JPS6323864Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improving the performance of a fuse operation indicator.

A typical structure of a fuse with a conventional operation display device will be explained with reference to FIG. Gold 2
The tension is between 0 and 20. Further, the spiral display fuse element 40 is fixed by the terminal metal 20 and the case 70, and stretched between them by the action of the spring. Further, the display fuse element 40 is connected to the end of the operation display rod 50 inside the case 70, goes back, penetrates the case 70, and is connected to the terminal metal 20 through the outside thereof. Display fuse element 40 is case 7
0, a wedge-shaped plug is driven into the case 70 or bonded with adhesive, and is fixed against the biasing force of the push spring 60, so that the load of the push spring is transferred to the case 7.
The display fuse element 40 other than 0 is not affected. In this way, the display fuse element 40 resists the biasing force of the push spring 60 and holds back the operation display bar 50. Here, the case 70 houses the operation display rod 50 and the push spring 60.

The main fuse element 30 may be bent into a zigzag shape and stretched, or the terminal metal 20 may be bent into a straight shape.
In some cases, it is strung for 20 minutes.

This main fuse element 30 is made of a material with low electrical resistance, and the display fuse element 40
Since it is made of a relatively high resistance material, at normal times most of the current flows through the main fuse element 30. Here, when a fault current flows through the fuse and the main fuse element 30 blows, the fault current is diverted to the display fuse element 40, and all display fuse elements including the display fuse element 40 inside the case 70 melt. Therefore, the push spring 6
With a biasing force of 0, the operation indicator rod 50 projects out of the fuse cylinder as indicated by the dotted line in FIG. 1, thereby notifying the operation of the fuse.

In a fuse with such a structure, both the main fuse element 30 and the display fuse element 40 are fixed to the terminal metal 20 or the case 70 at the ends and maintain their positions accurately, but in the center part Due to the curvature of both fuse elements, their positions were unstable and they sometimes came into contact. One point 31 of the current main fuse element 30 and one point 4 of the display fuse element 40
1 is in contact, a fault current causes the main fuse element 30 to be damaged at a point 32 on the opposite side of the operation display device and other main fuse elements 3.
0 is fused, only the display fuse element 42 on the side of the display fuse element 40 that is not holding the operation indicator bar 50 is blown, completing the cutoff, and the display fuse element 43 on the side that is holding the operation display bar 50 is Does not melt. Since the display fuse element 40 is fixed to the case 70 at the point where it exits from the case 70, the operation display bar 50 will not operate in this case.

Further, in order to avoid deterioration in breaking performance due to contact or closeness between the main fuse element 30 and the outer cylinder 10 near the center, the gap between the main fuse element 30 and the outer cylinder 10 may be increased at the center of the fuse. In this case, the distance between both fuse elements becomes narrower at the center of the fuse.
Malfunction due to the above-mentioned contact becomes a problem.

The present invention has been made with attention to this point, and an object thereof is to provide an operation display device that does not cause such malfunctions.

The configuration of the present invention will be described below with reference to the drawings. Fig. 2 shows an embodiment of the present invention, in which a main fuse element 3 is wound spirally in an outer cylinder 1 with terminal metals 2 having a U-shaped cross section attached to both ends. It is stretched between 2 and 2. Further, in parallel with the main fuse element 3, a spirally wound display fuse element 4 is fixed at one end to the terminal metal 2 and at the other end to the case 7, and is stretched between them by a spring action. . Further, the display fuse element 4 is connected to the end of the operation display rod 5 inside the case 7, passes back through the case 7, and is connected to the terminal metal 2 through the outside thereof. As in the past, the display fuse element 4 is fixed against the biasing force of the push spring 6 by driving a wedge-shaped plug into the case 7 or gluing it with adhesive at the point where it exits from the case 7, so that the load of the push spring is transferred to the case 7. The display fuse element 4 other than the display fuse element 7 is not affected. In this way, the display fuse element 4 fixes the operation display bar 5 against the biasing force of the push spring 6.

Here, the spiral display fuse element 4 is connected to the terminal metal 2 and the operation display rod 5 with a winding diameter smaller at the center of the fuse than at both ends of the fuse, as shown in FIG.

As described above, according to the configuration of the present invention, the distance between the main fuse element 3 and the display fuse element 4 increases in the center of the fuse where it is difficult to accurately maintain the relative positions of the two. In this manner, malfunctions of the fuse operation display device due to contact between the two can be extremely reduced, and a highly reliable fuse operation display device can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of the structure of a fuse with a conventional operation display device, and FIG. 2 is a sectional view showing an embodiment of the present invention. In these figures, the spiral fuse element is drawn for reproduction. 1, 10...outer cylinder, 2,20...terminal metal, 3,
30... Main fuse element, 4, 40... Display fuse element, 5, 50... Operation display bar.

Claims (1)

[Scope of utility model registration request] An indicator fuse element is provided in parallel with the main fuse element and is wound in a spiral shape and stretched within the fuse outer cylinder by its own tension, and is blown out after the main fuse element is blown out, the indicator fuse element comprising: The display bar is always fixed to the display bar and spring storage case with the display bar held near one end against the biasing force of the spring, and when the main fuse element is activated, it is fused to release the hold and display the display. An operation display device that displays the operation of a main fuse element by displacing a rod, characterized in that the winding diameter of the spirally wound display fuse element is smaller at the center of the fuse than at the ends of the fuse. Display device.