support 32, and an upper end portion of the support portion 34. And a substantially disk-shaped mounting table 36 provided on the disk. The support leg 12 is basically made of a metal material having high strength and excellent workability. That is, the base 32, the support column 34, and the mounting table 36 all have high conductivity.

The column part 34 is formed by integrating a substantially columnar columnar part 38 (lower half side) and a bottomed cylindrical hollow cylindrical part 40 (upper half side). The columnar portion 38 has a circumferential outer peripheral surface 42, and a male screw portion 44 is formed on the upper end side of the outer peripheral surface 42. The hollow cylindrical portion 40 has a circumferential outer peripheral surface 46, and a nut 48 is fixed to the lower end side of the outer peripheral surface 46. A female threaded portion (not shown) corresponding to the male screw portion 44 is formed on the inner wall of the nut 48. In other words, by screwing the nut 48 into the upper end portion of the columnar portion 38, the column portion 34 in which the columnar portion 38 and the hollow cylindrical portion 40 are arranged on the same axis is configured.

  The mounting table 36 has a receiving surface 50 that can receive the intersection of the four floor panels 14. The receiving surface 50 is formed with four engaging convex portions 52 arranged isotropically and radially. Accordingly, the support column 34 is placed at a height position away from the base floor F in a state where the engagement convex portion 52 of the mounting table 36 is engaged with the engagement concave portion (not shown) of the floor panel 14. The part 16 (a plurality of floor panels 14) can be supported.

  As can be understood from FIGS. 1 and 2, the grounding structure 30 includes a spiral spring 60 (or, alternatively, one or more turns wound around the support leg 12 along the support leg 12 and the outer peripheral surface 46 of the support column 34. , Main spring) and a conductive plate 62 fixed and held integrally with the ground wire W by the spiral spring 60. The spiral spring 60 is made of a material having a high elastic coefficient (for example, metal / resin), and more preferably has high conductivity. The plate material 62 is made of a highly conductive metal material such as copper or a copper alloy.

  By the way, when the floor space 18 is used for the purpose of an electronic computer room, it is necessary to pay attention to whiskers resulting from the electrogalvanizing process. Therefore, by taking a whisker measure for all of the support leg 12, the spiral spring 60, and the plate member 62, it is possible to prevent an electrical short circuit from occurring in the electric / electronic device.

  FIG. 3 is a development view of the spiral spring 60 showing the positional relationship between the ground wire W and the plate material 62. This figure is the figure which looked at the developed spiral spring 60 from the outer main surface 64. The left side of the figure corresponds to the center side of the spiral spring 60, and the right side of the figure corresponds to the outer side of the spiral spring 60. To do. The ground wire W and the plate material 62 are disposed on the side opposite to the outer main surface 64 (hereinafter, the inner main surface 65).

  Here, the developed view of the outer peripheral surface 46 in the hollow cylindrical portion 40 is also shown by a broken line. The position of the end of the spiral spring 60 on the center side is “P0”, the corresponding position that makes one round of the outer peripheral surface 46 is “P1”, the corresponding position that makes two rounds of the outer peripheral surface 46 is “P2”, and the outer peripheral surface 46 is The corresponding position after three turns is defined as “P3”. As understood from this figure, the spiral spring 60 is wound around the support leg 12 along the outer peripheral surface 46 by about 3.5 turns.

  The ground wire W includes a conductive wire 66 formed by twisting a plurality of strands and an insulating covering material 67 that covers the wire 66. A part of the covering material 67 is peeled off, so that the conductor wire exposed portion 68 is formed on the ground wire W so that the tip end side of the wire material 66 is exposed.

  The plate member 62 includes a plate-shaped main body portion 70, two crimping portions 72 and 72 provided integrally with the main body portion 70, and two claw portions 74 and 74 provided integrally with the main body portion 70. Have. The main body 70 has a shape that follows the outer peripheral surface 46 after deformation, and has a rectangular outer shape before deformation.

  The upper caulking portion 72 is a portion where the distal end side of the conductive wire exposed portion 68 inserted into the sleeve is crimped. The lower caulking portion 72 is a portion where the proximal end side of the conductor exposed portion 68 inserted into the sleeve is pressure-bonded. Thereby, the plate member 62 is fixed while being in contact with the conductor exposed portion 68 of the ground wire W.

  Each claw portion 74 is configured to be engageable with the upper end portion 76 of the spiral spring 60 that is wound. The two claw portions 74 are provided at substantially equal positions from the upper caulking portion 72. Further, the engaging portion by the claw portion 74 is provided between the end position P0 and the corresponding position P1, that is, at the winding position of the first turn of the spiral spring 60.

  Note that the cross-shaped closed region indicated by the alternate long and short dash line is a connection portion 78 where the support 34 is electrically connected to the ground line W. Here, the connection part 78 is composed of [1] a conductor exposed portion 68 that is a direct energization contact, and [2] a main body portion 70 and two caulking portions 72 that are indirect energization contacts.

[Method for constructing grounding structure 30]
The grounding structure 30 according to this embodiment is configured as described above. Then, the construction method (namely, grounding method) of the grounding structure 30 is demonstrated, referring FIGS. 1-3. At this stage, it is assumed that [1] the construction work of the floor 16, [2] the grounding work of the ground wire W, and [3] the preparatory work of the spiral spring 60 and the plate material 62 have already been completed.

  The worker places the grounding wire W so that the conductive wire exposed portion 68 passes through the midpoint of the long side of the main body portion 70 after placing the plate material 62 before deformation on the horizontal plane. Thereafter, by forming the two crimping portions 72, 72, the plate member 62 is fixed while being in contact with the conductor exposed portion 68 of the ground wire W.

  The worker holds the ground wire W while the conductor exposed portion 68 is opposed to the outer peripheral surface 46 of the support column 34 (specifically, the hollow cylindrical portion 40), and the plate member 62 fixed to the ground wire W is attached to the outer peripheral surface. Press along 46. Then, the main body 70 is bent into a shape (that is, a C shape) that follows the outer peripheral surface 46.

  The worker holds the spiral spring 60 with both hands while spreading and unfolds, and makes the inner main surface 65 of the spiral spring 60 face the plate member 62. Then, the worker presses one end (center side) of the spiral spring 60 against the plate material 62 and the ground wire W from a position that covers a part or all of the connection portion 78. When the plate member 62 is not used, the ground wire W is directly sandwiched between the support column 34 and the spiral spring 60.

  Thereafter, the operator moves along the circumferential direction while gripping the other end (outer side) of the spiral spring 60, so that the spiral spring 60 is elastically deformed in the direction of rewinding by the restoring force generated, and connected. While covering at least a part of the portion 78, the support leg 12 is wound two or more times (here, about 3.5 turns) along the outer peripheral surface 46. The plate member 62 is engaged with the upper end portion 76 of the spiral spring 60 by bending the two claw portions 74 toward the front side (outer main surface 64) during or after the operation. In particular, when each claw portion 74 is bent within the range of the end position P0 and the corresponding position P3, the spiral spring 60 covers a part of the engagement portion by the claw portion 74.

  Through this winding step, the ground wire W is stably held by being pressed toward the outer peripheral surface 46 of the support column 34. That is, since the spiral spring 60 can be elastically deformed according to the shape (for example, size, area, or curvature) of the outer peripheral surface 46, a separate processing process is performed on the support leg 12, or a separate fixing jig is used. There is no need to install. Moreover, since it is sufficient if it is long enough to be wound around the support leg 12 or more, it is not necessary to change the length type of the spiral spring 60 according to the type of the support leg 12 or the ground wire W.

[Effects of grounding structure 30]
The grounding structure 30 according to this embodiment connects the ground wire W routed from the upper side of the floor portion 16 of the free access floor 10 (here, the floor space 18) to the ground, and [1] the foundation of the free access floor 10 The support leg 12 including the conductive support column 34 that can support the floor 16 at a height away from the floor F, and [2] the ground line W are electrically connected to the outer peripheral surface 46 of the support column 34. And a spiral spring 60 wound around the support leg 12 along the outer peripheral surface 46 at least once at a height position covering at least a part of the connecting portion 78. In addition, the free access floor 10 according to this embodiment has the grounding structure 30 described above.

  In addition, the grounding method according to this embodiment is arranged along the outer circumferential surface 46 at a height position that covers at least a part of the connection portion 78 electrically connected to the grounding wire W on the outer circumferential surface 46 of the column portion 34. And a winding step of winding the support leg 12 one or more times. According to the grounding structure 30, the grounding method, and the free access floor 10, the grounding structure 30, the grounding method, and the free access floor 10 can be widely applied to many types of support legs 12 while minimizing the number of parts required for grounding work and the number of work steps.

  The grounding structure 30 further includes a conductive plate 62 fixed while being in contact with the conductor exposed portion 68 of the grounding wire W, and the connection part 78 has a plate 62 having a shape that follows the outer peripheral surface 46. A portion that contacts the surface 46 may be included. Since the area of the energizing contact increases through the conductive plate 62, the grounding behavior is stabilized.

  The plate member 62 has a main body portion 70 having a shape following the outer peripheral surface 46 and a claw portion 74 provided on the main body portion 70 and engageable with an upper end portion 76 of the spiral spring 60 wound. May be. When the ground wire W is pulled downward, downward tension is simultaneously generated not only in the ground wire W but also in the spiral spring 60 engaged by the claw 74 of the plate member 62. That is, since tension applied to the ground wire W is dispersed, the ground wire W is unlikely to come off the support leg 12.

  Further, the spiral spring 60 may be wound around the support leg 12 two or more times, and may cover at least a part of the engagement portion by the claw portion 74. By covering at least a part of the engagement portion with the spiral spring 60, it is possible to prevent the engagement state between the claw portion 74 and the spiral spring 60 from being released due to rolling up or the like.

  Moreover, the outer peripheral surface 46 may exist in the upper half side (in FIG. 2, the hollow cylindrical part 40) of the support | pillar part 34. As shown in FIG. In this case, the work position for the worker standing on the foundation floor F becomes higher, and the work efficiency is improved accordingly.

  Further, since the outer peripheral surface 46 has a circumferential surface shape close to a part of the spiral, the adhesion of the spiral spring 60 to the outer peripheral surface 46 is enhanced, and the grounding behavior is further stabilized correspondingly. Even if the outer peripheral surface 46 has a tapered surface shape that gradually decreases in diameter as it goes upward or downward, the same effect can be obtained.

[Modification]
FIG. 4 is a perspective view of a grounding structure 90 according to a modification. The grounding structure 90 is fixed and held integrally with the grounding wire W by the support leg 12, the spiral spring 60 wound around the support leg 12 along the outer peripheral surface 42 of the column portion 34, and the spiral spring 60. A conductive plate member 62. That is, the grounding structure 90 is different from the grounding structure 30 of FIG. 2 in that the spiral spring 60 is wound around the outer peripheral surface 42 on the lower half side of the support column 34. When the grounding wire W laid over the foundation floor F is used, the floating amount of the grounding wire W becomes small, so that the possibility that the worker's foot gets caught on the grounding wire W can be reduced.

[Remarks]
Note that the present invention is not limited to the above-described embodiments and modifications, and can of course be freely changed without departing from the gist of the present invention.

  For example, regarding the size of the spiral spring 60, it can be provided in any width or any length. It is more preferable that the size is applicable to various types of support legs 12 and various types of grounding wires W.

  In the example of FIG. 1, a method of providing the floor panel 14 on the plurality of support legs 12 arranged on the foundation floor F is adopted, but the construction method of the free access floor 10 is not limited to this. For example, you may employ | adopt the system which spreads the block with which the support leg 12 and the floor panel 14 were united.

DESCRIPTION OF SYMBOLS 10 ... Free access floor 12 ... Support leg 14 ... Floor panel 16 ... Floor part 18 ... Floor space 20 ... Under floor space 22 ... Hole part 30, 90 ... Grounding structure 32 ... Base 34 ... Supporting part 36 ... Mounting stand 38 ... Columnar shape Portion 40 · Hollow cylindrical portion 42, 46 · Outer peripheral surface 44 · Male thread portion · 48 · Nut 50 · Receiving surface 52 · Engaging convex portion 60 · Spiral spring 62 · Plate material 64 · Outer main surface 65 · Inner main surface 66 ... Wire material 67 ... Coating material 68 ... Conducted wire exposed part 70 ... Body part 72 ... Caulking part 74 ... Claw part 76 ... Upper end part 78 ... Connection part F ... Base floor W ... Grounding wire

Claims (9)

A grounding structure for grounding a ground wire routed from the upper side of the floor of the free access floor,
A support leg including a conductive support that can support the floor at a height away from the base floor of the free access floor;
A spiral wound around the support leg one or more times along the outer peripheral surface at a height position that covers at least a part of the connection portion electrically connected to the ground line on the outer peripheral surface of the support column. A grounding structure comprising: a spring. A conductive plate fixed while contacting the conductor exposed portion of the ground wire;
The grounding structure according to claim 1, wherein the connection part includes a part where the plate material having a shape following the outer peripheral surface is in contact with the outer peripheral surface. The plate material is
A main body having a shape following the outer peripheral surface;
The grounding structure according to claim 2, further comprising: a claw portion provided on the main body portion and engageable with an upper end portion of the spiral spring wound.   The grounding structure according to claim 3, wherein the spiral spring is wound around the support leg two or more times, and covers at least a part of an engagement portion by the claw portion.   The grounding structure according to any one of claims 1 to 4, wherein the outer peripheral surface is on an upper half side of the support column.   The grounding structure according to claim 1, wherein the outer peripheral surface is on a lower half side of the support column.   The grounding structure according to claim 1, wherein the outer peripheral surface has a circumferential surface shape or a tapered surface shape. A grounding method for grounding a ground wire routed from the upper side of the floor of the free access floor,
For a support leg including a conductive support column that can support the floor portion at a height away from the base floor of the free access floor,
A spiral spring is wound around the support leg one or more times along the outer peripheral surface at a height position that covers at least a part of the connection portion electrically connected to the ground wire on the outer peripheral surface of the support column. A grounding method characterized by comprising a winding process.   The free access floor which has a grounding structure of any one of Claims 1-7.

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