JPH059802Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to a fuse tube attached to a box-shaped cut-out switch.

(Prior art) Generally, in a box-shaped cut-out switch, a cover insulator is pivotally attached to a main body insulator containing a fixed electrode and an arc extinguishing chamber so that the cover insulator can be opened and closed, and the main body insulator is fixed inside the cover insulator. A fuse tube with a pair of upper and lower contact blades fixed vertically is removably attached to correspond to the electrodes.

(Problem to be Solved by the Invention) Then, when a fault current passes through, the internal fuse element is blown, and at this time, the gas generated inside the fuse cylinder is discharged downward in the axial direction of the fuse cylinder body.

However, as a result of this reaction, an upward force is applied to the fuse tube, and as a result, the positioning protrusion provided on the lid insulator side of the lower electrode fixed to the fuse tube collides with the inner surface of the lid insulator, causing the insulator to collide with the inner surface of the lid insulator. There was a risk of damage.

The present invention has been made in view of the problems of the prior art, and its purpose is to cover the positioning protrusion with a buffer member so that the protrusion does not touch the inner surface of the lid insulator. To provide a fuse tube that does not cause damage to the insulator even if it collides with the insulator.

(Means for Solving the Problem) In order to achieve the above object, in the fuse tube attached to the lid insulator of the box-shaped cut-out switch according to the present invention, the lower electrode of the fuse tube is attached to the lid insulator side. A regulating protrusion is provided and the protrusion is covered with a buffer member.

(Function) In the fuse tube configured as described above, an upward force is applied to the fuse tube due to the reaction force due to the gas pressure release force generated when the fuse element is blown.
As a result, even if the protrusion provided on the lid side of the lower electrode fixed to the fuse tube collides with the inner surface of the lid insulator,
Since the protrusion is covered with a cushioning material, the impact is absorbed.

(Example) Hereinafter, an example embodying the present invention will be described with reference to the drawings.

Upper and lower electrode chambers 3 and 4 separated by a partition wall 2 are formed in a box-shaped cutout body insulator 1.
Upper and lower fixed electrodes 5 and 6 and upper and lower arc extinguishing chambers 7 and 8 are provided in both electrode chambers 3 and 4, respectively. A lid insulator 9 is provided on the open side of the main body insulator 1.
is attached via a support shaft 11 to a mounting portion 10 protruding from its base end so as to be openable and closable. A clamping metal fitting 12 and a locking metal fitting 13 are fixed near the inner tip of the lid insulator 9, and a pair of contact blades 14a, 14b that can be inserted into the fixed electrodes 5, 6, respectively.
A fuse tube 15 equipped with a fuse tube 15 is removably attached to the lid insulator 9 via both metal fittings 12 and 13. Further, an arc protection plate 9 is provided on the inner surface of the lid insulator 9.
A is installed.

The fuse tube 15 is connected to the insulating tube 1 as shown in FIG.
An upper electrode portion 17 is placed on the tip of the electrode 6, and a cylindrical lower electrode portion 18 is fitted and fixed approximately in the center. A cylindrical insulating member 19 is fitted onto the insulating cylinder 16 between the electrode parts 17 and 18, and both ends of the insulating member 19 are fitted and fixed to the outer periphery of one end of each of the electrode parts 17 and 18. The upper electrode portion 17 has one contact blade 14a protruding from one side thereof, and a fuse cylinder cap 20 is screwed onto the tip surface. The lower electrode part 18 has a contact blade 14b protruding from one end side near the insulating member 19, and a male threaded part 21 is formed on the outer peripheral surface of the other end, and a lead wire of the fuse element F is formed perpendicularly to the male threaded part 21. A groove 22 is formed to allow the passage of L. Further, the flange portion 23 that contacts the contact blade 14b of the lower electrode portion 18 and the outer wall of the lower arc extinguishing chamber 8 is formed in a bulging manner.

A compression spring 25 is housed in a housing portion 24 provided between the base end outer peripheral surface of the insulating tube 16 and the inner surface of the lower electrode portion 18, and one end of a display tube 26 is loosely fitted therein. The display tube 26 has one end connected to the upper electrode section 1.
7 , the fuse tightening screw 27 is bent so that the other end engages with the display tube 26 , and is led out to the outside of the lower electrode part 18 through the groove 22 .
Due to the tension of the fuse element F, which is tightened and fixed by
a is held in a state housed in an insulating covering tube 28 screwed onto the male threaded portion 21.

The lower electrode part 18 has a mounting position regulating protrusion 2 having a T-shaped cross section as shown in FIG.
9 is provided. The protrusion 29 is covered with a buffer member 30. The buffer member 30 is a shock absorbing member integrally molded from synthetic resin, and the side surface 30a that contacts the lower electrode portion 18 is formed into a curved surface having an arcuate cross section so as to be in close contact with the outer peripheral surface of the lower electrode portion 18. There is. Further, the buffer member 30 has a fitting groove 30b having a T-shaped cross section cut from one end surface to approximately the center thereof, and the side surface 30
The communicating portion 30c, which opens at point a, allows the base end of the protrusion 29 to pass therethrough, and is removably fitted to the protrusion 29.

Next, the operation of the fuse tube attached to the box-shaped cutout switch constructed as described above will be explained.

When the fault current flows, the fuse element F blows out, cutting off the fault current. Then, the fuse element F, which was holding the display tube 26 in the insulating cover tube 28 against the elastic force of the compression spring 25,
As a result, the tension of the display tube 2 is lost.
6 is pushed out by the elastic force of the stored compression spring 25 to a position where its display portion 26a protrudes outside the insulating covering cylinder 28.

Furthermore, within the fuse tube 15, a force is applied to move the fuse tube 15 itself in the opposite direction to the ejection of the display tube 26 due to the gas pressure generated when the fuse element F is blown.
As a result, the attachment position regulating protrusion 29 provided on the lid insulator 9 side of the lower electrode portion 18 collides with the inner surface of the lid insulator 9, but the buffer member 30 fitted into the protrusion 29 collides with the inner surface of the lid insulator 9. serves to absorb the impact force and protect the inner surface of the lid insulator 9 from damage.

Note that this invention is not limited to the above-mentioned embodiment, and in the above-mentioned embodiment, the cross-sectional shape of the attachment position regulating protrusion 29 is L-shaped, the shape of the buffer member 30 is hemispherical, etc. Any changes can be made without departing from the spirit of this invention.

Effects of the Device As detailed above, according to the present invention, the fuse tube itself is flipped upward by the reaction of the gas released when the fuse is blown, and the protrusion provided on the lid side of the lower electrode part Even if there is a collision with the inner surface of the insulator, the shock absorbing effect of the buffer member has the excellent effect of eliminating the risk of damaging the inner surface of the lid insulator, which has been a problem in the past.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a box-shaped cut-out switch with a fuse tube attached, Figure 2 is a side sectional view of the fuse tube, Figure 3 is a partially exploded perspective view of the fuse tube, and Figure 4 is A of Figure 3. - A cross-sectional view. Main body insulator 1, lid insulator 9, fuse tube 15, mounting position regulating protrusion 29, and buffer member 30.

Claims (1)

[Scope of utility model registration request] A fuse tube attached to the lid insulator of a box-shaped cut-out switch is characterized in that a protrusion for regulating the mounting position is provided on the side of the lid insulator of the lower electrode of the fuse tube, and the protrusion is covered with a cushioning material. fuse tube.