JPH01621A - contact switching device - 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 opening/closing device commonly used in relays, switches, etc. for opening and closing electrical loads.

[Background Art] This type of contact switching device is usually disposed near a member made of an organic material such as plastic. Further, the operating temperature range of some relays, switches, etc. reaches 70°C to 100°C. Therefore, if the contact switching device has an ambient temperature of 70°C, for example,
If used in excess of 100%, black powder (insulating blackide particles) caused by organic gas generated from organic material members installed in the vicinity, and organic material drive members that drive movable contact springs. The organic material powder generated from the contact adheres between the contacts, thereby significantly reducing the contact reliability performance of the contact switching device.

As a countermeasure to this problem, it is conceivable to replace the organic material member with one that has excellent heat resistance or one that generates less volatile organic gas. However, at present, such replacement materials are extremely expensive, so there are limits to their practical use.

[Object of the Invention] The present invention has been made for the above reasons, and its object is to provide a contact opening/closing device with improved contact reliability.

[Disclosure of the Invention] A contact opening/closing device of the present invention includes a fixed contact mounting member provided with a fixed contact, and a movable contact spring mounting member fixed to the base end of a movable contact spring provided with a movable contact at its tip, In a contact opening/closing device in which a movable contact spring is driven by a drive member to cause both fixed and movable contacts to engage and separate, at least one of the fixed contact mounting member or the movable contact spring mounting member includes a heat-sensitive element that deforms depending on temperature. It is characterized in that the deformation at high temperatures is in the direction of increasing contact pressure between both fixed and movable contacts.

According to the present invention, even if the contact opening/closing device is used at high temperatures and black powder etc. adheres between the contacts, the contact pressure is increased and the contact resistance is reduced, and the contact By changing the points, the service life can be extended, thereby improving the contact reliability of the contact switching device.

(Example) Hereinafter, an example of the present invention will be described based on FIGS. 1 to 6.

Reference numeral 1 denotes a fixed contact mounting member provided with a fixed contact 2, which is fixed to a base of a relay or the like. This fixed contact mounting member 1 may also serve as a fixed contact terminal.

Reference numeral 3 denotes a movable contact spring mounting member, which is fixed to a base of a relay or the like by fixing the base end of a movable contact spring 5 having a movable contact 4 at its tip. This movable contact spring mounting member 3 may also serve as a movable contact terminal. Further, the movable contact spring 5 is driven by a drive member (not shown) to cause both the fixed and movable contacts 2.4 to move toward and away from each other.In this embodiment, the movable contact spring 5 is of a normally open type.

What is important here is that the fixed contact mounting member 1 is made of a heat-sensitive element, such as a bimetal, which deforms in a substantially proportional manner depending on the temperature. This fixed contact mounting member 1 is flat at room temperature, and deformation at high temperatures is in the direction of increasing the contact pressure of both the fixed and movable contacts 2.4. Further, the surface of the fixed contact mounting member l is plated with metal such as silver to increase its weight conductivity.

FIG. 2 shows the operation at room temperature (view from arrow A in FIG. 1), where (a) shows the contact open state and (b) shows the contact closed state. At room temperature, the fixed contact mounting member l maintains a substantially flat shape. Figure 3 shows the operation at a high temperature of 100°C, for example (view from arrow A in Figure 1), and (a ) is the contact open state, and (b) is the contact closed state. At high temperatures,
The fixed contact mounting member l is bent toward the movable contact 4, and a displacement of ΔX occurs near the tip. Therefore, the contact pressure in the contact closed state increases by k·Δx (k is the spring constant of the movable contact spring 5). Note that the gap between the contacts in the contact open state is reduced by ΔX, but the upper limit of the operating ambient temperature is set to 100° C. so that the minimum gap can be ensured at that temperature. Also, temperature and contact pressure have a relationship as shown in Figure 4, but the contact pressure P° at 100°C is 0.
It is set to about 1.5 to 2 times the contact pressure P at °C.

FIG. 5 shows the contact points of both the fixed and movable contacts 2.4, where (a) shows the state at normal temperature and (b) shows the state at high temperature. The contact point T1 in the normal temperature state moves to T2 due to the bending of the fixed contact mounting member l in the high temperature state. Of course, the contact point changes continuously depending on the temperature, that is, the amount of deflection.

FIG. 6 shows a relay in which such a contact opening/closing value W (substantially the same, although the shape has been partially changed) is used as a pair of normally open type and normally closed type. 11 is the base, 12 is the iron core, 1
3 is a coil, 14 is an armature, 21.21 is a fixed contact mounting member, 23.23 is a movable contact spring mounting member, 25.2
5 is a movable contact spring, 26, 26. - is each terminal.

FIG. 7 shows a modification of the fixed contact mounting member, in which a terminal portion 1a and a bimetallic heat-sensitive element portion ib provided with a fixed contact 2 are formed separately and then joined together.

According to this example, the heat-sensitive element portion Ib, that is, the bimetal, can be made smaller.

In this embodiment, the fixed contact mounting member includes a heat-sensitive element, but the movable contact spring mounting member may also include a heat-sensitive element, in short, the fixed contact mounting member or the movable It is sufficient that at least one of the contact spring mounting members includes a heat-sensitive element, and the heat-sensitive element is not limited to bimetal, but may also be a shape memory alloy. The f3 temperature is set at about 70° C., where black powder and the like are likely to occur. However, in this case, the relationship between the contact point and salinity and contact pressure does not change continuously. Furthermore, it is also applicable to those in which the movable contacts are twin contacts.

[Effects of the Invention] The contact opening/closing device of the present invention includes a fixed contact mounting member provided with a fixed contact, and a movable contact spring mounting member fixed to the base end of a movable contact spring provided with a movable contact at its tip. In a contact opening/closing device in which a contact spring is driven by a driving member to cause both fixed and movable contacts to engage and separate, the force of at least one of the fixed contact mounting member or the movable contact spring mounting member is <?
It is configured to include a heat-sensitive element that deforms depending on the temperature, and the deformation at high temperatures is fixed and the contact pressure between the two contact points increases, so it can be placed near the contact opening/closing device. Even if the contact opening/closing device is used at high temperatures and black powder, etc. adheres between the contacts, it can increase the contact pressure and reduce the contact resistance without using particularly expensive organic material components. By changing the contact points of the contacts at room temperature and high temperature, damage to the contacts is dispersed, extending the life of the contacts, thereby improving the contact reliability of the contact switching device.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of essential parts of an embodiment of the present invention, and FIG. 2 is a
This shows operation at room temperature; (a) is when the contact is open (b)
Fig. 3 shows the operation under high temperature, where (a) shows the contact open state, (b) shows the contact closed state,
Figure 4 shows the characteristics of temperature and contact pressure, Figure 5 shows the contact points of the contacts, and (a) shows the temperature (at room temperature).
b) shows each high temperature state; FIG. 6 is a perspective view of a relay using the contact opening/closing device of the present invention; and FIG. 7 shows a modification of the fixed contact mounting member. 1-- Fixed contact mounting member, 2-- Fixed contact, 3- Movable contact spring mounting member, 4- Movable contact, 5- Movable contact spring.

Claims (1)

[Claims] (1) Consisting of a fixed contact mounting member provided with a fixed contact and a movable contact spring mounting member fixed to the base end of a movable contact spring provided with a movable contact at its tip, the movable contact spring is driven by a drive member. In a contact opening/closing device that connects and separates both fixed and movable contacts, at least one of the fixed contact mounting member or the movable contact spring mounting member includes a heat-sensitive element that deforms according to temperature, and the deformation at high temperatures is prevented. A contact opening/closing device characterized in that the contact pressure between both fixed and movable contacts increases in the direction.