Electromagnetic relay

Abstract

To expand a space for extinguishing arc in an electromagnetic relay, while suppressing an increase in manufacturing cost.SOLUTION: An electromagnetic relay comprises a base, a fixed terminal, a fixed contact, a movable piece, a movable contact, a magnet, a base holder, and a case. The fixed terminal is supported by the base. The fixed contact is connected to the fixed terminal. The movable piece is supported by the base. The movable contact is connected to the movable piece, and it faces the fixed contact. The magnet applies Lorentz force to arc generated between the fixed contact and the movable contact. The base holder is a separate body from the base. The base holder is fitted to the base. The base holder is arranged at least in a direction for applying the Lorentz force, with respect to the base. The case is fitted to the base holder.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an electromagnetic relay.

Background Art

[0002] For example, as shown in Patent Document 1, an electromagnetic relay includes a fixed contact and a movable contact. When the movable contact contacts the fixed contact, electricity flows between the movable contact and the fixed contact. When the movable contact separates from the fixed contact, the electricity between the movable contact and the fixed contact is cut off. The fixed contact is connected to a fixed terminal. The movable contact is connected to a movable piece. The fixed terminal and the movable piece are supported by a base. A case is attached to the base.

[0003] On the other hand, some electromagnetic relays are provided with a magnet for extinguishing an arc. Due to the magnetic field from the magnet, a Lorentz force acts on the arc generated between the fixed contact and the movable contact. The arc is rapidly extinguished by being stretched by the Lorentz force.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In order to quickly extinguish the arc, it is desirable to have a large space around the contact. Therefore, for example, by enlarging the base, a large space is provided around the contact. However, the base is a component that defines the positional relationship among the fixed terminal, the fixed contact, the movable piece, and the movable contact, and high dimensional accuracy is required. Therefore, it is not easy to redesign the base. Further, when the shape of the base is changed, it is necessary to newly design the manufacturing line of the electromagnetic relay. In that case, the manufacturing cost increases. An object of the present invention is to expand the space for extinguishing the arc in the electromagnetic relay while suppressing an increase in the manufacturing cost.

Means for Solving the Problem

[0006] The electromagnetic relay according to one aspect of the present invention includes a base, a fixed terminal, a fixed contact, a movable piece, a movable contact, a magnet, a base holder, and a case. The fixed terminal is supported by the base. The fixed contact is connected to the fixed terminal. The movable piece is supported by the base. The movable contact is connected to the movable piece and faces the fixed contact. The magnet applies a Lorentz force to the arc generated between the fixed contact and the movable contact. The base holder is separate from the base. The base holder is attached to the base. The base holder is arranged in at least the direction in which the Lorentz force acts with respect to the base. The case is attached to the base holder.

[0007] In the electromagnetic relay according to this aspect, the base holder is arranged in at least the direction in which the Lorentz force acts with respect to the base. Therefore, in the case, the space for extinguishing the arc is expanded in the direction in which the Lorentz force acts. Further, the base holder is separate from the base. Therefore, the space for extinguishing the arc is expanded without changing the shape of the base. Thereby, the space for extinguishing the arc is expanded while suppressing an increase in the manufacturing cost.

[0008] The magnet may be arranged above the fixed contact and the movable contact. In this case, the magnet can apply a Lorentz force to the arc without interfering with the operation of the movable piece.

[0009] The movable contact may contact and separate from the fixed contact by moving in the front - rear direction. The Lorentz force may act in the left - right direction. The base holder may be arranged at least in the left - right direction of the base. In this case, inside the case, the space for arc extinction is expanded in the left - right direction where the Lorentz force acts.

[0010] The direction in which the movable contact contacts the fixed contact is defined as the front. The direction in which the movable contact separates from the fixed contact is defined as the rear. The base holder may include a front holder part, a rear holder part, a left holder part, and a right holder part. The front holder part may be arranged in front of the base. The rear holder part may be arranged behind the base. The left holder part may be arranged to the left of the base. The right holder part may be arranged to the right of the base. In this case, the base holders are arranged in the front, rear, left, and right of the base. Therefore, the base holder is firmly attached to the base.

[0011] The base holder may include an opening. The base may be arranged inside the opening. In this case, it is easy to attach the base holder to the base.

[0012] The base holder may include a holder frame and a convex part. The holder frame may include an opening. The convex part may protrude into the opening from the holder frame. The convex part may contact the base from above. In this case, the base is prevented from coming out upward by the convex part. Thereby, the base holder is stably attached to the base.

[0013] The base holder may include a protrusion. The protrusion may protrude into the opening from the holder frame. The protrusion may support the base from below. In this case, the base is prevented from coming out downward by the protrusion. Thereby, the base holder is stably attached to the base.

[0014] The base holder may include a step portion that supports the case from below. In this case, the case is stably supported by the base holder.

[0015] The case may include a magnet storage portion. The magnet storage portion may be disposed above the fixed contact and the movable contact. The magnet storage portion may be partitioned from the space inside the case. The magnet may be stored in the magnet storage portion. In this case, the magnet can be easily disposed near the fixed contact and the movable contact.

[0016] The case may further include a lid portion made of a soft magnetic material that closes the magnet storage portion. In this case, by the lid portion functioning as a yoke, the magnetic flux of the magnet is concentrated around the contact. Also, the magnetic flux of the magnet is less likely to leak outside the electromagnetic relay.

Advantages of the Invention

[0017] According to the present invention, it is possible to expand the space for extinguishing an arc in the electromagnetic relay while suppressing an increase in manufacturing cost.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0019] Hereinafter, with reference to the drawings, the electromagnetic relay 1 according to this embodiment will be described. FIG. 1 is a side view of the electromagnetic relay 1 according to the embodiment. As shown in FIG. 1, the electromagnetic relay 1 includes a base 2, a base holder 3, a case 4, fixed terminals 5, fixed contacts 6, a movable piece 7, movable contacts 8, and a driving device 9. In the following description, it is defined that the direction in which the contacts 6 and 8 are arranged with respect to the base 2 is upward, and the opposite direction is downward. The direction from the movable contact 8 toward the fixed contact 6 is defined as forward, and the opposite direction is defined as backward. Also, the left side toward the front is defined as the left side, and the opposite side is defined as the right side. Note that these definitions of directions are used for convenience of explanation and do not limit the arrangement direction of the electromagnetic relay 1 or the like.

[0020] The base 2 supports the fixed terminals 5, the movable piece 7, and the driving device 9. The base holder 3 is attached to the base 2. The base 2 and the base holder 3 are made of, for example, resin. The base 2 and the base holder 3 will be described in detail later. The case 4 is attached to the base holder 3. The case 4 covers the base 2, the base holder 3, the movable contacts 8, the fixed contacts 6, and the driving device 9.

[0021] The fixed terminals 5 extend upward from the base 2. The fixed contacts 6 are connected to the fixed terminals 5. The fixed terminals 5 protrude downward from the base 2. The movable piece 7 extends upward from the base 2. The movable contacts 8 are connected to the movable piece 7. The movable contacts 8 face the fixed contacts 6 in the front-rear direction. The movable piece 7 protrudes downward from the base 2.

[0022] The drive device 9 moves the movable piece 7 in the contact direction and the separation direction. The contact direction is the direction in which the movable contact 8 contacts the fixed contact 6. The separation direction is the direction in which the movable contact 8 separates from the fixed contact 6. The drive device 9 includes a coil block 11, a yoke 12, a pole piece 13, a hinge spring 14, and a card 15. The coil block 11 includes a coil 16, a spool 17, and a core 18. The coil 16 is wound around the spool 17. The spool 17 is supported by the base 2. The coil 16 generates a magnetic force that moves the movable piece 7 when energized. A coil terminal 19 is connected to the coil 16. The coil terminal 19 is supported by the base 2. The coil terminal 19 protrudes downward from the base 2.

[0023] The core 18 is disposed within the spool 17. The core 18 extends in the axial direction of the coil 16. The yoke 12 is supported by the base 2. The yoke 12 includes a first yoke 21 and a second yoke 22. The yoke 12 has a bent shape between the first yoke 21 and the second yoke 22. The first yoke 21 is disposed in front of the coil 16. The first yoke 21 extends in the vertical direction. The second yoke 22 extends in the front-rear direction. The second yoke 22 is connected to the lower end of the core 18.

[0024] The pole piece 13 is swingably supported by the yoke 12. The pole piece 13 includes a first portion 23 and a second portion 24. The pole piece 13 has a bent shape between the first portion 23 and the second portion 24. The first portion 23 faces the upper end of the core 18. The second portion 24 is connected to the card 15. The card 15 faces the movable piece 7. The card 15 presses the movable piece 7 in the contact direction. The hinge spring 14 is connected to the pole piece 13. The hinge spring 14 biases the pole piece 13 in the contact direction.

[0025] Figure 1 shows the electromagnetic relay 1 in the open state. As shown in Figure 1, when no current is flowing through the coil 16, the movable contact 8 is held at a position separated from the fixed contact 6 by the elastic force of the movable piece 7. When current flows through the coil 16, the first part 23 of the armature 13 is attracted to the iron core 18 by the magnetic force of the coil 16. Thereby, the armature 13 swings in the contact direction against the elastic force of the movable piece 7, and the second part 24 moves in the contact direction. Then, the card 15 moves in the contact direction and presses the movable piece 7 in the contact direction. Thereby, as shown in Figure 2, the movable piece 7 is elastically deformed and the movable contact 8 contacts the fixed contact 6. As a result, the electromagnetic relay 1 enters the closed state shown in Figure 2.

[0026] When the current to the coil 16 is cut off, the attraction of the armature 13 by the iron core 18 stops. Therefore, the armature 13 swings in the opening direction by the elastic force of the movable piece 7. Thereby, the first part 23 separates from the iron core 18 and the card 15 moves in the opening direction. Also, the movable contact 8 separates from the fixed contact 6 by the elastic force of the movable piece 7. Thereby, the electromagnetic relay 1 returns to the open state shown in Figure 1.

[0027] When the movable contact 8 separates from the fixed contact 6, an arc may occur between the contacts 6 and 8. As shown in Figure 1, the electromagnetic relay 1 is provided with a magnet 25 for extinguishing the arc. The magnet 25 is disposed above the fixed contact 6 and the movable contact 8. Figure 3 is an enlarged side view of the electromagnetic relay 1. Figure 4 is a front view of the electromagnetic relay 1. In Figures 3 and 4, the arrow A1 indicates the direction of the magnetic field of the magnet 25. As shown in Figures 3 and 4, the magnet 25 is disposed so as to generate a vertical magnetic field between the fixed contact 6 and the movable contact 8. For example, the magnet 25 generates a downward magnetic field between the fixed contact 6 and the movable contact 8. Alternatively, the magnet 25 may generate an upward magnetic field between the fixed contact 6 and the movable contact 8.

[0028] The magnet 25 applies a Lorentz force to the arc generated between the fixed contact 6 and the movable contact 8. Hereinafter, the Lorentz force when the magnet 25 generates a downward magnetic field between the fixed contact 6 and the movable contact 8 will be described. In FIG. 4, the solid arrow F1 indicates the direction of the Lorentz force (hereinafter referred to as the "first Lorentz force") when current flows from the movable contact 8 toward the fixed contact 6. The dashed arrow F2 indicates the direction of the Lorentz force (hereinafter referred to as the "second Lorentz force") when current flows from the fixed contact 6 toward the movable contact 8. The Lorentz forces F1 and F2 act on the arc in the left-right direction.

[0029] As shown in FIGS. 1 and 4, the case 4 includes a first side surface 31, a second side surface 32, a front surface 33, a rear surface 34, and an upper surface 35. The first side surface 31 and the second side surface 32 are arranged to be separated from each other in the left-right direction. The first side surface 31 is arranged to the left of the contacts 6 and 8. The second side surface 32 is arranged to the right of the contacts 6 and 8.

[0030] When current flows from the movable contact 8 toward the fixed contact 6, a first Lorentz force F1 acting to the left is applied to the arc. Thereby, the arc is extended to the space (hereinafter referred to as the "first space") S1 between the contacts 6 and 8 and the first side surface 31 and extinguished. When current flows from the fixed contact 6 toward the movable contact 8, a second Lorentz force F2 acting to the right is applied to the arc. Thereby, the arc is extended to the space (hereinafter referred to as the "second space") S2 between the contacts 6 and 8 and the second side surface 32 and extinguished. When the magnet 25 generates an upward magnetic field between the fixed contact 6 and the movable contact 8, the Lorentz force acts in the opposite direction to the above description.

[0031] The front surface 33 is disposed in front of the contacts 6, 8. The rear surface 34 is disposed behind the drive device 9. The upper surface 35 is disposed above the contacts 6, 8 and the drive device 9. The case 4 includes a magnet housing portion 36. The magnet housing portion 36 is disposed above the contacts 6, 8. The magnet housing portion 36 has a shape that is recessed downward from the upper surface 35. The magnet 25 is disposed in the magnet housing portion 36. The magnet housing portion 36 is partitioned from the space within the case 4. The magnet housing portion 36 is closed by a lid 37. The lid 37 is made of a soft magnetic material. Since the lid 37 is made of a soft magnetic material, the magnetic flux of the magnet 25 is concentrated around the contacts 6, 8. Also, the magnetic flux of the magnet 25 is less likely to leak outside the electromagnetic relay 1.

[0032] Figures 5 and 6 are perspective views of the base 2 and the base holder 3. Figure 7 is an exploded perspective view of the base 2 and the base holder 3. As shown in Figures 5 to 7, the base 2 includes a first support portion 41 and a second support portion 42. The first support portion 41 supports the fixed terminal 5. The first support portion 41 includes a first hole 43 that penetrates the base 2 in the vertical direction. The fixed terminal 5 is passed through the first hole 43. The second support portion 42 supports the movable piece 7. The second support portion 42 includes a second hole 44 that penetrates the base 2 in the vertical direction. The movable piece 7 is passed through the second hole 44.

[0033] The base 2 includes a yoke support portion 45 and a coil support portion 46. The yoke support portion 45 extends upward from the upper surface 35 of the base 2. The yoke support portion 45 supports the yoke 12. The coil support portion 46 supports the coil block 11. The base 2 includes a front edge 47 and a rear edge 48. The front edge 47 is disposed in front of the first support portion 41. The rear edge 48 is disposed behind the coil support portion 46.

[0034] The base holder 3 is separate from the base 2. The base holder 3 is disposed around the base 2 in the front, rear, left, and right directions. Specifically, the base holder 3 includes a holder frame 51. The holder frame 51 includes an opening 52. The base 2 is disposed within the opening 52. The holder frame 51 includes a stepped portion 53. The stepped portion 53 is provided along the outer edge of the holder frame 51. The stepped portion 53 supports the case 4 from below.

[0035] The holder frame 51 includes a front holder portion 54, a rear holder portion 55, a left holder portion 56, and a right holder portion 57. The front holder portion 54 is disposed in front of the base 2. The front holder portion 54 extends in the left-right direction. The rear holder portion 55 is disposed behind the base 2. The rear holder portion 55 extends in the left-right direction. The left holder portion 56 is disposed to the left of the base 2. The left holder portion 56 extends in the front-rear direction. The left holder portion 56 is connected to the front holder portion 54 and the rear holder portion 55. The right holder portion 57 is disposed to the right of the base 2. The right holder portion 57 extends in the front-rear direction. The right holder portion 57 is connected to the front holder portion 54 and the rear holder portion 55.

[0036] As shown in FIG. 4, the left holder portion 56 is disposed in the direction in which the first Lorentz force F1 acts on the base 2. The arc is stretched by the first Lorentz force F1 into the first space S1 above the left holder portion 56. The right holder portion 57 is disposed in the direction in which the second Lorentz force F2 acts on the base 2. The arc is stretched by the second Lorentz force F2 into the second space S2 above the right holder portion 57.

[0037] FIG. 8 is a perspective view of the base holder 3. FIG. 9 is a bottom view of the base holder 3. As shown in FIGS. 8 and 9, the base holder 3 includes a plurality of legs 61-64. The plurality of legs 61-64 project downward from the bottom surface 58 of the holder frame 51. The plurality of legs 61-64 includes a first leg 61, a second leg 62, a third leg 63, and a fourth leg 64. The first to fourth legs 61-64 are respectively disposed at the four corners of the bottom surface 58 of the holder frame 51.

[0038] The base holder 3 includes a plurality of recesses 65 - 68. The plurality of recesses 65 - 68 have a shape that is recessed upward from the bottom surface 58 of the holder frame 51. The plurality of recesses 65 - 68 include a first recess 65, a second recess 66, a third recess 67, and a fourth recess 68. The first recess 65 and the second recess 66 are provided on the bottom surface of the left holder portion 56. The first recess 65 and the second recess 66 extend in the front - rear direction. The third recess 67 and the fourth recess 68 are provided on the bottom surface of the right holder portion 57. The third recess 67 and the fourth recess 68 extend in the front - rear direction. Note that the plurality of recesses 65 - 68 may be omitted.

[0039] The base holder 3 includes a plurality of protrusions 71 - 73. The plurality of protrusions 71 - 73 protrude into the opening 52 from the holder frame 51. The plurality of protrusions 71 - 73 come into contact with the base 2 from above. The plurality of protrusions 71 - 73 include a first protrusion 71, a second protrusion 72, and a third protrusion 73. The first protrusion 71 and the second protrusion 72 are arranged at the corners of the opening 52. The first protrusion 71 is arranged at the corner between the front holder portion 54 and the left holder portion 56. The second protrusion 72 is arranged at the corner between the front holder portion 54 and the right holder portion 57. The first protrusion 71 and the second protrusion 72 are arranged above the front edge 47 of the base 2. The first protrusion 71 and the second protrusion 72 come into contact with the front edge 47 of the base 2 from above. The third protrusion 73 protrudes forward from the rear holder portion 55. The third protrusion 73 is arranged above the rear edge 48 of the base 2. The third protrusion 73 comes into contact with the rear edge 48 of the base 2 from above.

[0040] As shown in FIG. 9, the base holder 3 includes a plurality of protrusions 74, 75. The plurality of protrusions 74, 75 protrude into the opening 52 from the holder frame 51. The plurality of protrusions 74, 75 support the base 2 from below. The plurality of protrusions 74, 75 includes a first protrusion 74 and a second protrusion 75. The first protrusion 74 protrudes into the opening 52 from the left holder portion 56. The second protrusion 75 protrudes into the opening 52 from the right holder portion 57. The first protrusion 74 and the second protrusion 75 are disposed below the base 2. The base 2 is inserted into the opening 52 from below the base holder 3 by press-fitting and is disposed between the plurality of convex portions 71-73 and the plurality of protrusions 74, 75. The base 2 is held by the base holder 3 by being sandwiched between the plurality of convex portions 71-73 and the plurality of protrusions 74, 75.

[0041] The base holder 3 includes a plurality of locking portions 76, 77. The plurality of locking portions 76, 77 lock to the case 4. Thereby, the case 4 is attached to the base holder 3. The plurality of locking portions 76, 77 includes a first locking portion 76 and a second locking portion 77. The first locking portion 76 protrudes from the left holder portion 56. The first locking portion 76 locks to the first side surface 31 of the case 4. The second locking portion 77 protrudes from the right holder portion 57. The second locking portion 77 locks to the second side surface 32 of the case 4.

[0042] In the electromagnetic relay 1 according to the present embodiment described above, the base holder 3 is disposed with respect to the base 2 at least in the direction in which the Lorentz force acts. Therefore, in the case 4, the spaces S1, S2 for extinguishing the arc are expanded in the direction in which the Lorentz forces F1, F2 act. Further, the base holder 3 is separate from the base 2. Therefore, the spaces S1, S2 for extinguishing the arc are expanded without changing the shape of the base 2. Thereby, the spaces S1, S2 for extinguishing the arc are expanded while suppressing an increase in manufacturing cost.

[0043] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention.

[0044] The structures of the fixed contact 6 and the fixed terminal 5 are not limited to those of the above-described embodiment and may be changed. For example, the fixed contact 6 and the fixed terminal 5 are not limited to being separate from each other and may be integral. The structures of the movable contact 8 and the movable piece 7 are not limited to those of the above-described embodiment and may be changed. For example, the movable contact 8 and the movable piece 7 are not limited to being separate from each other and may be integral.

[0045] The structure of the drive device 9 is not limited to that of the above-described embodiment and may be changed. For example, the shape of the card 15 may be changed. The shape of the contact terminal 13 may be changed.

[0046] The structures of the base 2 and the base holder 3 are not limited to those of the above-described embodiment and may be changed. For example, the rear holder portion 55 or the front holder portion 54 may be omitted. Only one of the left holder portion 56 and the right holder portion 57 may be provided. For example, when the Lorentz force acts only on the left side of the contacts 6 and 8, the right holder portion 57 may be omitted. Or, when the Lorentz force acts only on the right side of the contacts 6 and 8, the left holder portion 56 may be omitted.

[0047] The structure of the convex portion is not limited to that of the above-described embodiment and may be changed. For example, the arrangement of the convex portions may be changed. The number of convex portions is not limited to three and may be more than three or less than three. The arrangement of the protrusions may be changed. The number of protrusions is not limited to two and may be one or more than two.

Industrial Applicability

[0048] According to the present invention, it is possible to expand the space for extinguishing an arc in an electromagnetic relay while suppressing an increase in manufacturing cost.

Explanation of Reference Numerals

[0049] 2: Base, 3: Base Holder, 4: Case, 5: Fixed Terminal, 6: Fixed Contact, 7: Movable Piece, 8: Movable Contact, 25: Magnet, 36: Magnet Accommodating Portion, 51: Holder Frame, 52: Opening, 53: Step Portion, 54: Front Holder Portion, 55: Rear Holder Portion, 56: Left Holder Portion, 57: Right Holder Portion, 71: Convex Portion, 74: Protrusion

Claims

1. A base, a fixed terminal supported by the base, a fixed contact connected to the fixed terminal, a movable piece supported by the base, a movable contact connected to the movable piece and facing the fixed contact, a magnet that applies a Lorentz force to an arc generated between the fixed contact and the movable contact, a base holder that is separate from the base, attached to the base, and arranged in at least the direction in which the Lorentz force acts with respect to the base, a case attached to the base holder, comprising: the base holder includes an opening, the base is arranged within the opening, an electromagnetic relay.

2. The magnet is arranged above the fixed contact and the movable contact, The electromagnetic relay according to Claim 1.

3. The movable contact contacts and separates from the fixed contact by moving in the front-rear direction, the Lorentz force acts in the left-right direction, the base holder is arranged at least in the left-right direction of the base, The electromagnetic relay according to Claim 1.

4. The direction in which the movable contact contacts the fixed contact is defined as the front, the direction in which the movable contact separates from the fixed contact is defined as the rear, the base holder, a front holder portion arranged in front of the base, a rear holder portion arranged behind the base, a left holder portion arranged to the left of the base, a right holder portion arranged to the right of the base, including: The electromagnetic relay according to Claim 3.

5. The base holder, a holder frame including the opening, a convex portion protruding from the holder frame into the opening and contacting the base from above, including: The electromagnetic relay according to Claim 1.

6. The base holder, a holder frame including the opening, a protrusion protruding from the holder frame into the opening and supporting the base from below, including: The electromagnetic relay according to Claim 1.

7. The base holder includes a stepped portion that supports the case from below, The electromagnetic relay according to Claim 1.

8. The case includes a magnet storage portion arranged above the fixed contact and the movable contact, the magnet storage portion is partitioned from the space within the case, the magnet is stored within the magnet storage portion, The electromagnetic relay according to any one of Claims 1 to 7.

9. The case further includes a lid portion made of a soft magnetic material that closes the magnet storage portion, The electromagnetic relay according to any one of claims 1 to 8.

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