JPS5840812B2 - Fuse operation indicator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a fuse operation display device.

FIG. 1 shows a conventional fuse and its operation display device.

That is, the conventional device has terminal metals 2 at both ends of an outer cylinder 1, and a fuse element 3 is stretched between the terminal metals 2.

The operation display device is attached to the terminal metal 2 at one end, and a display bar 5 biased by a spring 4 is normally held back by a display element 6 against the biasing force and housed in a cover 7. .

Both ends of the display element 6 are joined to the terminal metal 2, respectively.

8 is a plug for fixing the display element 6 in a stretched state.

In a display device with such a configuration, when the fuse element 3 operates, all the current is diverted to the display element 6, which melts and releases the hold on the display bar 5, and the display bar 5 is moved out of the fuse by the biasing force of the spring 4. It is activated to display the operation of the fuse.

Here, the spring 4 is set to a considerable load so that the display rod 5 can overcome resistance such as friction of the spring 4 and the terminal metal 2 and operate accurately.

Further, in many cases, the operation of the display rod 5 is linked to a microswitch to notify the operation of the fuse in the form of an electric signal, and in this case, the spring 4 is set to a stronger load.

On the other hand, in the case of a power fuse, a high resistance material such as a nichrome wire is usually used for the display element 6, and a constant current flows through the fuse element 3, which uses a low resistance material such as silver or copper.

However, when the fuse has a small rated current, the proportion of current flowing through the display element 6 increases.

When using such a fuse, the thickness of the fuse element 3 becomes extremely thin, and may be equal to or even thinner than the display element 6, and the breaking performance of such a fuse is the same as that of the display element 6. It is greatly influenced by the performance, and therefore the display element 6 is configured to be as thin as possible.

As mentioned above, the spring 4 is set to a considerable load, so if the display element 6 is made too thin, it may break due to vibration, impact, etc. and malfunction. It has an eclectic design that makes it slightly thicker.

In addition, in the semiconductor protection fuse of a rectifier, since multiple semiconductor elements are usually used in parallel, even if the fuse element 3 operates, the voltage applied to both ends of the fuse is low, and the high-resistance display element 6 will not blow out. There is.

In such a case, the display element 6 uses a material with a lower resistance than the nichrome wire used in the power fuse, such as an alloy of copper or silver, and since these have lower strength than the nichrome wire, the rating of the power fuse Problems such as wire breakage and malfunction due to vibration and impact of the display element are more serious than when the current is small.

This invention was made by focusing on the points mentioned above.
The present invention attempts to eliminate the above-mentioned drawbacks of the prior art by providing a structure that allows the use of low strength materials and a thin display element to hold back a large load spring.

FIG. 2 shows an embodiment of the present invention, in which the end of the display rod 5 is stopped by a retaining line 9, and a pulley 10a with a small radius is integrated into movable pulleys 10a and 10b with different radii.
A retaining line 9 of the display bar 5 is fixed to the display bar 5, and a display element 6 is fixed to a pulley 10b having a large radius to retain the display bar 5.

Here, 11 is a partition plate for supporting one end of the spring 4.

The pulley is configured to freely rotate around the fixed shaft 12.

Further, the retaining line 9 of the display rod 5 is made of a material with high tensile strength and flexibility.

Other structures such as the guide bar 7 and the plug 8 are the same as those shown in FIG.

In the present invention having the above structure, the retaining force of the display element 6 is amplified by the ratio of the radii of the pulleys 10a and 10b and is transmitted to the retaining line 9 of the display rod 5, so even a display element with low strength can be used. It can hold back extremely strong springs.

For example, if the pulley radius ratio is 5 times, the retaining force of the display element may be 115 times the spring load.

FIG. 3 shows the main part of another embodiment of the present invention, in which one or both of the pulleys in FIG.
Even if the retaining line 9 of the display rod or the display element 6 is fixed to this arm 13 (in the figure, only the side to which the display element 6 is connected is an arm), the same effect as in FIG. 2 can be produced.

Furthermore, although the case where the fuse element 3 is provided in parallel with the display element 6 has been described above, in the case of a fuse with a small rated current, the display element 6 may also serve as the fuse element 3 and be composed of a single element. However, the present invention is applicable to this case as well.

As described above, according to the present invention, a strongly loaded spring can be stopped with a weak display element or fuse element. This has the excellent effect that a display element can be constructed, and a fuse operation display device with excellent interrupting performance and high reliability can be obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a conventional fuse operation display device.
FIG. 2 is a partially perspective sectional view showing one embodiment of the present invention, and FIG. 3 is a perspective view showing essential parts of another embodiment of the invention. In the figure, 1 is an outer cylinder, 2 is a terminal metal, 3 is a fuse element, 4 is a spring, 5 is an indicator bar, 6 is an indicator element, 7 is a cover, 8 is a plug, 9 is a retaining line for the indicator bar, 10a,
10b is a pulley, 11 is a partition plate, 12 is a fixed shaft, and 13 is an arm. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1. An indicator rod for displaying operation is biased by a spring or the like,
A fuse operation display device includes a display element or a fuse element that holds a display rod against the biasing force, and when the fuse operates, the display element or fuse element releases the holding and the display rod operates, The retaining line of the display rod is fixed to the small radius pulley of an integrated pulley with different radii that rotates around a fixed axis, and the display element or fuse element is fixed to the large radius pulley to retain the display rod. A fuse operation display device characterized by: 2. In place of one or both of the integrated pulleys with different radii, extend an arm with a length equivalent to the radius of the pulley perpendicularly from the fixed axis, and attach a retaining line of the display rod to the pulley or arm with the smaller radius. 2. The fuse operation display device according to claim 1, wherein the display element or the fuse element is fixed to a pulley or arm having a large radius.