Electromagnetic relay

Abstract

In this electromagnetic relay, a movable member (16) is reciprocated along one direction (Da) in association with switching between energization and non-energization of an electromagnetic coil (21), and has a contact surface (161a) facing one side in the one direction. A stopper part (242) has an air hole (244) and a stopper surface (243) contacted by the contact surface when the movable member is moved to one side in the one direction. A movable contact (121) comes into contact with and separates from a fixed contact (14) as the movable member reciprocates. The air hole has an open end (244b) which is formed in the stopper surface and opened so as to face the contact surface in the one direction, and a hole opposite end (244a) which is a hole end on the opposite side to the open end and is open. In a state in which the contact surface is separated from the stopper surface, the air passing through the air hole is less likely to flow when flowing from the open end to the hole opposite end than when flowing from the hole opposite end to the open end.

Description

electromagnetic relay CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Patent Application No. 2024-4654, filed on January 16, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to electromagnetic relays.

[0003] Patent Document 1 describes an electromagnetic relay. The electromagnetic relay of Patent Document 1 includes a movable element having a movable contact that moves in contact with and away from a fixed contact, a plunger that moves the movable element back and forth so that the fixed contact and the movable contact move in contact with and away from each other, and a solenoid unit that moves the plunger back and forth in a predetermined direction. The solenoid unit includes an electromagnetic coil, a fixed core, and a movable core. When the electromagnetic coil of the solenoid unit of Patent Document 1 is energized, the magnetic force generated by the electromagnetic coil moves the movable core and plunger in one direction. As a result, the movable contact comes into contact with the fixed contact, and at the same time, the tip surface of the plunger hits a stopper surface formed on the fixed core. This hitting of the tip surface of the plunger against the stopper surface generates operating noise.

[0004] Japanese Patent Application Laid-Open No. 2021-144841

[0005] In the electromagnetic relay of Patent Document 1, for example, when the distance between the tip end face of the plunger and the stopper face of the fixed core changes as the plunger reciprocates, air flows in and out of the space between the tip end face and the stopper face. This air flow acts as resistance that impedes the reciprocating movement of the plunger.

[0006] Therefore, in the electromagnetic relay of Patent Document 1, the resistance caused by the air flow around the plunger reduces the impact speed when the tip surface of the plunger hits the stopper surface of the fixed core as current flows through the electromagnetic coil, thereby reducing operating noise. However, the tradeoff is that the contact opening speed at which the movable contact separates from the fixed contact when current flows through the electromagnetic coil is reduced, resulting in a decrease in the interrupting performance of the electromagnetic relay.

[0007] Therefore, the inventors conceived the idea of ​​providing a through-hole that penetrates the fixed core on the stopper surface, thereby reducing resistance caused by air flow around the plunger. It was anticipated that the interrupting performance would be improved if the through-hole in the fixed core were to promote air flow around the plunger and if the through-hole in the fixed core were to be large enough to obtain a sufficiently high contact opening speed. However, simply increasing the through-hole in the fixed core would increase the impact speed of the plunger against the stopper surface when current is applied to the electromagnetic coil, which would likely increase operating noise. For these reasons, further improvements were needed to simultaneously improve the interrupting performance of the electromagnetic relay and reduce operating noise. The inventors' detailed investigation led to the above findings.

[0008] In view of the above, an object of the present disclosure is to provide an electromagnetic relay that can achieve both improved interruption performance and reduced operating noise.

[0009] In order to achieve the above object, an electromagnetic relay according to one aspect of the present disclosure includes: an electromagnetic coil that generates a magnetic force when energized; a movable member that is moved in one direction by the magnetic force and that moves back and forth along the one direction as the electromagnetic coil is switched between energized and de-energized, and that has an abutment surface facing one side of the one direction; a stopper portion that is formed with a stopper surface that the abutment surface abuts against and stops the movement of the movable member when the movable member is moved to one side of the one direction; a fixed contact; and a movable contact that comes into contact with the fixed contact as the movable member moves to one side in the one direction and moves away from the fixed contact as the movable member moves to the other side in the one direction, wherein an air hole is formed in the stopper portion, and the air hole has an opening end that is formed on the stopper surface and opens so as to face the abutment surface in the one direction, and an opposite hole end that is an open hole end on the opposite side of the opening end, When the contact surface is separated from the stopper surface, air passing through the air hole flows less easily from the open end to the opposite end of the hole than from the opposite end of the hole to the open end.

[0010] In this way, when the movable member is moved to one side in the one direction, air flows from the open end to the opposite end of the air hole, and when the movable member is moved to the other side in the one direction, air flows from the opposite end of the air hole to the open end. As described above, air passing through the air hole is less likely to flow from the open end to the opposite end of the air hole than from the opposite end of the air hole to the open end.

[0011] Therefore, the air flow through the air hole acts as a resistance that suppresses movement of the movable member more strongly when the movable member is moved to one side in the one direction than when the movable member is moved to the other side in the one direction. In other words, the air flow through the air hole acts to strongly suppress the movement speed of the movable member moving to one side in the one direction, without significantly suppressing the movement speed of the movable member moving to the other side in the one direction.

[0012] Therefore, it is possible to improve the interrupting performance when the movable contact separates from the fixed contact, and at the same time, it is possible to reduce the operating noise caused by the contact surface of the movable member hitting the stopper surface. In short, it is possible to achieve both an improvement in the interrupting performance and a reduction in the operating noise of the electromagnetic relay.

[0013] In addition, in each section of the application documents, each element may be assigned a reference number in parentheses. In this case, the reference number merely indicates an example of the correspondence between the element and the specific configuration described in the embodiment described below. Therefore, the present disclosure is not limited in any way by the description of the reference number.

[0014] 1 is a longitudinal cross-sectional view showing a schematic configuration of an electromagnetic relay according to a first embodiment, illustrating the electromagnetic relay in a non-energized state where the electromagnetic coil is not energized; FIG. 2 is a longitudinal cross-sectional view showing the electromagnetic relay at the same cross section as FIG. 1, illustrating the electromagnetic relay in a energized state where the electromagnetic coil is energized; FIG. 3 is a partial enlarged view of a portion III in FIG. 1 according to a first embodiment; FIG. 4 is a partial enlarged view of a portion corresponding to the portion III in FIG. 1 according to a second embodiment, corresponding to FIG. 3; FIG. 5 is a partial enlarged view of a portion corresponding to the portion III in FIG. 1 according to a third embodiment, corresponding to FIG. 3;

[0015] Hereinafter, each embodiment will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

[0016] (First embodiment) An electromagnetic relay 10 of this embodiment is mounted on, for example, a vehicle, and opens and closes a current path to an on-vehicle component in response to switching between a current-carrying state and a current-de-carrying state of an electromagnetic coil 21. The current-carrying state of the electromagnetic coil 21 refers to a state in which the electromagnetic coil 21 is energized, and the current-de-carrying state of the electromagnetic coil 21 refers to a state in which the electromagnetic coil 21 is not energized. The electromagnetic relay 10 is also referred to as a relay device.

[0017] In the description of this embodiment, the device axis center CL shown in Fig. 1 may be used to represent the structure of the electromagnetic relay 10. The axial direction of the device axis center CL may be referred to as the device axis direction Da, which corresponds to one direction in the present disclosure. In Fig. 1, the lower side of the paper surface is one side of the device axis direction Da, and the upper side of the paper surface is the other side of the device axis direction Da.

[0018] The radial direction of the equipment axis center CL may also be referred to as the equipment radial direction Dr. This equipment radial direction Dr is a direction perpendicular to the equipment axis center CL and moving away from the equipment axis center CL. In other words, the equipment radial direction Dr is the radial direction of a circle drawn on an imaginary plane perpendicular to the equipment axis center CL, with the intersection of the imaginary plane and the equipment axis center CL as its center.

[0019] As shown in Figures 1 and 2, the electromagnetic relay 10 of this embodiment includes a mover 12, a plurality of fixed contacts 14, a plurality of fixed bus bars 141, a plunger 16, a solenoid portion 20, a movable wall portion 28, a housing 30, a mover biasing member 32, and a core biasing member 34.

[0020] The solenoid unit 20 reciprocates the plunger 16 in the equipment axial direction Da by a magnetic force generated by an electromagnetic coil 21 included in the solenoid unit 20. The mover 12 has a movable contact 121 that moves in and out of contact with the fixed contact 14. The plunger 16 reciprocates the mover 12 in the equipment axial direction Da so that the fixed contact 14 and the movable contact 121 move in and out of contact with each other. The number of movable contacts 121 provided is the same as the number of fixed contacts 14.

[0021] The solenoid unit 20 has an electromagnetic coil 21, a movable core 22, a support member 23, a fixed core 24, a first yoke 25, and a bobbin 26. The electromagnetic coil 21, the support member 23, the fixed core 24, the first yoke 25, and the bobbin 26 are fixed to a housing 30. The electromagnetic coil 21 generates a magnetic flux when energized. The movable core 22 is moved back and forth in the device axial direction Da as the electromagnetic coil 21 is switched between energized and de-energized.

[0022] The housing 30 forms the outer shell of the electromagnetic relay 10 and is made of an insulating material such as resin. The housing interior space 30a, which is the internal space of the housing 30, houses the mover 12, the fixed contact 14, the plunger 16, the solenoid unit 20, and the movable wall unit 28. For example, the housing 30 includes multiple resin parts that are connected to each other. The housing 30 is formed with a ventilation hole 30c that connects the housing interior space 30a with the outside of the housing 30, allowing air to pass between the housing interior space 30a and the outside of the housing 30 via the ventilation hole 30c.

[0023] The mover 12 has a plurality of movable contacts 121 as well as a movable conductor 122. The movable conductor 122 is made of a conductive metal plate-like member with its thickness direction aligned with the device axis direction Da. The movable conductor 122 extends in a direction perpendicular to the device axis direction Da, and a movable contact 121 is fixed to each of the movable conductor 122 near both ends in the longitudinal direction. For example, the movable contact 121 is fixed to the movable conductor 122 by crimping.

[0024] Furthermore, a movable element biasing member 32 is disposed between the movable element 122 and a wall portion of the housing 30 that is located on the other side of the movable element 122 in the equipment axis direction Da. The movable element biasing member 32 is a compression coil spring that is wound around the equipment axis center CL and expands and contracts in the equipment axis direction Da, and abuts against the movable element 122 to bias the movable element 12 to one side in the equipment axis direction Da. Because the movable element 122 is a metallic member that has conductivity, the multiple movable contacts 121 of the movable element 12 are electrically connected to one another via the movable conductor 122.

[0025] The fixed contacts 14 are arranged on one side of the movable contacts 121 in the device axis direction Da, and face each of the movable contacts 121. Two fixed bus bars 141 are provided, and each fixed bus bar is made of a conductive metal plate-like member. The fixed contacts 14 are fixed to the fixed bus bars 141 by, for example, crimping.

[0026] The housing 30 also has fixed contact support portions 301 that protrude from the inner wall surface of the housing 30 into the housing interior space 30a. Each of the multiple fixed bus bars 141 is fixed to the fixed contact support portions 301. That is, each of the multiple fixed contacts 14 is fixed to a part of the housing 30 via the fixed bus bar 141. A part of each fixed bus bar 141 protrudes outside the housing 30, and this protruding portion is connected to external wiring or the like.

[0027] Furthermore, the fixed contact support part 301 is formed with an insertion hole 301a that penetrates the fixed contact support part 301 in the device axial direction Da, and a part of the plunger 16 is inserted into this insertion hole 301a. A slight radial gap is formed between the inner wall surface of the insertion hole 301a of the fixed contact support part 301 and the plunger 16, and this radial gap allows the plunger 16 to move in the device axial direction Da without coming into contact with the fixed contact support part 301. The above-mentioned radial gap is a gap that opens in the device radial direction Dr.

[0028] When the plunger 16 moves to the other side in the equipment axis direction Da and pushes the movable element 12, the movable element 12 moves to the other side in the equipment axis direction Da together with the plunger 16 against the biasing force of the movable element biasing member 32. As a result, the movable contact 121 moves away from the fixed contact 14. Furthermore, when the plunger 16 moves to one side in the equipment axis direction Da, the biasing force of the movable element biasing member 32 moves the movable contact 121 to one side in the equipment axis direction Da until it abuts against the fixed contact 14. The plunger 16 is configured to move back and forth in the equipment axis direction Da in response to the operation of the solenoid unit 20.

[0029] When current is applied to the electromagnetic coil 21, the electromagnetic coil 21 generates a magnetic flux in a magnetic path formed by the fixed core 24, the movable core 22, the support member 23, and the one-side yoke 25, thereby generating a magnetic force. In this embodiment, the shaft 161 of the plunger 16 is made of a magnetic metal, as will be described later, and therefore the shaft 161 of the plunger 16 also becomes part of the magnetic path.

[0030] The electromagnetic coil 21 is made up of a conducting wire, i.e., a winding, wound around the outer periphery of a cylindrical portion 261 of the bobbin 26. The bobbin 26 is made up of an insulating material such as resin. The cylindrical portion 261 of the bobbin 26 is formed in a cylindrical shape centered on the device axis CL, and therefore the electromagnetic coil 21 is also formed in a cylindrical shape centered on the device axis CL.

[0031] A through-hole penetrating in the device axial direction Da is formed inside the cylindrical portion 261 of the bobbin 26, so that the cylindrical portion 261 is open to both sides in the device axial direction Da. A part of the plunger 16 is disposed inside the cylindrical portion 261.

[0032] The movable core 22 and the fixed core 24 are made of, for example, a soft magnetic metal. The movable core 22 and the fixed core 24 are disposed inside the cylindrical portion 261 of the bobbin 26. In other words, the movable core 22 and the fixed core 24 are disposed inside the electromagnetic coil 21 with the cylindrical portion 261 of the bobbin 26 interposed therebetween.

[0033] The movable core 22 and the fixed core 24 are each formed around the equipment axis center CL. The fixed core 24 is provided on one side of the movable core 22 in the equipment axis direction Da and is arranged to face the equipment axis direction Da.

[0034] 1 to 3, the fixed core 24 has a recess 241 and a stopper portion 242. The recess 241 is recessed from the other side to one side in the equipment axial direction Da in the fixed core 24, and is therefore open facing the other side in the equipment axial direction Da. In other words, the recess 241 is open facing the movable core 22. The recess 241 of the fixed core 24 forms an internal space 241a therein. The internal space 241a of the recess 241 forms the shape of a body of revolution, for example, with the equipment axial center CL as its center.

[0035] Furthermore, the portion of the recess 241 on the other side in the equipment axial direction Da is formed in a tapered shape that increases in diameter toward the other side in the equipment axial direction Da. Corresponding to the tapered shape of the recess 241, the portion of the movable core 22 on one side in the equipment axial direction Da is formed in a tapered shape that decreases in diameter toward the one side in the equipment axial direction Da.

[0036] The stopper portion 242 of the fixed core 24 has a stopper surface 243 that faces the other side in the equipment axis direction Da and faces the abutment surface 161a of the shaft portion 161. This stopper surface 243 is the bottom surface of the recess 241 of the fixed core 24 on one side in the equipment axis direction Da. Therefore, the stopper surface 243 faces the inner space 241a of the recess 241 and is in contact with the inner space 241a from one side in the equipment axis direction Da. The shaft portion 161 and the abutment surface 161a of the plunger 16 will be described later.

[0037] Furthermore, since the stopper surface 243 faces the abutment surface 161a of the shaft portion 161 as described above, when the plunger 16 is moved to one side in the device axis direction Da by energizing the electromagnetic coil 21, the abutment surface 161a abuts against the stopper surface 243. The stopper surface 243 stops the movement of the plunger 16 at the position where the abutment surface 161a abuts against the stopper surface 243. The position of the plunger 16 and the movable core 22 in this state where the abutment surface 161a abuts against the stopper surface 243 becomes the one-side stroke end position described below.

[0038] An air hole 244, which is a through-hole that penetrates the stopper portion 242, is formed in the stopper portion 242 of the fixed core 24. The air hole 244 has an opposite end 244a, which is one end provided on one side in the equipment axis direction Da, and an open end 244b, which is the other end provided on the other side in the equipment axis direction Da.

[0039] An opening end 244b of the air hole 244 is formed in the stopper surface 243 and opens to face the abutment surface 161a of the plunger 16 in the equipment axial direction Da. The opening end 244b is smaller than the abutment surface 161a, and is disposed so that the entire opening end 244b overlaps with one side of the abutment surface 161a in the equipment axial direction Da. In contrast, the opposite-hole end 244a of the air hole 244 is the hole end opposite the opening end 244b and is open to one side in the equipment axial direction Da. This opposite-hole end 244a remains open regardless of the position to which the plunger 16 is moved.

[0040] Specifically, the air hole 244 in this embodiment has a shape of a solid of revolution centered on the device axis CL, and the cross-sectional shape of the air hole 244 as seen in a cross section including the device axis CL (for example, the cross section shown in FIG. 3 ) is an isosceles trapezoid. The air hole 244 is formed so that it gradually expands from the opening end 244b to the opposite-hole end 244a. In other words, the air hole 244 is formed so that the cross-sectional area Ah of the air hole 244 gradually expands from the opening end 244b to the opposite-hole end 244a. In yet another way, the air hole 244 is formed so that the cross-sectional area Ah of the air hole 244 continuously expands from the opening end 244b to the opposite-hole end 244a.

[0041] Therefore, the cross-sectional area Ah of the air hole 244 at the opposite end 244a, that is, the opposite-hole-end cross-sectional area Aha, is the maximum cross-sectional area Ah of the air hole 244. On the other hand, the open-end cross-sectional area Ahb, ​​that is, the cross-sectional area Ah of the air hole 244 at the open end 244b, is the minimum cross-sectional area Ah of the air hole 244. Note that the cross-sectional area Ah of the air hole 244 is the area of ​​the cross section of the air hole 244 that appears in a cross section perpendicular to the device axis CL.

[0042] Due to the shape of the air hole 244, the first air flow Bd, which is the air flow Bd from the opening end 244b to the opposite end 244a of the hole, has a large air flow resistance because the cross-sectional area Ah of the air hole 244 suddenly decreases at the opening end 244b. In contrast, the second air flow Bu, which is the air flow Bu from the opposite end 244a of the hole to the opening end 244b, has a smaller air flow resistance than the first air flow Bd because the cross-sectional area Ah of the air hole 244 gradually decreases toward the opening end 244b.

[0043] In other words, when the abutment surface 161a is spaced apart from the stopper surface 243, the air passing through the air hole 244 is less likely to flow from the opening end 244b to the opposite end 244a than from the opposite end 244a to the opening end 244b. Note that, for example, when the electromagnetic coil 21 shown in FIG. 1 is in a non-energized state, the abutment surface 161a is spaced apart from the stopper surface 243.

[0044] The core biasing member 34 is, for example, a compression coil spring wound around the equipment axis CL, and expands and contracts in the equipment axis direction Da. The shaft portion 161 of the plunger 16 is inserted inside the core biasing member 34, and the core biasing member 34 is disposed between the movable core 22 and the fixed core 24 in the equipment axis direction Da.

[0045] With this arrangement, the core biasing member 34 biases the movable core 22 toward the other side in the equipment axis direction Da relative to the fixed core 24. In other words, by biasing the movable core 22, the core biasing member 34 biases the plunger 16 fixed to the movable core 22 toward the other side in the equipment axis direction Da. Note that the core biasing member 34 abuts against the stopper surface 243 of the fixed core 24, for example, on one side in the equipment axis direction Da.

[0046] 1 and 2, the support member 23 and the one-side yoke 25 are each made of a magnetic metal suitable for forming a magnetic path. The support member 23 and the one-side yoke 25 collectively function as a yoke formed around the electromagnetic coil 21. The support member 23 is disposed on the other side of the one-side yoke 25 in the device axis direction Da, and may therefore also be referred to as the other-side yoke.

[0047] The one-side yoke 25 has a cylindrical shape with a bottom centered on the equipment axis center CL and a bottom on one side in the equipment axial direction Da, and is provided from the radially outer side of the electromagnetic coil 21 to one side in the equipment axial direction Da. A through hole is formed in the bottom portion of the cylindrical shape of the one-side yoke 25, and the fixed core 24 is fixed to the one-side yoke 25 by being fitted into the through hole of the one-side yoke 25.

[0048] The support member 23 has an inner circumferential wall portion 231, an annular wall portion 232, and a corner portion 233. The inner circumferential wall portion 231 is formed in a cylindrical shape centered on the equipment axis center CL. The annular wall portion 232 is formed in a flat plate shape that extends outward in the equipment radial direction Dr from the other end of the inner circumferential wall portion 231 in the equipment axis direction Da. The annular wall portion 232 is provided on the other side of the electromagnetic coil 21 in the equipment axis direction Da and is arranged to cover the electromagnetic coil 21 from the other side in the equipment axis direction Da. The corner portion 233 is a portion that connects the other end of the inner circumferential wall portion 231 in the equipment axis direction Da and the inner circumferential end of the annular wall portion 232 in a curved shape. For example, when viewed in the equipment axis direction Da, the support member 23 forms an annular shape centered on the equipment axis center CL.

[0049] As described above, the inner circumferential wall portion 231 has a cylindrical shape, and therefore a sliding hole 231a, which is a through hole that penetrates the support member 23, is formed inside the inner circumferential wall portion 231. Therefore, the inner circumferential wall portion 231 has an inner circumferential surface 231b, which is a wall surface that faces the sliding hole 231a and faces inward in the device radial direction Dr.

[0050] The movable core 22 is inserted into a sliding contact hole 231a of the support member 23 and is movable in the equipment axial direction Da relative to the support member 23. Therefore, an outer peripheral surface 221 that the movable core 22 has on the outside of the equipment radial direction Dr slides in the equipment axial direction Da against an inner peripheral surface 231b of the support member 23. In other words, the support member 23 supports the movable core 22 while allowing it to slide in the equipment axial direction Da relative to the support member 23.

[0051] Since the outer peripheral surface 221 of the movable core 22 and the inner peripheral surface 231b of the support member 23 slide against each other in this manner, for example, an insulating coating layer made of fluororesin or the like and having a low coefficient of friction is formed on each of the outer peripheral surface 221 and the inner peripheral surface 231b.

[0052] 1 and 2, the movable core 22 is disposed inside the sliding contact hole 231a so as to be slidable relative to the support member 23. An inner peripheral surface 231b of the support member 23, which forms the sliding contact hole 231a, and an outer peripheral surface 221 of the movable core 22 are in sliding contact with each other.

[0053] As shown in Figures 1 to 3, when the plunger 16 is moved to one side in the equipment axis direction Da and the abutment surface 161a of the plunger 16 abuts against the stopper surface 243, the movable core 22 is moved to one side in the equipment axis direction Da so as to enter the recess 241 of the fixed core 24.

[0054] 1 and 2, the plunger 16 has a shaft portion 161 and an insulator portion 162. The shaft portion 161 and the insulator portion 162 are fixed to each other. The shaft portion 161 of the plunger 16 may be made of resin or a non-magnetic metal, but in this embodiment, it is made of a magnetic metal such as magnetic SUS. The plunger 16 corresponds to the movable member of the present disclosure.

[0055] The shaft portion 161 of the plunger 16 is formed in a cylindrical shape centered on the equipment axis center CL. Therefore, the shaft portion 161 is arranged coaxially with the movable core 22. As shown in FIGS. 1 to 3 , the shaft portion 161 has an abutment surface 161a, which is an end face of the shaft portion 161 provided on one side in the equipment axis direction Da, and the abutment surface 161a faces toward one side in the equipment axis direction Da. In detail, the abutment surface 161a is formed in a circular shape centered on the equipment axis center CL and in a planar shape perpendicular to the equipment axis direction Da.

[0056] 1 and 2, the shaft portion 161 of the plunger 16 is fitted into a through-hole that penetrates the movable core 22 in the equipment axial direction Da, and is provided so as to be immovable relative to the movable core 22 in the equipment axial direction Da. Specifically, the shaft portion 161 of the plunger 16 is fixed to the movable core 22. Therefore, the plunger 16 and the movable core 22 move together.

[0057] The plunger 16 and the movable core 22 are reciprocated within a predetermined stroke range along the equipment axial direction Da as the electromagnetic coil 21 is switched between energized and de-energized. Fig. 1 shows a state in which the plunger 16 and the movable core 22 have moved to an other-side stroke end position, which is a stroke end position on the other side of the equipment axial direction Da within that stroke range. In contrast, Fig. 2 shows a state in which the plunger 16 and the movable core 22 have moved to a one-side stroke end position, which is a stroke end position on one side of the equipment axial direction Da within that stroke range.

[0058] For example, when the electromagnetic coil 21 is energized, the plunger 16 and the movable core 22 are moved to one side in the equipment axial direction Da by the magnetic force generated by the electromagnetic coil 21 and stop at the stroke end position on that side, as shown in Fig. 2. Conversely, when the electromagnetic coil 21 is de-energized, the plunger 16 and the movable core 22 are moved to the other side in the equipment axial direction Da by the biasing force of the core biasing member 34 and stop at the stroke end position on the other side, as shown in Fig. 1.

[0059] The insulator portion 162 of the plunger 16 is provided so as to be coaxial with the shaft portion 161, and is disposed on the other side in the device axial direction Da of the shaft portion 161. The insulator portion 162 is made of an insulating material such as resin.

[0060] Furthermore, the insulator part 162 is disposed on one side in the equipment axis direction Da with respect to the movable conductor 122. When the plunger 16 is moved from this position to the other side in the equipment axis direction Da, the insulator part 162 comes into contact with the movable conductor 122 of the mover 12, pushing the mover 12 to the other side in the equipment axis direction Da.

[0061] The movable wall portion 28 is formed in a disk shape that expands in the device radial direction Dr around the device axis center CL. A press-fit hole 28a that penetrates the movable wall portion 28 in the device axis direction Da is formed in the movable wall portion 28, and the shaft portion 161 of the plunger 16 is press-fitted into the press-fit hole 28a, and the movable wall portion 28 is fixed to the shaft portion 161 of the plunger 16. Therefore, the plunger 16 and the movable wall portion 28 move together.

[0062] The movable wall portion 28 is disposed in the housing interior space 30a between the annular wall portion 232 of the support member 23 and the fixed contact support portion 301, and is disposed so as not to come into contact with either the housing 30 or any of the components fixed in position relative to the housing 30, even when the movable wall portion 28 moves back and forth in the device axis direction Da. The movable wall portion 28 is made of a metal such as an iron alloy.

[0063] For example, the movable wall portion 28 extends further outward in the device radial direction Dr than the inner circumferential wall portion 231 of the support member 23 and the movable core 22. In other words, an outer circumferential edge 281 that the movable wall portion 28 has on the outside in the device radial direction Dr is located further outward in the device radial direction Dr than the sliding contact hole 231 a of the support member 23.

[0064] Next, the operation of the electromagnetic relay 10 when the electromagnetic coil 21 is switched between energized and de-energized will be described.

[0065] First, a case where the electromagnetic coil 21 is switched from a non-energized state to an energized state will be described. As shown in Fig. 1, in the electromagnetic relay 10, when the electromagnetic coil 21 is energized, a magnetic flux is formed in a magnetic path formed by the fixed core 24, the movable core 22, the support member 23, the one-side yoke 25, and the shaft portion 161 of the plunger 16, and a magnetic attraction force is generated between the movable core 22 and the fixed core 24. That is, when the electromagnetic coil 21 is energized, the fixed core 24 applies the magnetic force generated by the electromagnetic coil 21 to the movable core 22 so as to move the movable core 22 to one side in the equipment axis direction Da. As a result, as shown in Fig. 2, the movable core 22 and the plunger 16 are attracted to the fixed core 24 and move to one side in the equipment axis direction Da against the biasing force of the core biasing member 34.

[0066] Accordingly, the pressure of the plunger 16 against the movable conductor 122 is released, so that the movable element 12 moves to one side in the equipment axis direction Da due to the biasing force of the movable element biasing member 32, and the multiple movable contacts 121 come into contact with the multiple fixed contacts 14. In other words, the multiple movable contacts 121 come into contact with the multiple fixed contacts 14 as the plunger 16 moves to one side in the equipment axis direction Da.

[0067] As a result, an electric current path is established that serially connects one fixed bus bar 141, the fixed contact 14 fixed to that fixed bus bar 141, the mover 12, the fixed contact 14 fixed to the other fixed bus bar 141, and the other fixed bus bar 141 in that order. Then, a current flows through this electric current path. In other words, the electromagnetic relay 10 is in a connected state. In this connected state of the electromagnetic relay 10, the insulator portion 162 is separated from the mover 12.

[0068] Next, a case where the electromagnetic coil 21 is switched from a conducting state to a non-conducting state will be described. In the electromagnetic relay 10, when the conduction of current to the electromagnetic coil 21 is interrupted, the magnetic attraction force between the movable core 22 and the fixed core 24 is eliminated. Here, the core biasing member 34 has a biasing force greater than that of the movable core biasing member 32. Therefore, when the magnetic attraction force is eliminated, the biasing force of the core biasing member 34 moves the movable core 22 toward the other side of the equipment axis direction Da, and the movable core 12 is pushed toward the other side of the equipment axis direction Da by the plunger 16, moving away from the fixed contact 14. In other words, as shown in FIG. 1 , the multiple movable contacts 121 move away from the multiple fixed contacts 14 toward the other side of the equipment axis direction Da as the plunger 16 moves toward the other side of the equipment axis direction Da.

[0069] This cuts off the current path between one fixed bus bar 141 and the other fixed bus bar 141 via the mover 12. In other words, the electromagnetic relay 10 is brought into an interrupted state.

[0070] When the electromagnetic relay 10 switches from the connected state to the disconnected state, the relay does not switch to the disconnected state while an arc is generated between the movable contact 121 and the fixed contact 14. Therefore, the electromagnetic relay 10 is provided with an arc-extinguishing magnet 36 to quickly extinguish the arc. The arc-extinguishing magnet 36 is disposed outside the movable contact 121 and the fixed contact 14 in the device radial direction Dr. The arc-extinguishing magnet 36 extinguishes the arc generated between the movable contact 121 and the fixed contact 14 by stretching it in a direction perpendicular to the device axial direction Da.

[0071] As described above, according to this embodiment, the plunger 16 is caused to reciprocate along the equipment axis direction Da as the electromagnetic coil 21 is switched between energized and de-energized states. The air around the plunger 16 is then moved along with the plunger 16. Therefore, in the air hole 244 of the stopper portion 242, when the plunger 16 is moved toward one side in the equipment axis direction Da, a first air flow Bd is generated from the opening end 244 b toward the opposite hole end 244 a. Conversely, when the plunger 16 is moved toward the other side in the equipment axis direction Da, a second air flow Bu is generated from the opposite hole end 244 a toward the opening end 244 b.

[0072] In this embodiment, when the abutment surface 161a is away from the stopper surface 243, the air passing through the air hole 244 is less likely to flow from the opening end 244b to the opposite end 244a of the hole than from the opposite end 244a of the hole to the opening end 244b.

[0073] Therefore, the air flow through the air hole 244 acts as a resistance to suppress movement of the plunger 16 more strongly when the plunger 16 is moved from the other side to one side in the equipment axis direction Da than when the plunger 16 is moved from one side to the other side in the equipment axis direction Da. In other words, the air flow through the air hole 244 acts to strongly suppress the movement speed of the plunger 16 moving to one side in the equipment axis direction Da, without significantly suppressing the movement speed of the plunger 16 moving to the other side in the equipment axis direction Da.

[0074] This improves the breaking performance when the movable contact 121 separates from the fixed contact 14, and also reduces the operating noise caused by the abutment surface 161a of the plunger 16 hitting the stopper surface 243. In short, it is possible to improve the breaking performance of the electromagnetic relay 10 while reducing the operating noise.

[0075] (1) Furthermore, according to this embodiment, the air hole 244 of the stopper portion 242 is formed so that the air hole 244 becomes larger from the opening end 244b toward the opposite-hole end 244a. Therefore, by simply limiting the shape of the air hole 244, it is possible to make the air flow resistance in the first air flow Bd shown in FIG. 3 greater than the air flow resistance in the second air flow Bu. In other words, when the contact surface 161a is separated from the stopper surface 243, air passing through the air hole 244 is less likely to flow from the opening end 244b to the opposite-hole end 244a than from the opposite-hole end 244a to the opening end 244b.

[0076] (2) Furthermore, according to this embodiment, as shown in Fig. 3, the opening end 244b of the air hole 244 is smaller than the contact surface 161a, and the entire opening end 244b is disposed so as to overlap one side of the contact surface 161a in the equipment axis direction Da. Therefore, compared to a case where, for example, only a portion of the opening end 244b overlaps one side of the contact surface 161a in the equipment axis direction Da, it is possible to increase the amount of air flowing through the air hole 244 in conjunction with the contact surface 161a's movement toward and away from the stopper surface 243. This strengthens the effect of the air flow through the air hole 244 strongly suppressing the movement speed of the plunger 16 moving toward one side in the equipment axis direction Da without significantly suppressing the movement speed of the plunger 16 moving toward the other side in the equipment axis direction Da.

[0077] (3) Furthermore, according to this embodiment, the stopper surface 243 of the fixed core 24 is provided as a bottom surface of the recess 241 on one side in the equipment axial direction Da. When the plunger 16 is moved toward the one side in the equipment axial direction Da and the abutment surface 161 a abuts against the stopper surface 243, the movable core 22 is moved toward the one side in the equipment axial direction Da so as to enter the recess 241.

[0078] As a result, when the plunger 16 is moved toward one side in the equipment axial direction Da, the air in the recess 241 is pushed toward one side in the equipment axial direction Da by the movable core 22. Therefore, compared to, for example, a case where the recess 241 is not present and the stopper surface 243 is a simple part of a flat surface, a larger amount of air flows toward the opening end 244b of the air hole 244 as the plunger 16 and the movable core 22 move. Therefore, when the plunger 16 is moved from the other side to one side in the equipment axial direction Da, it is possible to increase the air resistance that acts to suppress the movement of the plunger 16. As a result, it is possible to further reduce operating noise caused by the abutment surface 161a hitting the stopper surface 243.

[0079] Second Embodiment Next, a second embodiment will be described. In this embodiment, differences from the first embodiment will be mainly described. Furthermore, parts that are the same as or equivalent to the first embodiment will be omitted or simplified. This also applies to the following embodiments.

[0080] As shown in FIG. 4 , in this embodiment, the structure of the air hole 244 of the stopper portion 242 is different from that of the first embodiment. Specifically, the air hole 244 in this embodiment has a structure as a Tesla valve. The air hole 244 functioning as a Tesla valve is configured to impede a first air flow Bd from the opening end 244b toward the opposite-hole end 244a, compared to a second air flow Bu from the opposite-hole end 244a toward the opening end 244b. In other words, the air hole 244 makes it more difficult for air to flow from the opening end 244b toward the opposite-hole end 244a than from the opposite-hole end 244a to the opening end 244b.

[0081] Therefore, in this embodiment, as in the first embodiment, a difference in air flow resistance occurs between the first air flow Bd and the second air flow Bu. That is, when the abutment surface 161 a is separated from the stopper surface 243, the air passing through the air hole 244 is less likely to flow from the opening end 244 b to the opposite hole end 244 a than from the opposite hole end 244 a to the opening end 244 b.

[0082] (1) As described above, according to this embodiment, the air hole 244 has a Tesla valve structure that impedes the first air flow Bd from the opening end 244b to the opposite end 244a of the hole compared to the second air flow Bu from the opposite end 244a to the opening end 244b. Therefore, in this embodiment, compared to the first embodiment, it is easy to increase the difference in air flow resistance between the first air flow Bd and the second air flow Bu.

[0083] Except for the points described above, this embodiment is similar to the first embodiment. In this embodiment, the same effects as those of the first embodiment can be obtained from the configuration common to the first embodiment.

[0084] Third Embodiment Next, a third embodiment will be described. In this embodiment, differences from the first embodiment will be mainly described.

[0085] 5, the electromagnetic relay 10 of this embodiment includes a valve device 38 provided in the air hole 244 of the stopper portion 242. The valve device 38 prevents a first air flow Bd, which is an air flow from the open end 244b to the opposite end 244a of the hole, compared to a second air flow Bu, which is an air flow from the opposite end 244a of the hole to the open end 244b.

[0086] 5 has a movable lid 381 which is a valve body, and this movable lid 381 operates to open the air hole 244 when the second air flow Bu acts on the movable lid 381, and operates to close the air hole 244 when the first air flow Bd acts on the movable lid 381. By the operation of this movable lid 381, the valve device 38 functions as a check valve which allows the second air flow Bu through the air hole 244 while blocking the first air flow Bd.

[0087] Therefore, in this embodiment, as in the first embodiment, when the abutment surface 161a is away from the stopper surface 243, the air passing through the air hole 244 is less likely to flow from the opening end 244b to the opposite end 244a of the hole than from the opposite end 244a of the hole to the opening end 244b.

[0088] (1) As described above, according to this embodiment, the valve device 38 is provided in the air hole 244 of the stopper portion 242. The valve device 38 prevents the first air flow Bd from the open end 244b toward the opposite hole end 244a, compared to the second air flow Bu from the opposite hole end 244a toward the open end 244b.

[0089] By providing such a valve device 38, the air flow resistance generated against the first air flow Bd can be made larger in this embodiment than in the first embodiment, which results in a further reduction in the operating noise caused by the contact surface 161a hitting against the stopper surface 243.

[0090] Except for the points described above, this embodiment is similar to the first embodiment. In this embodiment, the same effects as those of the first embodiment can be obtained from the configuration common to the first embodiment.

[0091] (Other Embodiments) (1) In each of the above-described embodiments, as shown in Fig. 1, the plunger 16 corresponds to the movable member of the present disclosure, but this is merely an example. For example, the plunger 16 may not be provided, and the electromagnetic relay 10 may include another member that corresponds to the movable member of the present disclosure.

[0092] (2) Note that the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms. Furthermore, it goes without saying that, in each of the above-described embodiments, elements constituting the embodiments are not necessarily essential unless they are specifically stated as essential or are clearly considered essential in principle.

[0093] Furthermore, in each of the above embodiments, when numerical values ​​such as the number, values, amounts, and ranges of components of the embodiments are mentioned, they are not limited to the specific numbers, except when it is particularly clearly stated that they are essential or when they are clearly limited to a specific number in principle, etc. Furthermore, in each of the above embodiments, when the material, shape, positional relationship, etc. of components are mentioned, they are not limited to the material, shape, positional relationship, etc., except when it is particularly clearly stated or when they are clearly limited to a specific material, shape, positional relationship, etc. in principle, etc.

[0094] (Aspects of the present disclosure) The above-described present disclosure can be understood from the following aspects, for example. [First aspect] An electromagnetic relay comprising: an electromagnetic coil (21) that generates a magnetic force when energized; a movable member (16) that is moved in one direction (Da) by the magnetic force, that moves back and forth along the one direction as the electromagnetic coil is switched between energized and de-energized, and that has an abutment surface (161a) facing one side of the one direction; a stopper portion (242) that is formed with a stopper surface (243) that the abutment surface abuts against when the movable member is moved to the one side in the one direction, thereby stopping the movement of the movable member; a fixed contact (14); and a movable contact (121) that comes into contact with the fixed contact as the movable member moves to the one side in the one direction and moves away from the fixed contact as the movable member moves to the other side in the one direction, wherein an air hole (244) is formed in the stopper portion, The air hole has an opening end (244b) formed on the stopper surface and opening to face the abutment surface in the one direction, and an opposite-hole end (244a) that is an open hole end opposite the opening end, and when the abutment surface is away from the stopper surface, air passing through the air hole is less likely to flow from the opening end to the opposite-hole end than from the opposite-hole end to the opening end. [Second Aspect] The electromagnetic relay according to the first aspect, wherein the air hole is formed so that the air hole widens as it moves from the opening end to the opposite-hole end. [Third Aspect] The electromagnetic relay according to the first aspect, wherein the air hole has a Tesla valve structure that impedes air flow (Bd) from the opening end to the opposite-hole end compared to air flow (Bu) from the opposite-hole end to the opening end. [Fourth Aspect] The electromagnetic relay according to the first aspect, wherein the air hole is provided with a valve device (38) that prevents air flow (Bd) from the open end to the opposite end of the hole compared to air flow (Bu) from the opposite end of the hole to the open end. [Fifth Aspect] The electromagnetic relay according to any one of the first to fourth aspects, wherein the open end is arranged so that the entire open end overlaps with the one side in the one direction with respect to the abutment surface.[Sixth Aspect] An electromagnetic relay according to any one of the first to fifth aspects, comprising: a movable core (22) that is provided so as to be immovable relative to the movable member in the one direction; and a fixed core (24) that is provided on one side of the movable core in the one direction, has a recess (241) that is open facing the other side in the one direction, and causes the magnetic force to act on the movable core so as to move the movable core to the one side in the one direction when the electromagnetic coil is energized, wherein the stopper portion constitutes a part of the fixed core, and the stopper surface is provided as a bottom surface that the recess has on the one side in the one direction, and when the movable member is moved to the one side in the one direction and the abutment surface abuts against the stopper surface, the movable core is moved to the one side in the one direction so as to enter the recess.

Claims

1. An electromagnetic relay, comprising: an electromagnetic coil (21) that generates a magnetic force when energized; a movable member (16) that is moved in one direction (Da) by the magnetic force and reciprocated along the one direction as the electromagnetic coil is switched between energization and non-energization, the movable member having a contact surface (161a) facing one side of the one direction; a stopper portion (242) in which a stopper surface (243) is formed to stop the movement of the movable member when the movable member is moved to the one side of the one direction; a fixed contact (14); and a movable contact (121) that contacts the fixed contact as the movable member moves to the one side of the one direction and separates from the fixed contact as the movable member moves to the other side of the one direction. An air hole (244) is formed in the stopper portion. The air hole has an opening end (244b) formed in the stopper surface and opening so as to face the one direction with respect to the contact surface, and a hole opposite end (244a) that is an end opposite to the opening end and is open. In a state where the contact surface is separated from the stopper surface, the air flowing through the air hole is less likely to flow from the opening end to the hole opposite end than from the hole opposite end to the opening end. An electromagnetic relay.

2. The electromagnetic relay according to claim 1, wherein the air hole is formed so as to expand as it extends from the opening end to the hole opposite end.

3. The electromagnetic relay according to claim 1, wherein the air hole has a structure as a Tesla valve that obstructs an air flow (Bd) from the opening end to the hole opposite end as compared with an air flow (Bu) from the hole opposite end to the opening end.

4. The electromagnetic relay according to claim 1, wherein a valve device (38) that obstructs an air flow (Bd) from the opening end to the hole opposite end as compared with an air flow (Bu) from the hole opposite end to the opening end is provided in the air hole.

5. The electromagnetic relay according to any one of claims 1 to 4, wherein the opening end is arranged so that the entire opening end overlaps the one side of the one direction with respect to the contact surface.

6. A movable core (22) provided so as not to be relatively movable in the one direction with respect to the movable member, and a recess (241) provided on one side of the one direction with respect to the movable core and open toward the other side of the one direction, and when the electromagnetic coil is energized, a fixed core (24) that applies the magnetic force to the movable core so as to move the movable core to the one side in the one direction. The stopper portion constitutes a part of the fixed core, the stopper surface is provided as a bottom surface that the recess has on the one side in the one direction, and when the movable member is moved to the one side in the one direction and the contact surface abuts against the stopper surface, the movable core is moved to the one side in the one direction so as to enter the recess. The electromagnetic relay according to any one of claims 1 to 4.

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