JPH0217372Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of an electromagnetic contactor having an arc-extinguishing mechanism.

Generally, this type of electromagnetic contactor is used to start and stop three-phase induction motors, etc., but recently it has been used for control purposes such as starting and stopping motors that drive automation and labor-saving devices. As the use of the electric motor as a device expands, there is a demand for an arc extinguishing mechanism that can cope with inching operation in which the electric motor is frequently started and stopped.

1 to 4 show conventional electromagnetic contactors of this type. In Figures 1 to 3, reference numeral 1 denotes a mounting base made of a metal plate such as a steel plate, and this mounting base 1 has a plurality of mounting holes 1 for mounting an electromagnetic contactor.
A is provided. Reference numeral 2 denotes a base made of an insulating material, and this base 2 is fixed to the mounting base 1 with screws 3. Reference numeral 4 denotes a fixed core made of laminated silicon steel plates, and an operating coil 5 is attached to the fixed core 4, which is placed on the mounting base 1 with a leaf spring 6 as a cushioning material and with a gap provided. Reference numeral 7 denotes a movable core disposed on and opposite the fixed core 4, and the movable core 7 is configured to be attracted to the fixed core 4 when the operating coil 5 is energized. Reference numeral 8 denotes a crossbar made of an insulating material, and this crossbar 8 is connected to the movable iron core 7 by a pin 9. Reference numeral 10 denotes a tripping spring disposed between the crossbar 8 and the mounting base 1, which normally pushes up the crossbar 8 so that the main circuit of the electromagnetic contactor is opened. Reference numeral 11 denotes a movable contact having a contact point 11a, and this movable contact 11 is fitted into a holding hole 8a formed in the cross bar 8, and is pressed downward by a pressure spring 12 and supported by the holding hole 8a. ing. 13 is a fixed contact having a contact 13a opposite to the contact 11a of the movable contact 11; this fixed contact 13 is fixed to the terminals 15 on the power supply side and the load side with screws 14; It is fixed to the base 2 with screws 16 and 17. 18 is a terminal screw connected to the main circuit electric wire, and is attached to the terminal 15. Reference numeral 19 denotes an arc box made of an insulating material, and this arc box 19 is fixed to the base 2 with screws 20. Also,
The arc box 19 is the guide part 1 of the cross bar 8.
9a, a ceiling portion 19b for preventing the arc from ejecting upward, and a side plate 19c for preventing the arc and hot gas from ejecting directly to the outside. 21 is an arc extinguishing grid assembly, and as shown in FIG. 4, this arc extinguishing grid assembly 21 is provided with a V-shaped groove 21a in the center and
A case 22 made of an insulating material, in which a specified number of contacts 1c to 21g are arranged vertically facing the contacts 11 and 13 with a specified gap between them.
a, 22b, and is further fixed to arc box 1.
It is installed on 9.

Next, the opening/closing operation of the electromagnetic contactor configured as described above will be explained. When a voltage is applied to the operating coil 5 with the main circuit shown in FIG. The movable iron core 7 is attracted to the fixed iron core 4. As a result, the cross bar 8 connected to the movable iron core 7 similarly moves and lowers, and the contact 11a of the movable contact 11 comes into contact with the contact 13a of the fixed contact 13, and the pressure spring 12 causes a predetermined Pressure is applied to close the main circuit. Next, when the operation coil 5 is demagnetized, the crossbar 8 rises due to the biasing force of the tripping spring 10, and moves with it, causing the movable iron core 7 to separate from the fixed iron core 4 and rise. Therefore, the crossbar 8 returns to the state shown in FIG. 3, and the contact 11a of the movable contact 11 and the contact 13 of the fixed contact 13
a and are separated. When these are opened, an arc is generated between the contacts 11a and 13a at a portion indicated by A in FIG. The arc is driven to the V-shaped groove portion, and de-ion arc extinguishing is performed by the arc series gap between the arc extinguishing grids 21a to 21g, and as the arc voltage rises, the arc positive column is extended and the arc is extinguished.

However, in the conventional magnetic contactor as mentioned above,
Contact point 11a between movable contact 11 and fixed contact 13
The arc generated between the contacts 11a and 13a is not quickly driven toward the arc-extinguishing grid assembly 21 and sticks to the contact surface, resulting in contact points 11a, 13
The thermal energy of the arc generated between the points 11a and 13a is consumed by the movable contact 11 and its contact 11a, and the fixed contact 13 and its contact 13a.
13a is severely worn out. In addition, since the movable contact 11 has a smaller heat capacity than the fixed contact 13,
The temperature of the movable contact itself rises abnormally during inching opening and closing, which is frequently repeated, resulting in peeling or falling of the contact 11a, breakage of the crossbar due to insulation deterioration of the holding hole 8a of the crossbar 8, and short circuit between phases. There was a problem.

This idea was designed to extinguish the arc on the power supply side and load side of the movable contact in order to quickly move the upper end of the arc generated between the contacts of the movable contact and the fixed contact to the commutating electrode. A commutating electrode is formed by joining the grid with a metal body, and in order to quickly move the lower end of the arc generated between the contacts from the contact of the fixed contact, the fixed contact is connected to the arc extinguishing grid on the fixed contact side. By constructing an arc runner by connecting the terminal and the terminal with a metal body, the above-mentioned drawbacks of the conventional ones are eliminated, the wear of the contacts of the movable contact and the fixed contact is reduced, and the electrical life such as the life against inching switching is improved. can be made longer,
Furthermore, it is an object of the present invention to provide an electromagnetic contactor that can improve the shearing performance.

An embodiment of this invention will be described below with reference to FIG. In FIG. 5, the same reference numerals as in FIGS. 1 to 4 indicate the same or similar parts. In FIG. 5, a movable contact 11 having a contact 11a is inserted and supported in a holding hole 8a of a cross bar 8 made of an insulating material. The contact 13a of the fixed contact 13 is disposed opposite to the contact 11a of the movable contact 11, and the fixed contact 13 is fixed to a terminal 15, and the terminal 15 has a terminal screw 18 connected to the main circuit electric wire. It is provided. Reference numeral 19 denotes an arc box made of an insulating material, and this arc box 19 has a ceiling part 19b for preventing the arc from ejecting upward, and a side plate 19c for preventing the arc and hot gas from ejecting directly to the outside. are doing. Reference numeral 21 denotes an arc extinguishing grid assembly, which is made of a magnetic material and includes a prescribed number of arc extinguishing grids 21c arranged vertically with a prescribed mutual gap.
It consists of ~21g and is installed inside the arc box 19. 23 is a commutation electrode formed by connecting the power supply side on the movable contact 11 side and the arc extinguishing grid 21g on the load side with a metal body, and 24 is the commutation electrode formed by connecting the arc extinguishing grid 21c on the fixed contact 11 side and the fixed contact 13. This is an arc horn or arc runner made up of metal bodies. It should be noted that the configuration of this embodiment other than those described above is substantially the same as the conventional structure shown in FIGS. 1 to 4, and therefore a description thereof will be omitted.

Next, the opening/closing operation of the electromagnetic contactor according to this embodiment will be explained. The operation from the open state to the closed circuit of the main circuit is the same as that of the conventional circuit described above, so a description thereof will be omitted, and the operation from the closed state to the open state will be described. When the operating coil 5 is demagnetized, the crossbar 8 rises due to the biasing force of the tripping spring, and in conjunction with this, the movable iron core separates from the fixed iron core and rises, and the crossbar 8 returns to the open position. At the same time, the contact 1 of the movable contact 11
1a and the contact 13a of the fixed contact 13 are separated. When these contacts open, an arc is generated between the contacts 11a and 13a at the part indicated by A in FIG. (see Figure 4) direction and moves to the V-shaped groove part, de-ion arc extinguishing is performed by the arc series gap between the arc extinguishing grids 21c to 21g, and the increase in arc voltage expands the arc sunlight and extinguishes the arc. be done.

In the electromagnetic contactor according to this embodiment, the power supply side on the movable contact 11 side and the arc extinguishing grid 21g on the load side are connected with a metal body to form a commutating electrode 23, thereby connecting the contact 11a of the movable contact 11 with the arc extinguishing grid 21g on the load side. The upper end of the arc generated between the contact 13a of the fixed contact 13 can be quickly moved from the contact 11a of the movable contact 11 to the commutation electrode 23, and the upper end of the arc generated between the contact 13a of the fixed contact 13 and the fixed contact 13 side can be quickly moved from the contact 11a of the movable contact 11 to the commutation electrode 23. The arc runner 24 is connected to the arc extinguishing grid 21c with a metal body.
By configuring this, the lower end of the arc can be quickly moved from the contact point 13a of the fixed contactor 13 to the arc runner 24. Therefore, this embodiment prevents the abnormal temperature rise of the movable contact 11, and prevents the contact 11a from peeling or falling off, and the holding hole of the crossbar 8, which occurs in the conventional case due to this temperature rise. It is possible to prevent breakage of the crossbar 8 and short circuit between phases due to insulation deterioration of the crossbar 8a.
Further, the wear of the contacts 11a and 13a can be reduced, and the electrical life such as the life with respect to inching opening and closing can be extended.

In addition, in the above embodiment, as shown in FIG.
Although the commutation electrode 23 is provided above the movable contact 11, this invention, as shown in FIG. Alternatively, the commutation electrode 23 may be disposed at the same height as the contact surface of the movable contact. Also,
In the above embodiment, the arc runner 24 is the fixed contact 1
However, in this invention, the arc runner may be provided at the same level as the contact point of the fixed contactor or below the fixed contactor.

Furthermore, in this invention, as shown in FIG. 6, the gap between the commutation electrode 23 and the arc runner 24 may be smaller than the gap between the contacts 11a and 13a. Compared to the embodiment shown, the arc generated between the contacts 11a and 13a can be quickly moved to the commutation electrode 23 and the arc runner 24, and the arc generated between the contacts 11a and 13a can be moved more quickly to the commutating electrode 23 and the arc runner 24 than the embodiment shown in FIG. It is possible to reduce wear and tear, extend the life of inching opening and closing, and further improve cutting performance.

As explained above, according to the electromagnetic contactor of this invention, the arc-extinguishing grids on the power supply side on the movable contact side and the load side are connected with a metal body to form a commutating electrode, and the fixed contactor and the arc extinguishing grid on the load side are By constructing an arc runner by joining the arc extinguishing grid with a metal body, the arc generated between the contacts of the movable contact and the fixed contact is quickly transferred from the contact surfaces of these contacts to the commutating electrode and the arc runner. Since the arc is quickly extinguished by the arc runner, arc extinguishing grid, and commutation electrode, it is possible to reduce the wear and tear on the above-mentioned contacts, which previously occurred due to abnormal temperature rise of the movable contact. It is possible to prevent breakage of the crossbar and short circuit between phases due to peeling or falling off of contacts, deterioration of the insulation of the holding hole of the crossbar, and it is also possible to extend the electrical life such as the life against inching switching, and to improve the breaking performance. It can be measured.

Furthermore, according to this invention, commutation electrodes and arc runners are installed using conventional arc extinguishing grids, so manufacturing and installation of commutation electrodes and arc runners is relatively easy, and electromagnetic Another advantage is that the contactor can be provided at a low cost.

[Brief explanation of drawings]

Figure 1 is a cross-sectional front view of the right side of a conventional magnetic contactor, Figure 2 is a bottom view of the right half of the same, Figure 3 is a right cross-sectional view of the same, and Figure 4 is a conventional arc extinguishing grid assembly. FIG. 5 is a right sectional view showing the upper part of an electromagnetic contactor according to an embodiment of this invention, and FIG. 6 is a right sectional view showing the upper part of an electromagnetic contactor according to another embodiment of this invention. . 8... Cross bar, 8a... Holding hole, 11...
Movable contact, 11a... contact, 13... fixed contact, 13a... contact, 19... arc box,
21... Arc extinguishing grid assembly, 21a... V-shaped groove, 21a to 21g... Arc extinguishing grid, 23...
Commutation electrode, 24... arc runner. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A movable contact that is attached to a crossbar and has a movable contact; a fixed contact that is attached to a power supply side terminal and a load side terminal and has a fixed contact that faces the movable contact of the movable contact; and the movable contact. In an electromagnetic contactor comprising an arc box surrounding a fixed contact, and a plurality of arc extinguishing grids having the same shape arranged inside the arc box,
All of the plurality of arc extinguishing grids are provided in the upper space of the fixed contact and perpendicular to the direction of contact and separation between the movable contact and the fixed contact, and the extinguishing grid is provided on the power supply side and load side of the movable contact. An electromagnetic contactor characterized in that a commutating electrode is formed by connecting an arc grid with a metal body, and an arc runner is constructed by connecting the arc extinguishing grid on the fixed contact side and the fixed contact with a metal body.