JPH0577853U - Small timed fuse for 200 volt circuit - Google Patents

Abstract

(57) [Abstract] [Purpose] The size of the fuse body is reduced to about 3 by reducing the number of members used for the time-limited fusible element body placed in the insulating cylinder.
Providing a compact time-duration fuse for 200-volt circuits with a structure that can achieve 0% miniaturization and labor saving in the process to improve productivity. [Structure] A low-current operating piece X having a hook washer at one end of a coil spring and an inverted S-shaped piece at the other end, and a single fusible body, an insulating holding plate, a heat storage body, a resistance shaft conductor, and The timed fusible element body Y formed of a low melting point metal is arranged in a state in which tension is applied to the coil spring from one end of the insulating cylinder, and after fitting the first and second cup-shaped bases from both ends of the insulating cylinder, The resistance shaft conductor is pushed in and the arc-extinguishing agent is filled around the fusible body.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a small timed fuse used for circuit protection of capacitors, motors, etc., which have a rated voltage of more than 200 V and a rated current value of 5 amperes or more in an electric circuit. is there.

[0002]

[Prior Art]

 Conventionally, the timed fuses used in the above circuits have a large delay fusing function that does not cause a fast disconnection even if the starting current is several times the rated current value and the duration flows for several seconds. Is generally disclosed as a structure having a so-called double fusing function for quick disconnection. Specifically, as shown in the sectional view of FIG. 7, if the rated current value is 5 amperes or more, A pair of fusible elements on the left and right, a holding plate c, and a timed element composed of a conductor d having a relatively large volume in the center are connected in series, and arc extinguishing agents are alternately arranged around the left and right fusible elements. It is known that the terminal is filled with e and fitted into both terminal caps, but due to its structure, there are many in-cylinder storage members, so a small size cannot be achieved.

[0003]

[Problems to be solved by the device]

 As described in the prior art, this type of timed fuse has a structure in which the fusible body is placed on the left and right inside the insulating cylinder, so there is almost no space inside the cylinder. It had a problem that it could not withstand the recovery voltage of 200 V or more, and had a minimum diameter of 15 mm and a total length of 50 mm, and it was impossible to manufacture a smaller size.

In addition, there are many members for constructing the timed element body, and in particular, the step of fixing the insulating holding plate and the L-shaped metal fitting for hooking and fixing the contact coil spring (not shown) is a difficult task. It had the problem of being inefficient.

Further, since at least one pair of right and left fusible elements in the insulating tube is required, the arc extinguishing agent to be filled around the fusible element must be separately charged from the left and right openings of the insulating tube. However, this filling process also had the problem of poor productivity due to lack of continuity.

The present invention has been made in order to eliminate the above-mentioned problems. The purpose of the present invention is to reduce the size of the fuse main body by reducing the number of members used for the timed element body arranged in the insulating cylinder by half. We provide a compact timed fuse for 200 volt circuits with a structure that can improve productivity by reducing the size by about 30% and labor saving in the process.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, in the present invention, a heat storage body made of a copper flat plate, a support conductor made of a resistance material, and an insulating holding plate are fixed, and a single fusible body and one end thereof are joined to form a coil. A low-voltage shielding element consisting of an S-shaped copper piece that holds the pulling is melt-bonded with a low-melting metal to form a timed fusible element body. The latch washer is arranged so as to protrude outside the insulating cylinder, the second cup-shaped mouthpiece is fitted and the supporting conductor made of the resistance material of the required length is pushed in and soldered, and The arc-extinguishing agent is filled from the opening at the other end, the first cup-shaped mouthpiece is fitted to this, and a single fusible body is soldered to produce a small-sized timed fuse.

[0008]

[Action]

 The hook washer of the timed fusible element that is placed in the insulating cylinder is tensioned between it and the S-shaped copper piece by joining the support made of a resistance material of the required length to the second cup-shaped base. It is possible to lock the position of a single fusible body through the insulating holding plate while it is in the state, and in this state, the arc-extinguishing agent can reduce the number of man-hours to half by filling only around the single fusible body. Therefore, the productivity becomes good.

With respect to the breaking performance in a 200-volt circuit, when a low overload current is continuously applied to the timed element body, an inverted S-shaped copper cutoff connecting a single fusible body and a heat storage body is performed. At the same time that the low melting point metal melts, it can be cut off by reliably separating it by the contracting force of the coil spring that is locked to the hook washer. Since the narrow portion of a single fusible material melts instantly, there is no problem in terms of electrical breakdown voltage of 200 volts or more.

[0010]

【Example】

 The present invention will be described below based on an embodiment. FIG. 1 is a disassembled perspective view of a member constituting a small time-duration fuse for a 200-volt circuit according to the present invention. 12 is an insulating cylinder having heat resistance and mechanical strength, and 13 is a conductive first cup shape. The caps and 14 are second cup-shaped caps, which have holes 13a and 14a at predetermined portions, and are fitted into the insulating cylinder 12. Reference numeral 1 denotes a holding plate made of an insulating material, which has a fusible body insertion hole 1a in the center and a heat storage body locking hole 1b therebelow, and has an outer diameter of a circular shape that matches the inner diameter of the insulating cylinder 12. Reference numeral 2 is a rectangular heat storage body made of a copper plate of a good conductor metal and having a convex portion 2a at the front end and a hole 2b at the rear end. Reference numeral 3 is a resistance shaft conductor made of a copper-nickel alloy that is responsible for heat conduction to generate heat by passing an overcurrent through the heat storage body 2, and is a wire or rod. 4 is an inverted S-shaped piece of a good conductor copper plate bent in an inverted S shape and having a circular hole 4a, an upper groove 4b, a lower groove 4c and a bottom surface 4d on the upper surface, which is further made of stainless steel in the groove 4c. When the tip 5a of the coil spring 5 is fixed by squeezing it, the rear end 5b of the coil spring 5 is semi-circular and has a hooking protrusion 6a at its center. It is formed by forming a current-operation fragment X. Reference numeral 7 denotes a single fusible body made of a thin metal plate of silver or copper having at least one narrow portion 7a at the center of the wide portion 7b.

FIG. 2 is a perspective view showing a process of assembling the timed fusible element body used in the present invention. First, as shown in FIG. 2A, the heat storage under the insulation holding plate 1 is stored. Insert the tip convex portion 2a of the heat storage body 2 into the body locking hole 1b, crush the tip of the heat storage body 2 and join them, and then insert the resistance shaft conductor 3 into the hole 2b at the rear end of the heat storage body 2 as shown in FIG. Insert the tip of the and connect with solder 20. In this state, as shown in FIG. 2C, the wide portion 7b of the fusible body 7 is inserted through the upper hole 1a of the insulating holding plate 1, and the low current operating fragment X is mounted from above the heat storage body 2. Then, as shown in FIG. 7D, Y is formed as a time-limited fusible element body integrated with the single fusible body 7 and the heat storage body 2.

FIG. 3 is a cross-sectional view for explaining a joined state of the timed fusible element body Y. The wide part 7b of the single fusible body 7 inserted through the upper hole 1a of the insulating holding plate 1 is shown in FIG. , Inserted into the groove 4b above the inverted S-shaped shield piece 4 which constitutes the low-current operating shield piece X, and further with the bottom surface 4d placed on the surface of the heat storage body 2, above the inverted S-shaped shield piece 4. The low-melting-point metal 10 made of tin, lead, and lead is melted from the circular hole 4a of the above, and the surface of the heat storage body 2 and the bottom surface 4d of the shield piece 4 are joined to each other. A flow path is formed from the solution 7 to the reverse S-shaped shield piece 4 of the low-current operating shield piece 4, the heat storage body 2, and the resistance shaft conductor.

As shown in FIG. 4A, the semi-circular hook washer 6 of the fragmentary body X of the time-resolvable element Y formed as described above is fitted to the outer periphery of the insulating cylinder 12. As shown in FIG. 7B, the first cup-shaped mouthpiece 13 is provided from the side of the single fusible body 7 and the second cup-shaped mouthpiece 14 is provided from the side of the resistance shaft conductor 3 into the holes 13a and 14a, respectively. Insert it so that it can be inserted through.

Next, the resistance shaft conductor 3 previously cut to a required length is pushed into the second cup-shaped die 14 as shown in FIG. By this pushing, the coil spring 5 hooked on the convex portion 6a of the hook washer 6 is pulled, and in this state, the hole 14a of the second cup-shaped base 14 is closed with the solder 20 and the resistance shaft. The conductor 3 is joined.

Further, as shown in FIG. 2D, after the arc-extinguishing agent 15 made of silica sand of the meshes 30 to 40 is filled from the hole 13a of the first cup-shaped die 13 on the single fusible body 7 side, One fusible body 7 and the first cup-shaped base 13 are joined by solder 20, and the surplus length of the single fusible body 7 is cut to complete the timed fuse having the structure as shown in FIG.

The finished product of FIG. 5 manufactured in this way does not electrically melt at a passing current up to 110% of the rated current value, but it does not melt at 135% to 800% of the rated current. %, The low-current operating fragment X formed from the reverse S-shaped shield piece 4 and the coil spring 5 is heat-conducted by the heat generation effect of the resistance shaft conductor 3 to cause the reverse S-shape. The meltable body 7 of the character-shaped fragment 4, the low melting metal 10 of the heat storage body 2 are melted, and the contraction force of the coil spring 5 connected thereto melts a sufficient gap G as shown in FIG. 6 (a). Close the circuit. On the other hand, when a large current of 1000% or more of the rated current or a short-circuit current passes, the narrow portion 7b of the single fusible body 7 in the arc-extinguishing agent 15 melts instantly as shown in FIG. Then, the circuit is disconnected with the gap H generated. In any of the disconnection conditions, a recovery voltage equal to or higher than the circuit voltage is generated at the same time as the cutoff, but the arc current generated is all limited by the arc extinguishing agent 15 and the insulation resistance after the cutoff can also clear the specified value.

[0017]

[Effect of the device]

 Since the present invention is configured as described above, it has the following effects.

The small time-duration fuse for a 200-volt circuit according to the present invention has a withstand voltage structure while being structurally small, and therefore safely supports circuit protection of 200-volt electric equipment which is expected to become more and more popular in the future. it can.

Since the fusible body placed in the insulating cylinder is a single fusible body, it is easy to downsize the volume and the total length by about 30% compared to this type of conventional timed fuse in terms of volume ratio. And

In addition, the timed fusible element body arranged in the insulating cylinder is low in cost because all the constituent parts can be covered by a single part. Since it can be performed in the process, it is efficient and the productivity can be improved.

Electrically, the breakage arc energy caused by the interruption of the fusible body, which occurs during the passage of a large current during a short circuit, is caused by the current limiting action due to the small area of the fusible body and the filling of the arc-extinguishing agent. The structure is highly safe because the structure is such that the insulation holding plate that intersects each other and divides the inside of the insulating cylinder depending on the magnitude of the blocking current can prevent ripples.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of components of a small time-duration fuse for a 200-volt circuit according to the present invention.

FIG. 2 is a perspective view showing a process of assembling the timed fusible element body used in the device of the present invention.

FIG. 3 is a cross-sectional view showing a joined state of the timed fusible element body used in the product of the present invention.

FIG. 4 is an explanatory view of an assembling process of a small time-duration fuse for a 200 volt circuit of the present invention.

FIG. 5 is a sectional view of a completed product of a small time-duration fuse for a 200-volt circuit of the present invention.

FIG. 6 is a cross-sectional view showing an operating state of the device of the present invention.

FIG. 7 is a sectional view of a conventional time-duration fuse for a 200-volt circuit.

[Explanation of symbols]

 X Low-current operation shield piece Y Timed fusible element body G, H Gap 1 Insulation holding plate 2 Heat storage body 3 Resistance shaft conductor 4 Reverse S-shaped shield piece 5 Coil spring 6 Hooking washer 7 Single fusible body 10 Low melting point Alloy 12 Insulating cylinder 13 First cup-shaped base 14 Second cup-shaped base 15 Arc-extinguishing agent 20 Solder

Claims (1)

[Scope of utility model registration request] 1. A pair of fusible bodies on the left and right sides, a holding plate, and a U-shaped heat storage body having a relatively large volume in the center, and a copper block interrupter is joined to one end of the fusible body with a low melting point metal. Further, the other end of the fusible body is joined to the heat storage body and one of the holding plates and a coil spring are used to apply tension to the copper block to lock it, and this is arranged together with the arc extinguishing agent in the insulating cylinder. In a timed fuse, a low-current operating shield X having a hook washer at one end of a coil spring and an inverted S-shaped shield at the other end, and a single fusible body, holding plate, heat storage body, and resistance shaft conductor And fusible element body Y formed of low melting point metal
Is placed in a state where tension is applied to the coil spring from one end of the insulating cylinder, the first and second cup-shaped caps are fitted from both ends of the insulating cylinder, and the resistance shaft conductor is attached to the second cup-shaped cap. Small size for a 200-volt circuit characterized by a structure in which the fusible body and the first cup-shaped mouthpiece are soldered by pushing them in and soldering them and filling the arc-extinguishing agent around the fusible body through the hole of the first cup-shaped mouthpiece. Timed fuse.