JPH0129701Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an auxiliary switch for a control circuit used in a bridge, disconnector, switch, etc.

Conventionally, a vacuum valve 2 of a vacuum breaker/switch 1 shown in FIGS. 1 and 2 has been fixed to an insulating frame 3 and operated by an opening/closing shaft 4. Reference numeral 5 denotes an auxiliary switch attached to the side surface of the insulating frame 3, and the auxiliary switch 5 is operated by an operating piece 6 integrated with the opening/closing shaft 4.

It is extremely important to reduce the size of this type of disconnector/switch 1 in view of the need to reduce the installation space for storage panels and the like. In other words, the width dimension A influences the width dimension of the board, especially when there are many boards in a row. In order to reduce this width dimension A, since the auxiliary switch 5 is attached to the side surface of the insulating frame 3 as described above, it is important to reduce the thickness dimension d of the auxiliary switch 5.

On the other hand, this type of disconnector/switch generates a large impact force even when it is operated, and is often installed in locations where large impact forces are applied. Therefore, the contacts of the auxiliary switch must have high contact reliability even under these conditions of large impact force. In order to improve this contact reliability, twin contacts or sliding contacts are usually used. In addition, it is important to downsize the auxiliary switch for the reasons mentioned above, so it is usually a sliding type with butt contacts, but in this case, due to the structure, a sufficiently large sliding stroke cannot be obtained, and it is extremely It is a slight sliding stroke. In order to obtain a large sliding stroke, a pinch-type (knife-shaped) contact may be used, but in this case,
Since the auxiliary switch has the disadvantage of being large in size, it is usually of the rotary type.

As shown in FIGS. 3 and 4, this rotary operation type is a contact type in which, for example, the movable contact 11 sandwiches the fixed contact 12. Therefore, by clockwise rotation of the operating rod 13, the movable contact 11 and the fixed contact 12 When they come into contact, they slide against each other, and at the same time, in the contact state, they do not separate from each other even under large impact forces.
Furthermore, even when the surface layer of the contact point is deteriorated due to adhesion of dust or corrosive gas in the surroundings, the sliding effect removes these foreign substances and maintains good contact. Therefore, high contact reliability can be ensured in the rotary operation type. However, since it is a sandwiching contact method, the contact itself is thin, but the width of the contact, that is, the width of both the movable and fixed contacts 11 and 12.
Since B ₁ and B ₂ are large, there is a drawback that the d dimension, which is the width dimension of the auxiliary switch, becomes large. On the other hand, this type of contact has the advantage of being able to use a strong slit arc as an arc extinguishing method because the contact itself is thin.
With the pair of movable contacts 11, two sets of contacts can be arranged side by side without providing a partition insulating plate or the like between the contacts, and in this case, one movable contact 11 is omitted, which is economical. This is because the adoption of the above-mentioned slit arc extinguishing makes it possible to extremely shorten the arcing time when the current is cut off.

In other words, in the embodiments shown in FIGS. 3 and 4, the number of movable contacts is reduced to, for example, half the logarithm of the fixed contacts by employing slit arc extinguishing, which has high contact reliability and excellent arc extinguishing performance. However, since it is a rotary operation type, there is a drawback that the width dimension d of the auxiliary switch is large.

Next, in the auxiliary switch using the conventional butt contact type contact system shown in Figs. 5 and 6, because it is a direct operation method, the contact force may decrease due to large vibration impact in the contact force direction. In addition to the essential drawback that they may open in some cases, they also have the drawback that electrical contact is interrupted if the contact surface layer deteriorates due to adhesion of dust or corrosive gas. In order to stochastically avoid this electrical contact failure, it is common practice to adopt a twin contact structure, or to make sliding contact by adding a twisting motion to the movable contact in addition to the linear motion. However, in the case of the linear operation method, the operating rod 13A moves linearly, so it is structurally impossible to perform large twisting movements. Therefore, it is essentially impossible to eliminate the above-mentioned poor contact with only a slight sliding movement.

Furthermore, since the width d of the auxiliary switch shown in FIG. 5 is determined by the width of one movable or fixed contact, the width of the rotary operation type auxiliary switch shown in FIGS. 3 and 4 is determined by the width of one movable or fixed contact. It has the advantage of being considerably smaller than d. That is, whereas the rotary operation type auxiliary switch shown in FIGS. 3 and 4 is cylindrical or polygonal,
This is because the butt-contact type auxiliary switch shown in FIG. 5 has a flat plate shape. However, although the width d is certainly small for an auxiliary switch, the dimension in the direction perpendicular to the moving direction of the contact itself is approximately the same as the diameter of the contact, so it is considerably larger than the auxiliary switch shown in FIG. That is, in the case of the auxiliary switch shown in FIG. 5, the slit arc extinguishing method like the auxiliary switch shown in FIG. 3 cannot be adopted.
Therefore, the shearing performance is poorer than that of the auxiliary switch shown in FIG. 3, and the arcing time is long. Therefore, a partition wall 14 made of an insulating material is provided for each contact to prevent an electrical short circuit between the contacts and to prevent the maximum movement dimension B of the operating rod 13A from increasing. For this reason, the maximum movement dimension B of the operating rod 13A can be reduced, but it is not possible to use one movable contact (one pair) for two pairs of fixed contacts as in the auxiliary switch shown in FIG. 1 pair of fixed contacts and 1
The movable contacts (one pair) constitute one set of contacts. Therefore, in this respect, the cost becomes high. That is, although the auxiliary switches shown in FIGS. 5 and 6 have a small width d, they inherently have low contact reliability, poor shearing performance, and high cost.

In view of the above-mentioned drawbacks of the conventional technology, the present invention has developed a slit arc-extinguishing sliding contact type that has a small width, high contact reliability against vibration shock, dust, and corrosive gas, and excellent shearing performance. It is possible to obtain an inexpensive auxiliary switch.

Hereinafter, the present invention will be explained in detail with reference to an embodiment shown in FIGS. 7 to 10.

In the embodiments of FIGS. 7 to 10, 21
is an insulating frame. Reference numeral 22 denotes an operating rod that is attached to the substantially central portion of the insulating frame 21 so as to be able to reciprocate. 23a, 23b, 23c, 23
d, 23e, and 23f are two pairs (in this embodiment, six pairs) of fixed contacts arranged oppositely on both sides of the insulating frame 21 with the operating rod 22 in between. 24a, 24b, 24c are the operating rods 2
2, the pair of fixed contacts arranged opposite to each other are elastically sandwiched from both sides to bridge them, and the operating rod is reciprocated to contact any one of the six pairs of fixed contacts. This movable contact 24a, 24b, 24c is the ninth movable control point that is released.
As shown in the figure, it is composed of two sheets so that the fixed contacts 23a to 23f can be inserted thereinto. 25
is a slit arc extinguishing chamber formed from an upper insulator 26 and a lower insulator 27 attached to the operating rod 22 so as to surround the movable contacts 24a, 24b, and 24c.

In the above configuration, the movable contacts 24a, 24b, 24 are
c also reciprocates in the same direction, so fixed contact 2
The movable contacts 24a, 24b, 24c which were in contact with the contacts 3a, 23c, 23e, respectively, are separated and come into contact with the fixed contacts 23b, 23d, 23f. That is, the embodiment of the present invention is a sliding contact type that uses linear motion, and has one (one pair) movable contact 24a.
This is a flat plate type auxiliary switch which has two sets of contacts, including the two pairs of fixed contacts 23a and 23b.

As is clear from the above description, the present invention has the following effects.

(1) The width dimension d of the present invention is determined by the thickness T ₁ of the movable contact, whereas in the case of conventional butting, the width dimension is approximately determined by the diameter of the contact. Since the thickness dimension T ₁ of the movable contact is smaller than the diameter of the contact,
The width dimension d can be made into a flat plate shape which is smaller than that of the conventional butt.

(2) In this invention, the arc extinguishing chamber is attached to the movable contact, so (A) the arc extinguishing chamber is not placed over the entire stroke of the movable contact in the movement direction, that is, it is not placed over the entire stroke between the fixed contacts. Partially (approx. W1/2)
This means that the insulation between the fixed contacts is excellent. The arc extinguishing chamber intensely cools the arc and extinguishes the current, but on the other hand, molten matter and free carbon from the contacts adhere to the walls of the arc extinguishing chamber, reducing insulation performance. However, in the case of the present invention, only part of the arc extinguishing chamber is provided as described above. That is, in terms of insulation, it is solid insulation + air insulation, and air is excellent in insulation because it does not deteriorate the insulation. (B) The present invention uses a method in which the movable contacts sandwich the fixed contacts, and by installing an arc extinguishing chamber on the sandwiching side, excellent shearing performance is achieved. If the arc extinguishing chamber is fixed and the arc extinguishing chamber covers the entire stroke, a gap between the upper arc extinguishing chamber and the lower arc extinguishing chamber is required to allow movement of the maximum dimension T ₁ in the direction perpendicular to the movement direction of the movable contact.
If the arc extinguishing chamber is placed on the nipping side, that is, on the movable contact side, the gap in the movement direction of the arc extinguishing chamber will be the same as that of the fixed contact.
It can be determined by T ₂ (<T ₁ ). The arc extinguishing chamber is structured to surround the movable contact, that is, as shown in FIG. 9, the upper insulator 26 and the lower insulator 27 are arranged in a concave shape and face each other to form a gap G necessary for the thickness of the fixed contact. As a result, the slit effect of the arc extinguishing chamber is increased, the arc time with excellent shearing performance is shortened, and the dimension B including the amount of movement of the operating rod shown by the dotted line can be reduced. In addition, since the insulating frame and the arc extinguishing chamber are not integrated, the arc extinguishing chamber can be made of a material that is excellent only in terms of cutting performance, such as generating a large amount of gas for cooling the arc. It is possible to obtain an auxiliary switch with excellent breaking performance.

[Brief explanation of the drawing]

Figures 1 and 2 are explanatory diagrams of a conventional disconnector with an auxiliary switch attached, Figures 3 and 4 are explanatory diagrams showing one conventional embodiment, and Figure 5 is a different conventional implementation. An explanatory diagram showing an example, Fig. 6 is a view from the P arrow in Fig. 5,
The figure is a plan view showing one embodiment of the present invention, FIG. 8 is a front view of FIG. 7, FIG. 9 is a view taken along arrow P in FIG.
FIG. 0 is an enlarged sectional view of part A in FIG. 8. 21... Insulating frame, 22... Operation rod,
23a to 23f...Fixed contacts, 24a, 24b,
24c...Movable contact, 25...Slit arc extinguishing chamber, 26
...Top insulator, 27...Bottom insulator.

Claims (1)

[Claims for Utility Model Registration] 1. An insulating frame, an operating rod reciprocably provided approximately in the center of the insulating frame,
At least two pairs of fixed contacts are disposed on both sides of the insulating frame, facing each other with the operating rod in between, and are arranged at a predetermined interval, each of which is attached to the insulating frame; the pair of stationary contacts disposed opposite to each other are elastically sandwiched from both upper and lower surfaces to bridge them, and the reciprocating movement of the operating rod brings the operating rod into contact with or separates from either pair of the two pairs of fixed contacts. An auxiliary device comprising: a movable contact; and a slit isolation chamber fixed to the operating rod, surrounding the movable contact from above and below, and formed of an insulator with a gap between which the fixed contact can pass. switch. 2. In the utility model registration claim described in paragraph 1, the operating rod has a plurality of movable contacts and a slit extinction chamber, and a plurality of corresponding sets of fixed contacts are provided on an insulating frame. An auxiliary switch characterized by: 3. The auxiliary switch according to claim 1 or 2 of the utility model registration claim, characterized in that the operating rod and the slit extinction chamber are integrally molded insulators.