ELECTROMAGNETIC RELAY

Abstract

Electromagnetic relay, including: a box-shaped insulating housing (1) in which a closed space (70) is formed; a pair of fixed terminals (31a, 31b) which are electrically independent of each other and which each have a fixed contact arrangement surface (311) in the enclosed space (70); a plate-like movable contact transmitter (32) with a conductivity, which is arranged in the enclosed space (70) and has a first surface (321) which is a movable contact arrangement surface which is arranged opposite the fixed contact arrangement surface (311) of the pair of fixed terminals (31a, 31b), and which is movably arranged such that the first surface (321) approaches and separates from each of the fixed contact arrangement surfaces (311) of the pair of fixed terminals (31a, 31b); a movable shaft (35) which extends along a direction of movement of the movable contactor (32) to one side of a second surface (322) of the movable contactor (32) which is opposite to the first surface (321), and is movable together with the movable contactor (32); an electromagnetic drive unit (40) which is housed on the side of the second surface (322) of the movable contactor (32) in the housing (1) and drives the movable shaft (35) to move the movable contactor (32) back and forth in the direction of movement; and a damping mechanism unit (60) which is provided in the enclosed space (70) and has an insulating damping element (61) which is arranged between the movable contact transmitter (32) and the electromagnetic drive unit (40), and a sound-insulating gap (62) which is provided between the damping element (61) and the electromagnetic drive unit (40), where the movable shaft (35) has a movement-limiting unit (35a) which separates from the damping element (61) when the movable contactor (32) approaches the stationary contact arrangement surface (311), and after the movable contactor (32) separates from the stationary contact arrangement surface (311) comes into contact with the damping element (61) to limit the movement of the movable shaft (35) in a direction in which the movable contactor (32) separates, and the damping element (61) has a collision noise damping unit (63) which is configured to make a path along which the collision noise propagates longer than a path along which the collision noise propagates towards the outside of the housing (1) in a state in which the damping element (61) and the electromagnetic drive unit (40) are in contact with each other without the sound-insulating gap (62), wherein the collision noise is generated when the motion-limiting unit (35a) of the movable shaft (35) comes into contact with the damping element (61).

Description

TECHNICAL FIELD

[0001] The present invention relates to an electromagnetic relay. STATE OF THE ART

[0002] An electromagnetic relay disclosed in Patent Document 1 includes: a housing having a closed space therein; a pair of fixed terminals electrically independently fixed to the housing; a plate-like movable contactor movably disposed in the closed space opposite to each of the pair of fixed terminals so as to approach or separate from each of the pair of fixed terminals; and an electromagnetic drive unit housed in the housing and disposed opposite to the movable contactor on a side opposite to the pair of fixed terminals.

[0003] The electromagnetic relay further includes a movable shaft extending along the moving direction of the movable contactor and driven by the electromagnetic drive unit, and a magnet holder disposed between the movable contactor and the electromagnetic drive unit in the enclosed space, which holds a pair of permanent magnets between which the pair of fixed terminals are arranged. The movable shaft is provided with an annular stroke limiting portion that separates from the magnet holder when the movable contactor approaches the pair of fixed terminals and comes into contact with the magnet holder when the movable contactor separates from the pair of fixed terminals, thus restricting the movement of the movable shaft in a separating direction of the movable contactor. Other related art is provided by Patent Documents 2 and 3. DOCUMENT OF THE PRIOR ART OF THE PATENT SPECIFICATION Patent Document 1: Japanese Patent No. 5310936 Patent Document 2: European patent publication with publication number EP 2 942 798 A1 Patent document 3: German patent publication with publication number DE 10 2011 078 426 A1 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] In the electromagnetic relay, a buffer material is arranged between the magnet holder and the electromagnetic drive unit to reduce a collision noise caused by the annular stroke limiting portion of the movable shaft coming into contact with the magnet holder when changing from a working state in which the pair of fixed terminals and the movable contactor are close to each other to a rest state in which the pair of fixed terminals and the movable contactor are separated from each other.

[0005] However, since the buffer material is provided in the electromagnetic relay to dampen collision noise, the number of parts increases. Therefore, there is a need to reliably reduce collision noise without increasing the number of parts.

[0006] That is, an object of the present invention is to provide an electromagnetic relay capable of reducing collision noise generated when a working state transitions to a return state without increasing the number of parts. This object is achieved by an electromagnetic relay according to claim 1. Preferred embodiments are subject to the subclaims. The invention is defined by the claims, with aspects of the invention being set forth below. MEANS TO SOLVE THE PROBLEM

[0007] An electromagnetic relay of one aspect of the invention as defined by claim 1 comprises: a box-shaped insulating case in which a closed space is formed; a pair of fixed terminals electrically independently fixed to the case and each having a fixed contact arrangement surface in the closed space; a plate-like movable contactor having conductivity, disposed in the closed space and having a first surface that is a movable contact arrangement surface opposite to the fixed contact arrangement surface of the pair of fixed terminals, and movably disposed such that the first surface approaches and separates from each of the fixed contact arrangement surfaces of the pair of fixed terminals; a movable shaft,which extends along a moving direction of the movable contactor to a side of a second surface of the movable contactor opposite the first surface and is movable together with the movable contactor; an electromagnetic drive unit housed in the housing on the side of the second surface of the movable contactor and driving the movable shaft to move the movable contactor back and forth in the moving direction; and a damping element provided in the closed space and comprising an insulating damping element arranged between the movable contactor and the electromagnetic drive unit, and a sound-insulating gap provided between the damping element and the electromagnetic drive unit. The movable shaft has a movement-restricting unit separate from the damping element.when the movable contactor approaches the fixed contact arrangement surface, and which comes into contact with the damping element after the movable contactor separates from the fixed contact arrangement surface to restrict the movement of the movable shaft in a direction in which the movable contactor separates, and the damping element has a collision noise damping unit configured to make a path along which the collision noise propagates toward an exterior of the housing longer than a path along which the collision noise propagates in a state in which the damping element and the electromagnetic drive unit are in contact with each other without the sound-insulating gap, wherein the collision noise is generated when the movable shaft movement-restricting unit comes into contact with the damping element. EFFECT OF THE INVENTION

[0008] According to the electromagnetic relay of the above aspect, the damping mechanism is provided, which includes the insulating damping member disposed between the movable contactor and the electromagnetic drive unit, and the sound-absorbing gap provided between the damping member and the electromagnetic drive unit. Furthermore, the damping member includes the collision noise damping unit configured to make a path along which the collision noise propagates toward an exterior of the housing longer than a path along which the collision noise propagates in a state where the damping member and the electromagnetic drive unit are in contact with each other without the sound-absorbing gap, and the collision noise is generated when the movable shaft movement-restricting unit comes into contact with the damping member.This makes it possible to reduce a collision noise generated when the movable contactor separates from the pair of fixed terminals without increasing the number of parts. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view illustrating an electromagnetic relay according to an embodiment of the present invention. Fig. 2 is a sectional view along the line II-II of the electromagnetic relay of Fig. 1 in a return state. Fig. 3 is a sectional view along the line II-II of the electromagnetic relay of Fig. 1 in a working condition. Fig. 4 is an enlarged partial view of Fig. 2. Fig. 5 is an enlarged partial sectional view taken along the line VV of Fig. 1. Fig. 6 is an enlarged partial sectional view taken along line II-II of Fig. 1, which is another example of a collision noise damping unit of the electromagnetic relay of Fig. 1 represents. Fig. 7 is an enlarged partial sectional view taken along line II-II of Fig. 1, which is another example of the collision noise damping unit of the electromagnetic relay of Fig. 1 represents. EMBODIMENT OF THE INVENTION

[0009] An embodiment of the present invention will be described below with reference to the accompanying drawings. In the following description, terms (such as "upper", "lower", "right", "left", "side", and "end") are used to indicate specific directions or positions, but the use of these terms is for the purpose of facilitating an understanding of the invention with reference to the drawings, and the technical scope of the present invention is in no way limited by the meaning of these terms. The following description is merely exemplary and is not intended to limit the present invention, its application, or uses. Furthermore, the drawings are schematic, and proportions and the like may not necessarily correspond to actual ones.

[0010] As in Fig. 1, an electromagnetic relay 100 of an embodiment of the present invention includes an insulating case 1 and a pair of fixed terminals 31a, 31b fixed to the case 1. As shown in Fig. 2, the electromagnetic relay 100 is arranged symmetrically to a plane CP passing through the centers of the pair of fixed terminals 31a, 31b and extending in a direction orthogonal to the arrangement direction of the pair of fixed terminals 31a, 31b.

[0011] As in Fig. 2 and Fig. As shown in Figure 3, a closed space 70 is formed inside the housing 1, and the electromagnetic relay 100 includes a conductive plate-like movable contactor 32 disposed within the closed space 70, which is disposed opposite the pair of fixed terminals 31a, 31b. The movable contactor 32 is movably disposed to approach and separate from a fixed contact arrangement surface 311 of each of the pair of fixed terminals 31a, 31b.

[0012] The electromagnetic relay 100 includes a movable shaft 35 provided in the closed space 70 and movable together with the movable contactor 32, an electromagnetic drive unit 40 housed in the housing 1 opposite to the movable contactor 32 on the side opposite to the pair of fixed terminals 31a, 31b, and a damper mechanism unit 60 provided in the closed space 70.

[0013] Fig. 2 illustrates the electromagnetic relay 100 in a return state in which the movable contactor 32 is separated from the fixed contact arrangement surface 311 of each of the pair of fixed terminals 31a, 31b. Fig. 3 illustrates the electromagnetic relay 100 in a working state in which the movable contactor 32 is located near the fixed contact arrangement surface 311 of each of the pair of fixed terminals 31a, 31b.

[0014] A direction in which the pair of fixed terminals 31a, 31b is arranged (ie, a horizontal direction in Fig. 2), is defined as X direction, and a height direction of the electromagnetic relay 100 (ie, a vertical direction in Fig. 2) is defined as the Z direction. Furthermore, a direction orthogonal to the X and Z directions is defined as the Y direction.

[0015] As in Fig. 2 and Fig. 3, the housing 1 is composed of a box 10, a lid 20 and a closed space forming portion 30 which forms the closed space 70 provided in the interior of the box 10 and the lid 20.

[0016] As in Fig. 1, the box 10 has a rectangular box shape. As shown in Fig. 2, the box 10 also has an opening on the top side in the Z direction.

[0017] As in Fig. 1, the side surface of the box 10 in the Y direction is provided with a terminal notch 11 in which a coil terminal 43 projects, and a snap hole 12 for fixing the box 10 and the cover 20.

[0018] As in Fig. 1, the lid 20 has a rectangular box shape and is mounted so as to cover the opening of the box 10. In addition, the lid 20 has an opening on the lower side in the Z direction, as shown in Fig. 2 and Fig. 3 shown.

[0019] The upper surface of the cover 20 is provided with a partition 21 located substantially at the center in the X direction and extending in the Y direction. A terminal hole 22 is provided on either side of the partition 21 in the X direction, into which a pair of fixed terminals 31a, 31b protrude. Although not shown, the opening of the cover 20 is provided with locking pawls for securing the box 10 and the cover 20 together with the locking holes 12 of the box 10.

[0020] As in Fig. 2 and Fig. As shown in Figure 3, the enclosed space forming portion 30 is composed of an insulating quadrilateral ceramic plate 52 along an XY plane, a quadrangular cylindrical flange 51 extending downward from the edge of the ceramic plate 52 in the Z direction, a plate-like first yoke 53 disposed at the lower end of the flange 51 along the XY plane, and a circular or square-bottomed cylindrical body 54 extending downward in the Z direction from the vicinity of the flat surface of the first yoke 53. The flange 51, the ceramic plate 52, and the first yoke 53 are integrated, and the first yoke 53 and the bottomed cylindrical body 54 are hermetically sealed together.

[0021] The flange 51 has an opening at its upper and lower ends in the Z direction and has an inner insulating cover 511 covering its outer periphery.

[0022] The ceramic plate 52 is arranged to close the opening on top of the flange 51 in the Z direction. The ceramic plate 52 is provided with a pair of terminal holes 521 arranged opposite the terminal holes 22 of the cover 20. The pair of fixed terminals 31a, 31b are inserted into respective terminal holes 521 and fixed by brazing.

[0023] The first yoke 53 extends along the XY plane and is arranged to close the opening on the underside of the flange 51 in the Z direction. A hole portion 531 is provided in the flat surface of the first yoke 53. A substantially cylindrical movable shaft 35 is movably inserted into the hole portion 531. The first yoke 53 forms part of the closed space forming portion 30 and forms part of the electromagnetic drive unit 40.

[0024] The flanged cylindrical body 54 with a bottom extends from the first yoke 53 to the bottom of the box 10 and is arranged to cover the hole portion 531 of the first yoke 53. The cylindrical body with a bottom 54 accommodates the movable shaft 35, a fixed iron core 57 fixed to the first yoke 53, and a movable iron core 58 fixed to the lower end of the movable shaft 35. A return spring 59 is provided between the fixed iron core 57 and the movable iron core 58 to drive the movable iron core 58 downward in the Z direction. The fixed iron core 57, the movable iron core 58, and the return spring 59 constitute part of the electromagnetic drive unit 40.

[0025] The fixed iron core 57 extends downward from the edge of the hole portion 531 of the first yoke 53 along the bottomed cylindrical body 54 in the Z direction. The center of the fixed iron core 57 is provided with a through hole through which the movable shaft 35 can move up and down in the Z direction. As shown in Fig. 2, in a state where the pair of fixed contacts 33a, 33b and the pair of movable contacts 34a, 34b are separated from each other, a gap is formed between the fixed iron core 57 and the movable iron core 58.

[0026] As in Fig. 2 and Fig. As shown in Figure 3, each of the pair of fixed terminals 31a, 31b has a substantially cylindrical shape and is electrically independently fixed to the ceramic plate 52 constituting the housing 1. The pair of fixed terminals 31a, 31b are arranged at a distance along a first direction (i.e., the X direction), which is their arrangement direction, and a part of each fixed terminal 31a, 31b is located in the closed space 70.

[0027] On the end surface of the pair of fixed terminals 31a, 31b located within the closed space 70 (ie, on the lower end surface in the Z direction), a fixed contact arrangement surface 311 is provided along the XY plane. Fixed contacts 33a, 33b are provided on the fixed contact arrangement surfaces 311, respectively. The respective fixed contacts 33a, 33b may be formed integrally with the corresponding fixed terminals 31a, 31b or may be formed separately from the corresponding fixed terminals 31a, 31b.

[0028] As in Fig. 2 and Fig. 3, the movable contactor 32 has a first surface 321 along the XY plane facing the pair of fixed terminals 31a, 31b, and a second surface 322 along the XY plane on the side opposite the first surface 321.

[0029] A pair of movable contacts 34a, 34b is provided on the first surface 321 of the movable contactor 32. That is, the first surface 321 is a movable contact arrangement surface, and the pair of movable contacts 34a, 34b are electrically connected to each other through the movable contactor 32. The pair of movable contacts 34a, 34b are arranged to face the pair of fixed contacts 33a, 33b, respectively. The movable contacts 34a, 34b can be formed integrally with the movable contactor 32 or formed separately from the movable contactor 32.

[0030] As in Fig. 2 and Fig. 3, the movable shaft 35 extends from a second surface 322 of the movable contactor 32 along the moving direction of the movable contactor 32 (ie, in the Z direction), and its upper end (the end on the upper side in the Z direction) is connected to the movable contactor 32 via a retaining ring 38. That is, the movable shaft 35 is located on the second surface side of the movable contactor 32 and is movable together with the movable contactor 32.

[0031] The movable iron core 58 is fixed to the lower end of the movable shaft 35 (i.e., the end on the lower side in the Z direction), and in an intermediate region of the movable shaft 35, an annular stroke limiting portion 35a is provided as an example of a movement limiting unit, extending on the entire circumference of the movable shaft 35. The stroke limiting portion 35a protrudes from the movable shaft 35 along the XY plane and separates from the damper 61 when the movable contactor 32 approaches the fixed contact arrangement surface 311. After the movable contactor 32 separates from the contact arrangement surface 311, the stroke limiting portion 35a comes into contact with a damper 61. This restricts the movement of the movable shaft 35 in the separation direction of the movable contactor 32.

[0032] Between the annular stroke limiting portion 35a and the movable contactor 32, a coil spring 36, in the center of which a movable shaft 35 is arranged, and a spring plate 37 are provided. The spring plate 37 is held by the annular stroke limiting portion 35a and clamps the coil spring 36 together with the movable contactor 32. The movable contactor 32, the movable shaft 35, the coil spring 36, and the spring plate 37 are integrally movable in the Z direction.

[0033] As in Fig. 2 and Fig. 3, the electromagnetic drive unit 40 is composed of an electromagnet portion 40a surrounding the outer periphery of the bottomed cylindrical body 54, a first yoke 53 and a second yoke 44 surrounding the electromagnet portion 40a in the X and Z directions, a fixed iron core 57 fixed to the first yoke 53 in the closed space 70, and a movable iron core 58 fixed to the lower end in the Z direction of the movable shaft 35.

[0034] The electromagnet section 40a is composed of an insulating coil body 41, a coil 42 wound around the coil body 41, and the coil terminal 43 (in Fig. 1) fixed to the coil body 41. When a voltage is applied to the coil 42 of the electromagnet portion 40a, the movable iron core 58 is attracted to the fixed iron core 57, causing the movable shaft 35 to move up and down along the Z direction. This causes the movable contactor 32 to approach or separate from the fixed contact arrangement surface 311 of each of the pair of fixed terminals 31a, 31b. That is, the electromagnetic drive unit 40 drives the movable shaft 35 to move the movable contactor 32 back and forth in the moving direction (i.e., in the Z direction).

[0035] The second yoke 44 is substantially U-shaped in a sectional view along the XZ plane, and both ends of the second yoke 44 are fixed to the first yoke 53.

[0036] As in Fig. 2 and Fig. 3, the damping mechanism unit 60 includes an insulating damping member 61 disposed between the movable contactor 32 and the electromagnetic drive unit 40, and a sound-insulating gap 62 provided between the damping member 61 and the electromagnetic drive unit 40.

[0037] As in Fig. 4 and Fig. 5, the damping element 61 comprises, in particular, a first vertical cylindrical portion 61a extending downward from the annular stroke limiting portion 35a along the movable shaft 35, a collar portion 61b projecting from the upper end of the first vertical cylindrical portion 61a laterally along the first yoke 53 into the vicinity of the flange 51, and a second vertical cylindrical portion 61c extending from the vicinity of the flange 51 of the collar portion 61b along the flange 51 to the ceramic plate 52 (only in Fig. 5). The damping element 61 and the annular stroke limiting portion 35a of the movable shaft 35 come into contact with each other at the upper end of the first vertical cylindrical portion 61a. The movable shaft 35 is movable up and down in the Z direction relative to the first vertical cylindrical portion 61a.

[0038] The sound-insulating gap 62 is provided between the collar portion 61b and the first yoke 53 and the fixed iron core 57 of the electromagnetic drive unit 40 and between the first vertical cylindrical portion 61a and the fixed iron core 57 of the electromagnetic drive unit 40.

[0039] In addition, a collision noise damping unit 63 is provided on the collar portion 61b of the damping element 61. As shown in Fig. As shown in Fig. 4, the collision noise damping unit 63 is configured to make a path R1 along which the collision noise propagates longer than a path R0 along which the collision noise propagates toward the outside of the housing 1 in a state where the damping member 61 and the first yoke 53 and / or the fixed iron core 57 of the electromagnetic drive unit 40 are in contact with each other without the sound-insulating gap 62, and the collision noise is generated when the annular stroke limiting portion 35a of the movable shaft 35 comes into contact with the damping member 61. This makes it possible to demonstrate the collision noise damping effect.

[0040] The collision noise damping unit 63 specifically includes a winding portion 64 which, in a sectional view, is U-shaped in the moving direction of the movable contactor 32 (i.e., in the Z direction) and causes the path R1 along which the collision noise propagates to be winding. The winding portion 64 is composed of a first peripheral wall portion 641 extending from the collar portion 61b, which extends along a direction intersecting the moving direction (i.e., the Z direction) of the movable contactor 32 of the damping member 61, along the movable shaft 35 upward in the Z direction, a connecting wall portion 642 extending from the end of the first peripheral wall portion 641 remote from the collar portion 61b in a direction intersecting the movable shaft 35 (i.e.,, along the XY plane), and a second peripheral wall portion 643 extending downward from one end of the connecting wall portion 642 remote from the first peripheral wall portion 641 along the movable shaft 35 in a direction opposite to the first peripheral wall portion 640 (ie, in the Z direction).

[0041] A pair of permanent magnets 55, 55 and an arc shielding member 71 are provided in the closed space 70 of the housing 1.

[0042] The pair of permanent magnets 55, 55 are arranged at both ends in the X direction, opposite each other, inside the flange 51, such that the pair of fixed contacts 33a, 33b and the pair of movable contacts 34a, 34b are located therebetween. The pair of permanent magnets 55, 55 are held by the damping element 61.

[0043] The arc shielding member 71 is arranged to cover both sides of the pair of fixed contacts 33a, 33b and the pair of movable contacts 34a, 34b in the Y direction (the rear and front sides in Fig. 2) and its outer side in the X direction (ie the side closer to the adjacent permanent magnets 55).

[0044] Next, the operation of the electromagnetic relay 100 will be described with reference to Fig. 2 and Fig. 3 described.

[0045] In a return state of the electromagnetic relay 100 in which no voltage is applied to a coil 42 of the electromagnet section 40a, as shown in Fig. As shown in Figure 2, the annular stroke limiting portion 35a of the movable shaft 35 and the damping element 61 of the damping mechanism unit 60 are in contact with each other, and the pair of fixed terminals 31a, 31b and the movable contactor 32 are separated. At this time, the movable iron core 58, which is fixed to the tip of the movable shaft 35, is driven downward in the Z direction by the return spring 59.

[0046] In the return state, when a voltage is applied to the coil 42 of the electromagnetic drive unit 40 of the electromagnetic relay 100, the movable iron core 58 is magnetically attracted to the fixed iron core 57 and moves upward in the Z direction against the spring force of the return spring 59. As the movable iron core 58 moves, the movable shaft 35 moves upward in the Z direction to move the movable contactor 32 upward in the Z direction via the coil spring 50, and the first surface 321 of the movable contactor 32 approaches the pair of fixed terminals 31a, 31b. When the movable contactor 32 approaches the pair of fixed terminals 31a, 31b, the pair of movable contacts 34a, 34b provided on the first surface 321 of the movable contactor 32 comes into contact with the corresponding fixed contacts 33a, 33b, respectively.

[0047] When the voltage is removed from the coil 42 of the electromagnetic relay 100 in the working state, the magnetic attraction force of the fixed iron core disappears, and the movable iron core 58 is driven downward in the Z direction by the spring force of the return spring 59. The movable shaft 35 moves downward in the Z direction due to the pressing force of the movable iron core 58, the movable contactor 32 is moved downward in the Z direction via the coil spring 50, and the first surface 321 of the movable contactor 32 is separated from the pair of fixed terminals 31a, 31b. As shown in Fig. 2, the pair of movable contacts 34a, 34b provided on the first surface 321 of the movable contactor 32 are respectively separated from the pair of fixed contacts 33a, 33b when the movable contactor 32 is separated from the pair of fixed terminals 31a, 31b.

[0048] As described above, when the electromagnetic relay 100 is shifted from the working state to the return state, the annular stroke limiting portion 35a of the movable shaft 35 comes into contact with the damping element 61 of the damping mechanism unit 60 to generate a collision noise. For example, when the damping element 61 is in contact with the fixed iron core 57 and the first yoke 53 of the electromagnetic drive unit 40, the generated collision noise propagates from the damping element 61 to the fixed iron core 57 and the first yoke 53, and is then conducted to the outside of the housing 1. That is, the collision noise propagates linearly along the Fig. 4 shown path R0.

[0049] The electromagnetic relay 100 is provided with the damping mechanism unit 60, which includes the insulating damping member 61 arranged between the movable contactor 32 and the fixed iron core 57 and the first yoke 53 of the electromagnetic drive unit 40, and the sound-insulating gap 62 provided between the damping member 61 and the fixed iron core 57 and the first yoke 53 of the electromagnetic drive unit 40.Further, the electromagnetic relay 100 is provided with the collision noise damping unit 63 configured to make the path along which the collision noise propagates longer than the path R0 along which the collision noise propagates to the outside of the housing 1 in a state in which the damping member 61 and the fixed iron core 57 and the first yoke 53 are in contact with each other without the sound-insulating gap 62, the collision noise being generated when the annular stroke limiting portion 35a of the movable shaft 35 comes into contact with the damping member 61.As a result, the collision noise generated when the movable contactor 32 separates from the fixed contact arrangement surface 311 of each of the pair of fixed terminals 31a, 31b and the annular stroke limiting portion 35a and the damper member 61 come into contact with each other propagates through the damper member 61 without propagating through the sound-insulating gap 62 to the fixed iron core 57 and the first yoke 53 of the electromagnetic drive unit 40. The collision noise propagated through the damper member 61 is attenuated by the collision noise attenuating unit 63 before reaching the exterior of the housing 1. That is, it is possible to reduce the collision noise generated when the movable contactor 32 separates from the pair of fixed terminals 31a, 31b without increasing the number of parts.

[0050] In addition, the collision noise damping unit 63 is U-shaped in a sectional view along the moving direction of the movable contactor 32 (ie, the Z direction) and has the winding portion 64, which causes the path R1 on which a collision noise propagates to be winding. Thereby, it is possible to make a path R1, along which the collision noise propagates, longer than the path R0, along which the collision noise propagates from the damping member 61 to the outside of the housing 1 via the fixed iron core 57 and the first yoke 53, in a state in which the damping member 61 and the fixed iron core 57 and the first yoke 53 are in contact without the sound-insulating gap 62, wherein the collision noise is generated when the annular stroke limiting portion 35a of the movable shaft 35 comes into contact with the damping member 61.

[0051] Generally, during the opening and closing of a pair of fixed contacts and a pair of movable contacts, the powder of the contact melted by arc heat (the powder of the scattered contact is hereinafter referred to as scattering powder) is scattered along with the opening and closing of the pair of fixed contacts and the pair of movable contacts, generating an arc between the pair of fixed contacts and the pair of movable contacts. If this scattering powder adheres to and accumulates on the movable shaft 35 and the coil spring 36, the movable contactor 32 cannot operate as intended, and the contact reliability between the fixed contacts 33a, 33b and the movable contacts 34a, 34b may deteriorate.

[0052] In the electromagnetic relay 100, the coiled portion 64 includes the first peripheral wall portion 641 extending upward in the Z direction from the collar portion 61b of the damping member 61 along the movable shaft 35, the connecting wall portion 642 extending along the XY plane from the end of the first peripheral wall portion 641 remote from the collar portion 61b, and the second peripheral wall portion 643 extending downward in the Z direction from the end of the connecting wall portion 642 remote from the first peripheral wall portion 641 along the movable shaft 35. This makes it possible to reduce the accumulation of stray powder on the movable shaft 35 and the coil spring 36, which is generated when the fixed contact 33a and the movable contact 49a come into contact with each other and separate.This makes it possible to prevent deterioration of the contact reliability between the fixed contacts 33a, 33b and the movable contacts 34a, 34b by operating the movable contactor 32 as intended.

[0053] In the electromagnetic relay 100 according to the first embodiment, the collision noise damping unit 63 includes the coiled portion 64 composed of the first peripheral wall portion 641, the connecting wall portion 642, and the second peripheral wall portion 643, but this is not limitative. The collision noise damping unit 63 may also be configured so that the path R1 over which the collision noise propagates via the damping member 61 is longer than the path R0 in the case without the sound-insulating gap 62, that is, the path R0 over which the collision noise propagates toward the outside of the housing 1 in a state where the damping member 61 and the electromagnetic drive unit 40 are in contact with each other. That is, the coiled portion 64 may be omitted if possible.

[0054] Furthermore, the collision noise damping unit 63 is not limited to one winding section 64, but may, for example, also comprise a plurality of winding sections 64 which are sequentially connected to each other as shown in Fig. 6. By providing a plurality of wound portions as the collision noise damping unit in this way, it is possible to more reliably reduce the collision noise generated when the movable contactor separates from the pair of fixed terminals.

[0055] In addition, the collision noise damping unit 63 is not limited to the winding portion 64 composed of the first peripheral wall portion 641, the connecting wall portion 642, and the second peripheral wall portion 643. As shown in Fig.7, the collision noise damping unit 63 may also include, for example, one or more winding portions 164 composed of the first peripheral wall portion 641, the connecting wall portion 642, a third peripheral wall portion 644 extending on the extension line of the connecting wall portion 642, a connecting wall portion 645 extending downward in the Z direction from the end on the outer side of the third peripheral wall portion 644 in the X direction (ie, the end farther from the movable shaft 35), and a fourth peripheral wall portion 646 extending parallel to the third peripheral wall portion 644 from the lower end of the connecting wall portion 645 to be connected to the second peripheral wall portion 643. That is, the collision noise damping unit can adopt a freely selectable shape and structure corresponding to the design of the electromagnetic relay.

[0056] In addition, the sound-insulating gap 62 is provided at a position at least closer to the movable shaft 35 than the collision noise-damping unit 63 in the direction (ie, along the XY plane) crossing the moving direction of the movable contactor 32 (ie, the Z direction), whereby it is possible to more reliably reduce the collision noise generated when the movable contactor separates from the pair of fixed terminals.

[0057] Various embodiments of the present invention have been described in detail with reference to the drawings, and finally, various aspects of the present invention will be described.

[0058] An electromagnetic relay of one aspect of the present invention comprises: a box-shaped insulating case in which a closed space is formed; a pair of fixed terminals electrically independently fixed to the case and each having a fixed contact arrangement surface in the closed space; a plate-like movable contactor having conductivity, arranged in the closed space and having a first surface that is a movable contact arrangement surface opposite to the fixed contact arrangement surface of the pair of fixed terminals, and movably arranged such that the first surface approaches and separates from each of the fixed contact arrangement surfaces of the pair of fixed terminals; a movable shaft,which extends along a moving direction of the movable contactor to a side of the second surface of the movable contactor opposite the first surface and is movable together with the movable contactor; an electromagnetic drive unit housed in the housing on the side of the second surface of the movable contactor and driving the movable shaft to move the movable contactor back and forth in the moving direction; and a damping mechanism provided in the closed space and comprising an insulating damping element arranged between the movable contactor and the electromagnetic drive unit, and a sound-absorbing gap provided between the damping element and the electromagnetic drive unit. The movable shaft has a movement-restricting unit separate from the damping element.when the movable contactor approaches the fixed contact arrangement surface, and after the movable contactor separates from the fixed contact arrangement surface, it comes into contact with the damping element to restrict the movement of the movable shaft in a direction in which the movable contactor separates, and the damping element has a collision noise damping unit configured to make a path along which the collision noise propagates longer than a path along which the collision noise propagates toward an exterior of the housing in a state in which the damping element and the electromagnetic drive unit are in contact with each other without the sound-insulating gap, wherein the collision noise is generated when the movement-restricting unit of the movable shaft comes into contact with the damping element.

[0059] According to the electromagnetic relay of the first aspect, the damping mechanism is provided, including the insulating damping member disposed between the movable contactor and the electromagnetic drive unit, and the sound-absorbing gap provided between the damping member and the electromagnetic drive unit. Furthermore, the damping member includes the collision noise damping unit configured to make a path along which the collision noise propagates longer than a path along which the collision noise propagates toward the outside of the housing in a state where the damping member and the electromagnetic drive unit are in contact with each other without the sound-absorbing gap, and the collision noise is generated when the movement-restricting unit of the movable shaft comes into contact with the damping member.As a result, the collision noise propagates through the damping member without propagating through the sound-insulating gap to the fixed iron core or the first yoke of the electromagnetic drive unit. The collision noise generated when the movable contactor separates from the fixed contact arrangement surface of each of the pair of fixed terminals and the movable shaft movement-restricting unit and the damping member come into contact with each other is prevented from propagating through the damping member. The collision noise propagated through the damping member is attenuated by the collision noise-damping unit before reaching the exterior of the housing. This makes it possible to reduce the collision noise generated when the movable contactor separates from the pair of fixed terminals.

[0060] In an electromagnetic relay of a second aspect of the present invention, the sound-insulating gap is provided at a position closer to the movable shaft than the collision noise-insulating unit in a direction crossing the moving direction of the movable contactor.

[0061] According to the electromagnetic relay of the second aspect, it is possible to reduce a collision noise generated when the movable contactor separates from the pair of fixed terminals.

[0062] In the electromagnetic relay according to a third aspect of the present invention, the collision noise damping unit is U-shaped in a sectional view along the moving direction of the movable contactor and has a winding portion so that a path on which a collision noise propagates is winding.

[0063] According to an electromagnetic relay of the third aspect, it is possible to make a path along which a collision noise propagates longer than a path along which the collision noise propagates toward the outside of the housing in a state where the damping member and the electromagnetic drive unit are in contact with each other without the sound-insulating gap, wherein the collision noise is generated when the movement-restricting unit of the movable shaft comes into contact with the damping member.

[0064] In an electromagnetic relay of a fourth aspect of the present invention, the damping member is composed of the coiled portion and a collar portion extending in a direction crossing the moving direction of the movable contactor, and the coiled portion includes a first peripheral wall portion extending from the collar portion of the damping member along the movable shaft, a connecting wall portion extending from a farther end of the first peripheral wall portion remote from the collar portion in a direction crossing the movable shaft, and a second peripheral wall portion extending from an end of the connecting wall portion remote from the first peripheral wall portion in a direction opposite to a first peripheral wall portion.

[0065] According to the electromagnetic relay of the fourth aspect, it is possible to reduce the accumulation of dust particles around the drive shaft, which is generated in association with the moving contactor approaching and separating from the fixed contact arrangement surface of the pair of fixed terminals. This makes it possible to operate the moving contactor as intended and prevent deterioration of contact reliability.

[0066] In an electromagnetic relay of a fifth aspect of the present invention, the collision noise damping unit includes a plurality of wound portions sequentially connected to each other.

[0067] According to the electromagnetic relay of the fifth aspect, it is possible to reliably reduce the collision noise generated when the movable contactor separates from the pair of fixed terminals.

[0068] By appropriately combining freely selected embodiments or modifications of the above embodiments, the respective effects of these combinations can be achieved. While it is possible to combine embodiments, combine examples, or combine an embodiment and an example, it is also possible to combine features in different embodiments or examples.

[0069] Although the present invention has been fully described with reference to preferred embodiments and the accompanying drawings, various modifications and variations will occur to those skilled in the art. It is understood that such modifications and variations are within the scope of the present invention as defined by the appended claims, unless they depart therefrom. INDUSTRIAL APPLICABILITY

[0070] The electromagnetic relay of the present invention is not limited to the above embodiment, but is also applicable to other electromagnetic relays. DESCRIPTION OF REFERENCE SYMBOLS 1 housing 10 boxes 11 Connection notch 12 Snap hole 20 lids 21 Partition wall 22 connection hole 30 section forming the closed space 31a, 31b fixed connection 311 fixed contact arrangement surface 32 movable contactors 321 first area 322 second area 33a, 33b fixed contact 34a, 34b movable contact 35 movable shaft 35a annular stroke limiting section 36 coil spring 37 Spring shell (an example of a support plate section) 38 retaining ring 40 electromagnetic drive unit 40a electromagnet 41 coil bodies 42 coil 43 Coil connection 44 second yoke 51 flange 52 ceramic plates 521 connection hole 53 first yoke 531 hole section 54 cylindrical body with bottom 55 permanent magnet 57 fixed iron core 58 movable iron core 59 Return spring 60 Damping mechanism unit 61 Damping element 61a first vertical cylindrical section 61b Collar section 61c second vertical cylindrical section 62 sound-insulating gap 63 collision noise dampening unit 64 winding section 641 first peripheral wall section 642 connecting wall 643 second peripheral wall section 644 third peripheral wall section 645 connecting wall 646 fourth peripheral wall section 70 closed room 71 Arc shielding 100 electromagnetic relay

Claims

[1] Electromagnetic relay comprising: a box-shaped insulating housing (1) in which a closed space (70) is formed; a pair of fixed terminals (31a, 31b) which are electrically independently attached to the housing (1) and each have a fixed contact arrangement surface (311) in the closed space (70); a plate-like movable contactor (32) having conductivity, which is arranged in the closed space (70) and has a first surface (321) which is a movable contact arrangement surface arranged opposite to the fixed contact arrangement surface (311) of the pair of fixed terminals (31a, 31b), and which is movably arranged such that the first surface (321) approaches and separates from each of the fixed contact arrangement surfaces (311) of the pair of fixed terminals (31a, 31b); a movable shaft (35) extending along a moving direction of the movable contactor (32) to a side of a second surface (322) of the movable contactor (32) opposite to the first surface (321) and movable together with the movable contactor (32); an electromagnetic drive unit (40) housed on the side of the second surface (322) of the movable contactor (32) in the housing (1) and driving the movable shaft (35) to move the movable contactor (32) back and forth in the moving direction; and a damping mechanism unit (60) provided in the closed space (70) and having an insulating damping element (61) arranged between the movable contactor (32) and the electromagnetic drive unit (40), and a sound-insulating gap (62) provided between the damping element (61) and the electromagnetic drive unit (40), where the movable shaft (35) has a movement-restricting unit (35a) which separates from the damping element (61) when the movable contactor (32) approaches the fixed contact arrangement surface (311), and comes into contact with the damping element (61) after the separation of the movable contactor (32) from the fixed contact arrangement surface (311) to restrict the movement of the movable shaft (35) in a direction in which the movable contactor (32) separates, and the damping element (61) has a collision noise damping unit (63) configured to make a path along which the collision noise propagates longer than a path along which the collision noise propagates toward the outside of the housing (1) in a state in which the damping element (61) and the electromagnetic drive unit (40) are in contact with each other without the sound-insulating gap (62), wherein the collision noise is generated when the movement-restricting unit (35a) of the movable shaft (35) comes into contact with the damping element (61). [2] An electromagnetic relay according to claim 1, wherein the sound-insulating gap (62) is provided at a position at least closer to the movable shaft (35) than the collision noise-damping unit (63) in a direction crossing the moving direction of the movable contactor (32). [3] The electromagnetic relay according to claim 1 or 2, wherein the collision noise damping unit (63) is U-shaped in a sectional view along the moving direction of the movable contactor (32) and has a winding portion (64), whereby a path on which the collision noise propagates is winding. [4] Electromagnetic relay according to claim 3, wherein the damping element (61) is composed of the wound portion (64) and a collar portion (61b) extending in a direction that crosses the direction of movement of the movable contactor (32), and the winding section (64) comprises: a first peripheral wall portion (641) extending from the collar portion (61b) of the damping element (61) along the movable shaft (35), a connecting wall portion (642) extending from another end of the first peripheral wall portion (641) further away from the collar portion (61b) in a direction crossing the movable shaft (35), and a second peripheral wall portion (643) extending from another end of the connecting wall portion (642) further away from the first peripheral wall portion (641) along the movable shaft (35) in a direction opposite to the first peripheral wall portion (641). [5] An electromagnetic relay according to claim 3 or 4, wherein said collision noise damping unit (63) comprises a plurality of wound portions (64) sequentially connected to each other.

Images