JPS61173418A - Contact switchgear - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a contact switching device.

[Background technology]

For example, relays used around IA to 30A.

The performance and lifespan of contact switching devices such as switches and contactors are greatly affected by arcs that occur when they are turned on and off. In particular, welding occurs due to bounce arcs when opening and closing loads where inrush current flows instantaneously. Silver (Ag) or an Ag alloy is usually used for contacts, but to improve welding resistance, we use a sintered alloy of Ag and a high melting point material such as tungsten, or we use an internal oxidation method to improve high temperature or heat resistance. Increased Ag-(:dQ, Agent,,
Ir1tOs etc. are used.

However, since these contact materials mix impurities into Ag, which already has a stable contact resistance, the contact resistance characteristics become unstable and temperature rise becomes a problem.

Also, considering the condition of the contact surface of the contact, these -.

As the concentration of Wc, Sn, In, or their oxides increases, the welding resistance and abrasion resistance generally improve, but the contact resistance characteristics also become unstable.

Furthermore, these contact resistances are related to the contact pressure, and although the change is not linear, the contact resistance value is inversely proportional to the pressure, but considering the recent trend of technological development toward making devices lighter, thinner, and smaller. An important issue is how to reduce the contact pressure. This is because an increase in contact pressure increases the frictional force in each part of the mechanism9.
This is because the parts become larger and, for relays and contactors, the spring load and stroke that must be driven by electromagnets increases.

[Purpose of the invention]

An object of the present invention is to provide a contact switching device that can stabilize contact resistance, reduce welding, and improve lifespan.

[Disclosure of the invention]

In the present invention, a high-melting-point arc contact and a low-resistance conductive contact are arranged side by side through grooves, and the grooves are arranged opposite to each other so as to be offset from each other in the direction in which the arc contacts and the conductive contacts are arranged. It is provided with a first and a second contact, and operates on or off by driving at least one of the contacts, and between the off state and the on state in which only the conductive contacts are in contact with each other, the on state is controlled. When the arc contacts are in contact with each other, the conductive contacts are in contact with each other and the conductive contacts are in contact with each other, and when the conductive contacts are in contact with each other, the electrically conductive contacts roll in the opposite direction.

Arc and rush current are carried by the arc contact, and current is carried by the conductive contact, so contact resistance is stabilized, welding can be reduced by rolling, and the service life can be improved compared to conventional products.

In addition, since the grooves are provided, consumable powder can be collected and it is possible to reduce the adhesion to the conductive contact side, and since the grooves are offset from each other, even if an arc occurs on the conductive contact side, it can be easily arced. The current can be commutated to the contact side, reducing damage.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 8. That is, the first and second contacts 1.2 are fixed to the free ends of the contacts 3, 4, respectively. contact 3
．． 4 is rotatably supported at its proximal end by a shaft 5.6, the contact 3 is supported at its middle by a spring 7, and a drive section 8 is opposed to the contact 4. In the first contact 1, a conductive contact 9 and an arc contact 10 are arranged in the longitudinal direction of the contact 3 so that the arc contact 10 is on the tip side, and a groove 11 with a width and depth of 5 or more is formed between them. There is.

Further, the second contact 2 is connected to the conductive contact 12 and the arc contact 1 in the longitudinal direction of the contact 4 so that the conductive contact 12 is located on the tip side.
3 are lined up, and a groove 14 having the same shape as the groove 11 is formed between them. When the first contact 1 and the second contact 2 face each other, the grooves 11 and 14 are arranged so that the arrangement of the arc contact and the conductive contact is shifted from each other.

The arc contact 10.13 is made of a high melting point material such as A.

-Wc, Ag-first grade sintered contact system contains -C9- or -+Wc at 10% by weight or more, and Ag5nO
*, An oxide system such as Ag-Cd0 contains MeO (meaning a metal oxide; the same applies hereinafter) in an amount of 5% or more. In addition, the conductive contacts 9.12 are made of a low resistance material, for example, in the case of a sintered contact system, -, Wc or W+Wc is 1.
The content of MeO is 5% or less, and MeO is 15% or less in oxide systems, but only Ag may be used. These arc contacts 10
．． The conductive contacts 9 and 12 may be integrated with each other by brazing or the like, but they may also be separately attached using a copper pedestal provided with rivets or welding projections. Note that the contacts are manufactured by the infiltration method when the contact material is a sintered material, and by the selective oxidation method when the contact material is internal oxidation. Furthermore, these contacts 9, 10° 12.13 are attached to each contact 3.4 by caulking, brazing, welding or the like.

FIG. 4(a) shows the off state, and FIG. 4(b) shows the drive unit 8.
presses down the contact 4, and in the exposed state, first press the arc contact 10.
．． 13 comrades make contact. At this time, the contacts 3 and 4 are not parallel but have a closing angle e1 according to the taper of the surface of the arc contact 13. Also, at this time, it is a closed state, and depending on the load, an inrush current will flow. In the same figure (c), when the contact 4 is further pushed down, the contacts are rolling (
After the grooves 11.14 come into contact with each other in a deviated state (rolling contact), the conductive contacts 9.12 make contact and the arc contacts 10.13 separate, as shown in FIG. 2(d). This state is the final on state. Also at this time, the contacts 3.4 are not parallel but have a resting angle θ2 taking into consideration the taper of the conductive contact 12 and the contact pressure. The operation from on to off is shown in (e) in the same figure (
In the operation g), a rolling operation is performed which is the reverse of the above operation, and finally the arc contact 10.13 is disengaged. Therefore, at this time an arc occurs between the arc contacts 10.13. In addition, FIG. 2 shows the spring load f with respect to the movement
According to 9. Also, from b to C is the input angle θ, and from the resting angle θ
Due to the movement up to 2, the spring 7 is applied and contact pressure is applied.

Figure 5 shows a relay that is compatible with this contact switching device.
5 is a case, 16 is a relay coil, 17 is a cork, 18
is an armature with a drive section 8 provided at its tip. 19
is the return spring described above.

With this structure, in this contact switching device, the arc contact 10.13 contacts first in the on operation, and the arc contact 10.13 is the last to separate in the off operation, so the arc contact 10.13 is protected against inrush current and arc. 10.1
3 carries the conductive contact 9°] Since the conductive contact 2 is not damaged, the contact resistance is stabilized. Moreover, it is difficult to weld due to rolling,
Arc contacts can also reduce contact wear and improve lifespan.

In addition, the pushing amount Xa of the contactor 4 necessary to secure the predetermined contact pressure, and the pushing amount Xb used for rolling.
, the amount by which the drive unit 8 must operate (contact position replacement value) Xc, the amount has a relationship as shown in FIG.

Furthermore, since the groove 11.14 is provided between the arc contact 10.13 and the conductive contacts 9, 12, the consumable powder of the arc contact 10.13 accumulates in the groove 11.14, reducing the possibility of scattering to the conductive contact 9.12. .

Furthermore, as shown in Figure 8, if the wear of the arc contact progresses and the contact resistance of the arc contact 10.13 increases to R as shown in Figures (a) to (b), then Figure 4 ( In the state f), a voltage of R×i is generated between the conductive contacts 11.14, and when the voltage exceeds the minimum arc voltage, the conductive contacts 19.1
However, even if an arc occurs, the arc contact 1 will be in the state shown in Fig. 7(a) to Fig. 7(b).
In the process of moving away from each other, the arc A moves between the conductive contact and the seek contact due to the deviation of the groove 11.14 as shown in FIG.
13 is shorter than the distance between the conductive contacts 11.14, the arc A will transfer between the arc contacts 10.13, and the commutation of the arc A will easily occur, causing damage to the conductive contacts 11.14. It can be reduced.

Furthermore, by making the contact area of the arc contact 10.13 more than twice as large as that of the conductive contact 11.14, it is effective to increase the surface area as well as the volume since contact wear occurs in the height direction from the contact surface. There is. In this embodiment, the contact wear margin can be increased by increasing the contact area of the arc contact 10.13, so that the conductive contact 11.14 and the arc contact 10.13 are finally opened and closed at the same time. It is possible to extend the period (number of opening/closing times) until the

On the other hand, by reducing the size of the conductive contact 11.14, Ag
Since the amount used is reduced, costs are reduced. Furthermore, by reducing the surface area of the conductive contact 11.14, the probability that consumable powder generated on the arc contact 10.13 side will adhere to the conductive contact 11.14 is reduced, which is effective in stabilizing the contact resistance. .

As a variant of this embodiment, the contact 3.4 may be formed by a leaf spring and the spring 7.19 may be omitted. Although the contacts 3.4 are of the normally open type, they may be of the normally closed type, and the contact mechanism is not limited to the above embodiments as long as it is capable of approaching/separating operations and rolling operations.

〔Effect of the invention〕

According to this invention, each contact is provided with an arc contact and a conductive contact, and a rolling action is performed between on and off operations, so that when on, the arc contacts contact each other first, and when off, the arc contacts contact each other first. At the same time, a groove is formed between the arc contact and the conductive contact, and the good conductor is opposed to the other in a mutually shifted relationship, which improves the life of the contact, reduces welding and wear, and ensures contact stability. be able to. Moreover, the grooves have the effect of reducing the adhesion of consumable powder to the conductive contacts, and even if an arc occurs between the conductive contacts, the flow can easily be commutated to the arc contact side due to the deviation of the grooves.

[Brief explanation of the drawing]

FIG. 1 is a side view of an embodiment of the present invention in an operating state, and FIG.
The figure is a vector diagram of the stroke of the second contact versus the amount of spring j+, Figure 7 is an illustration of arc commutation, and Figure 8 is a circuit explaining the state in which the minimum arc generation voltage occurs between conductive contacts. It is a diagram. 3.4... Contact, 9.12... Conductive contact, 10° Figure 1 Figure 2 Figure 3 Figure 5 Figure 6 - Oath. ℃ ＾! A comment to Φ - Procedural amendment (viewed March 29, 1985)

Claims (2)

[Claims] (1) A high-melting-point arc contact and a low-resistance conductive contact are arranged side by side through a groove, and the grooves are arranged opposite to each other so that the positions of the arc contact and the conductive contact are shifted from each other in the direction in which the arc contact and the conductive contact are lined up. The contactor comprises a first and a second contact, and is turned on or off by driving at least one of the contacts, and at the time of the on operation, between the off state and the on state in which only the conductive contacts are in contact with each other. A contact opening/closing device characterized in that the contact opening/closing device is configured to roll from a contact state of the arc contacts to a contact state of the conductive contacts, and perform a rolling action opposite to the above during the off operation. (2) The contact switching device according to claim 1, wherein the arc contact has a larger surface area than the conductive contact.