JP5781966B2 - Ring reducer - Google Patents

Description

  The present invention relates to a ring used for fixing a connector having a diameter smaller than the inner diameter of a fixing hole to a fixing hole such as a knockout of a wiring box formed to fix a connector such as a connector for connecting a pipe. It is about reducer.

  Conventionally, a ring reducer 61 shown in FIG. 7 is used to fix a connector having a diameter smaller than the inner diameter of a fixing hole in a fixing hole such as a knockout formed in a wiring box or the like. In FIG. 7, a connection tool 41 such as a connector for connecting a pipe 51 such as a conduit shown in FIG. 5 to a fixing hole 32 formed by knocking out the wiring box 31 includes a male screw portion 42 of the connection tool 41 connected to the wiring box. After being inserted into the fixing hole 32 of 31, the nut 43 is tightened from the opposite side of the wall surface 33 to be fixed to the fixing hole 32.

  Here, the male screw portion 42 of the connection tool 41 is different in size from the fixing hole 32, and the outer diameter of the male screw portion 42 is smaller than the inner diameter of the fixing hole 32, so that connection between both is possible. A ring reducer 61 for leveling is used. The ring reducer 61 is formed of a metal plate material or a synthetic resin material, and has a plate shape having a circular hole 63 having a diameter corresponding to the small diameter connector 41 at the center of the reducer main body 62 as shown in FIG. In the periphery of the circular hole 63 of the reducer main body 62, a plurality of positioning projections 64 are inserted on the same radius and engaged with the inner surface thereof, and three in FIG. As shown in FIG. 7B, the positioning protrusion 64 is engaged with the fixing hole 32, and the circular hole 63 is positioned concentrically with respect to the fixing hole 32. The positioning protrusions 64 are formed in an elliptical spherical shape by pressing a metal plate material or by resin molding, and have a predetermined rigidity that is difficult to deform. As this type of ring reducer, for example, a ring reducer described in Patent Document 1 is disclosed.

Japanese Utility Model Publication No. 56-152512

  However, in the conventional ring reducer 61, due to the dimensional tolerance of the fixing hole 32 of the wiring box 31 and the variation in the hole diameter at the time of knockout formation, the diameter of each of the plurality of positioning projections 64 formed on the same radius is on the outer peripheral end. In this case, as shown in FIG. 7C, the entire positioning projection 64 does not fit in the fixing hole 32, and a part of the positioning projection 64 rides on the wall surface 33 of the wiring box 31. And floats from the wall surface 33. Here, the positioning protrusion 64 is formed in an elliptical spherical shape or the like, and has a predetermined rigidity. For this reason, the positioning protrusion 64 that has ridden is in point contact with the peripheral corner portion 32 b of the fixing hole 32 of the wiring box 31 and is not easily deformed. Therefore, when the nut 43 is tightened, the ring reducer 61 is fixed to the fixing hole 32. On the other hand, it is easy to slip in a direction parallel to the wall surface 33 and cannot be positioned concentrically with respect to the fixing hole 32. Further, since a gap S is formed between the reducer main body 62 and the wall surface 33, when the wiring box 31 is to be embedded in concrete, the toro passes through the fixing hole 32 from the gap S when the concrete is placed. There were times when it invaded.

  Therefore, the present invention prevents a part of the fixing hole from climbing on the peripheral wall of the fixing hole and floating even when the hole diameter of the fixing hole is smaller than the circle connecting the outer peripheral end portions of the positioning protrusions due to the dimensional tolerance of the fixing hole. An object of the present invention is to provide a ring reducer that can position itself in a concentric position with respect to the fixing hole.

The ring reducer according to claim 1 is used to fix a connecting tool having a diameter smaller than the inner diameter of the fixing hole to a fixing hole formed to fix the connecting tool for connecting a pipe, And a reducer body formed in a plate shape having a circular hole having a diameter corresponding to the small diameter connector. The reducer body includes a positioning protrusion that is inserted into the fixing hole and engages with an inner surface of the fixing hole in order to position the circular hole with respect to the fixing hole, around the circular hole. The positioning projection is formed to be elastically deformable so as to be flush with the flat surface of the reducer body .

The ring reducer according to claim 2 is an elastic piece in which the positioning projection protrudes toward the radially inner side with the outer edge side of the reducer body as the base end portion and is inclined toward the fixed hole side from the base end portion. Formed and elastically deformable in the direction opposite to the fixing hole.
The ring reducer according to claim 3 is provided with three or more positioning projections at equal intervals in the circumferential direction.
According to a fourth aspect of the present invention, the ring reducer includes a small protrusion for temporarily fixing the positioning protrusion by engaging with a small-diameter connection tool.

  In the first aspect of the present invention, since the positioning projection of the ring reducer for positioning the circular hole with respect to the fixing hole is formed to be elastically deformable, the dimensional tolerance of the fixing hole and the hole diameter at the time of knockout formation When the hole diameter is smaller than the diameter of the circle connecting the base ends of each of the positioning protrusions formed on the same radius due to variations in the diameter, the positioning protrusion is inserted into the fixing hole and engaged with the inner surface to fix. When positioning, the positioning protrusion does not fit in the fixing hole, and even if a part of the positioning protrusion protrudes to the peripheral wall of the fixing hole, the positioning protrusion will move in the opposite direction to the fixing hole as the connector nut is tightened. It is elastically deformed and finally comes into surface contact with the wall surface so that the reducer body does not float from the wall surface. Further, since the positioning protrusion is elastically deformed, the ring reducer is hardly displaced in the direction parallel to the wall surface when the nut is tightened, and is arranged and fixed at a concentric position with respect to the fixing hole. Further, since no gap is formed between the reducer body and the wall surface, the tros do not enter the fixing hole through the gap when the concrete is placed in the concrete.

  According to a second aspect of the present invention, the positioning protrusion is formed of an elastic piece that protrudes toward the radially inner side with the outer edge side of the reducer body as a base end portion and is inclined toward the fixed hole side, and is opposite to the fixed hole. Therefore, when the positioning protrusion is inserted into the fixing hole and engaged with the inner surface of the fixing hole, or when the nut is tightened thereafter, the positioning protrusion naturally tends to be concentric with the fixing hole. Therefore, after the nut is tightened, the ring reducer is fixed in a concentric position without being displaced with respect to the fixing hole.

  In the invention of claim 3, since the positioning protrusions are provided at three or more positions at equal intervals in the circumferential direction, in combination with the action according to claim 2, the positioning protrusions are inserted into the fixing holes and formed on the inner surface thereof. When engaging or tightening the nut after that, the positioning protrusion is more easily concentric with the fixing hole.

  In the invention of claim 4, since the small protrusion is provided at the tip of the positioning protrusion, at the time of fixing operation, after inserting the end of the small diameter connector into the fixing hole and fitting the ring reducer into the fixing hole, The small protrusion engages with the threaded portion at the end of the connector and is temporarily fixed and held. As a result, when the end of the small diameter connector is inserted into the fixing hole from above and the ring reducer is fitted to this end from below, the ring reducer engages and holds the end of the connector. Since it is prevented from falling from the end of the connector, it is not necessary to hold the ring reducer by hand while holding the connector by hand and tightening the nut. Workability is improved.

1A and 1B show a ring reducer according to an embodiment of the present invention, in which FIG. 1A is a perspective view seen from the front side, and FIG. 2B is a perspective view seen from the back side. The ring reducer of FIG. 1 is shown, (a) is a front view, (b) is a cross-sectional view taken along the line AA of (a), and (c) is an enlarged cross-sectional view of part B of (b). When the inner diameter of the fixing hole is the same or slightly larger than the circle connecting the base ends of the positioning protrusions, the arrangement state of the ring reducer with respect to the fixing hole immediately before tightening the nut of the connector is shown, (a) is a front view, (b) is a sectional view. When the inner diameter of the fixing hole is slightly smaller than the circle connecting the base ends of the positioning protrusions, the arrangement state of the ring reducer with respect to the fixing hole immediately before tightening the nut of the connector is shown, (a) is a front view, (b ) Is a cross-sectional view. It is sectional drawing which shows the fixed state of the connection tool to the fixing hole after the nut of a connection tool is tightened. It is sectional drawing which shows the temporary fixation state by the small processus | protrusion of the ring reducer just before tightening of the nut of a connection tool. A conventional ring reducer is shown, (a) is a perspective view, (b), (c) shows the arrangement state of the ring reducer with respect to the fixing hole just before tightening the nut of the connector, of which (b) is the fixing hole The arrangement state when the diameter of the positioning projection is the same as or slightly larger than the circle connecting the outer peripheral end portions of the positioning projections, (c) shows the arrangement state when the diameter of the fixing hole is smaller than the circle.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2, the ring reducer 1 has a fixing hole 32 made of a knockout formed to fix a connection tool 41 for connecting a pipe 51 such as a conduit to the wiring box 31 shown in FIGS. 4 and 5. In addition, it is used when the connector 41 having a diameter smaller than the inner diameter of the fixing hole 32 is fixed. There are various sizes of knockout hole diameters in the wiring box 31, and the small-diameter connector 41 has an outer diameter of the male screw portion 42 that is one size or smaller than this hole diameter. The ring reducers 1 are mounted in pairs on opposite sides of the fixing hole 32 of the wiring box 31 so as to face each other.

  The ring reducer 1 includes a reducer body 11 formed in a plate shape having a circular hole 12 having a diameter corresponding to a small-diameter connector 41 at the center, and is integrally formed of a synthetic resin such as vinyl chloride. . Here, the diameter corresponding to the small-diameter connector 41 means a diameter substantially the same as the outer diameter of the male screw portion 42 of the connector 41, that is, the same or slightly larger diameter.

  The reducer body 11 is inserted into the fixed hole 32 around the central circular hole 12 to engage the inner surface of the fixed hole 32 in order to position the circular hole 12 with respect to the fixed hole 32 of the wiring box 31. A plurality of positioning protrusions 21, three in this embodiment, are provided.

The positioning protrusion 21 is provided in a space in which a part of the periphery of the circular hole 12 is cut out in a U shape. The positioning projection 21 protrudes toward the radially inner side with the outer edge side of the reducer body 11 as a base end portion 22, that is, a circular hole with a substantially intermediate portion in the radial direction of the annular plate portion of the reducer body 11 as a base end portion 22. 12, and is formed of a rectangular flat plate-like elastic piece that linearly inclines toward the fixing hole 32 starting from the base end portion 22. The positioning protrusion 21 can be elastically deformed in the direction opposite to the fixing hole 32, that is, the direction away from the fixing hole 32, starting from the base end portion 22.
Further, three positioning protrusions 21 are provided at equal intervals in the circumferential direction around the circular hole 12 at a phase of 120 degrees.

  Further, the positioning projection 21 is formed with a small projection 24 at the tip for temporarily fixing the ring reducer 1 by engaging with the male screw portion 42 of the small-diameter connector 41. The small protrusions 24 are formed to have a size slightly smaller than the thread pitch of the male thread portion 42 of the connection tool 41. The small protrusion 24 is formed with a small radius on the surface facing the fixing hole 32 on the outer surface side. The reason why the round is formed is to make it easier for the small protrusion 24 to enter the male screw portion 42 of the connector 41.

Here, the length of the positioning protrusion 21 in the protruding direction and the size of the small protrusion 24 at the tip thereof will be described.
The length of the positioning projection 21 in the protruding direction is such that the tip end is substantially on the inner circumference of the circular hole 12 of the reducer body 11 in a state where the inclined surface 23 falls down due to elastic deformation and is flush with the flat surface of the reducer body 11. The size of the circle, in other words, the diameter of the circle connecting the tips of the three positioning protrusions 21 is set to be substantially the same as that of the circular hole 12. The hole diameter of the circular hole 12 is substantially the same as the outer diameter of the male threaded portion 42 of the connector 41, and if the protruding amount of the tip of the positioning protrusion 21 is large, the inclined surface 23 is elastically deformed and is flush with the flat surface of the reducer body 11. This is because the front end interferes with the male threaded portion 42 of the connector 41 before entering the state, and the nut 43 cannot be tightened after the ring reducer 1 is extrapolated to the male threaded portion 42. However, if the distal end of the positioning protrusion 21 slightly enters the valley of the male screw portion 42 and the nut 43 can be tightened without hindrance, the distal end of the positioning protrusion 21 protrudes somewhat to the inner side from the inner circumferential circle of the circular hole 12. May be.

  On the other hand, the small protrusion 24 at the tip of the positioning protrusion 21 is sized so as to be slightly inserted into the valley portion of the male screw portion 42 in a state where the ring reducer 1 is externally inserted into the male screw portion 42 of the connector 41, and The size is set such that the inclined surface 23 of the positioning projection 21 can be extrapolated to the male screw portion 42 without elastically deforming. When the latter point is explained, the inclined surface 23 of the positioning protrusion 21 is inclined in the same direction as the extrapolation direction of the second ring reducer 1b with respect to the male screw portion 42 of the connection tool 41. For this reason, if the small protrusion 24 is too large, the inclined surface 23 of the positioning protrusion 21 is elastically deformed during the extrapolation due to interference with the male screw part 42, and the tip of the positioning protrusion 21 extends to deeply enter the valley of the male screw part 42. It becomes difficult or impossible to insert the second ring reducer 1b into the male screw portion 42. Therefore, the small protrusion 24 is set to a size that can be extrapolated to the male screw portion 42 without elastically deforming the inclined surface 23 of the positioning protrusion 21.

Next, an operation of fixing the small diameter connector 41 to which the pipe 51 is connected to the fixing hole 32 of the wiring box 31 using the ring reducer 1 of the present embodiment formed as described above will be described.
First, the first ring reducer 1 a is externally inserted into the male screw portion 42 of the connection tool 41 with the positioning projection 21 facing the fixing hole 32. Next, after the male screw portion 42 is inserted into the fixing hole 32, the second ring reducer 1 b is extrapolated to the male screw portion 42 protruding to the inner side of the wiring box 31. Note that the same ring reducer 1 is used for the first ring reducer 1a and the second ring reducer 1b, and they are used in different directions when fixed.

  Here, at the stage where the ring reducer 1 is extrapolated to the male screw portion 42, the inner diameter of the fixing hole 32 indicated by a two-dot chain line in FIG. It is the same as or slightly larger than the circle 25 indicated by the alternate long and short dash line connecting the end portions 22. In this case, the peripheral wall 32 a of the fixing hole 32 is more than the base end portion 22 of the positioning projection 21 as shown in FIG. Since it slightly contacts the surface of the reducer main body 11 on the outer peripheral side, there is no gap S between the ring reducer 1 and the peripheral wall 32 a of the fixing hole 32. In this case, since the positioning projection 21 does not contact the peripheral wall 32a of the fixing hole 32, there is no change in the posture of inclining and projecting in an oblique direction without elastic deformation.

  On the other hand, when the ring reducer 1 is extrapolated to the male threaded portion 42 of the connector 41, the inner diameter of the fixing hole 32 has three positioning protrusions 21 due to the dimensional tolerance of the fixing hole 32, the variation in the hole diameter when the knockout is formed, or the like. When it is slightly smaller than the circle 25 connecting the base end portions 22, as shown in FIG. 4, the peripheral corner portion 32 b of the fixing hole 32 comes into contact with the inclined surface 23 on the outer side of the positioning projection 21 and before the nut 43 is tightened. Is slightly lifted from the wall surface 33, and a gap S is generated between the reducer body 11 and the wall surface 33 of the wiring box 31.

However, in this case, the positioning protrusions 21 are provided at three positions at equal intervals in the circumferential direction, and are formed of elastic pieces that are inclined toward the fixing hole 32 with the base end portion 22 on the reducer body 11 as a starting point. Therefore, even if it is slightly deviated from the concentric position with the fixing hole 32 due to the action of the ring reducer 1 described later, as the nut 43 is tightened, it moves to the center position and easily fits therein. Therefore, after the second ring reducer 1b is extrapolated to the male threaded portion 42 of the connector 41, the ring reducer 1 is tightened while the nut 43 is slightly lifted by the inclined surface 23 of the positioning projection 21. 1 is naturally positioned and fixed at a position concentric with the fixing hole 32. Further, the positioning protrusion 21 is elastically deformed in the opposite direction to the fixing hole 32, that is, in the direction indicated by the arrow in FIG. 4B, and becomes flush with the surface of the reducer main body 11 as shown in FIG. Thus, after the nut 43 is tightened, the gap S between the reducer body 11 and the wall surface 33 of the wiring box 31 is eliminated.
Thus, the fixing of the small diameter connector 41 to the fixing hole 32 of the wiring box 31 is completed.

  Here, since the small protrusion 24 is provided at the tip of the positioning protrusion 21 in fixing the connection tool 41, when the second ring reducer 1b described above is extrapolated to the male screw portion 42 of the connection tool 41, In addition, the small protrusion 24 engages with the male screw portion 42 of the connector 41, and the second ring reducer 1 b is temporarily held by the male screw portion 42. For this reason, as shown in FIG. 6, when the external thread portion 42 of the connector 41 is inserted into the fixing hole 32 of the wiring box 31 from above, and the second ring reducer 1 b is extrapolated from below to the external thread portion 42. The small protrusion 24 engages with and is held by the male screw portion 42 of the connector 41, and the second ring reducer 1b is prevented from falling from the male screw portion 42, so that the connector 41 is held by hand. Therefore, it is not necessary to hold the second ring reducer 1b by hand while tightening the nut 43, so that the workability at the time of attaching the connector is improved.

Next, the operation of the ring reducer 1 of this embodiment will be described.
Usually, the diameter of the fixing hole 32 is the same as or slightly larger than the circle 25 connecting the base end portions of the three positioning projections 21, so that the fixing hole 32 is slightly outside the base end portion 22 of the positioning projection 21. Located in. For this reason, the ring reducer 1 is disposed concentrically with respect to the fixing hole 32, and accordingly, the male screw portion 42 of the connection tool 41 is also fixed to the fixing hole 32 in a concentric position.

  On the other hand, when the diameter of the fixing hole 32 is smaller than the circle 25 connecting the base ends of the three positioning protrusions 21, the positioning protrusion 21 is inserted into the fixing hole 32 and engaged with the inner surface thereof as described above. When the positioning protrusion 21 is fixed, the entire positioning projection 21 does not fit in the fixing hole 32, and a part of the positioning protrusion 21 protrudes to the peripheral wall 32 a of the fixing hole 32 and rides on the peripheral corner portion 32 b. However, in the ring reducer 1 of the present embodiment, the positioning protrusion 21 is formed so as to be elastically deformable. Therefore, the positioning protrusion 21 is elastically deformed in the direction opposite to the fixing hole 32 as the nut 43 of the connection tool 41 is tightened. Finally, no gap S is generated between the reducer body 11 and the wall surface 33. Further, since the positioning protrusion 21 is elastically deformed as it is tightened with the nut 43 to be flush with the reducer main body 11, the ring reducer 1 is concentric with the fixing hole 32 without being displaced in a direction parallel to the wall surface 33. Is positioned and fixed. Further, since the gap S is not formed between the reducer body 11 and the wall surface 33, it is possible to prevent the trowel from entering the fixed hole 32 through the gap S when the concrete is placed in the concrete.

  The positioning protrusion 21 is formed of an elastic piece that is inclined toward the fixing hole 32 from the base end portion 22, and the peripheral corner portion 32 b of the fixing hole 32 is in contact with the inclined surface 23 of the positioning protrusion 21. Even if the ring reducer 1 slightly deviates from the concentric position with the fixing hole 32 before the nut 43 is tightened, as the nut 43 is tightened, the peripheral corner portion 32b of the fixing hole 32 and the inclined surface 23 of the positioning protrusion 21 contact each other. The contact position naturally moves so as to slide on the inclined surface 23, and the ring reducer 1 moves so as to slide into the center side with respect to the fixed hole 32, and tends to be concentric with the fixed hole 32. Therefore, after the nut 43 is tightened, the ring reducer 1 is positioned and fixed in a concentric position with respect to the fixing hole 32.

  In addition, since the positioning protrusions 21 are provided at three positions at equal intervals in the circumferential direction and are arranged uniformly, the peripheral corner portion 32b of the fixing hole 32 and the inclined surface 23 of each positioning protrusion 21 are in good balance. Touch. Thereby, in combination with the above-described elastic deformation of the positioning protrusion 21 and the action of the inclined surface, the positioning protrusion 21 is more easily concentric with the fixing hole 32.

  By the way, although the positioning protrusion 21 of the said embodiment is formed with the rectangular flat-plate-shaped elastic piece, it is not limited to this shape, For example, it becomes taper toward the circular hole 12 from the base end part 22. A triangular plate shape, a wedge plate shape, or a U-shaped tip may be formed. Or the positioning protrusion 21 is good also as an elastic piece formed with the curved surface which becomes convex on either the front or back side of the reducer main body 11 as a whole.

  Moreover, although the positioning protrusion 21 of the said embodiment is provided in three places at equal intervals in the circumferential direction around the circular hole 12, you may provide in four or more places at equal intervals in the circumferential direction. Further, it is not always necessary to provide them at regular intervals.

  Further, the positioning projection 21 is provided with a small projection 24 at the tip, but when the small projection 24 is extrapolated to the male screw portion 42 of the connection tool 41, resistance is received by the outer peripheral surface having the irregularities of the male screw portion 42. Therefore, when the resistance is remarkably large and affects workability, the small protrusions 24 may not be provided in all the positioning protrusions 21 or in some of the positioning protrusions 21.

  After the ring reducer 1 is inserted into the fixing hole 32 of the wiring box 31 from the upper side and the ring reducer 1 is fitted into the male screw portion 42 from below when the connecting tool is attached. The small protrusion 24 of the positioning protrusion 21 engages with the male screw portion 42 and is temporarily fixed and held therein. The male screw portion 42 of the connection tool 41 is inserted into the fixing hole 32 of the wiring box 31 from below. When the ring reducer 1 is inserted into the male threaded portion 42 from above, the small protrusion 24 engages with the male threaded portion 42 to prevent the connection tool 41 from falling without being held by hand. Is also possible.

  In addition, the ring reducer 1 is formed of a synthetic resin, but may be formed of a metal plate material having spring properties.

  In addition, although the ring reducer 1 of the said embodiment is used when connecting and fixing the connection tool 41 of the pipe | tube 51 to the fixing hole 32 which consists of a knockout of the wiring box 31, the fixing hole provided in the other electrical installation apparatus The same applies to the case where the connection is fixed.

1, 1a, 1b Ring reducer 24 Small protrusion 11 Reducer main body 32 Fixing hole 12 Circular hole 41 Connector 21 Positioning protrusion 51 Tube
22 Base end

Claims (4)

A ring reducer used for fixing a connector having a diameter smaller than the inner diameter of the fixing hole to a fixing hole formed for fixing a connector for connecting a pipe,
A reducer body formed in a plate shape having a circular hole with a diameter corresponding to the small diameter connector in the center,
The reducer body includes a positioning protrusion that is inserted into the fixing hole and engages with an inner surface of the fixing hole in order to position the circular hole with respect to the fixing hole, around the circular hole.
The ring reducer , wherein the positioning protrusion is formed to be elastically deformable so as to be flush with a plane of the reducer main body .
  The positioning projection is formed of an elastic piece that protrudes toward the radially inner side with the outer edge side of the reducer body as a base end portion and is inclined toward the fixing hole side with the base end portion as a starting point. The ring reducer according to claim 1, wherein the ring reducer can be elastically deformed in a direction opposite to the hole.   The ring reducer according to claim 1 or 2, wherein the positioning protrusions are provided at three or more locations at equal intervals in the circumferential direction.   The ring reducer according to any one of claims 1 to 3, wherein a small protrusion is provided at a distal end of the positioning protrusion to be engaged with and temporarily fixed to the small diameter connector.

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