JP2009081283A - Bushing for electric apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bushing for an electric apparatus capable of planning a reduction of cost by reducing parts count and of simplifying an installation to a case of the electric apparatus. <P>SOLUTION: The bushing for the electric apparatus unifies: a porcelain bushing body 101; and a porcelain bushing base 102 projectingly provided at one end in the axial direction of the porcelain bushing body 101 in such a fashion that the porcelain bushing body 101 and an axis are shared so as to have an outer diameter smaller than that of the one end in the axial direction of the porcelain bushing body 101. A bushing BG is constituted by: a resin made porcelain bushing 1 arranged in such a fashion that the porcelain bushing base 102 penetrates a mounting hole 302 established in a case 3 of the electric apparatus; and a bushing conductor 2 provided such that a porcelain bushing is penetrated in the axial direction. A latch 103 engaging with the case 3 of the electric apparatus to fasten the porcelain bushing in the case 3 when inserting the porcelain bushing base 102 into the mounting hole 302 is integrated with an end surface of the one end of the porcelain bushing body 101 or the porcelain bushing base 102. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bushing for an electric device that is attached to a case of an electric device such as a transformer, a reactor, or a switch.

  Bushings for porcelain appliances that use porcelain pipes made of porcelain are widely used. However, porcelain is a brittle material, easy to chip, and cumbersome to handle. Came to be used. Since the resin is a ductile material, the resin bushing has a characteristic that it does not break even if it is deformed with some distortion.

The resin bushing includes a resin soot tube and a bushing conductor provided in a state of penetrating the soot tube in the axial direction, and is attached to the case in a state of penetrating a mounting hole provided in the case of the electrical device. . In the conventional resin bushing, as shown in Patent Document 1, a plastic pipe is inserted into the case through a pipe main body arranged outside the case of the electrical device and a mounting hole provided in the case. A peripheral wall provided on a part of the inner side pipe on the outer periphery of the distal end portion of the base part of the outer side pipe that has penetrated the mounting hole. It is attached to the case of the electric device by fitting the parts and screwing the nuts to the threaded portions provided on the outer periphery of the tip of the bushing conductor that penetrates the outer and inner side pipes to fasten both side pipes.
JP 2005-19089 A

  When attaching the bushing shown in Patent Document 1 to a case of an electric device, first, the bushing conductor is passed through the through hole in the axial center portion of the outer side pipe, and then the base part of the outer side pipe and the bushing conductor protruding from the base part The tip is inserted into the case through the mounting hole of the case of the electric device. Next, the outer wall tube and the inner wall tube are tightened by fitting the peripheral wall portion of the inner wall tube from the inside of the case of the electrical equipment to the outer periphery of the base portion of the outer wall tube and screwing the nut screwed to the outer periphery of the bushing conductor. Are fixed in the case of the electric device by tightening in the direction of pulling them together.

  In the conventional resin bushing as shown in Patent Document 1, since the soot tube is composed of an outer soot tube and an inner soot tube, it is inevitable that the number of parts increases and the cost increases. In addition, since the number of man-hours for attaching the bushing to the electric device is large, there is a problem of increasing the manufacturing cost of the electric device.

  An object of the present invention is to reduce the cost by reducing the number of parts and simplify the installation of the electrical device to the case so that the manufacturing cost of the electrical device can be reduced. Is to provide.

  The present invention is directed to a bushing for an electric device that is attached in a state of passing through an attachment hole provided in a case of the electric device. The bushing for electrical equipment according to the present invention is formed so as to have an outer diameter smaller than the outer diameter of one end in the axial direction of the soot tube main body and the soot tube body, and in the axial direction of the soot tube body while sharing the axis with the soot tube body And a bushing conductor provided in a state of penetrating the pipe in the axial direction, and having a pipe base integrally protruding from one end of the pipe and being arranged in a state where the pipe base penetrates the mounting hole. The engaging portion that engages with the case of the electrical device and locks the soot tube to the case when the soot base is inserted into the mounting hole of the case of the electrical device is an end surface of one end of the soot tube body or the soot tube Provided integrally with the base.

  If comprised as mentioned above, since it is not necessary to divide a tub tube into an outer side tub tube and an inner side tub tube, the number of parts can be decreased and the cost of bushing can be reduced.

  Moreover, if comprised as mentioned above, a soot tube base is inserted in the attachment hole of the case of an electric equipment, and a soot pipe is attached to the case of an electric equipment only by engaging the latching | locking part integrally provided in the soot pipe with the case. Therefore, the man-hour required for attaching the bushing can be reduced, and the manufacturing cost of the electric device can be reduced.

  According to a second aspect of the invention, the bushing for an electric device includes a plurality of the locking portions, and the plurality of locking portions are arranged so as to be arranged at equal angular intervals in the circumferential direction of the soot tube. The stop portion is constituted by a protruding piece that protrudes from the end surface of one end of the soot tube body toward the soot tube base side. At the tip of each projecting piece, a claw projecting outward in the radial direction of the soot tube base is integrally formed, and when the soot tube base is inserted into the mounting hole of the case of the electric device, the claw portion is located around the mounting hole. The soot tube is locked to the case by elastically engaging.

  When configured as described above, the bushing is attached to the case of the electric device by simply inserting the tub tube base into the attachment hole of the case of the electric device and engaging the claw portion at the tip of the protruding piece with the peripheral portion of the attachment hole. Therefore, the bushing can be attached to the case of the electric device with a single touch, and the number of steps required to assemble the electric device can be reduced.

  In the bushing for electrical equipment according to the invention described in claim 3, a plurality of locking portions are provided, and each locking portion extends obliquely projecting from the side surface or tip of the tube base to the tube body side. When the soot tube base is inserted into the mounting hole of the case of the electrical device, the tip of each of the projecting pieces constituting the plurality of locking portions is the periphery of the mounting hole. It is comprised so that an abutment tube may be contact | abutted and a stub tube may be latched to a case.

  Even when configured as described above, the bushing can be attached to the case of the electric device simply by inserting the tub tube base into the attachment hole of the case of the electric device and engaging the tip of the protruding piece with the peripheral portion of the attachment hole. Therefore, the bushing can be attached to the case of the electric device with one touch.

   In the bushing for an electric device according to the invention described in claim 4, the bushing conductor has a screw portion in a portion arranged in the case of the electric device, and a nut screwed into the screw portion has the screw portion. It is fixed to the soot tube by being fastened to the end surface of the tip of the soot tube base through a washer fitted to the threaded portion. When the bushing is configured in this manner, each locking portion is connected to the distal end portion of the tubule base portion at one end near the axial center portion of the tubule base portion, and is centered on the connection portion with the distal end portion of the tubule base portion. A locking piece base provided to be able to rotate along a plane including the axis of the soot tube, and a locking piece arm portion bent from the other end of the locking piece base and extending obliquely toward the soot tube body side It is set as the structure provided integrally. In this case, when the nut screwed into the threaded portion of the bushing conductor is tightened, the locking piece base is pressed by the washer and restrained in a state along the distal end surface of the soot tube base, thereby The tip is held in a state of being pressed against the peripheral portion of the mounting hole of the case, and the soot tube is locked to the case.

  When configured as described above, the end of each locking piece is pressed against the periphery of the mounting hole of the locking piece while the locking piece base is locked by a nut with a washer, so that the bushing is firmly locked. Can be done.

  Further, in the bushing for an electric device according to the invention described in claim 5, a packing is disposed along the end face of the soot tube main body, and this packing is brought into contact with the case of the electrical device so that one end of the soot tube main body is provided. The latching portion is configured to lock the soot tube to the case when the soot tube base is inserted into the mounting hole until it is compressed between the end surface and the case.

  If comprised as mentioned above, since the latching | locking part can be strongly engaged with the case of an electric equipment with the repulsive force which the compressed packing generate | occur | produces, latching of a bushing can be performed firmly. Moreover, since the sealing of the through portion of the bushing can be achieved by the packing, it is possible to prevent water or the like from entering the case through the attachment portion of the bushing.

  As described above, according to the present invention, since it is not necessary to divide the soot tube into an outer soot tube and an inner soot tube, the number of parts can be reduced and the cost of the bushing can be reduced.

  Further, according to the present invention, it is possible to attach the soot tube to the case of the electrical device simply by inserting the soot tube base into the mounting hole of the case of the electrical device and engaging the locking portion provided integrally with the soot tube with the case. Therefore, the man-hour required for attaching the bushing can be reduced, and the manufacturing cost of the electric device can be reduced.

  In particular, according to the invention described in claim 2 or 3, the tubule base is inserted into the mounting hole of the case of the electric device, and the claw portion at the tip of the protruding piece is engaged with the peripheral portion of the mounting hole, or is attached. The bushing can be attached to the electrical device case simply by bringing the tip of the piece into contact with the periphery of the mounting hole, so the bushing can be attached to the electrical device case with one touch, and the number of man-hours required to assemble the electrical device Can be reduced.

  According to the invention described in claim 4, the distal end of the arm portion of each locking piece is pressed against the peripheral portion of the mounting hole of the case in a state where the locking piece base portion is locked by the nut with the washer. As a result, the bushing can be firmly attached by firmly locking the bushing.

  According to the fifth aspect of the present invention, since the engaging portion can be strongly engaged with the case of the electric device by the repulsive force generated by the compressed packing, the bushing is firmly engaged. Can do. Moreover, since the sealing of the through portion of the bushing can be achieved by the packing, it is possible to prevent water or the like from entering the case through the attachment portion of the bushing.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. 1 to 3 show a first embodiment of the present invention. FIG. 1 shows a state in which the bushing is attached to a case of an electric device in the first embodiment of the present invention, and a half of the bushing is shown in cross section. FIG. 2 is a front view showing a half of the bushing according to the embodiment in section, and FIG. 3 is a bottom view of the bushing.

  In these figures, 1 is a soot tube made of an insulating resin such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), 2 is a bushing conductor provided in a state of penetrating the axial center portion of the soot tube 1, The bushing conductor 2 constitutes an electrical equipment bushing BG.

  The illustrated bushing conductor 2 is formed in a round bar shape, and a screw portion 201 is formed on the outer periphery of one end in the axial direction (an end portion disposed in the case of the electric device), and a terminal portion 202 is formed on the other end. Are integrally formed. The terminal portion 202 includes a flange portion 202a formed integrally with the other end of the bushing conductor, and a terminal plate portion 202b integrated with the flange portion 202a. A mounting hole 202c is formed in the terminal plate portion 202b. Yes.

  Reference numeral 3 denotes a case of an electric device. The case 3 is provided with a plate-like bushing attachment portion 301, and a bushing attachment hole 302 is formed in a state of passing through the bushing attachment portion.

  The soot tube 1 is formed to have an outer diameter smaller than the outer diameter of the soot tube body 101 and one end 101a of the soot tube body 101 in the axial direction, and shares the axis with the soot tube body 101 in the axial direction of the soot tube body 101. It integrally has a soot tube base 102 projecting from one end. The tub tube main body 101 integrally includes ridge portions 101A and 101B provided on one end side and the other end side in the axial direction thereof, and a constricted portion 101C formed between the both heel portions. In the illustrated saddle tube, the outer diameter of the flange portion 101A is set larger than the outer diameter of the flange portion 101B, and a skirt portion 101D having a short axial dimension is provided at a portion near the outer periphery of the end surface of the axial direction of the saddle tube main body 101. Is formed.

  A packing 4 made of an elastic material such as rubber is fitted and held inside a skirt portion 101D formed at a portion near the outer periphery of one end face of the soot tube main body. An annular recess 101 </ b> E that coaxially surrounds the portion of the soot tube base 102 near the soot tube main body is formed on the inner peripheral portion of one end face of the soot tube body 101. A bushing conductor insertion hole 1a is formed through the axial center portion of the soot tube 1, and the bushing conductor 2 is arranged in a state of passing through the bushing conductor insertion hole 1a. A recess 101G is formed on the end surface of the other end of the vertical tube body 101 in the axial direction, and a flange 202a of the terminal portion 202 provided at the other end of the bushing conductor 2 is fitted in the recess 101G. The packing 5 is inserted between the bottom surface of the recess 101G and the flange portion 202a of the terminal portion, and the seal between the bushing conductor and the bushing conductor insertion hole 1a is achieved by this packing.

  In the present invention, when the soot tube base 102 is inserted into the mounting hole 302, the locking portion 103 that engages with the case 3 of the electrical device and locks the soot tube 1 to the case 3 is an end surface of one end of the soot tube body 101 or Provided integrally with the soot tube base 102.

  As shown in FIGS. 2 and 3, in the present embodiment, a plurality of locking portions 103 (four in the illustrated example) are provided, and the plurality of locking portions are arranged in the circumferential direction of the soot tube. Are arranged at equal angular intervals. Each locking portion 103 includes a protruding piece 103 a that protrudes from the end face of one end of the soot tube main body 101 toward the soot tube base 102 side. As shown in FIG. 3, each protruding piece 103 is formed to have a circular cross section along the circumferential direction of the mounting hole 302. An arrow-shaped claw portion 103a1 protruding only outward in the radial direction of the base portion 102 is integrally formed, and the packing 4 is sandwiched between the end face of one end of the soot tube body and the peripheral portion of the mounting hole of the case of the electric device. Until the compressed tube base 102 is inserted into the mounting hole 302 of the case of the electric device until it is compressed, the claw portion 103a1 is elastically engaged with the peripheral portion of the mounting hole 302, and the closed tube 1 is attached to the case. 3 to be locked.

  The bushing conductor 2 is provided in a state of passing through the bushing conductor insertion hole 1a of the soot tube 1, and a washer 7 in which a nut 6 screwed into a screw portion 201 protruding from the tip of the soot tube base 102 is fitted to the screw portion. It is fixed to the soot tube 1 by being tightened with respect to the end surface of the front end of the soot tube base 201 via

  When the bushing BG is attached to the case 3 of the electric device, the tub tube base 102 is inserted into the attachment hole 302, and the claw portion 103 a 1 at the tip of the protruding piece 103 a is inserted into the peripheral portion of the attachment hole 302 while compressing the packing 4. Engage elastically. Thereafter, the bushing conductor 2 is disposed through the bushing conductor insertion hole 1a in the axial center portion of the soot tube, and the washer 7 is fitted to the screw portion 201 at one end of the bushing conductor 2 protruding from the tip of the soot tube base 102. The bushing conductor 2 is fixed to the soot tube 1 by screwing the nut 6 into the screw portion 201 and tightening.

  In the above description, the bushing conductor 2 is attached after the soot pipe 1 is attached to the case 3. However, after the bushing conductor 2 is attached to the soot pipe 1, the soot base 102 is inserted into the mounting hole 302 and the protruding piece 103a. The claw portion 103 a 1 at the tip of the mounting hole 302 may be elastically engaged with the peripheral portion of the mounting hole 302.

  With the above configuration, the bushing soot tube can be obtained simply by inserting the soot tube base 201 into the mounting hole 302 of the case 3 of the electric device and engaging the claw portion 103a1 at the tip of the protruding piece 103a with the peripheral edge of the mounting hole 302. Can be attached to the case of the electric device, so that the bushing bush can be attached to the case of the electric device with one touch, and the man-hour required for assembling the electric device can be reduced.

  In addition, as described above, the packing 4 is disposed along the end surface of the soot tube main body 101, and the soot base 102 is compressed until the packing is compressed between the end surface of one end of the soot tube main body 101 and the case 3. If the locking portion 103 is in a state where the hook tube 1 is locked to the case 3 when the is inserted into the mounting hole 302, the locking portion 103 is urged by the repulsive force generated by the compressed packing 4. Thus, the bushing can be firmly engaged with the case of the electric device.

  4 to 6 show a second embodiment of the present invention. In this embodiment, a plurality of locking portions 103 (four in the illustrated example) are provided, and the plurality of locking portions are equiangularly spaced in the circumferential direction of the soot tube 1 (in the illustrated example 90 ° intervals). In) are arranged side by side. Each locking portion 103 protrudes and extends from the distal end of the soot tube base 102 obliquely toward the soot tube main body side (inclined away from the soot tube base 102 as it goes toward the soot tube body side). It consists of the protrusion piece 103b provided integrally. In this example, the soot tube base 102 is projected while elastically deforming so that the inclination angle of the projecting piece 103b with respect to the soot tube base portion 102 is reduced and sliding the projecting piece 103b on the inner peripheral surface of the mounting hole 302 of the case of the electric device. When the packing 4 is inserted into the mounting hole 302 together with the piece 103b until it is compressed to an appropriate amount, the protruding pieces 103b respectively constituting the plurality of locking portions 103 open through the mounting holes 302 (the protruding pieces 103b The length and inclination angle of each protruding piece 103b are set so that the tip of each protruding piece comes into contact with the peripheral portion of the mounting hole 302. When the tip of each protruding piece 103b comes into contact with the periphery of the mounting hole 302, the soot tube 1 is locked to the case of the electrical device. In this example, an annular groove (groove 101E shown in FIG. 2) is not provided on one end face of the soot tube body 101, and the packing 4 is disposed between the skirt portion 101D and the soot tube base 102. A shallow recess is formed. Other points are the same as those of the embodiment shown in FIGS.

  7 to 9 show a third embodiment of the present invention. In this embodiment, one end is connected to the distal end portion of the soot tube base 102 at a portion near the axial center of the soot tube base 102, and A locking piece base 103b1 provided so as to be able to rotate along a plane including the central axis of the soot tube around the connecting portion p with the tip of the soot tube base 102, and the other end of the locking piece base 103b1 Each locking portion 103 is constituted by a rotatable member that integrally has a locking piece arm portion 103b2 that is bent from the side and extends obliquely toward the side of the tubule body 101. In this embodiment, as shown in FIG. 7, when the nut 6 screwed into the threaded portion of the bushing conductor 2 is tightened, the locking piece base portion 103b1 is pressed by the washer 7, and the locking piece base portion is By being constrained to be in a state along the distal end surface of the base portion 102, the distal end of the locking arm portion 103 b 2 is held in a state of being pressed against the peripheral portion of the mounting hole 302 of the case, and the soot tube 1 is locked to the case 3. The Other points are configured in the same manner as the embodiment shown in FIGS.

  With this configuration, the locking piece base portion 103b1 is restrained by the nut 6 via the washer 7, and the tip of the arm portion of each locking piece is urged toward the periphery of the mounting hole of the case. Since it can be pressed against the periphery of the mounting hole, the bushing BG can be firmly locked.

  10 to 12 show a fourth embodiment of the present invention. Also in this embodiment, a plurality of locking portions 103 (four in the illustrated example) are provided, and the plurality of locking portions are arranged so as to be arranged at equal angular intervals in the circumferential direction of the tub tube 1. . In the embodiment shown in FIG. 4 to FIG. 6, the projecting piece 103 b constituting each locking portion 103 is provided so as to project obliquely from the distal end of the soot tube base 102 toward the soot tube body 101 side. Each projecting piece 103b is provided to project obliquely from the side surface of the soot tube base 102 toward the soot tube body 101 side. Other points are configured in the same manner as the embodiment shown in FIGS.

  In each of the above-described embodiments, the packing 4 is interposed between the end face on the one end side in the axial direction of the soot tube main body and the case of the electric device, and the repulsive force generated when the packing is compressed is used. The stopper 103 is firmly engaged with the case, but it is not particularly necessary to make the bushing attachment part a liquid-tight holding structure, or at least the part of the soot tube body 101 that contacts the case 3 is elastic. The packing 4 can be omitted in the case where the portion formed by the resin having high flexibility and the portion formed by the resin having high elasticity can be provided with the function as packing.

It is the front view which showed the state which attached the bushing to the case of the electric equipment in the 1st Embodiment of this invention, and cut | disconnected the half part of the bushing. It is the front view which carried out the cross section and showed the half part of the bushing concerning the embodiment. It is a bottom view of the bushing concerning the embodiment. It is the front view which showed the state which attached the bushing to the case of the electric equipment in the 2nd Embodiment of this invention, and cut | disconnected the half part of the bushing. It is the front view which carried out the cross section and showed the half part of the bushing concerning the embodiment. It is a bottom view of the bushing concerning the embodiment. It is the front view which showed the state which attached the bushing to the case of the electric equipment in the 3rd Embodiment of this invention, and cut | disconnected the half part of the bushing. It is the front view which carried out the cross section and showed the half part of the bushing concerning the embodiment. It is a bottom view of the bushing concerning the embodiment. It is the front view which showed the state which attached the bushing to the case of the electric equipment in the 4th Embodiment of this invention, and cut | disconnected the half part of the bushing. It is the front view which carried out the cross section and showed the half part of the bushing concerning the embodiment. It is a bottom view of the bushing concerning the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steel pipe 101 Steel pipe main body 102 Steel pipe base part 103 Locking part 1a Bushing conductor insertion hole 2 Bushing conductor 201 Screw part 3 Case of electric equipment 302 Mounting hole SG bushing

Claims (5)

A bushing for electrical equipment that is attached in a state of passing through a mounting hole provided in a case of the electrical equipment,
It is formed so as to have an outer diameter smaller than the outer diameter of one end in the axial direction of the soot tube body and the soot tube body, and protrudes from one end in the axial direction of the soot tube body in a state of sharing the axis with the soot tube body A resin-made soot pipe that is integrally provided with a soot pipe base and is arranged in a state where the soot pipe base penetrates the mounting hole, and a bushing conductor provided in a state of penetrating the soot pipe in the axial direction,
A locking portion that engages with the case of the electrical device and locks the soot tube to the case when the soot tube base portion is inserted into the mounting hole is integrated with the end surface of the one end of the soot tube body or the soot tube base portion. Bushings for electrical equipment provided in A plurality of the locking portions are provided, and the plurality of locking portions are arranged so as to be arranged at equiangular intervals in the circumferential direction of the soot tube,
Each locking part consists of a protruding piece protruding from the end face of the one end of the soot tube body toward the soot tube base side,
At the tip of each protruding piece, a claw portion protruding outward in the radial direction of the tubule base is integrally formed,
When the soot tube base is inserted into the mounting hole of the case of the electric device, the claw portion is elastically engaged with the peripheral portion of the mounting hole to lock the soot tube to the case. The bushing for electrical equipment according to claim 1. A plurality of the locking portions are provided, and the plurality of locking portions are arranged so as to be arranged at equiangular intervals in the circumferential direction of the soot tube,
The locking portion is composed of a projecting piece integrally provided in the soot tube base so as to extend obliquely from the side surface or tip of the soot tube base to the soot tube body side,
When the soot tube base is inserted into the mounting hole of the case of the electrical device, the tips of the protruding pieces respectively constituting the plurality of locking portions abut against the peripheral portion of the mounting hole, and the soot tube is connected to the case. The bushing for an electric device according to claim 1, wherein the bushing is configured to be locked to. A plurality of the locking portions are provided, and the plurality of locking portions are arranged so as to be arranged at equiangular intervals in the circumferential direction of the soot tube,
The bushing conductor has a screw portion at a portion disposed in the case of the electric device, and a nut screwed into the screw portion is inserted into the screw base portion through a washer fitted into the screw portion. It is configured to be fixed to the soot tube by being tightened against the end face of the tip,
The locking portion includes one end of which is connected to the distal end portion of the soot tube base portion at a portion near the axial center portion of the soot tube base portion and includes the axis of the soot tube centering on the connecting portion with the distal end portion of the soot tube base portion A locking piece base provided so as to be able to rotate along a plane, and a locking piece arm portion that is bent from the other end of the locking piece base and extends obliquely toward the side of the tubule body;
When the nut screwed into the threaded portion of the bushing conductor is tightened, the locking piece base is pressed by the washer and restrained in a state along the distal end surface of the soot tube base, whereby the locking piece arm 2. The bushing for an electric device according to claim 1, wherein a tip of the portion is held in a state of being pressed against a peripheral portion of the mounting hole of the case, and the soot tube is locked to the case. A packing is disposed along the end surface of the soot tube body,
When the soot tube base is inserted into the mounting hole until the packing comes into contact with the case of the electrical device and is compressed between the end surface of the one end of the soot tube body and the case, the engagement is performed. The bushing for an electric device according to any one of claims 1 to 4, wherein a stop portion is configured to be in a state in which the soot tube is locked to the case.

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