JP2010282918A - Vacuum switch fuse mounting structure - Google Patents

Abstract

To provide a fuse mounting structure for a vacuum switch capable of reliably contacting a fuse holder and a power fuse.
A fuse mounting structure for a vacuum switch provided with a power fuse, wherein a fuse holder 24 for holding and fixing both ends of a power fuse 15 is fixed to a fixing portion 25a and a fixing portion 25a. A fuse clip 25 that has a fuse contact portion 25b that is raised from both ends and is inclined in a V-shape and faces each other, and a power fuse 15 that is connected to both ends of the fuse clip 25 and is inserted into the fuse clip 25 And a fuse presser 26 that urges the fuse contact portion 25b to be pressed against the fuse contact portion 25b, and the power fuse 15 is brought into electrical contact at least at two locations in contact with the fuse contact portion 25b.
[Selection] Figure 3

Description

  The present invention relates to a fuse mounting structure for a vacuum switch with a power fuse.

A conventional vacuum switch with a power fuse is shown in FIG. As shown in the figure, a vacuum valve 32 having a fixed contact and a movable contact (both not shown) is arranged on the frame 31 side by side for three phases. The movable contact side of the vacuum valve 32 is connected to an operation lever 35 attached to the operation shaft 34 via an insulating rod 33. The operating shaft 34 is provided with a movable iron core 36, and when the movable iron core 36 is attracted by the electromagnet 37, the operating shaft 34 rotates and the operating lever 35 is driven, and the movable contact via the insulating rod 33. Comes in contact with and away from the fixed contact.
On the other hand, the fixed contact side is electrically connected to a fixed side terminal 38 fixed to the frame 31, and power is connected between the fixed side terminal 38 and a main circuit conductor (not shown) arranged on the back side. A fuse 39 is connected. The power fuse 39 is inserted into a fuse holder 41 attached to the mounting bracket 40 and is fastened with bolts by applying a fastening plate 42 from above (see, for example, Patent Document 1).

Japanese Utility Model Publication No. 62-33451 (first page, FIG. 1)

  In the conventional vacuum switch fuse mounting structure shown in Patent Document 1, the inner shape of the fuse holder 41 is formed in a curved surface in accordance with the shape of the power fuse 39. Although the conductive portion of the power fuse 39 and the inner surface of the fuse holder 41 seem to be in surface contact with each other over a wide area, they are actually a plurality of point contacts or line contacts. The contact location is not constant due to the variation in the shape dimensions and the tightening, and it is difficult to specify at which part the contact is made. For this reason, depending on the case, there was a problem that the contact portion is biased and abnormal heat generation may occur.

  Patent Document 1 also discloses a structure in which a terminal plate is provided on both end faces in the length direction of the power fuse, and the terminal plate is attached to a mounting bracket by bolting. If the power fuse has such a shape, the problem of the bias of the contact portion can be solved. However, in a commercially available power fuse, a power fuse having a cylindrical terminal (cap) as shown in FIG. 5 is generally used. The cap type is widely adopted as a power fuse for vacuum switches. Therefore, the vacuum switch using the cap type power fuse still has the above-mentioned problems.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a fuse mounting structure for a vacuum switch that can reliably contact a fuse holder and a power fuse.

The fuse mounting structure for a vacuum switch according to the present invention includes a vacuum valve having a built-in fixed contact and a movable contact, a fixed side terminal conductively connected to the fixed contact, and a fixed side main circuit conductor connected to the power source side. In a fuse mounting structure of a vacuum switch having a power fuse connected in series between the fuse holder, a fuse holder for holding and fixing both ends of the power fuse includes a fixing portion fixed to the electric circuit side and both ends of the fixing portion. A fuse clip that has a fuse contact portion that rises toward the end and is inclined in a V-shape and is opposed to each other, and the power fuse is configured to be in electrical contact at least at two locations that contact the fuse contact portion. .

  According to the fuse mounting structure of the vacuum switch of the present invention, the fuse holder for holding and fixing the both ends of the power fuse is fixed to the electric circuit side and is raised from both ends of the fixing portion so as to spread from the both ends. A fuse clip having a fuse contact portion that is inclined and opposed to each other, and the power fuse is in an energized contact at least at two locations in contact with the fuse contact portion. Therefore, since the contact can be surely made at least in two places assumed in advance, there is little variation in contact resistance, stable energization contact can be obtained, and a highly reliable vacuum switch can be provided.

It is a front view of the vacuum switch using the fuse attachment structure by Embodiment 1 of this invention. It is a side view of FIG. It is a figure which shows the fuse holder of the fuse attachment part of FIG. It is sectional drawing which shows the other example of the fuse holder used for the fuse attachment structure by Embodiment 1 of this invention. It is a front view which shows the fuse attachment structure of the conventional vacuum switch.

Embodiment 1 FIG.
Hereinafter, a fuse mounting structure for a vacuum switch according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a vacuum switch using the fuse mounting structure according to the first embodiment, showing a state in which a part of the face plate on the front side is cut away and the inside can be seen. FIG. 2 is a side view of FIG.

As shown in FIG. 1 and FIG. 2, vacuum valves 3 constituting main circuit contacts of the vacuum switch are arranged side by side in an insulating frame 2 mounted on the carriage 1. The vacuum valve 3 has a fixed contact 4 and a movable contact 5 built in a vacuum container, a fixed rod 6 is led out from the fixed contact 4, and a movable rod 7 is led out from the movable contact 5. The distal end side of the fixed rod 6 is connected to a fixed side terminal 8 fixed to the insulating frame 2, and the distal end side of the movable rod 7 is connected to the rotating shaft 10 via the insulating rod 9 and a lever 11 having one end fixed thereto. It is connected to. The intermediate portion of the movable rod 7 is connected to a movable terminal 12 fixed to the insulating frame 2 via a flexible conductor.
An electromagnetic operation mechanism having a movable iron core 13 and an electromagnet 14 is disposed below the vacuum valve 3. When the movable iron core 13 is attracted by the electromagnet 14, the rotation shaft 10 is rotated and the lever 11 is driven in conjunction with this, and this driving force is transmitted to the insulating rod 9, the movable rod 7, and the movable contact 5. The contacts 4 and 5 are made to contact and separate.

Above the vacuum valve 3, a power fuse 15 for interrupting the electric circuit when a predetermined current or more flows is arranged with the axis line parallel to the direction in which the fixed terminal 8 is led out for each phase. Yes. One fuse cap 15 a (terminal portion) of the power fuse 15 is connected to the fixed-side terminal 8 via a connection conductor 16 fixed to the insulating frame 2. The other fuse cap 15 a is connected to the fixed-side main circuit conductor 18 via the connection conductor 17. The fixed-side main circuit conductor 18 is supported by a support member 19 fixed to the carriage 1, and a contact 20 connected to the power-side main circuit conductor is provided at the tip. An insulating barrier 21 is provided between the phases of the power fuses 15 of each phase.
On the other hand, the movable side terminal 12 is connected to a movable side main circuit conductor 22 which is led out in the same direction as the fixed side main circuit conductor 18 and supported by the support member 19, and is connected to the load side at the tip. A contact 23 is provided.

Depending on the capacity of the vacuum switch, the power fuse 15 has an electric energy of several hundred amperes or more. Therefore, it is very important that the power fuse 15 is securely connected. For this purpose, the fuse holder 24 for fixing the power fuse 15 includes a fuse clip 25 fixed to the connecting conductors 16 and 17 by bolting, and the power fuse 15 is inserted into the fuse clip 25 and fixed by pressing from above. And a fuse presser 26 to be configured.
Since the vacuum switch according to the present embodiment is characterized by this fuse mounting structure, the fuse holder 24 will be described in more detail below.

  FIG. 3A is a perspective view of the fuse holder 24. The fuse clip 25 of the fuse holder 24 is formed by bending a thin copper strip in a U-shape in the longitudinal direction and expanding the folded opposing surface in a V-shape so as to spread toward the opening end side. . The U-shaped bottom surface portion is formed as a flat surface and serves as a fixing portion 25a for fixing to the connection conductor 16 or 17 on the electric circuit side. Then, a facing portion that rises from the both ends of the fixed portion 25a and is inclined in a V shape and faces the fuse contact portion 25b. A locking claw 25c bent in an L shape toward the outside is formed at one tip of the fuse contact portion 25b, and the other tip is bent outward to form a connection allowance 25d. An attachment hole 25e is formed in the center of the fixing portion 25a, and a screw hole 25f is formed in the connection allowance 25d.

On the other hand, the fuse presser 26 slightly curves the central portion of the thin copper strip, and one end portion is provided with an engagement hole 26a that engages with the locking claw 25c of the fuse clip 25, and the other end portion. A mounting hole 26b is provided in accordance with the screw hole 25f of the fuse clip 25.
The fuse retainer 26 is designed to have a shape and dimensions that, when combined with the fuse clip 25, can urge the power fuse 15 inserted into the fuse clip 25 so as to press it against the fuse contact portion 25b.
Although the material of the fuse retainer 26 has been described as a thin copper strip, it is not necessary to function as a current-carrying part in particular, and therefore a steel material may be used.

Next, the operation of the fuse holder 24 will be described.
FIG. 3B is a view showing a state in which the power fuse 15 is inserted into the fuse clip 25, is pressed by the fuse retainer 26, and is tightened by a fastening member 27 such as a bolt or a screw.
Since the fuse contact portion 25b is formed in a V-shaped straight line, when the power fuse 15 is mounted, the inner surface of the fuse contact portion 25b and the fuse cap 15a of the power fuse 15 are in two contact points. It contacts at a point and becomes an energizing contact portion. Of course, contact is made on the fuse presser 26 side, but contact is always made at at least two contact points. These two locations are calculated and expected from the diameter of the fuse cap 15a and the shape of the fuse clip 25, and do not vary greatly due to assembly errors.
Therefore, according to the fuse holder 24, stable energization contact can be obtained.

FIG. 4 shows another example of the fuse holder. FIG. 4 is a cross-sectional view of a portion corresponding to FIG.
It is composed of a fuse clip 28 formed by bending a thin copper strip in a U shape in the longitudinal direction and spreading it in a V shape so that the opposing surface becomes wider toward the opening end side, and a fuse retainer 29. This is the same as FIG. Hereinafter, the difference will be mainly described.
The difference is the shape of the fuse contact portion 28b on the side where the connection allowance 28d of the fuse clip 28 is provided. The fuse contact portion 28b is curved inward with a curvature larger than the diameter of the fuse cap 15a on the tip side from the contact point where the energization contact is made, and the connection allowance 28d is obliquely above the fixed portion 28a (for example, It is the point which inclines in about 45 degree | times.
The fuse retainer 29 has substantially the same shape as that of FIG. 3, and determines the curvature of the central portion and the inclination of the joint portion at the end according to the fuse clip 28.

The operation of the fuse holder formed as shown in FIG. 4 will be described. In this fuse holder, it can be seen that the dimension D between the end faces on the opening side of the fuse clip 28 is smaller than that in the case of FIG. The dimension D is a dimension necessary for fixing the fuse retainer 29 to the fuse clip 28. When the power fuses 15 are arranged side by side for three phases, it is necessary to secure a predetermined insulation distance from each other, and the minimum interphase distance is (D dimension + insulation distance). Therefore, if the D dimension is reduced, the interphase distance can be shortened.
When the diameter of the power fuse 15 is large, the effect of reducing the size is particularly great, so that the switch can be miniaturized.
However, since the shape of FIG. 3 is easier to manufacture, use the fuse holder of the shape of FIG. 3 when the diameter of the power fuse 15 is small, and use the fuse holder of the shape of FIG. 4 when the diameter increases. In addition, you should use properly.

  In addition, the vacuum switch demonstrated in FIG.1 and FIG.2 shows an example, and is not limited to the structure of a figure. The present invention is characterized by a fuse mounting structure and can be applied to any vacuum switch with a power fuse.

  As described above, according to the fuse mounting structure of the vacuum switch according to the present embodiment, the fuse holder that holds and fixes both ends of the power fuse includes the fixing portion that is fixed to the electric circuit side and both ends of the fixing portion. A fuse clip that has a fuse contact portion that rises from the end and inclines in a V shape and opposes the power fuse, and the power fuse is in electrical contact at least at two locations that contact the fuse contact portion. At the connection part between the fuse and the fuse clip part, it can be reliably contacted at least in two places assumed in advance, so there is little variation in contact resistance, stable energization contact is obtained, and a highly reliable vacuum switch Can be provided.

  Also, a locking claw is provided at one tip of the fuse contact portion of the fuse clip, a connection margin is provided at the other tip, one end is engaged with the locking claw of the fuse clip, and the other end is connected. The fuse retainer is connected to both ends of the fuse clip and has a fuse retainer that urges the power fuse inserted into the fuse clip to press the fuse contact portion. The fuse contact portion can be reliably pressed.

  Also, the fuse contact portion on the side where the connection allowance of the fuse clip is provided is curved inward on the tip end side from the contact point where the current contact is made, and the connection allowance is inclined obliquely upward with respect to the fixed portion. Since it is formed, in addition to the above effect, the interphase dimension can be reduced, so that the switch can be miniaturized.

1 bogie 2 insulating frame 3 vacuum valve 4 fixed contact 5 movable contact 6 fixed rod 7 movable rod 8 fixed side terminal 9 insulating rod 10 rotating shaft 11 lever 12 movable side terminal 13 movable iron core 14 electromagnet 15 power fuse 15a fuse cap 16, 17 Connection conductor 18 Fixed side main circuit conductor 19 Support member 20, 23 Contact 21 Insulation barrier 22 Movable side main circuit conductor 24 Fuse holder 25, 28 Fuse clip 25a, 28a Fixed portion 25b, 28b Fuse contact portion 25c, 28c Locking Claw 25d, 28d Connection allowance 25e Mounting hole 25f Screw hole 26, 29 Fuse retainer 26a, 29a Engagement hole 26b Mounting hole 27 Fastening member.

Claims (3)

A vacuum valve having a fixed contact and a movable contact; and a power fuse connected in series between a fixed-side terminal conductively connected to the fixed contact and a fixed-side main circuit conductor connected to the power supply side In the fuse mounting structure of the vacuum switch,
A fuse holder for holding and fixing both ends of the power fuse is:
A fuse clip having a fixed portion fixed to the electric circuit side and a fuse contact portion that is raised from both ends of the fixed portion and is inclined in a V shape and opposed to each other;
A fuse mounting structure for a vacuum switch, wherein the power fuse is in electrical contact at least at two locations in contact with the fuse contact portion. In the fuse mounting structure of the vacuum switch according to claim 1,
A locking claw is provided at one tip of the fuse contact portion of the fuse clip, and a connection allowance is provided at the other tip.
One end portion engages with the locking claw of the fuse clip, the other end portion is fastened to the connection allowance to connect the both end portions of the fuse clip, and the power fuse inserted into the fuse clip A fuse mounting structure for a vacuum switch, comprising a fuse presser that urges the fuse contact portion to be pressed. In the fuse mounting structure of the vacuum switch according to claim 2,
The fuse contact portion on the side where the connection allowance of the fuse clip is provided is curved inward on the tip end side from the contact point where the energization contact is made, and the connection allowance is obliquely upward with respect to the fixing portion. A fuse mounting structure for a vacuum switch, which is formed to be inclined.

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