JPS61104520A - Electromagnetic contactor - 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 an electromagnetic contactor.

[Background Art] FIG. 7 shows a schematic configuration diagram of a conventional electromagnetic contactor. When the coil 1 wound around the coil frame 2 is energized, the movable iron core 4 is attracted to the fixed iron core 3. A movable contact plate 11 provided on a movable body 5 that is urged upward in the figure and is interlocked with the movable iron core 4 due to the suction of the movable iron core 4.
The movable contact 6 comes into contact with the fixed contact 7. When the coil 1 is no longer energized, the movable iron core 4, that is, the movable body 5 returns, and the movable contact 6 is separated from the fixed contact 7.

Here, the movable body 5 is connected to both contacts 6 and 7 by the coil spring 8'.
In other words, the movable body 5 is urged upward in the direction of separation.

That is, when the contacts 6 and 7 are in the on state (adsorption state), the movable iron core 4 is attracted to the fixed iron core 3, so the coil spring 8' is compressed by the movable body 5 as shown in FIG. 9(a). The upward spring pressure (returning force) is at its strongest. And both contacts 6 and 7 are off! ! ! (In the non-excited state), the fixed iron core 3 is not energized, so the movable iron core 4 (movable body 5) is released and the coil spring 8' is in the extended state as shown in FIG. 9(b). Become. Therefore, in the case of FIG. 9(a), the urging force (returning force) exerted on the movable body 5 by the coil spring 8' is the strongest, and becomes weaker in the case of FIG. 9(1)). FIG. 8 is a characteristic diagram showing this state, that is, the relationship between the stroke of the movable iron core 4 and the spring load (return spring indenter contact spring pressure). From this FIG. 8, the following can be understood. That is, first of all, it operates even below the impression voltage. Furthermore, when operating with an attraction force within the shaded range in the figure, the attraction force of the electromagnet (point X) is lower than the spring pressure (point B'), causing contact flapping. Furthermore, since the spring load (A'E') in the ON state of the contact is high, the contact is cut off quickly and the contact is easily worn out. Furthermore, since the contact spring pressure (A'F') is low, the contact reliability of the contacts is low.

Furthermore, the spring pressure in the off state of the contact (C'D')
Because of its low vibration, it has the problem of being susceptible to vibrations.

FIG. 10 shows another conventional example, in which a C-ring shaped C spring 14' is used instead of the coil spring 8' as a means for biasing the movable body 5. Other configurations are the same. This C spring 14' has the following features.

That is, as shown in FIG. 12(, ), when the contact is in the on state (adsorption state), the movable body 5 is driven by suction, so that the C spring 14' is almost horizontal, and the spring pressure is exerted in two directions. becomes weaker. Next, the contact is off! ! ! (In the non-excited state), as shown in FIG. 12(b), the C spring 14' faces diagonally upward, so the upward spring pressure is strong. FIG. 11 is a characteristic diagram showing the relationship between the movable iron core stroke and the spring load (return spring indenter contact spring pressure), and the following can be seen.

In other words, since the spring pressure (CD) in the non-excited state is high,
It does not operate below the touching voltage. Since the spring load (AE) is low, the contact breaking speed is slow and the contacts are less likely to wear out.

Furthermore, since the contact spring pressure (AF) is high, the contact reliability of the contacts is high. Furthermore, since the spring pressure (CD) in the non-excited state is high, it is resistant to vibration.

By the way, Fig. 13(,) is the same as Fig. 11, and Fig. 13(b) is
) are diagrams schematically showing Fig. 8, and the same figure (
A) is referred to as a negative characteristic, and (b) in the same figure is referred to as a positive characteristic. The larger the diagonally shaded area in the figure, the larger the energy at the time of input. Therefore, in the case of a negative characteristic spring (C spring 14'), if an excellent buffer mechanism is not provided when the spring is turned on, the bounce will be large and the contacts will be severely worn out. However, with a negative characteristic spring, the contact pressure can be increased and the contact opening speed can be suppressed, so the arc energy at the time of interruption is small and the contact wear is low. That is, it is suitable for severe use such as inching. That is, when a return spring (coil spring 8') with positive characteristics is used, the contact speed is high when the contact is opened, and the arc energy is large, so there is a problem that the contact wear is large when the contact is closed. Also, if a return spring with negative characteristics (C spring 14') is used,
Since the surplus energy at the time of turning on increases, there is a problem in that contact bounce is likely to occur and contact wear is large at the time of turning on.

[Object of the Invention] The present invention has been provided in view of the above-mentioned points, and provides an electromagnetic contactor that can reduce contact bounce and suppress contact wear even in the case of a large inrush current such as a capacitor load. The purpose is to provide

[Disclosure of the invention 1 Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIGS. 5 and 6, an E-shaped fixed iron core 3 is arranged inside a body 9 with an open top surface, and a coil frame with a coil 1 wound around the fixed iron core 3. 2 is placed. The central part of the fixed iron core 3 is fitted into the lower part of the hollow part of the coil frame 2. A movable iron core 4 that is attracted to the fixed iron core 3 when the coil 1 is energized is attached to the lower part of the frame 10a and the movable return body 5 that constitute the outer shell of the contact part 10 that is movable in the vertical direction. The movable iron core 4 and the frame 10a are interlocked via a connecting rod 18. The lower part of the movable iron core 4 is fitted into the hollow part of the coil frame 2 so as to correspond to the magnetic pole surface of the fixed iron core 3. A contact portion 10 is formed above the movable return body 5, and the contact portion 10 is composed of a plurality of contacts, and the movable contact 6 is fixed to the tip of a movable contact plate 11 that protrudes on both sides. The frame 10a of this contact portion 10 and the movable return rod 5
A movable frame is constructed. A plurality of terminal parts 13 are arranged on both sides of a terminal part cover 12 that covers the movable return rod 5 and the frame 10a and is placed on the upper surface of the body 9. The movable return rod 5 and the frame 10a are urged upward by a C-ring-shaped C spring 14 and a coil-shaped fill spring 8, which will be described later.
When the current supply to the coil 1 is stopped, the C spring 14 returns the movable return rod 5, and the coil spring 8 returns the frame 10a upward. The terminal portions j3 are each separated by a partition wall 15, and a fixed terminal plate 16 having a fixed contact 7 fixed to its tip facing the movable contact 6 is fixed to the terminal portion cover 12 with screws 17.

Next, the gist of the present invention will be described.

As shown in FIGS. 1 and 6, the movable return rod 5 is formed into a substantially cylindrical shape, and a recess 21 for locking the end of the C spring 14 is cut into the outer periphery of the movable return rod 5. ing. Further, the upper surface of the movable return rod 5 is formed with four parts 22, into which a cylindrical part 23, which is integrally hung down from the lower surface of the frame 10a of the contact part 10, is fitted. The coil spring 8 is located within the four parts 22 of the movable return rod 5 and within the recess 24 of the cylindrical portion 23. The upper end of the coil spring 8 is in elastic contact with the lower surface of the frame body Oa, and the lower end is elastically in contact with the upper surface of the movable return rod 5. are in contact with each other.

FIG. 2(a) shows the off state, in which the coil spring 8 is in its most extended state and the C spring 14 is in its state to urge the movable return rod 5 upward most strongly. Here, when the coil 1 is energized and the movable iron core 4 is attracted to and driven by the fixed iron core 3, the frame 1. Oa is also driven downward in the figure at the same time (states shown in FIGS. 2(a) to (e)). At this time, that is, when reaching the on state, the upward spring pressure of the C spring 14 becomes weak, but the coil spring 8 acts in a compressed direction so that the upward spring pressure becomes the strongest. Therefore, at the time of closing, the coil spring 8 serves as an excellent buffering mechanism for the negative characteristic spring (C spring 14), making it possible to reduce bounce and reduce wear and tear on the contacts.

Next, the case of releasing from the on state shown in FIG. 2(e) will be explained. When the power to the coil 1 is cut off, the frame 1
0a returns upward, but at this time, the C spring 14 moves from a slightly horizontal direction to a slightly upward direction, so the initial return force by the C spring 14 is weak. Therefore, the coil spring 8
The strong return force is buffered by the C spring 14, and the contact opening speed can be suppressed, the arc energy at the time of breaking is reduced, and contact wear is reduced. Fig. 3 is a characteristic diagram showing the relationship between the above-mentioned movable iron core stroke and spring load. It is.

FIG. 4 is a diagram corresponding to the conventional FIG. 13, and as shown by diagonal lines in the diagram, the area is smaller and the surplus energy at the time of input is small and bounce is reduced. Therefore, contact wear can be reduced both when turning on and cutting off.

[Effects of the Invention] As described above, the present invention includes a fixed iron core that is excited by a coil wound around a coil frame, a movable iron core that is attracted to the fixed iron core by the electromagnetic conduction of the coil, and a movable iron core that is attracted to the fixed iron core by the electromagnetic conduction of the coil. An electromagnetic device has a movable frame that is interlocked with a core and has a movable contact facing a fixed contact, and the movable contact provided on the movable frame is brought into contact with the fixed contact when the movable iron core is attracted to the fixed iron core. In the contactor, the first spring is biased in the compression direction by the movement of the movable frame when both contacts are closed, and the return force due to the movement of the movable frame is minimized from the time both contacts are closed to the on state. , and a second spring that maximizes the return force from the time when both contacts are cut off to the OFF state is biased against the movable frame. Therefore, when the contacts are closed, the spring $1 is compressed by the movable frame. Therefore, it becomes a buffer mechanism for the second spring that minimizes the return force when the contact is in the on state, reducing wear on the contact, and also reduces surplus energy and bounce. In addition, when the second spring is in contact, the return force in the on state is small, so the breaking speed is slow and wear and tear on the contact point can be reduced. is tangent, α
Since the return force is minimum in the ON state, the contact pressure can be increased. In other words, the advantages of the second spring with negative characteristics and the first spring with positive characteristics are combined, and as mentioned above, the second spring reduces contact wear when disconnecting, and increases contact pressure. In addition, the first spring can reduce the wear of the contact during closing, and the surplus energy can be reduced, resulting in a reduction in bounce.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of main parts of an electromagnetic contactor according to an embodiment of the present invention, Fig. 2 is an explanatory diagram of the same operation, Fig. 3 is a characteristic diagram of the same, and Fig. 4 is a diagram illustrating the operation of the same.
FIG. 5 is a cutaway front view of the electromagnetic contactor as above, FIG. 6 is an exploded perspective view of the same as above, FIG. 7 is a configuration diagram of the conventional example, FIG. 8 is a characteristic diagram as above, 9(a) and 9(b) are explanatory diagrams of the same operation as above, FIG. 10 is a configuration diagram of another conventional example, and
1 is a characteristic diagram same as above, FIGS. 12(a) and 12(b) are operation explanatory diagrams, and FIGS. 13(a) and (b) are characteristic diagrams same as above. 1 is a coil, 2 is a coil frame, 3 is a fixed iron core, 4 is a movable iron core, 6 is a movable contact, 7 is a fixed contact, 8 is a coil spring which is a first spring, and 14 is a second spring C Showing a spring. Agent Patent Attorney Ishi 1) Long 7″/:, Shubai Yasu Den Suha - Figure 6 Figure 5 (豐 - Rami Seven 1 Arrogance J S 1 + Kudoberiguse ← Nagi No 116
= ゛ω KanA惺(b) 正＊mode

Claims (1)

[Claims] (1) A fixed iron core that is excited by a coil wound around a coil frame, a movable iron core that is attracted to the fixed iron core when the coil is energized, and a movable contact that works in conjunction with this movable iron core and faces the fixed contact. In an electromagnetic contactor, the electromagnetic contactor has a movable frame having a movable frame, and a movable contact provided on the movable frame is brought into contact with the fixed contact when the movable iron core is attracted to the fixed iron core, when both of the contacts are turned on, The first spring is biased in the compression direction by the movement of the movable frame, and the return force due to the movement of the movable frame is minimized from the time when both contacts are closed to the on state, and the return force is minimized from the time when both contacts are closed to the off state. An electromagnetic contactor characterized in that a second spring having a maximum of .