JPH087608Y2 - Insulator mounting bracket - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a porcelain tube mounting bracket. More specifically, the present invention relates to a mounting bracket for mounting a porcelain insulator forming a bushing on a device generally called an oil-filled device such as a transformer, a condenser, and a voltage regulator.

A small-capacity transformer such as a pole transformer, which is an example of oil-filled equipment, supplies the high voltage of several thousand volts sent from a distribution substation to 100-200 volts by reducing it to general households and small customers. Used for. The primary bushing is a connecting device of the high voltage side distribution line in these transformers,
The secondary bushing is a connecting device for the distribution line on the low voltage side.
These bushings are configured as a unit in which a charging terminal fitting, a knob, and the like are attached and integrated to a porcelain insulator.

The mounting bracket of the present invention is a mounting bracket used for mounting the porcelain bushing constituting the bushing as described above.

[Prior Art] Fig. 6 shows a typical small capacity transformer currently in use.
Shows 50.

In the figure, 51 is a cylindrical case with a bottom, 52 is a cover,
53 is a bushing pocket and 54 is a bottom plate of the bushing pocket 53. Reference numeral 10 is a porcelain insulator forming the primary bushing B, to which a high-voltage side distribution line 56 is connected. In addition,
57 is a secondary bushing to which the low voltage side distribution line 58 is connected. Reference numeral 59 is an internal lead wire, which is connected to the primary coil of the transformer body (not shown).

FIG. 7 is a perspective view of a conventional mounting bracket 60. The mounting bracket 60 is a generally disk-shaped member, and has three female screw holes 61 formed at equal intervals so that three mounting bolts 62 can be screwed into it. Also, in the center of the mounting bracket 60,
A through hole 63 through which the porcelain insulator is inserted is formed, and a seat plate 64 recessed in a shallow dish shape is formed around the through hole 63. The seat plate 64 is a portion that receives a ring-shaped spring 15 for retaining that will be described later.

FIG. 8 shows a state where the primary bushing B is attached to the transformer 50 of FIG. 6 by using the conventional mounting bracket 60.

A shoulder portion 11 is formed on the porcelain bushing 10 of the primary bushing B, and a bottom plate 54 of the bushing pocket 53 is applied to the shoulder portion 11 via a packing 12. On the other hand, an annular groove 14 is formed in the distal end tube portion 13 of the porcelain bushing 10, and a ring-shaped spring 15 is fitted in the annular groove 14. This spring
Reference numeral 15 is a metal tension spring wound in a coil shape connected in a ring shape and is expandable and contractible, but has a strength such that it is not crushed even when the mounting pressure of the mounting bracket 60 is applied.
The fitting 60 is loosely inserted into the tip tube portion 13 of the porcelain bushing 10 so as to be located below the spring 15, and the bottom plate 54 of the bushing pocket 53 is fixed by the three (only two shown) mounting bolts 62.
Is pressing. The seat plate 64 of the mounting bracket 60 is the spring
The bottom plate 54 is pinched between the mounting bolts 62 and the shoulder portions 11 of the porcelain bushing 10 as a result of hitting against the fifteen, and as a result, the primary bushing B is firmly fixed to the transformer 50. It has become so.

[Problems to be Solved by the Invention] However, the conventional mounting bracket 60 has the following problems.

It takes time to install because three mounting bolts 62 are tightened.

One-sided tightening is likely to occur, and the porcelain bushing 10 is likely to crack or have a poor seal. For example, the sealing pressure for tightening the packing 12 needs to be 0.2 kgf / cm ² or more, but if the one-sided tightening occurs, the sealing pressure may partially drop below the required value.

The operation of attaching the primary bushing B to the bottom plate 54 of the bushing pocket 53 is performed by opening the cover 52 of the transformer 50 and inserting a hand from above, but the mounting site is deep (see
(See the figure), workability is very poor.

In view of such circumstances, an object of the present invention is to provide a mounting bracket that can be mounted in a short time, does not cause partial tightening that causes cracks and defective sealing of the porcelain bushing, and has high mounting workability.

[Means for Solving the Problems] The porcelain bushing mounting metal fitting of the present invention is oil-filled between the shoulder portion of the porcelain bushing constituting the bushing and the mounting metal fitting fitted to the tip tubular portion of the porcelain bushing so as not to come off. In a mounting structure for pinching a device-side mounting plate and fixing the bushing to an oil-filled device, a through hole for inserting a distal end tube portion of a porcelain bush is formed in a central portion of the mounting metal fitting. A seat plate for receiving a ring-shaped spring fitted in the annular groove of the distal end tube portion of the porcelain bushing is formed at the inner edge of the, and the apex of the imaginary triangle surrounding the through hole is considered at the peripheral edge of the through hole. The female screw holes into which the mounting bolts can be screwed are formed at the positions corresponding to, and the leg portions are formed at the positions corresponding to the other two vertices, respectively.

The bottom plate of the bushing pocket in the embodiment corresponds to the mounting plate referred to in the claims for utility model registration. Further, the bushing includes not only those used for the primary side but also those used for the secondary side, the tertiary side, and the like.

[Operation] As in the conventional example, the mounting bracket of the present invention is mounted so as to be positioned below the ring-shaped spring fitted in the distal end tube portion of the porcelain bushing, and the shoulder portion of the porcelain bushing is fitted with packing through the packing. The mounting plate of the oil-filled device is applied. When one mounting bolt is tightened in this state, the seat plate of the mounting bracket is held against the spring so that it will not come out, so the bolt and the two leg parts sandwich the mounting plate. It can be strongly clamped by 3 points.

In the present invention, since there is only one mounting bolt, it does not take much time to tighten, and the mounting work can be performed in a short time. Further, since the tightening force of the packing on the leg is determined by the height of the leg, partial tightening does not occur. As a result, cracking of the porcelain insulator and defective sealing are prevented. Moreover, since the overall tightening force is determined by the tightening amount of one mounting bolt, it is easy to manage the seal pressure. Furthermore, since the tightening work only requires one mounting bolt,
Work is easy even in deep places such as bushing pockets of oil-filled equipment.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.

 1 and 2 show a mounting bracket A of the present invention.

This mounting bracket A is made of pressed sheet metal,
It has a substantially pentagonal shape in a plan view. The shape is not limited to the pentagon, and may be a round shape or another polygon.

A through hole 1 for inserting a porcelain bush is formed in the substantially central portion. This through hole 1 is oval in plan view. A seat plate 2 is formed in the rear half of the inner edge of the through hole 1 (right side in the drawing). The seat plate 2 is formed so as to be slightly recessed from the upper surface of the mounting bracket A, and has a shallow dish shape in cross section.

When an imaginary triangle T is positioned so as to surround the through hole 1 at the peripheral edge of the mounting bracket A, the vertices P1 and P
2, P3 can be envisioned on the periphery. Among them, a female screw hole 3 into which the mounting bolt 6 is screwed is formed at the apex P1 on the tip side of the mounting bracket A (the left side in the figure, that is, the side on which the seat plate 2 is not formed).

Further, a leg portion 5 formed by bending the side wall portion of the mounting member A is provided at the rear end side (right side in the drawing), that is, at the positions of the remaining two vertices P2 and P3. The side wall on the tip side of the leg portion 5 is bent in the same manner as the leg portion 5, and the reinforcing rib 4
Is composed.

The leg portion 5 has an inclined surface 5a that is inclined with respect to the upper surface of the mounting member A, and a parallel bottom surface 5b. The height of the leg portion 5, that is, the distance from the center of the spring 15 located on the seat plate 2 to the lower end surface is such that the height h2 of the bottom surface 5b is the height of the slope 5a.
It is higher than h1. The difference between the heights h2 and h1 is a margin for the packing 12. That is, in FIGS. 3 to 4, if the original thickness of the packing 12 is 6 mm and the difference between h1 and h2 is 2 mm, the thickness of the packing 12 after tightening is 4 mm. And, by this interference, the required sealing pressure of 0.2 kgf / cm ² or more can be obtained.

Next, the work of mounting the bushing B using the mounting bracket A will be described.

First, as shown in FIG. 3, the tip tube portion 13 of the porcelain bushing 10 is inserted into the hole of the bottom plate 54 of the bushing pocket, and the shoulder portion of the porcelain bushing 10 is inserted.
11 is pressed against the bottom plate 54 through the packing 12. Then,
The mounting bracket A and the ring-shaped spring 15 of this embodiment are inserted into the distal end tube portion 13 of the porcelain insulator 10. The ring-shaped spring 15 is fitted in the annular groove 14, but since the packing 12 remains in the original thickness in the initial stage of the mounting work, the leg portion 5
Since the slope 5a having a low height is in contact with the surface of the bottom plate 54, the mounting bracket A can be inserted only in an inclined state. Therefore, the ring-shaped spring 15 is only partially fitted in the annular groove 14.

In this state, when the tip of the mounting bracket A is pushed down as shown by the arrow P, the seat plate 2 at the rear end of the mounting bracket A is supported by the ring-shaped spring 15 so as not to come off, so that the spring 15 serves as a fulcrum. It works like a lever and tries to move to a posture parallel to the bottom plate 54 while compressing the packing 12.

Completely push down the mounting bracket A and press the spring 15
When the entire spring 15 is fitted into the annular groove 14 by pushing down the left side of the, the mounting bracket A becomes parallel to the bottom plate as shown in FIG. In this state, the ring-shaped spring 15 completely fitted in the annular groove 14 acts as a stopper, and the fitting A never comes out. And the mounting bolt 6
Is screwed into the female screw 3 and screwed with appropriate torque to tighten the bolt 6
The attachment is completed by putting the tip of the above into the recess 55 of the bottom plate 54 to prevent the mounting bracket A from shifting in the lateral direction.

In this case, since the height of the bottom surface 5b of the leg portion 5 is the same in both places, the packing 12 can be compressed with a uniform force. Then, the mounting bolt 6 and the two leg portions 5
Since the compressive force at the three locations including the above can be controlled only by the amount of screwing of the mounting bolt 6, if the torque during tightening is accurately controlled, the sealing pressure of the packing 12 at the shoulder 11 will be the entire circumference. Therefore, it is possible to make it uniform and to avoid problems such as partial tightening. Therefore, in the case of the previous packing, the thickness of the packing 12 is uniformly compressed to 4 mm, and a sealing force of 0.2 kgf / cm ² or more can be obtained over the entire circumference.

FIG. 5 shows the bushing B attached to the transformer 50 in the above manner. Mounting bolt 6 as shown
Is tightened inside the bushing pocket 53, but in the present embodiment, since the tightening work only requires one bolt, the workability is not hindered even in a deep place. Moreover, according to the present embodiment, since the one-sided tightening does not occur, the porcelain bushing 10 does not crack or the seal fails.

[Advantages of the Invention] According to the present invention, the work of attaching the bushing to the transformer can be easily performed in a short time, and cracking of the insulator and defective sealing can be prevented.

[Brief description of drawings]

FIG. 1 is a perspective view of a porcelain bushing fitting according to an embodiment of the present invention, FIG. 2 is a sectional view of the porcelain bushing fitting, and FIGS. 3 to 4 are explanatory views showing the work of mounting the porcelain bushing fitting of the present invention. FIG. 5 is an explanatory view showing a state in which the bushing is attached using the porcelain bushing fitting of the present invention, FIG. 6 is an explanatory view showing a conventional fitting and a transformer, and FIG. 7 is a perspective view of the conventional fitting. , FIG. 8 is an explanatory view showing a mounting state of a bushing using a conventional mounting bracket. (Main symbols in the drawing) A: Insulator mounting bracket B: Bushing 1: Through hole 2: Seat plate 3: Female screw hole 5: Leg 10: Insulator 11: Shoulder 12: Packing 13: Tip cylinder 14: Annular groove 15: Ring-shaped spring

Claims (1)

[Scope of utility model registration request] 1. A mounting plate on the oil-filled device side is clamped between a shoulder portion of a porcelain bushing constituting a bushing and a mounting metal fitting which is fitted to a tip end tubular portion of the porcelain bushing and held so as not to slip out, and the bushing is oiled. In a mounting structure for fixing to an input device, the mounting bracket has a through hole for inserting a distal end tube portion of the porcelain bushing at a substantially central portion, and an annular groove of the distal end tube portion of the porcelain bushing is formed at an inner edge of the through hole. A seat plate for receiving the ring-shaped spring fitted in the through hole is formed, and a mounting bolt is screwed into the peripheral portion of the through hole at a position corresponding to one vertex when an imaginary triangle surrounding the through hole is considered. Insulating pipe mounting bracket, in which female female screw holes are formed, and legs are formed at positions corresponding to the other two vertices, respectively.