electromagnetic contactor

Abstract

To provide an electromagnetic contactor that prevents an arc extinguishing cover from being blown off by discharging arc gas generated in an arc extinguishing chamber to the outside, and improves the dustproofness of the arc extinguishing chamber and reliably prevents contact malfunctions.SOLUTION: An electromagnetic contactor 1 includes a case 3 with an arc extinguishing chamber 14, a contact portion 16 having a movable contact and a fixed contact housed in an arc extinguishing chamber, and an arc extinguishing cover 8 that is attached to the case and covers the contact portion stored in the arc extinguishing chamber. Gas vent holes 17a to 17c are formed in the case to communicate the arc extinguishing chamber with the outside of the case. Hole closing plates 2a to 22c which are arranged to cover the gas vent holes from the outside and are elastically deformable toward the outside are formed in a part of the arc extinguishing cover.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an electromagnetic contactor provided with an arc-extinguishing cover that covers a contact portion in an arc-extinguishing chamber. [Background technology]

[0002] The electromagnetic contactor has a lower case and an upper case, terminals each having a contact fixed to the upper case, an arc-extinguishing chamber provided inside the upper case houses a contact unit having a movable contact and a fixed contact, and an arc-extinguishing cover is attached to the upper case to cover the contact unit in the arc-extinguishing chamber. An electromagnet that drives the contact unit is housed inside the lower case. If an abnormally large current flows through the contacts of an electromagnetic contactor due to a short circuit or other accident, the arc gas generated may increase the internal pressure in the arc extinguishing chamber, causing the arc extinguishing cover to be blown off.

[0003] Therefore, for example, in Patent Document 1, a terminal cover is fitted in a direction perpendicular to the fitting direction of the arc-extinguishing cover, and the terminal cover is engaged with the front case so as not to rotate, and a part of the terminal cover is engaged with the arc-extinguishing cover, thereby restraining the arc-extinguishing cover with the terminal cover against an increase in internal pressure in the arc-extinguishing chamber due to arc gas. Also, the arc-extinguishing cover is provided with a gas vent hole that connects the arc-extinguishing chamber to the outside. The electromagnetic contactor of Patent Document 1 suppresses the rise in internal pressure in the arc extinguishing chamber by releasing the arc gas generated in the arc extinguishing chamber to the outside through a gas vent hole provided in the arc extinguishing cover, thereby preventing the arc extinguishing cover from being blown off from the front case. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-332588 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the electromagnetic contactor of Patent Document 1 is installed in a dusty factory, dust may enter the arc-extinguishing chamber through the gas vent hole provided in the arc-extinguishing cover, causing the contact portion to malfunction.

[0006] Therefore, the present invention aims to provide an electromagnetic contactor that can reduce internal pressure by releasing arc gas generated in the arc extinguishing chamber to the outside, preventing the arc extinguishing cover from being blown away, while at the same time improving dust resistance to the arc extinguishing chamber and reliably preventing malfunction of the contact parts. [Means for solving the problem]

[0007] In order to achieve the above object, an electromagnetic contactor according to one embodiment of the present invention is an electromagnetic contactor comprising a case provided with an arc-extinguishing chamber, a contact section having a movable contact and a fixed contact housed in the arc-extinguishing chamber, and an arc-extinguishing cover attached to the case to cover the contact section housed in the arc-extinguishing chamber, wherein a gas vent hole connecting the arc-extinguishing chamber to the outside of the case is formed in the case, and a hole blocking plate that is positioned to cover the gas vent hole from the outside and is elastically deformable outward is formed in part of the arc-extinguishing cover. [Effects of the Invention]

[0008] According to the electromagnetic contactor of the present invention, the arc gas generated in the arc extinguishing chamber is released to the outside, thereby reducing the internal pressure and preventing the arc extinguishing cover from being blown away, while at the same time increasing the dust-proofness of the arc extinguishing chamber and reliably preventing malfunction of the contact portion. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view showing an electromagnetic contactor according to the present invention; [Figure 2] 1 is a top view of an electromagnetic contactor according to the present invention; [Figure 3] FIG. 2 is a perspective view showing a state in which an arc-extinguishing cover is removed from an upper case of the electromagnetic contactor. [Figure 4] FIG. 10 is a side view showing the state in which the arc-extinguishing cover is removed from the upper case. [Figure 5]FIG. 10 is a side view showing the state in which the arc-extinguishing cover is attached to the upper case. [Figure 6] 6(a) shows the arc extinguishing cover attached to the upper case, viewed from the arrows VI-VI in FIG. 5. FIG. 6(a) shows the state during normal use, and FIG. 6(b) shows the state in which the internal pressure of the arc gas in the arc extinguishing chamber rises and the hole blocking plate is elastically deformed outward. DETAILED DESCRIPTION OF THE INVENTION

[0010] Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are designated by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc., may differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. Furthermore, it goes without saying that the drawings may include parts with different dimensional relationships and ratios. Furthermore, the embodiments shown below are merely examples of devices and methods for embodying the technical concept of the present invention, and the technical concept of the present invention does not limit the materials, shapes, structures, arrangements, etc. of the components to those described below. The technical concept of the present invention can be modified in various ways within the technical scope defined by the claims. In the following description, terms indicating directions such as "front," "rear," "left," "right," "upper," and "lower" are used with reference to the directions in the accompanying drawings.

[0011] 1 and 2 show the entire electromagnetic contactor 1, which includes a lower case 2 and an upper case 3 made of an insulating synthetic resin material. Power supply side terminals 4a to 4d and one coil terminal 6a of the electromagnet are arranged on the left side of the upper case 3, and load side terminals 5a to 5d and the other coil terminal 6b of the electromagnet are arranged on the right side of the upper case 3. In addition, a first terminal cover 7a that covers the power supply side terminals 4a to 4d and the coil terminal 6a, and a second terminal cover 7b that covers the load side terminals 5a to 5d and the coil terminal 6b are detachably engaged with the upper case 3, and an arc-extinguishing cover 8 is detachably engaged with the upper case 3.

[0012] 3, the upper case 3 includes a pair of case outer walls 10a, 10b spaced apart in the front-to-rear direction, a plurality of case inner walls 10c extending parallel to each other between the pair of case outer walls 10a, 10b and disposed in a space on the left side of the upper case 3, and a plurality of case inner walls 10d extending parallel to each other between the pair of case outer walls 10a, 10b and disposed in a space on the right side of the upper case 3. Arc-extinguishing chamber partitions 11a extending in the front-to-rear direction are formed from the right ends of the plurality of case inner walls 10c, respectively, and arc-extinguishing chamber partitions 11b extending in the front-to-rear direction are formed from the left ends of the plurality of case inner walls 10d, respectively. The case outer walls 10a, 10b, the plurality of case inner walls 10c, and the arc-extinguishing chamber partitions 11a form five power-supply side terminal chambers 12 in the front-to-rear direction on the left side of the upper case 3, in which the power-supply side terminal portions 4a to 4d and one coil terminal 6a of the electromagnet are disposed. In addition, five load side terminal chambers 13 are formed in the front-to-back direction on the right side of the upper case 3 by the case outer walls 10a, 10b, multiple case inner walls 10d, and the arc extinguishing chamber partition 11b, in which the aforementioned load side terminal portions 5a to 5d and the other coil terminal 6b of the electromagnet are arranged.

[0013] An arc-extinguishing chamber accommodating section 15 that accommodates an arc-extinguishing chamber 14 is provided between the multiple arc-extinguishing chamber partitions 11a, 11b, and a contact section 16 is arranged in the arc-extinguishing chamber 14. The contact section 16 includes a movable contact support 16a, fixed contacts (not shown) connected to the power supply side terminal sections 4a to 4d and the load side terminal sections 5a to 5d, fixed contacts (not shown) provided on the fixed contacts of the power supply side terminal sections 4a to 4d and the load side terminal sections 5a to 5d, a movable contact (not shown) supported by the movable contact support 16a, and multiple movable contacts (not shown) provided on the movable contact so as to come into contact with and separate from the fixed contacts of the fixed contacts of the power supply side terminal sections 4a to 4d and the load side terminal sections 5a to 5d. A movable iron core (not shown) that constitutes an electromagnet is connected to the movable contact support 16a, and when the excitation coil (not shown) of the electromagnet is excited, the movable contact support 16b moves toward one end in the longitudinal direction against the movable return spring, and the multiple movable contacts of the movable contactor come into contact with the fixed contacts of the power supply side terminal portions 4a to 4d and the load side terminal portions 5a to 5d, resulting in a closed state.

[0014] 4, one gas vent hole 17a to 17c is formed in the center of each of the plurality of arc-extinguishing chamber partitions 11a that form the power-supply side terminal chamber 12 and face the power-supply side terminal portions 4b to 4d. Although not shown, each of the plurality of arc-extinguishing chamber partitions 11b that form the load-side terminal chamber 13 and face the load-side terminal portions 5b to 5d also has one gas vent hole 17a to 17c formed in the center.

[0015] The arc extinguishing cover 8 is a member formed from an insulating synthetic resin material, and as shown in Figures 3 and 4, it comprises a rectangular arc extinguishing cover main body 19, a first engagement leg 20 and a second engagement leg 21 formed on both edges of one long side 19a of the arc extinguishing cover main body 19, and a plurality of hole blocking plates 22a to 22c formed along one long side 19a between the first engagement leg 20 and the second engagement leg 21. A hook portion 20a is formed at the tip of the first engagement leg portion 20, protruding outward (rearward) in the longitudinal direction of the arc-extinguishing cover main body 19, and a hook portion 21a is also formed at the tip of the second engagement leg portion 21, protruding outward (frontward) in the long side direction of the arc-extinguishing cover main body 19.

[0016] As shown in Figure 4, the multiple hole blocking plates 22a to 22c are formed by providing multiple slits 23 parallel to each other along the longitudinal direction of the arc-extinguishing cover main body 19 in the side wall formed between the first engagement leg 20 and the second engagement leg 21, and each of the hole blocking plates 22a to 22c has a fixed portion adjacent to the arc-extinguishing cover main body 19 and other portions that are free to elastically deform.

[0017] In addition, although not shown, a first engagement leg 20 and a second engagement leg 21 are formed on both edges of the other long side 19b of the arc-extinguishing cover main body 19, and a plurality of hole blocking plates 22a to 22c are formed along the other long side 19b between the first engagement leg 20 and the second engagement leg 21.

[0018] 3, two engagement slits 24 extending upward from the lower case 2 side are formed in the case outer wall 10a of the upper case 3. In addition, although not shown, two engagement slits extending upward from the lower case 2 side are also formed in the case outer wall 10b of the upper case 3. When the first engagement leg 20 and second engagement leg 21 of the arc-extinguishing cover 8 are inserted into the engagement slit 24 formed on the case outer side 10a of the upper case 3 and the engagement slit formed on the case outer wall 10b, the hook portion 20a of the first engagement leg 20 engages with the upper edge of the engagement slit 24, and the hook portion 21a of the second engagement leg 21 engages with the upper edge of the engagement slit formed on the case outer wall 10b, so that the arc-extinguishing cover 8 is attached to the upper case 3 while covering the arc-extinguishing chamber accommodating portion 15, as shown in Figure 5.

[0019] 5 and 6(a), the arc-extinguishing cover 8 attached to the upper case 3 has hole closing plates 22a-22c formed along one long side 19a of the arc-extinguishing cover main body 19 overlapping from the outside (left side) the three arc-extinguishing chamber partitions 11a facing the power-supply side terminal portions 4b-4d, and covering the gas vent holes 17a-17c formed in the center of the arc-extinguishing chamber partitions 11a. Although not shown, hole closing plates 22a-22c formed along the other long side 19b of the arc-extinguishing cover main body 19 also overlap from the outside (left side) the three arc-extinguishing chamber partitions 11b facing the load-side terminal portions 5b-5d, and covering the gas vent holes 17a-17c formed in the center of the arc-extinguishing chamber partitions 11b.

[0020] On the other hand, if an abnormally large current flows through the contact portion 16 of the electromagnetic contactor 1 due to a short circuit or the like, and the internal pressure of the arc extinguishing chamber 14 rises excessively due to arc gas generated between the movable contact and the fixed contact, as shown in Fig. 6(b), the hole closing plates 22a to 22c formed along one long side 19a of the arc extinguishing cover main body 19 of the arc extinguishing cover 8 are elastically deformed outward (leftward) by the internal pressure of the arc extinguishing chamber 14, and the arc gas in the arc extinguishing chamber 14 is released to the outside through the gas vent holes 17a to 17c. Furthermore, although not shown, the hole closing plates 22a to 22c formed along the other long side 19b of the arc extinguishing cover main body 19 are also elastically deformed outward (rightward) by the internal pressure of the arc extinguishing chamber 14, and the arc gas in the arc extinguishing chamber 14 is released to the outside through the gas vent holes 17a to 17c. In this way, when the internal pressure of the arc extinguishing chamber 14 rises excessively, the hole blocking plates 22a to 22c of the arc extinguishing cover 8 elastically deform, causing the arc gas in the arc extinguishing chamber 14 to be released to the outside, thereby reducing the internal pressure of the arc extinguishing chamber 14 and preventing the arc extinguishing cover 8 from being blown away.

[0021] Therefore, in the electromagnetic contactor 1 of this embodiment, if an abnormally large current flows through the contact portion 16 due to a short circuit accident or the like and the internal pressure of the arc extinguishing chamber 14 rises excessively due to the generated arc gas, the arc gas will be ejected from the arc extinguishing chamber 14, causing the hole blocking plates 22a to 22c of the arc extinguishing cover 8 to elastically deform outward in a direction away from the arc extinguishing chamber partitions 11a, 11b, and the arc gas within the arc extinguishing chamber 14 will be released to the outside through the gas vent holes 17a to 17c, reducing the internal pressure of the arc extinguishing chamber 14, thereby reliably preventing the arc extinguishing cover 8 from being blown off from the upper case 3. In addition, a total of six gas vent holes 17a to 17c are formed in the three arc extinguishing chamber partitions 11a facing the power supply side terminal portions 4b to 4d and the three arc extinguishing chamber partitions 11b facing the load side terminal portions 5b to 5d, thereby improving the gas venting performance of the arc extinguishing chamber 14.

[0022] Furthermore, during normal use of the electromagnetic contactor 1, the hole blocking plates 22a to 22c of the arc-extinguishing cover 8 attached to the upper case 3 cover the gas vent holes 17a to 17c formed in the arc-extinguishing chamber partition 11a, so even when the electromagnetic contactor 1 is installed in a dusty factory, the dust-proofing of the arc-extinguishing chamber 14 can be improved and malfunction of the contact portion 16 can be reliably prevented. Furthermore, since the hole closing plates 22a to 22c of the arc-extinguishing cover 8 are arranged overlapping the arc-extinguishing chamber partitions 11a and 11b from the outside, the path for dust to enter from the gaps at the overlapping portions of the hole closing plates 22a to 22c and the arc-extinguishing chamber partitions 11a and 11b to the gas vent holes 17a to 17c is long. As a result, by arranging the hole closing plates 22a to 22c of the arc-extinguishing cover 8 overlapping the arc-extinguishing chamber partitions 11a and 11b from the outside, the dustproofness of the arc-extinguishing chamber 14 can be further improved. [Explanation of symbols]

[0023] 1 Magnetic contactor 2 Lower case 3 Upper case (case) 4a~4d Power supply side terminal section 6a, 6b Coil terminals 5a~5d Load side terminal section 7a Terminal 1 cover 7b Second terminal cover 8 Arc extinguishing cover 10a, 10b Case outer wall 10c, 10d Case inner wall 11a Arc chamber bulkhead (1st arc chamber bulkhead) 11b Arc-extinguishing chamber bulkhead (second arc-extinguishing chamber bulkhead) 12 Power side terminal room 13 Load side terminal room 14 Arc room 15 Arc extinguishing chamber housing 16 Contact point 16a Movable contact support 17a~17c Gas vent holes 19 Arc extinguishing cover body 19a One long side of the arc extinguishing cover body 19b The other long side of the arc extinguishing cover body 20 First engaging leg 21 Second engagement leg 22a~22c Hole closing plate 23 Slit 24 Engagement slit

Claims

1. A case with an arc extinguishing chamber, a contact portion having a movable contact and a fixed contact housed in the arc extinguishing chamber; an arc-extinguishing cover attached to the case to cover the contact portion housed in the arc-extinguishing chamber, A gas vent hole communicating the arc extinguishing chamber with the outside of the case is formed in the case, An electromagnetic contactor characterized in that a hole closing plate that is disposed on a part of the arc-extinguishing cover so as to cover the gas vent hole from the outside and is elastically deformable outward is formed.

2. 2. The electromagnetic contactor according to claim 1, wherein the hole closing plate is disposed in an overlapping state on the outside of the case where the gas vent hole is formed.

3. The case includes a first arc-extinguishing chamber partition provided between the power supply side terminal chamber and the arc-extinguishing chamber, and a second arc-extinguishing chamber partition provided between the load side terminal chamber and the arc-extinguishing chamber, the gas vent holes are formed in the first arc-extinguishing chamber partition wall and the second arc-extinguishing chamber partition wall, The electromagnetic contactor of claim 2, characterized in that the arc-extinguishing cover has a plurality of hole-blocking plates integrally formed on the edge portion of the arc-extinguishing cover main body that covers the contact portion, and each of the plurality of hole-blocking plates is arranged in an overlapping state on the outside of the first arc-extinguishing chamber partition and the second arc-extinguishing chamber partition.

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