JP2012094397A - Fuse device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuse device capable of preventing fuse wrench caused by rotation of fastening metal hardware when tightening a fuse having claws with the fastening metal hardware, the fuse device not requiring structural change of existing fuse boxes or CKS (Covered Knife Switch).SOLUTION: A fuse device to be connected between edges of two electric wires, includes: an insulation case in which the fuse is fixed; two fitting terminal members, each being electrically connected to an edge conductor of each of the electric wires; female screw holes, each provided on each of the fitting terminal members; attachment screws, each having a male screw part to be screwed with each of the female screw holes and a head fixed at one end of each of the male screw parts; a piece of fuse, at both ends thereof, having insertion parts, which each of the male screw parts of the attachment screws penetrates through, with each end of the piece of fuse being in contact with each of the two fitting terminal members; and washers, each provided between each of the heads of the attachment screws and one end of the piece of fuse, each of the washers having a rotation stopper for stopping rotation of the washer by making a contact with a portion of the insulation case.

Description

  The present invention relates to an improvement in a fuse device which is provided in an electric circuit and protects the electric circuit from a large current exceeding a rating, and prevents accidents such as overheating and ignition due to the large current.

Conventionally, a low-voltage lead-in line branched from a low-voltage distribution line has been used as means for supplying electric power from an overhead line to facilities of electric power consumers such as factories and ordinary households. This low-voltage lead-in line protects the electric circuit when a short circuit occurs in the equipment of the power consumer and a large current exceeding the rating flows, and also prevents accidents such as overheating and ignition caused by the large current flowing. An electric wire fuse is used.
Further, a CKS (Cover Knife Switch) is used for a power line of a power device or the like, and the CKS is also provided with a fuse for the purpose of short-circuiting or overcurrent protection. In such a wire fuse or CKS, a claw-type fuse is usually used.
Claw-type fuses used for electric wire fuses and CKS are fused when the claws are tightened with bolts or other fasteners, and the fuse is twisted by the rotation of the clamps, and an overcurrent flows through the copper part of the fuse claws. There is a problem in that stress is applied to the joint portion with the lead portion and fusing occurs below the rated current.

In Patent Document 1 (Japanese Patent Laid-Open No. 7-296711), a nail is used to prevent the fuse from being twisted by the rotation of the tightening tool when the nail fuse is attached to the insulating base with a tightening tool such as a bolt. Fitting with a claw having two locking parts for preventing the rotation of the part and a gripping part that can be gripped by hand in order to hold the rotation blocking state of the claw part by these locking parts A tool is disclosed.
In Patent Document 2 (Japanese Patent Laid-Open No. 2000-195408), a plate fuse is fastened with a bolt, and when the bolt is loosened, the plate fuse is rotated by the rotation of the bolt, and the fuse element is deformed. In order to prevent damage, the electrical junction box is integrally formed with a detent protruding from the metal plate to prevent rotation between the metal plate portion into which the bolt is inserted and the plate fuse. Is disclosed.
However, the fuse mounting tool disclosed in Patent Document 1 requires a mounting tool for gripping the connecting portion of the fuse to prevent the rotation of the fuse, and in order to provide the mounting tool in the fuse box, There was a problem that the structure had to be changed and the existing fuse box and CKS could not be used.
Further, the electrical junction box disclosed in Patent Document 2 also requires a metal plate integrally formed with a detent portion for preventing rotation inside, and the existing fuse box and CKS cannot be used. was there.

JP 7-296711 A JP 2000-195408 A

As described above, when using a claw-type fuse in an electric wire fuse or CKS, when the claw portion of the claw fuse is tightened with a bolt or other tightening bracket, the fuse is twisted by the rotation of the tightening bracket, and the fuse claw portion There is a problem that stress is applied to the joint portion between the copper portion and the lead portion that is blown when an overcurrent flows, resulting in fusing below the rated current. Patent Document 1 discloses a mounting tool for holding a fuse connecting portion to prevent the rotation of the fuse, and Patent Document 2 discloses a metal plate having a rotation preventing portion for preventing the accompanying rotation of the fuse. However, each of the prior arts has a problem that it is necessary to change the structure of the fuse box or the electrical junction box, and the existing fuse box and CKS cannot be used.
The present invention has been made in view of the above, and can prevent twisting of the fuse caused by rotation of the fastening bracket when fastening the claw-type fuse with the fastening bracket, and can also change the structure of the existing fuse box or CKS. An object of the present invention is to provide a fuse device that does not.

In order to achieve the above object, the invention according to claim 1 is a fuse device connected between the end portions of two electric wires, and is provided with an insulating case for fixing the fuse, and spaced apart from the inside of the insulating case. Two mounting terminal members electrically connected to the end conductors of the respective electric wires, female screw holes provided in the respective mounting terminal members, a male screw portion screwed into the female screw holes, and the male screw The fastening screw having a head fixed to one end of the part and the male screw part of the fastening screw are inserted into the insertion parts provided at the two end parts in contact with the two attachment terminal members. And a washer disposed between a head of the fastening screw and an end of the fuse piece, and the washer comes into contact with a part of the insulating case to thereby remove the washer. It has a rotation stopper that prevents rotation. It is characterized in.
When fixing the fuse piece to the mounting terminal member, the rotational force of the fastening screw is not directly applied to the fuse piece, and the washer has a rotation stopper that contacts the part of the insulating case and prevents the washer from rotating. Therefore, the rotational force of the fastening screw is applied to the washer. However, since the washer does not rotate, the rotational force does not propagate to the fuse. Therefore, when the fuse is fixed to the terminal member, the rotational force of the fastening screw is not applied to the fuse, and a force such as twisting is not applied to the fuse, so that a fusing characteristic of the fuse does not change and a safe fuse device is provided. Can do.

The invention of claim 2 is the dish-type structure of claim 1, wherein the washer comprises a bottom plate and an edge formed integrally with the bottom plate, and contacts the fuse with the bottom plate of the dish-type structure, And it is provided with the L-shaped rotation stop part extended from a part of edge outer periphery and contacting a part of said insulation case.
Since the washer has a dish-type structure, it is easy to insert the fuse onto the mounting terminal member, so that the workability of replacing the fuse can be improved.
According to a third aspect of the present invention, in the first aspect, the washer has an L-shaped structure, contacts the fuse at the bottom of the L-shaped member, and at the end of the other side of the L-shaped. An anti-rotation portion that contacts a part of the insulating case is provided.
Since the washer has an L-shaped structure, it can be configured at a lower cost than a dish-shaped washer.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the insulating case includes a ketch holder in which two insulating case pieces are configured to be openable and closable.
Since the insulating case piece is a ketch holder, it can be used as a wire fuse.
According to a fifth aspect of the present invention, in the first to third aspects, the insulating case is a cover knife switch.
Since the insulating case piece is a cover knife switch, it can be used as a fuse device built in the cover knife switch.

  According to the present invention, when the fuse is disposed below the washer and the fuse is fixed to the mounting terminal member by the fastening screw, the rotation of the fastening screw is transmitted to the washer, and the end of the washer is a ketch holder. The rotation of the fastening screw is not transmitted to the fuse because it is prevented from rotating by contacting a part of the insulating structure inside the cover knife switch or inside the cover knife switch, so that the fuse is not twisted and fused with the claw of the fuse. No stress is applied to the joint portion with the portion, and the fusing characteristics do not fluctuate.

(A) is a front view of a sealed ketch holder used for an electric wire fuse when the fuse device according to the present invention is applied to an electric wire fuse, and (b) is a sectional view thereof. The elements on larger scale near one attachment terminal part in a ketch holder. (A) is a top view of a washer, (b) is a side sectional view, and (c) is a perspective view. It is a figure which shows other embodiment of the washer used for the fuse apparatus concerning this invention, (a) is the elements on larger scale near an attachment terminal part, (b) is a perspective view of a washer. It is a figure showing an embodiment at the time of applying a fuse device concerning the present invention to a cover knife switch, (a) is a top view of a cover knife switch in the state where a cover was opened, and (b) and (c) are fuses It is an enlarged view of an attaching part.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
FIGS. 1A and 1B are a front view and a cross-sectional view, respectively, of a sealed ketch holder used for a wire fuse when the fuse device according to the present invention is applied to a wire fuse. The wire fuse 100 includes two ketch holders 102 that are configured to freely open and close two insulating cases 102a and 102b, and mounting terminal members that are spaced apart from the ketch holder 102 and electrically connected to the conductor ends of the wires 104 and 105, respectively. 106 and 107.
Each of the mounting terminal members 106 and 107 is provided with female screw holes 108 and 109, and the male screw portions 110a and 111a and the male screw portions to be screwed into the female screw holes 108 and 109 are inserted into the female screw holes 108 and 109, respectively. Fastening screws 110, 111 having heads 110b, 111b fixed at one end are screwed.
Furthermore, between the mounting terminal members 106 and 107, both ends of the mounting terminal members 106 and 107 are in contact with each other, and male screw portions 110a for fastening screws are inserted into holes or notch insertion portions 115a provided at both ends. A fuse piece 115 through which 111a is inserted is provided. The fuse piece 115 is attached to the attachment terminal members 106 and 107 via the washers 117 and 118 by fastening screws 110 and 111.
The electric wire fuse 100 configured in this way is connected to a low-voltage lead-in wire in which one electric wire 104 is branched from the low-voltage distribution line, and the other electric wire 105 is connected to a power facility of a general consumer, and is short-circuited by the power facility of the general consumer. When an abnormal current such as the above occurs and an excessive current flows, the fuse piece 115 is melted to prevent an accident.

  FIG. 2 is a partially enlarged view of the vicinity of one mounting terminal portion 107 in the ketch holder 102. As shown in FIG. 2, the fuse piece 115 is inserted into a hole or notch insertion portion 115a provided at an end portion thereof and a fastening screw. The male screw portion 111a is inserted, and a washer 118 having an extended end portion 118d in contact with a part of the insulating structure 120 in the ketch holder 102 is disposed between the head portion 111b and the attachment terminal member 107. By being fixed through the washer 118, the fuse piece 115 and the conductor end portion 105 of the electric wire are electrically connected.

3A is a plan view of the washer 118, FIG. 3B is a side sectional view, and FIG. 3C is a perspective view. The washer 118 used in the fuse device according to the present invention has a dish type structure including a bottom plate 118a and an edge 118b formed integrally with the bottom plate 118a, and the bottom plate 118a of the dish is not flat and has a fastening screw. It warps so that it may float up so that it may approach an outer peripheral part from the hole 118c which penetrates. This is because the insertion portion 115a of the fuse piece 115 can be easily inserted into the fastening position with the washer 118 disposed. Further, a substantially L-shaped end portion 118 d extends from the edge portion 118 b of the washer 118, and the end portion 118 d functions as a rotation stop portion by contacting a part of the insulating structure 120 in the ketch holder 102. is doing.
Accordingly, when the fuse pieces 115 are respectively arranged below the washers 117 and 118 and the fuse pieces 115 are fixed to the mounting terminal members 106 and 107 by the fastening screws 110 and 111, the fastening screws 110 and 111 are rotated. The washer 117, 118 is transmitted to the washer 117, 118. Since the end 118d of the washer 117, 118 is in contact with a part of the insulating structure 120 in the ketch holder 102 and is prevented from rotating, rotation of the fastening screws 110, 111 is prevented. The fuse piece 115 is not transmitted, the fuse piece 115 is not twisted, no stress is applied to the joint portion between the fuse claw portion and the fusing portion, and the fusing characteristics of the fuse do not fluctuate.

Next, FIG. 4 is a figure which shows other embodiment of the washer used for the fuse apparatus concerning this invention, (a) is the elements on larger scale near the attachment terminal part 107, (b) is a perspective view of a washer. is there. Note that the structure of the washer is different from that of the embodiment shown in FIGS. 1 and 2, and the other parts are the same, so the description thereof is omitted.
As shown in the figure, the washer 122 in this embodiment has a substantially L-shaped cross section, functions as a washer, and a portion provided with a hole 122a into which a fastening screw is inserted, and a direction orthogonal to the portion. And has an end 122b extending to the end. The end 122b functions as a rotation stopper by contacting a part of the insulating structure 120 in the ketch holder 102 when the fuse piece 115 is mounted.
In the above description, a washer having a rotation stopper is used when fixing the fuse piece 115 to either of the attachment terminal members 106, 107. However, it is preferable that either of the attachment terminal members 106, 107 is provided with a washer. Also good. That is, when the fuse piece 115 is attached to the fuse device, a hole or notch insertion portion provided in one end portion of the fuse piece 115 is fixed to one of the attachment terminal members 106 and 107 with a fastening screw, and the other end. The insertion part provided in the part is fixed to the mounting terminal member on the other end side with a fastening screw, but the stress on the insertion part of the fuse to be fixed first is applied by the rotation of the connecting screw, but the other end side is fixed This is because it is not subjected to a stress that fluctuates the fusing characteristics of the fuse.
Therefore, when the insertion portion at one end of the fuse is fixed to the attachment terminal member with the fastening screw, and then the insertion portion at the other end is fixed to the attachment terminal member with the fastening screw, the washer is attached to the attachment terminal member on the other end side. Even if it is the structure provided with, the influence which the rotational force by the screw for fastening at the time of attachment exerts on a fuse can be reduced, and the same effect can be acquired.

FIG. 5 is a diagram showing an embodiment in which the fuse device according to the present invention is applied to a CKS. FIG. 5A is a plan view of the CKS with the cover opened, and FIGS. 5B and 5C are attached to the fuse. It is an enlarged view of a part.
The CKS 130 has a main body 132 made of an insulating base, a cover 134, a switch lever 136, a mounting terminal portion 138, a fuse piece 140, a washer 142, and a fastening screw 144 for fastening both ends of the fuse piece 140. The washer 142 has an outer shape with a substantially L-shaped cross section, and the vertical portion contacts a part of the insulating base 132 and functions as a rotation stopper. Therefore, when the fuse piece 140 is attached to the attachment terminal portion 138 with the fastening screw 144, the fuse piece 140 receives a rotational force generated from the fastening screw, and a part of the washer 142 is in contact with a part of the insulating base 132. The washer 142 does not rotate and does not generate a stress that causes twisting or the like to the fuse piece 140.
As described above, the fuse device according to the present invention does not receive the rotational force of the fastening screw for fixing when fixing the fuse piece to the insulating case, and therefore, the fuse piece is not twisted and the fusing characteristics of the fuse do not fluctuate. . Also, since the washer is provided with an end and the end is in contact with a part of the case to prevent the washer from rotating, the fuse device can be configured without changing the structure of the existing wire fuse, cover knife switch, etc. Has the advantage of being able to

102 Ketch holder (insulating case), 132 Cover knife switch insulating base (insulating case), 106, 107 Mounting terminal member, 110, 111 Fastening screw, 115, 140 Fuse piece, 118, 122, 142 Washer, 118d, 122a, 142a Washer end (rotation stop)

Claims (5)

A fuse device connected between the ends of two wires,
An insulating case for fixing the fuse, two mounting terminal members spaced apart from each other and electrically connected to the end conductors of the electric wires, and female screw holes provided in the mounting terminal members A fastening screw having a male screw portion screwed into the female screw hole, a head fixed to one end of the male screw portion, and both ends in a state where both end portions are in contact with the two attachment terminal members. A fuse piece for inserting the male screw part of the fastening screw into the insertion part provided in the part, and a washer arranged between the head of the fastening screw and the end of the fuse piece,
The fuse device according to claim 1, wherein the washer includes a rotation stopper for preventing rotation of the washer by contacting a part of the insulating case.   The washer has a dish-shaped structure comprising a bottom plate and an edge formed integrally with the bottom plate, the bottom plate of the dish-shaped structure is in contact with the fuse and extends from a part of the outer periphery of the edge. The fuse device according to claim 1, further comprising an L-shaped rotation stopper that contacts a part of the case.   The washer has an L-shaped structure, is in contact with the fuse at the bottom of the L-shaped member, and is in contact with a part of the insulating case at the end of the other side of the L-shaped The fuse device according to claim 1, further comprising:   4. The fuse device according to claim 1, wherein the insulating case includes a ketch holder in which two insulating case pieces are configured to be openable and closable.   4. The fuse device according to claim 1, wherein the insulating case is a cover knife switch.

Images