electromagnetic contactor

Abstract

To provide an electromagnetic contactor that can simultaneously provide an operation display unit protection function and a charging unit protection function.SOLUTION: An opening 9 provided in a housing 4 is covered by a connecting piece 25 connected to the housing. Power supply side and load side terminals 6a to 6d, 7a to 7d provided in a housing 2B are covered by a flat protective cover 26 connected to the connecting piece 25.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electromagnetic contactor provided with a protective cover for protecting a terminal portion detachably.

Background Art

[0002] On the top cover of an electromagnetic contactor, primary and secondary terminal portions are provided, and an opening is formed between the primary and secondary terminal portions. Inside the housing of the electromagnetic contactor, a contact support of a contact mechanism fixed to the movable iron core of an electromagnet unit is arranged, and by the operation convex portion of this contact support protruding into and retracting from the opening, it functions as an operation display portion.

[0003] In the electromagnetic contactor of Patent Document 1, a first protective cover (operation display protective cover) that covers the opening of the operation display portion is detachably attached to the top cover, and it has a function of protecting the operation display portion, such as preventing dust from entering from the opening into the contact mechanism inside the housing, or preventing incorrect operation of the contact support of the contact mechanism in the operation display portion.

[0004] Also, in the electromagnetic contactor of Patent Document 2, a second protective cover (charging portion protective cover) that covers the primary and secondary terminal portions is detachably attached to the periphery of the opening of the top cover, and it has a function of protecting the charging portion, such as preventing electric shock to the primary and secondary terminal portions.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, as shown in Patent Documents 1 and 2, conventional electromagnetic contactors are fitted with either a first protective cover or a second protective cover, and cannot simultaneously have both an operation indicator protection function and a charging function.

[0007] The present invention aims to provide an electromagnetic contactor that can simultaneously provide both an operation indicator protection function and a charging function. [Means for solving the problem]

[0008] To achieve the above objective, an electromagnetic contactor according to one aspect of the present invention is provided in which a contact mechanism and an electromagnet device are arranged inside a housing, and terminals and an opening are formed in the housing on the power supply side and the load side, and an operation indicator unit provided on the contact support of the contact mechanism moves in and out inside the opening by the on / off drive of the electromagnet device, and a connecting piece covering the opening is detachably attached to the housing, and the connecting piece has a piece opening that allows the operation indicator unit to be seen from the outside, and a cover connecting part is provided for detachably connecting a flat plate-shaped protective cover that covers the terminals on the power supply side and the load side. [Effects of the Invention]

[0009] The electromagnetic contactor of the present invention has protective covers connected to the housing via connecting pieces to cover the terminals on the power supply side and the load side. This allows for both an operation indicator protection function, which prevents dust from entering the contact mechanism inside the housing through the opening, and a live part protection function, which prevents electric shock to the terminals on the primary and secondary sides. [Brief explanation of the drawing]

[0010] [Figure 1] This is an exploded perspective view showing the state in which a connecting piece and a protective cover are connected to an electromagnetic contactor in the first embodiment of the present invention. [Figure 2] This is a view of an electromagnetic contactor from the front. [Figure 3] This is a view along line AA in Figure 2. [Figure 4]This is a view along the line BB in Figure 2. [Figure 5] This is a perspective view showing the shape of the connecting piece used in the first embodiment. [Figure 6] This is a cross-sectional view of a key part showing a state in which a part of the connecting piece is inserted into the cover opening of the electromagnetic contactor in the first embodiment. [Figure 7] This is a cross-sectional view of the main part showing the state in which a connecting piece is connected to the arc extinguishing cover of an electromagnetic contactor in the first embodiment. [Figure 8] This is a perspective view showing the state in which a protective cover is connected to the electromagnetic contactor via a connecting piece in the first embodiment. [Figure 9] This is an exploded perspective view showing the state in which a connecting piece and a protective cover are connected to an electromagnetic contactor in a second embodiment of the present invention. [Figure 10] This is a perspective view showing the shape of the connecting piece used in the second embodiment. [Figure 11] This is a perspective view showing the electromagnetic contactor with a protective cover connected via a connecting piece in the second embodiment. [Figure 12] This is a cross-sectional view showing the state in which a protective cover is connected to the housing of an electromagnetic contactor via a connecting piece in the second embodiment. [Modes for carrying out the invention]

[0011] Next, embodiments of the present invention will be described with reference to the drawings. In the following drawings, identical or similar parts are denoted 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 ratio of the thickness of each layer, etc., may differ from reality. Therefore, specific thicknesses and dimensions should be determined by referring to the following explanation. Furthermore, it should be noted that there are parts where the relationships and ratios of dimensions differ between drawings.

[0012] In addition, the embodiments described below illustrate devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention does not specify the materials, shapes, structures, arrangements, etc. of the components as the following. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

[0013] In addition, the terms indicating directions such as "up", "down", "front", "rear", "left", "right", etc. described in the following description are used referring to the directions of the attached drawings. [First Embodiment]

[0014] As shown in FIG. 1, the electromagnetic contactor 1 according to the first embodiment of the present invention is configured with a housing formed by a first frame 2A and a second frame 2B made of a synthetic resin having electrical insulation properties. Note that the housing according to the present invention corresponds to the second frame 2B and the arc extinguishing cover.

[0015] The first frame 2A is a bottomed rectangular cylindrical body, and mounting plate portions 3 are formed at the four corners of the rear end. The second frame 2B is a rectangular cylindrical body with an open rear end, and an arc extinguishing cover 4 that covers a contact mechanism 10 described later is detachably attached to the front end. As shown in FIG. 2, power supply side terminals 6a, 6b, 6c, 6d and a coil terminal portion 8 are formed on the upper side of the second frame 2B. Load side terminals 7a, 7b, 7c, 7d are formed on the lower side of the second frame 2B. The electromagnetic contactor 1 is arranged in a distribution board or the like by fixing a fixing screw passing through the mounting plate portion 3 to a wall-mounted distribution board or the like, although not shown.

[0016] FIG. 3 shows the internal structure of the electromagnetic contactor 1, and includes a contact mechanism 10 installed inside the second frame 2B and an electromagnet unit 12 installed inside the first frame 2A and used to drive the contact mechanism 10 to turn on and off. The electromagnet unit 12 includes a fixed iron core 13 arranged on the bottom side of the first frame 2A, a movable iron core 14 with its electrode surface 14a arranged opposite to the electrode surface 13a of the fixed iron core 13, an electromagnetic coil 15 inserted through and arranged on the central protruding portion 13b of the fixed iron core 13, and a return spring 16 arranged between the front side of the electromagnetic coil 15 and the movable iron core 14. The electromagnetic coil 15 has a bobbin 21 and a winding 22 wound around the cylindrical portion of the bobbin 21.

[0017] The contact mechanism 10 includes a plurality of sets of power - side fixed contacts 18a and load - side fixed contacts 18b fixed to the second frame 2B and arranged side by side in the left - right direction, a contact support 19 movably mounted in the front - back direction inside the second frame 2B, and a plurality of movable contacts 20 supported by the contact support 19 and moving in the front - back direction so that the movable contacts 20a, 20b can be separated from and contacted with the fixed contacts 18a1 of the plurality of sets of power - side fixed contacts 18a and the fixed contacts 18b1 of the plurality of sets of load - side fixed contacts 18b.

[0018] As shown in FIG. 2, a square - shaped cover opening 9 is formed in the arc - extinguishing cover 4 mounted on the second frame 2B. Inside the cover opening 9, an operation display portion 23, which is an operation display part, and a pair of frame convex portions 24a, 24b are arranged. On the lower edge portion of the opening 9, a pair of anti - rotation grooves 5a, 5b extending linearly downward in parallel with each other are formed. Note that the opening according to the present invention corresponds to the cover opening 9.

[0019] As shown in Figure 4, the operation indicator unit 23 is integrally formed on the upper part of the contact support 19. It extends and retracts toward the opening 9 as the contact support 19 moves in the front-to-back direction during the opening and closing operation of the electromagnetic contactor 1, and functions as an operation indicator unit for the electromagnetic contactor 1. When the electromagnetic contactor 1 is in the open position, the operation indicator unit 23 moves to a position where it does not protrude outward from the opening 9 (in front of the arc extinguishing cover 4). As shown in Figure 4, the pair of frame protrusions 24a and 24b are integrally formed on the second frame 2B, spaced apart from the operation indicator unit 23 in the left-right direction. One of the frame protrusions 24a has its tip bent to the right to form a first engagement recess 24a1. The other frame protrusion 24b also has its tip bent to the left to form a first engagement recess 24b1. The housing engagement portion according to the present invention corresponds to the first engagement recess 24a1 and the first engagement recess 24b1.

[0020] Reference numeral 25 in Figure 1 indicates a connecting piece connected to the opening 9 of the electromagnetic contactor 1, and reference numeral 26 in Figure 1 indicates a protective cover that covers the power supply side terminals 6a, 6b, 6c, 6d, the load side terminals 7a, 7b, 7c, 7d and the connecting piece 25 from the front.

[0021] The connecting piece 25 is made of an electrically insulating synthetic resin and, as shown in Figures 5(a) and (b), comprises a rectangular plate-shaped piece body 27 and a piece opening 28 formed through the thickness direction approximately in the center of the piece body 27. On one surface of the piece body 27, as shown in Figure 5(a), a pair of legs 29a and 29b are formed, extending parallel to each other from two opposing sides to surround the piece opening 28, and leg engaging portions 30a and 30b are formed, projecting in an L-shape from the tips of the pair of legs 29a and 29b in opposing directions. Furthermore, on one surface of the piece body 27, anti-rotation projections 31a and 31b are formed on one of two opposing sides other than the two sides on which the pair of legs 29a and 29b are formed, and engaging claw portions 32 are formed on the other side of those two sides. Furthermore, as shown in Figure 5(b), a boss 33 protrudes from the periphery of the piece opening 28 on the other side of the piece body 27, and fitting protrusions 35a and 35b, which constitute a pair of snap-fit ​​mechanisms 34a and 34b, are formed therein.

[0022] The protective cover 26 is a rectangular plate made of electrically insulating transparent synthetic resin. As shown in Figure 1, a boss hole 36 into which the boss 33 of the connecting piece 25 fits is formed in the center of the longitudinal direction, and fitting holes 37a and 37b that constitute a pair of snap-fit ​​mechanisms 34a and 34b are formed. In addition, four voltage detection insertion holes 38a to 38d are formed on the upper side of the protective cover 26.

[0023] Next, the procedure for connecting the connecting piece 25 to the arc extinguishing cover 4 of the electromagnetic contactor 1 and connecting the protective cover 26 to the connecting piece 25 will be explained with reference to Figures 6 to 8. In Figures 6 and 7, the parts indicated by the shaded lines are the leg engagement parts 30a, 30b, the anti-rotation projections 31a, 31b, and the engagement claw part 32 of the connecting piece 25.

[0024] First, the pair of legs 29a, 29b and leg engagement parts 30a, 30b of the connecting piece 25 are inserted into the opening 9 of the arc extinguishing cover 4. At this time, a portion of the anti-rotation projections 31a, 31b of the connecting piece 25 is inserted into a portion of the anti-rotation grooves 5a, 5b formed on the periphery of the opening 9.

[0025] Next, as shown in Figure 7, by sliding the connecting piece 25 downward, the leg engaging portions 30a and 30b engage with the first engaging recesses 24a1 and 24b1 of the frame protrusions 24a and 24b, the entire area of ​​the anti-rotation projections 31a and 31b of the connecting piece 25 enters the anti-rotation grooves 5a and 5b, and with the engaging claw portion 32 engaged with the periphery of the cover opening 9, the connecting piece 25 is connected to the arc extinguishing cover 4.

[0026] Next, as shown in Figure 8, the boss 33 of the connecting piece 25 is inserted into the boss hole 36 of the protective cover 26. Then, the claws of the fitting projections 35a and 35b formed on the connecting piece 25 engage with the periphery of the fitting holes 37a and 37b of the protective cover 26, and the boss 33 fits into the boss hole 36, thereby connecting the protective cover 26 to the connecting piece 25.

[0027] According to the first embodiment, since the protective cover 26 covers all of the power supply side terminals 6a, 6b, 6c, 6d and the load side terminals 7a, 7b, 7c, 7d and the cover opening 9 from the front, it is possible to simultaneously provide an operation indicator protection function that prevents dust from entering the contact mechanism 10 from the cover opening 9 or erroneous operation of the operation indicator unit 23 of the contact mechanism 10, and a charging unit protection function that can reliably prevent electric shock to the user from the power supply side terminals 6a, 6b, 6c, 6d and the load side terminals 7a, 7b, 7c, 7d.

[0028] Furthermore, the boss 33 of the connecting piece 25 fits into the boss hole 36 of the protective cover 26, and the fitting projections 35a and 35b of the connecting piece 25 snap-fit ​​into the fitting holes 37a and 37b of the protective cover 26, thereby firmly connecting the protective cover 26 to the connecting piece 25. In addition, the arc extinguishing cover 4 connected to the connecting piece 25 has anti-rotation projections 31a and 31b that fit into anti-rotation grooves 5a and 5b of the arc extinguishing cover 4. Therefore, even if a rotational force acts on the protective cover 26 along the surface direction, the anti-rotation grooves 5a and 5b of the arc extinguishing cover 4 will receive the rotational force. Thus, the connection strength of the protective cover 26 to the electromagnetic contactor 1 when a rotational force acts on the protective cover 26 can be increased.

[0029] Furthermore, when the connecting piece 25 is slid downward while covering the cover opening 9, the leg engaging portions 30a and 30b of the connecting piece 25 engage with the first engaging recesses 24a1 and 24b1 of the frame protrusions 24a and 24b inside the cover opening 9, and the engaging claw portion 32 of the connecting piece 25 engages with the periphery of the cover opening 9, allowing the connecting piece 25 to be easily attached to the arc extinguishing cover 4. Then, by releasing the engagement of the engaging claw portion 32 from the periphery of the cover opening 9 and sliding it upward, the engagement of the leg engaging portions 30a and 30b and the first engaging recesses 24a1 and 24b1 can be released, allowing the connecting piece 25 to be easily removed. In this way, the connecting piece 25 of this embodiment allows for easy attachment and detachment of the arc extinguishing cover 4 from the cover opening 9.

[0030] Furthermore, when measuring the voltage of the power supply terminals 6a, 6b, 6c, and 6d, the protective cover 26 can be attached to the electromagnetic contactor 1, and the tester can be inserted into the power supply terminals 6a, 6b, 6c, and 6d through the voltage detection insertion holes 38a to 38d to measure the voltage, making it easy to perform checks on the sequence control circuit.

[0031] Furthermore, since the protective cover 26 is made of a transparent synthetic resin and the connecting piece 25 has a piece opening 28, the movement of the operation indicator 23, which comes in and out of the cover opening 9 that functions as an operation indicator, can be easily confirmed visually through the piece opening 28 and the protective cover 26. [Second Embodiment]

[0032] Next, Figure 9 shows the connecting piece 40 and protective cover 41 of the second embodiment, which are attached to the electromagnetic contactor 1 according to the present invention. Note that the same reference numerals are used for components identical to those of the connecting piece 25 and protective cover 26 of the first embodiment, and their descriptions are omitted.

[0033] As shown in Figures 10(a) and (b), the connecting piece 40 of this embodiment has a plate-shaped release portion 42 that protrudes in a stepped manner in the same direction as the boss 33 and the fitting projections 35a and 35b from one side of the rectangular plate-shaped piece body 27 on which the engaging claw portion 32 is formed.

[0034] Furthermore, as shown in Figure 9, the protective cover 41 of this embodiment has a release insertion hole 43 formed between the voltage detection insertion holes 38a to 38d formed on one side in the longitudinal direction and the pair of fitting holes 37a, 37b and boss hole 36 formed on the other side in the longitudinal direction.

[0035] Next, the procedure for connecting the connecting piece 40 to the arc extinguishing cover 4 of the electromagnetic contactor 1, and connecting the protective cover 41 to the connecting piece 40, will be explained with reference to Figures 11 and 12.

[0036] Similar to the connecting piece 25 in the first embodiment, the connecting piece 40 has a pair of legs 29a, 29b and leg engaging portions 30a, 30b inserted into the cover opening 9 of the arc extinguishing cover 4, with a portion of the anti-rotation projections 31a, 31b engaging into a portion of the anti-rotation grooves 5a, 5b formed on the periphery of the cover opening 9. Then, by sliding the connecting piece 25 downward, the leg engaging portions 30a, 30b engage with the first engaging recesses 24a1, 24b1 of the frame protrusions 24a, 24b, and the anti-rotation projections 31a, 31b of the connecting piece 25 engage into the anti-rotation grooves 5a, 5b, so that the engaging claw portion 32 engages with the periphery of the cover opening 9, and the connecting piece 40 is connected to the arc extinguishing cover 4.

[0037] As shown in Figure 11, the boss 33 of the connecting piece 40 is inserted into the boss hole 36 of the protective cover 41. The claws of the fitting projections 35a and 35b of the connecting piece 40 engage with the periphery of the fitting holes 37a and 37b of the protective cover 41, and the boss 33 fits into the boss hole 36, thereby connecting the protective cover 41 to the connecting piece 40. At this time, as shown in Figure 12, the release portion 42 of the connecting piece 40 is inserted into the release insertion hole 43 of the protective cover 41 from the back side of the protective cover 41 (the side that contacts the connecting piece 40). As a result, the tip of the release portion 42 contacts the front surface of the protective cover 41.

[0038] Then, when an external force is applied to the connecting piece 40 and protective cover 41 connected to the arc extinguishing cover 4 of the electromagnetic contactor 1 in the direction of arrow T1 (forward direction) in Figure 12, the release part 42 engaged with the front surface of the protective cover 41 moves forward, releasing the engagement of the engaging claw part 32 with the periphery of the cover opening 9. Subsequently, by moving the protective cover 41 in the direction of arrow T2 (upward direction) in Figure 12, the engagement of the anti-rotation projection 31b (31a) of the connecting piece 40 with the anti-rotation groove 5b (5a) of the arc extinguishing cover 4 is released, making it possible to remove the connecting piece 40 and protective cover 41 from the arc extinguishing cover 4.

[0039] Therefore, the second embodiment can obtain the same effects as the first embodiment, and when an external force is applied to the protective cover 41 in a forward direction away from the arc extinguishing cover 4, the release portion 42 engaged with the front surface of the protective cover 41 moves forward, and the engagement of the engaging claw portion 32 from the periphery of the cover opening 9 is released. Then, by moving the protective cover 41 upward, the engagement of the anti-rotation projections 31a and 31b of the connecting piece 40 with the anti-rotation grooves 5a and 5b of the arc extinguishing cover 4 is released, and the protective cover 41 and the connecting piece 40 can be removed simultaneously from the cover opening 9 of the arc extinguishing cover 4. Therefore, the protective cover 41 and the connecting piece 40 can be easily removed from the cover opening 9.

[0040] In the first and second embodiments, the connecting piece 25(40) and the protective cover 26(41) are connected by the interlocking of a boss 33 and a boss hole 36, and a snap-fit ​​connection using snap-fit ​​mechanisms 34a and 34b. However, the present invention is not limited to this connecting structure. For example, a connecting structure in which connecting holes are formed in the connecting piece 25(40) and the protective cover 26(41) and push rivets are interlocked into these connecting holes, or a connecting structure in which a connecting hole is formed in one of the connecting piece 25(40) and the protective cover 26(41), and a projection is provided in the other, and the head of the projection protruding from the connecting hole is crimped, can also be used to obtain the same effects as in the first and second embodiments. [Explanation of symbols]

[0041] 1 Magnetic contactor 2A 1st Frame 2B 2nd frame 3. Mounting plate section 4. Arc extinguishing cover 5a, 5b Anti-rotation groove 6a, 6b, 6c, 6d Power supply terminals 7a,7b,7c,7d Load side terminal 8. Coil terminal section 9 Cover opening 10 Contact mechanism 12 Electromagnet Units 13 Fixed iron core 13a Electrode surface 13b Central protrusion 14 Movable Iron Core 14a Electrode surface 15 Electromagnetic coil 16. Return spring 18a Power supply side fixed contact 18b Load side fixed contact 18a1,18b1 Fixed contact 19 Contact support 21 bobbins 22 windings 20a,20b Movable contact 20 Movable contacts 23 Operation display section 24a, 24b Frame protrusions 24a1, 24b1 First engagement recess 25,40 Connecting pieces 26,41 Protective cover 27 Piece body 28 Opening of the frame 29a,29b Legs 30a,30b Leg engaging part 31a, 31b Anti-rotation protrusions 32 Engaging claw portion 33 Boss 34a, 34b Snap-fit ​​mechanism 35a,35b Fitting protrusion 36 Boss Hole 37a,37b Fitting hole part 38a~38d Voltage tester insertion holes 42 Disengagement section 43 Disengagement insertion hole

Claims

1. In an electromagnetic contactor in which a contact mechanism and an electromagnet device are arranged inside a housing, and terminals and an opening are formed in the housing for the power supply side and the load side, and an operation indicator unit provided on the contact support of the contact mechanism moves in and out inside the opening when the electromagnet device is turned on and off, A connecting piece covering the opening is detachably attached to the housing. The connecting piece is provided with a piece opening that allows the operation indicator to be visually observed from the outside, and a cover connecting portion that detachably connects a flat plate-shaped protective cover that covers the terminal portions on the power supply side and the load side. The electromagnetic contactor is characterized in that the protective cover is connected to the connecting piece via a cover connecting portion and covers the opening of the piece.

2. The connecting piece comprises a plate-shaped cover body that closes the opening, a pair of leg engagement portions formed on a pair of legs protruding from one side of the cover body, and an engagement claw portion formed at a position away from the pair of legs. The electromagnetic contactor according to claim 1, characterized in that when the pair of legs are inserted into the opening and the cover body is slid, the leg engaging portion engages with the housing engaging portion in the opening, and the engaging claw portion engages with the opening periphery of the opening, thereby allowing the connecting piece to be detachably attached to the housing.

3. The protective cover has a release insertion hole, and the connecting piece is inserted into the release insertion hole and has a release portion that overlaps the outer surface of the protective cover. The electromagnetic contactor according to claim 2, characterized in that when an external force is applied to the protective cover in a direction that separates it from the connecting piece, the engagement between the engaging claw portion of the connecting piece and the opening periphery of the opening is released via the release portion.

4. The electromagnetic contactor according to any one of claims 1 to 3, characterized in that the protective cover has a voltage test insertion hole formed at a position facing at least the terminal portion on the power supply side.

5. The electromagnetic contactor according to any one of claims 1 to 3, characterized in that the protective cover is formed of a transparent material.

6. The electromagnetic contactor according to any one of claims 1 to 3, characterized in that the cover connecting portion comprises a boss formed on one of the connecting piece and the protective cover, and a boss hole formed on the other of the connecting piece and the protective cover into which the boss fits.

7. The electromagnetic contactor according to claim 6, characterized in that the cover connecting portion is a snap-fit ​​mechanism further comprising a mating projection formed on one of the connecting piece and the protective cover, and a mating hole formed on the other of the connecting piece and the protective cover into which the mating projection fits.

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