Electromagnetic relay

Abstract

To provide an electromagnetic relay which can improve performance of shutting off an arc.SOLUTION: An electromagnetic relay (10) includes: a pair of fixation contacts (11, 13) arranged at a predetermined interval; a movable contact (15, 17) for making the pair of fixation contacts conductive with each other or insulated from each other by approaching the pair of fixation contacts or by being separated from the pair of fixation contacts; contact housings (20, 21, 31, 32) for storing contact parts (13, 15) between the pair of fixation contacts and the movable contact, an arc-extinguishing chamber (22) being formed in the contact housings as a space for extending an arc generated between the fixation contacts and the movable contact; and a magnet for extending the arc in a predetermined direction and generating a magnetic field which is introduced into the arc-extinguishing chamber. In a position of the contact housing which is distant from the contact part by a predetermined direction, there is formed a communication hole (40) for making the arc-extinguishing chamber communicated with the outside of the arc-extinguishing chamber.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] For example, there is an electromagnetic relay that has a movable member whose both ends move in contact with and out of contact with a first fixed member and a second fixed member, and an arc-extinguishing chamber is formed in the contact housing to the side of first and second contact pairs that are formed at the contact portions between the first and second fixed members and the movable member, respectively, and the arc generated at the contact pair is guided to the arc-extinguishing chamber by the magnetic field of a magnet (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-73352 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, it has become difficult for an electromagnetic relay to interrupt an arc because a large current flows through the electromagnetic relay in an electric vehicle or the like. For this reason, it is desired to improve the arc interrupting performance of the electromagnetic relay.

[0005] The present invention has been made to solve the above problems, and a main object of the present invention is to provide an electromagnetic relay capable of improving the arc interruption performance. [Means for solving the problem]

[0006] The first means for solving the above problem is an electromagnetic relay (10) comprising: a pair of fixed contacts (11, 12, 13, 14) arranged at a predetermined interval; a movable contact (15, 17, 18) moving toward and away from the pair of fixed contacts to establish and break electrical connection between the pair of fixed contacts; a contact housing (20, 21, 31, 32) that houses contact portions (13, 14, 17, 18) between the pair of fixed contacts and the movable contact and in which an arc-extinguishing chamber (22) is formed, the arc-extinguishing chamber being a space for extending an arc generated between the fixed contact and the movable contact; and a magnet (51, 52) that generates a magnetic field that extends the arc in a predetermined direction and guides it to the arc-extinguishing chamber, A communication hole (40, 140, 240) for communicating the arc-extinguishing chamber with the outside of the arc-extinguishing chamber is formed in the contact housing at a position further in the predetermined direction than the contact portion.

[0007] According to the above configuration, the pair of fixed contacts are arranged at a predetermined interval. The movable contact moves toward and away from the pair of fixed contacts to establish and break electrical continuity between the pair of fixed contacts. Therefore, when the movable contact moves from a state in which it approaches the pair of fixed contacts to establish electrical continuity between the pair of fixed contacts to a state in which it moves away from the pair of fixed contacts to break electrical continuity between the pair of fixed contacts, an arc may be generated between the fixed contact and the movable contact.

[0008] In this regard, the contact housing houses the contact portions between the pair of fixed contacts and the movable contact, and has an arc extinguishing chamber formed therein, which is a space for stretching the arc generated between the fixed contacts and the movable contacts. The magnet generates a magnetic field that stretches the arc in a predetermined direction and guides it to the arc extinguishing chamber. Therefore, the arc generated between the fixed contacts and the movable contacts can be stretched in a predetermined direction by the magnetic field of the magnet and guided to the arc extinguishing chamber, and the arc can be cooled and interrupted. However, when a large current flows through the electromagnetic relay, it becomes difficult for the electromagnetic relay to interrupt the arc.

[0009] Therefore, a communication hole that communicates the arc extinguishing chamber with the outside of the arc extinguishing chamber is formed in the contact housing at a position in the predetermined direction from the contact portion. Therefore, the arc can be extended in a direction approaching the communication hole. Then, the heat generated by the arc and the pressure increased by the arc can be released from the communication hole to the outside of the arc extinguishing chamber. Therefore, the arc can be efficiently cooled, and the performance of interrupting the arc can be improved.

[0010] In a second aspect, the communication hole is formed at an end of the contact housing in the predetermined direction. With this configuration, when the arc is extended to the end of the contact housing in the predetermined direction, the arc can be brought closest to the communication hole. Therefore, when the arc is extended to the end of the contact housing in the predetermined direction without being interrupted, the arc can be easily interrupted.

[0011] In the direction in which the movable contact extends from one of the pair of fixed contacts to the other, the starting point of the arc may move within a range of the width of the end of the fixed contact in the predetermined direction.

[0012] In this regard, in the third means, in the direction in which the movable contact extends from one of the pair of fixed contacts to the other, the width (W1, W1A) of the communicating hole is wider than the width (W2, W2A) of the end (11a, 12a) of the fixed contact in the predetermined direction. With this configuration, even if the starting point of the arc moves within the width range of the end of the fixed contact in the predetermined direction, the starting point of the arc can be prevented from moving out of the width range of the communicating hole. Therefore, the arc stretched in the predetermined direction can be prevented from moving out of the width range of the communicating hole, and the arc can be cooled efficiently.

[0013] In the fourth aspect, the opening (40a) of the communication hole on the side of the arc-extinguishing chamber is larger than the opening (40b) of the communication hole on the side opposite to the arc-extinguishing chamber. With this configuration, the arc, heat generated by the arc, and pressure increased by the arc can be easily guided from the arc-extinguishing chamber to the inside of the communication hole. Therefore, the arc can be efficiently cooled, and the performance of interrupting the arc can be improved.

[0014] The fifth means includes an electromagnetic coil (71) that generates an electromagnetic force that brings the movable contact closer to the pair of fixed contacts, and a coil housing (20, 31, 32) that accommodates the electromagnetic coil, and the communication hole connects the arc extinguishing chamber with the inside of the coil housing.

[0015] According to the above configuration, the communication hole connects the arc extinguishing chamber to the inside of the coil housing, so that heat and pressure caused by the arc can be released from the arc extinguishing chamber to the inside of the coil housing through the communication hole, and the inside of the coil housing can be used as a space for releasing the heat and pressure in the arc extinguishing chamber.

[0016] In a sixth aspect, the coil housing is formed with an air vent (47) that connects the inside of the coil housing to the outside air. With this configuration, the heat and pressure released into the inside of the coil housing can be released to the outside air through the air vent. Therefore, the inside of the coil housing and, in turn, the inside of the arc-extinguishing chamber can be efficiently cooled, improving the arc interruption performance. Furthermore, since the arc-extinguishing chamber is connected to the outside air via the inside of the coil housing, it is possible to prevent the heat and pressure in the arc-extinguishing chamber from being forcefully discharged to the outside air.

[0017] In the seventh aspect, the end of the coil housing in the predetermined direction communicates with the arc extinguishing chamber through the communication hole, and the end opposite to the predetermined direction communicates with the outside air through the air hole. With this configuration, since the communication hole and the air hole are respectively arranged at both ends of the coil housing, it is possible to prevent the heat and pressure released into the inside of the coil housing from being immediately discharged from the communication hole to the air hole. Therefore, it is possible to effectively prevent the heat and pressure in the arc extinguishing chamber from being forcefully discharged to the outside air. [Brief description of the drawings]

[0018] [Figure 1] FIG. [Diagram 2] FIG. 4 is a perspective view showing the electromagnetic relay with the case removed. [Diagram 3] FIG. 4 is a plan view showing the electromagnetic relay with the case and the housing member removed. [Figure 4] Cross-sectional view taken along line IV-IV in Figure 3. [Diagram 5] Rear view of the electromagnetic relay. [Figure 6] FIG. 4 is a longitudinal sectional view showing a state in which the arc is stretched. [Figure 7] 13 is a plan view showing a modified example of the fixing member and the communication hole. FIG. [Figure 8] FIG. 11 is a plan view showing a modified example of the communication hole. [Figure 9] FIG. 11 is a plan view showing another modified example of the communication hole. [Figure 10] FIG. 11 is a plan view showing another modified example of the communication hole. [Figure 11] Cross-sectional view taken along line XI-XI in Figure 10. [Figure 12] FIG. 11 is a vertical plan view showing another modified example of the communication hole. [Figure 13] FIG. 11 is a vertical plan view showing another modified example of the communication hole. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of an electromagnetic relay connected between a power source and an inverter in a hybrid vehicle or an electric vehicle will be described with reference to the drawings.

[0020] As shown in Figures 1 and 2, the electromagnetic relay 10 includes a base 30, a magnetic yoke 74, a plate 75, an auxiliary yoke 76, an electromagnetic coil 71, a shaft 72, a spring 73, a movable core 77, a housing member 21, a movable contactor 15, fixed contactors 11, 12, an insulating member 85, a first magnet 51, a second magnet 52, a case 20, etc.

[0021] The base 30 is made of an insulating material and includes a back plate 31 and a partition 32. The back plate 31 is formed in a rectangular plate shape. The partition 32 protrudes forward (in a direction perpendicular to the back plate 31) from the middle of the back plate 31 in the up-down direction (longitudinal direction).

[0022] Below the partition portion 32 of the base 30, a magnetic yoke 74, a plate 75, an electromagnetic coil 71, a spring 73, an auxiliary yoke 76, a movable core 77, etc. are arranged.

[0023] The magnetic yoke 74 is formed in a groove shape (U-shaped in side view). A plate 75 is fixed to the open end of the magnetic yoke 74. A cylindrical portion 75a is formed in the center of the plate 75. A cylindrical (columnar) auxiliary yoke 76 is fixed to the center of the bottom of the magnetic yoke 74. A movable core 77 is housed inside the cylindrical portion 75a so as to be capable of reciprocating in the vertical direction (first direction D1). An electromagnetic coil 71 is provided on the outer periphery of the movable core 77 and the auxiliary yoke 76. A magnetic circuit is formed by the magnetic yoke 74, the plate 75, the auxiliary yoke 76, and the movable core 77. A spring 73 biases the movable core 77 in a direction away from the auxiliary yoke 76.

[0024] A cylindrical shaft 72 is connected to the movable core 77. The shaft 72 extends in a first direction D1. The shaft 72 and the movable core 77 penetrate a plate 75. The movable contactor 15 is connected (coupled) to the shaft 72 via an insulating member 85. The movable contactor 15 is formed in a rectangular plate shape from a conductive material. Movable contacts 17 and 18 are attached (provided) to both ends of the movable contactor 15 in the longitudinal direction. The movable contacts 17 and 18 are formed in a cylindrical shape from a conductive material. The movable contacts 17 and 18 protrude from the movable contactor 15 towards the fixed contactor 11. The movable contactor 15 includes the movable contacts 17 and 18.

[0025] Above the partition 32 of the base 30, the storage member 21, the movable contactor 15, the movable contacts 17, 18, the fixed contactors 11, 12, the fixed contacts 13, 14, the first magnet 51, the second magnet 52, etc. are arranged.

[0026] The housing member 21 is made of an insulating and magnetically permeable material (e.g., resin or ceramic) and is formed in a groove shape (U-shaped in side view). A pair of fixed contacts 11, 12 are attached to a partition portion 32 penetrating a back plate portion 31 of the base 30.

[0027] The fixed contacts 11, 12 are made of a conductive material and are arranged at a predetermined interval. The direction in which the fixed contacts 11, 12 are arranged coincides with the longitudinal direction of the movable contact 15 (the direction in which the movable contact 15 extends from one of the fixed contacts 11, 12 to the other). The fixed contacts 11, 12 are formed in an "L" shape (a bent rectangular plate shape) and are aligned along the partition section 32 and the back plate section 31 of the base 30. The fixed contacts 13, 14 are attached (provided) to the front ends of the fixed contacts 11, 12, respectively. The fixed contacts 13, 14 are formed in a cylindrical shape from a conductive material. The fixed contacts 13, 14 protrude toward the movable contact 15 side on the fixed contacts 11, 12. The fixed contacts 13, 14 attached to the fixed contacts 11, 12 face the movable contacts 17, 18 attached to the movable contact 15, respectively. The fixed contacts 11 and 12 include fixed contacts 13 and 14, respectively.

[0028] A first magnet 51 and a second magnet 52 are attached to the outer edge of the housing member 21. The first magnet 51 (magnet) is arranged on the side of the fixed contact 13 and the movable contact 17 in the longitudinal direction of the movable contactor 15. The second magnet 52 (magnet) is arranged on the side of the fixed contact 14 and the movable contact 18 in the longitudinal direction of the movable contactor 15.

[0029] The case 20 is attached to the base 30. The case 20 is formed in a rectangular cylindrical shape with a bottom (see FIGS. 3 and 4). An opening on the rear side of the case 20 is closed (covered) by a back plate portion 31 of the base 30.

[0030] A coil housing is formed by the portion of back plate portion 31 below partition portion 32 of base 30, partition portion 32, and the portion of case 20 below partition portion 32. The coil housing houses electromagnetic coil 71, and the inside of the coil housing serves as a coil chamber.

[0031] A contact housing is formed by the portion of the back plate portion 31 above the partition portion 32 of the base 30, the partition portion 32, the storage member 21, and a front portion of the case 20 above the partition portion 32. The contact housing accommodates the fixed contacts 11, 12, the movable contact 15, as well as the fixed contacts 13, 14 and the movable contacts 17, 18 (contact portions between the pair of fixed contacts 11, 12 and the movable contact 15). The inside of the contact housing forms a contact chamber.

[0032] When no current flows through the electromagnetic coil 71, the fixed contacts 13, 14 and the movable contacts 17, 18 are separated by the biasing force of the spring 73. When a current flows through the electromagnetic coil 71, an electromagnetic force acts on the movable core 77 in a direction that brings it closer to the auxiliary yoke 76. As a result, the movable contactor 15 connected to the movable core 77 via the shaft 72 and the insulating member 85 moves in a direction that brings it closer to the fixed contacts 11, 12 against the biasing force of the spring 73 and comes into contact with the fixed contacts 11, 12. That is, the electromagnetic coil 71 generates an electromagnetic force that brings the movable contacts 17, 18 (the movable contactor 15) closer to the pair of fixed contacts 13, 14 (the pair of fixed contacts 11, 12). As a result, the fixed contactor 11 and the fixed contactor 12 are brought into electrical conduction by the movable contactor 15. That is, the movable contact 15 approaches and moves away from the pair of fixed contacts 11, 12 to establish and break electrical continuity between the pair of fixed contacts 11, 12. More specifically, the movable contacts 17, 18 approach and move away from the pair of fixed contacts 13, 14, respectively.

[0033] When the fixed contacts 13, 14 and the movable contacts 17, 18 move from a contacted state to a separated state, an arc may occur between the fixed contacts 13, 14 and the movable contacts 17, 18. In response to this, an arc extinguishing chamber 22, which is a space for stretching and interrupting the arc, is formed inside the contact housing (see Figs. 3 and 4). The arc extinguishing chamber 22 is formed on the side of the fixed contacts 13, 14 and the movable contacts 17, 18 (in a direction perpendicular to the paper surface in Fig. 1) in the short direction of the movable contact 15 (the long direction of the fixed contacts 11, 12). The first magnet 51 generates a magnetic field that stretches (induces) the arc generated between the fixed contact 13 and the movable contact 17 in the direction of the arc extinguishing chamber 22. The second magnet 52 generates a magnetic field that stretches (induces) the arc generated between the fixed contact 14 and the movable contact 18 in the direction of the arc extinguishing chamber 22.

[0034] Therefore, the arc generated between the fixed contacts 13, 14 and the movable contacts 17, 18 can be extended forward (the opposite direction to the back plate portion 31, the predetermined direction) by the magnetic field of the magnets 51, 52 and guided to the arc-extinguishing chamber 22, where the arc can be cooled and interrupted. However, in a hybrid vehicle or an electric vehicle in which a large current flows through the electromagnetic relay 10, it becomes difficult for the electromagnetic relay 10 to interrupt the arc.

[0035] Therefore, as shown in FIG. 4, a communication hole 40 is formed in the partition portion 32 of the contact housing at a position forward (opposite to the back plate portion 31, in a predetermined direction) of the fixed contact 13 (14) and the movable contact 17 (18), which communicates between the upper side (the side of the fixed contacts 11, 12 and the movable contact 15) and the lower side (the side of the electromagnetic coil 71) of the partition portion 32. The communication hole 40 communicates the arc extinguishing chamber 22 (contact chamber) with the coil chamber (inside the coil housing, outside the arc extinguishing chamber 22). The communication hole 40 is formed at the front end of the partition portion 32 (contact housing). In other words, the communication hole 40 is a gap of a predetermined width formed between the front end of the partition portion 32 and the case 20. 3, in the direction in which the movable contact 15 extends from one of the pair of fixed contacts 11, 12 to the other (the longitudinal direction of the movable contact 15), the width W1 of the communicating hole 40 is wider than the width W2 of the front ends 11a, 12a of the fixed contacts 11, 12. More specifically, in the longitudinal direction of the movable contact 15, the width W1 of the communicating hole 40 is wider than the width W2 of the fixed contacts 11, 12 throughout the entire fixed contacts 11, 12.

[0036] As shown in Figs. 4 and 5, the back plate portion 31 of the base 30 has an air vent 47 formed in the vertical middle portion (coil housing) to communicate the coil chamber (inside the coil housing) with the outside of the coil chamber (outside air). More specifically, a pair of terminal portions 71a of the electromagnetic coil 71 protrude backward through the back plate portion 31. The air vent 47 is formed directly below (below) each terminal portion 71a of the electromagnetic coil 71 in the back plate portion 31. That is, the arc extinguishing chamber 22 communicates with the outside air through the coil chamber. The air vent 47 is formed in the back plate portion 31 near both the left and right ends. The air vent 47 is formed at a position (middle portion of the coil chamber) at a predetermined distance from the partition portion 32 in the vertical direction (axial direction of the electromagnetic coil 71 and the shaft 72). In the coil housing, the front end (in the predetermined direction) communicates with the arc extinguishing chamber 22 through a communication hole 40, and the rear end (opposite the predetermined direction) communicates with the outside air through an air vent 47. The through holes 46, 48 are holes into which an adhesive is poured to fix the components when assembling the electromagnetic relay 10.

[0037] In the electromagnetic relay 10 having the above configuration, for example, it is assumed that an arc occurs between the fixed contact 13 and the movable contact 17. As shown in Fig. 6, the arc Ac is stretched forward of the case 20 (to the right in Fig. 6) by the magnetic field generated by the first magnet 51 and is guided to the arc-extinguishing chamber 22. The arc Ac is further stretched forward in the arc-extinguishing chamber 22 and reaches the case 20. At this time, the front end of the arc Ac is located above the communication hole 40. That is, the arc Ac is stretched from between the fixed contact 13 and the movable contact 17 in a direction approaching the communication hole 40.

[0038] Here, the arc Ac generates a large amount of heat, causing an increase in the temperature of the air in the arc-extinguishing chamber 22 and the pressure in the arc-extinguishing chamber 22. The heat generated by the arc Ac and the pressure increased by the arc Ac are exhausted (released) to the coil chamber (inside the coil housing) through the communication hole 40. This allows the arc Ac in the arc-extinguishing chamber 22 to be efficiently cooled.

[0039] Furthermore, in the longitudinal direction of the movable contact 15, the starting point of the arc Ac may move within a range of a width W2 of the front (predetermined direction) end 11a of the fixed contact 11. In this regard, as shown in Fig. 3, in the longitudinal direction of the movable contact 15, the width W1 of the communicating hole 40 is wider than the width W2 of the front end 11a of the fixed contact 11. Therefore, even if the starting point of the arc Ac moves in the longitudinal direction of the movable contact 15 between the generation of the arc Ac and its interruption, it is possible to prevent the arc Ac stretched forward from going out of the range of the width W1 of the communicating hole 40.

[0040] When the heat and pressure due to the arc Ac are released from the arc extinguishing chamber 22 to the coil chamber, the temperature and pressure in the coil chamber rise. The heat and pressure in the coil chamber are then released to the outside air (outside the coil chamber) through the ventilation hole 47 formed in the back plate portion 31 of the base 30. At this time, in the coil housing, the communication hole 40 is disposed at the front end, and the ventilation hole 47 is disposed at the rear end. Therefore, the heat and pressure discharged from the communication hole 40 to the coil chamber pass through the coil chamber from the front to the rear, and then are discharged to the atmosphere from the ventilation hole 47.

[0041] The present embodiment described above in detail has the following advantages.

[0042] In the contact housing (the upper part of the back plate portion 31, the partition portion 32, the storage member 21, and the upper part of the front portion of the case 20), a communication hole 40 that communicates the arc-extinguishing chamber 22 with the outside of the arc-extinguishing chamber 22 is formed at a position forward (in a predetermined direction) of the fixed contacts 13, 14 and the movable contacts 17, 18 (contact portions). Therefore, the arc Ac can be extended in a direction approaching the communication hole 40. Then, the heat generated by the arc Ac and the pressure increased by the arc Ac can be released from the communication hole 40 to the outside of the arc-extinguishing chamber 22. Therefore, the arc Ac can be efficiently cooled, and the performance of interrupting the arc Ac can be improved.

[0043] The communication hole 40 is formed at the front end of the partition portion 32 in the contact housing. With this configuration, when the arc Ac is extended forward to the end of the contact housing, it is possible to bring the arc Ac closest to the communication hole 40. Therefore, when the arc Ac is extended to the front end of the contact housing without being interrupted, it becomes easier to interrupt the arc Ac.

[0044] In the longitudinal direction (left-right direction) of the movable contact 15, the width W1 of the communicating hole 40 is wider than the width W2 of the front end portions 11a, 12a of the fixed contacts 11, 12. With this configuration, even if the starting point of the arc Ac moves within the range of the width W2 of the front end portions 11a, 12a of the fixed contacts 11, 12, it is possible to prevent the starting point of the arc Ac from moving out of the range of the width W1 of the communicating hole 40. Therefore, it is possible to prevent the arc Ac extended forward from moving out of the range of the width W1 of the communicating hole 40, and the arc Ac can be efficiently cooled.

[0045] The communication holes 40 communicate the arc extinguishing chamber 22 with the inside of the coil housing (the lower part of the back plate portion 31, the partition portion 32, and the lower part of the case 20). Therefore, the heat and pressure due to the arc Ac can be released from the arc extinguishing chamber 22 to the inside of the coil housing through the communication holes 40. Therefore, the inside of the coil housing can be used as a space for releasing the heat and pressure in the arc extinguishing chamber 22.

[0046] The coil housing is formed with ventilation holes 47 that connect the inside of the coil housing to the outside air. With this configuration, the heat and pressure released into the inside of the coil housing can be released to the outside air through the ventilation holes 47. Therefore, the inside of the coil housing, and in turn the inside of the arc-extinguishing chamber 22, can be efficiently cooled, and the performance of interrupting the arc Ac can be improved. Furthermore, since the arc-extinguishing chamber 22 is connected to the outside air via the inside of the coil housing, the heat and pressure in the arc-extinguishing chamber 22 can be prevented from being forcefully discharged to the outside air.

[0047] The front end of the coil housing communicates with the arc extinguishing chamber 22 through the communication hole 40, and the rear end (opposite the predetermined direction) communicates with the outside air through the ventilation hole 47. With this configuration, since the communication hole 40 and the ventilation hole 47 are respectively disposed at both ends of the coil housing in the front-to-rear direction, it is possible to prevent the heat and pressure released into the coil housing from being immediately discharged from the communication hole 40 to the ventilation hole 47. Therefore, it is possible to effectively prevent the heat and pressure in the arc extinguishing chamber 22 from being forcefully discharged to the outside air.

[0048] The above embodiment can be modified as follows: The same parts as those in the above embodiment are denoted by the same reference numerals and the description thereof will be omitted.

[0049] As shown in FIG. 7 with the movable contactor 15 and the movable contacts 17, 18 omitted, the width W2A of the front end portions 11a, 12a of the fixed contactors 11, 12 may be narrower than the width W2 of the other portions of the fixed contactors 11, 12. As a result, the width W1A of the communication hole 40 may be wider than the width W2A of the front end portions 11a, 12a of the fixed contactors 11, 12 in the longitudinal direction (left-right direction) of the movable contactor 15. Even with this configuration, even if the starting point of the arc moves within the range of the width W2A of the front end portions 11a, 12a of the fixed contactors 11, 12, it is possible to prevent the starting point of the arc from moving out of the range of the width W1A of the communication hole 40. Therefore, it is possible to prevent the arc stretched forward from moving out of the range of the width W1A of the communication hole 40, and the arc can be cooled efficiently.

[0050] In the longitudinal direction (left-right direction) of the movable contact 15, the width W1 of the communicating hole 40 can be made equal to the width W2 of the front ends 11a, 12a of the fixed contacts 11, 12. Also, as shown in Fig. 8, in the longitudinal direction (left-right direction) of the movable contact 15, the width W1B of the communicating hole 40 can be made narrower than the width W2 of the front ends 11a, 12a of the fixed contacts 11, 12.

[0051] 9, a plurality of communication holes 140 may be formed within a range of a width W2 of the front end 11a (12a) of the fixed contact 11 (12). In this case, a width W1C of the communication hole 140 is narrower than a width W2 of the front end 11a (12a) of the fixed contact 11 (12) in the longitudinal direction (left-right direction) of the movable contact 15. With this configuration, the arc is easily interrupted by applying the arc to a partition portion 140a that partitions the plurality of communication holes 140.

[0052] 10 and 11, a plurality of communication holes 240 may be formed in the partition portion 32 of the base 30 in the front-rear direction (the longitudinal direction of the fixed contacts 11 and 12). With this configuration, the heat generated by the arc and the pressure increased by the arc can be efficiently released to the outside of the arc-extinguishing chamber 22 through the plurality of communication holes 240. Therefore, the arc can be efficiently cooled, and the performance of interrupting the arc can be improved. Furthermore, the arc can be easily interrupted by applying the arc to the partition portion 240a that separates the plurality of communication holes 240.

[0053] As shown in FIG. 12, the opening 40a on the arc extinguishing chamber 22 side of the communication hole 40 may be larger than the opening 40b on the coil chamber side (opposite the arc extinguishing chamber 22) of the communication hole 40. In detail, in the front-rear direction of the electromagnetic relay 10 (the longitudinal direction of the fixed contacts 11, 12), the width W3 of the opening 40a on the arc extinguishing chamber 22 side is wider than the width W4 of the opening 40b on the coil chamber side. The width is reduced from the opening 40a to the opening 40b by the inclination of the inner surface of the communication hole 40. In this case, the openings 40a, 40b are also formed at the front end of the partition portion 32. According to this configuration, the arc, heat generated by the arc, and pressure increased by the arc are easily guided from the arc extinguishing chamber 22 to the inside of the communication hole 40 through the opening 40a. Therefore, the arc can be efficiently cooled, and the performance of interrupting the arc can be improved.

[0054] 13, the width of the communicating hole 40 may be reduced from opening 40a to opening 40b by forming the inner surface of the communicating hole 40 in a stepped shape. In this case, the openings 40a and 40b are also formed at the front end of the partition portion 32. This configuration also makes it easier to guide the arc, heat generated by the arc, and pressure increased by the arc from the arc-extinguishing chamber 22 to the inside of the communicating hole 40 via opening 40a.

[0055] The openings 40a, 40b may be formed closer to the fixed contact 13 and the movable contact 17 (contact portion) than the front end of the partition portion 32. The opening 40a on the arc extinguishing chamber 22 side of the communication hole 40 may be equal in size to the opening 40b on the coil chamber side of the communication hole 40 or smaller than the opening 40b.

[0056] The ventilation holes 47 may be formed in the back plate portion 31 at the middle portions in the left and right directions, one for each side.

[0057] The front end of the coil housing may communicate with the arc-extinguishing chamber 22 through the communication holes 40, 140, 240, and the middle part in the front-rear direction may communicate with the outside air (outside the coil chamber) through an air hole.

[0058] One of the two ventilation holes 47 may be omitted. Also, both of the two ventilation holes 47 may be omitted. Even in this case, the heat and pressure due to the arc can be released from the communication holes 40, 140, 240 to the coil chamber (outside the arc-extinguishing chamber 22), so that the arc can be cooled efficiently. Therefore, the arc interruption performance can be improved compared to a case where the communication holes 40, 140, 240 are not formed in the contact housing.

[0059] A vent hole (communication hole) that connects the arc-extinguishing chamber 22 (contact chamber) to the outside air (outside of the arc-extinguishing chamber 22) can be formed in the contact housing that accommodates the fixed contacts 11, 12 and the movable contact 15. For example, the vent hole can be formed in the front part (position forward of the fixed contacts 13, 14 and the movable contacts 17, 18) of the case 20 (contact housing). With this configuration, the heat and pressure due to the arc can be released from the vent hole to the outside of the arc-extinguishing chamber 22, so that the arc can be cooled efficiently.

[0060] The fixed contactor 11 and the fixed contacts 13 may be formed as one member (integrally). The fixed contactor 12 and the fixed contacts 14 may be formed as one member (integrally). The movable contactor 15 and the movable contacts 17, 18 may be formed as one member (integrally).

[0061] It is also possible to arrange magnets in the longitudinal direction (front-rear direction) of the fixed contacts 11, 12, and form arc-extinguishing chambers on the left and right sides of the longitudinal direction (left-right direction) of the movable contact 15. In this case, communication holes that communicate the arc-extinguishing chamber with the outside of the arc-extinguishing chamber may be formed in the contact housing at positions to the left (predetermined direction) and to the right (predetermined direction) of the contact portion between the pair of fixed contacts and the movable contact.

[0062] The above-described embodiments and their modifications can be combined to the extent possible. [Explanation of symbols]

[0063] 10...electromagnetic relay, 11...fixed contactor, 12...fixed contactor, 13...fixed contact, 14...fixed contact, 15...movable contactor, 17...movable contact, 18...movable contact, 20...case, 21...storage member, 22...arc-extinguishing chamber, 30...base, 31...back plate portion, 32...partition portion, 40...communication hole, 51...first magnet, 52...second magnet, 71...electromagnetic coil, 140...communication hole, 240...communication hole.

Claims

1. an electromagnetic relay (10) comprising: a pair of fixed contacts (11, 12, 13, 14) arranged at a predetermined interval; a movable contact (15, 17, 18) that moves toward and away from the pair of fixed contacts to establish and break electrical continuity between the pair of fixed contacts; a contact housing (20, 21, 31, 32) that houses contact portions (13, 14, 17, 18) between the pair of fixed contacts and the movable contact and in which an arc-extinguishing chamber (22) that is a space for stretching an arc generated between the fixed contact and the movable contact is formed; and a magnet (51, 52) that is arranged on the side of the contact portion in a direction in which the movable contact extends from one of the pair of fixed contacts to the other, and that generates a magnetic field that stretches the arc in a predetermined direction and guides it to the arc-extinguishing chamber, An electromagnetic relay, wherein a communication hole (40, 140, 240) for communicating the arc-extinguishing chamber with the outside of the arc-extinguishing chamber is formed in the contactor housing at a position further in the predetermined direction than the contact portion.

2. 2. The electromagnetic relay according to claim 1, wherein the communication hole is formed at an end of the contact housing in the predetermined direction.

3. An electromagnetic relay as described in claim 1 or 2, wherein in the direction in which the movable contact extends from one of the pair of fixed contacts to the other, the width (W1, W1A) of the communicating hole is wider than the width (W2, W2A) of the end (11a, 12a) of the fixed contact in the specified direction.

4. 3. The electromagnetic relay according to claim 1, wherein an opening (40a) of the communication hole on the side of the arc-extinguishing chamber is larger than an opening (40b) of the communication hole on the side opposite to the arc-extinguishing chamber.

5. an electromagnetic coil (71) that generates an electromagnetic force that moves the movable contact toward the pair of fixed contacts; and a coil housing (20, 31, 32) that houses the electromagnetic coil; 3. The electromagnetic relay according to claim 1, wherein the communication hole connects the arc extinguishing chamber with the inside of the coil housing.

6. 6. The electromagnetic relay according to claim 5, wherein the coil housing is formed with a vent hole (47) for communicating the inside of the coil housing with the outside air.

7. 7. The electromagnetic relay according to claim 6, wherein the end of the coil housing facing the predetermined direction is connected to the arc extinguishing chamber through the communication hole, and the end opposite the predetermined direction is connected to the outside air through the air hole.

Images