Patent Publication Number: US-10325741-B2

Title: Electromagnetic relay

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2016-020160 filed on Feb. 4, 2016, the entire contents of which are incorporated herein by reference. 
     FIELD 
     A certain aspect of the embodiments is related to an electromagnetic relay. 
     BACKGROUND 
     When the vibration (e.g. vibration generated at the time of opening and closing of a contact) of an electromagnetic relay (hereinafter referred to as “a relay”) propagates to the outside, it causes a noise. There has been known a relay in which a spring member is arranged between a relay body and a plug terminal and the spring member elastically supports the relay body, in order to restrict the propagation of the vibration caused from the relay body toward the plug terminal (e.g. see Japanese Laid-open Patent Publication No. 2012-142210). In the relay, a space is provided between the relay body and an outer cover. 
     SUMMARY 
     According to an aspect of the present invention, there is provided an electromagnetic relay including: a relay body that includes a first terminal; a base that includes a second terminal which contacts the first terminal and supports the relay body; an outer cover that covers the relay body; and an elastic member that is attached between the relay body and the outer cover. 
     The objects and advantages of the invention will be realized and attained by the elements and combinations particularly pointed out in the claims. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an exploded perspective view of an electromagnetic relay according to a first embodiment; 
         FIG. 2  is a diagram illustrating the assembly structure of the electromagnetic relay; 
         FIGS. 3A and 3B  are cross-section diagrams of springs for pressing the electromagnetic relay; 
         FIG. 4  is a cross-section diagram taken along line A-A in  FIG. 2 ; 
         FIG. 5  is an exploded perspective view of an electromagnetic relay according to a second embodiment; 
         FIG. 6  is a diagram illustrating the assembly structure of the electromagnetic relay; 
         FIG. 7  is a cross-section diagram of a spring for pressing the electromagnetic relay; 
         FIG. 8  is a cross-section diagram taken along line B-B in  FIG. 6 ; 
         FIG. 9  is a cross-section diagram taken along line A-A in  FIG. 6 ; 
         FIG. 10  is an exploded perspective view of an electromagnetic relay according to a third embodiment; 
         FIG. 11  is a diagram illustrating the structure of an outer cover as viewed from below; 
         FIG. 12  is a perspective view of an electromagnetic relay according to a fourth embodiment before an elastic member is inserted; 
         FIG. 13  is a perspective view of the electromagnetic relay according to the fourth embodiment after the elastic member is inserted; 
         FIG. 14A  is a diagram illustrating a shape of the elastic member; 
         FIG. 14B  is a diagram illustrating a shape of the elastic member before insertion; 
         FIG. 15  is a cross-section diagram taken along line A-A in  FIG. 12 ; 
         FIG. 16  is an exploded perspective view of an electromagnetic relay according to a fifth embodiment; 
         FIG. 17  is a diagram illustrating the assembly structure of the electromagnetic relay; 
         FIG. 18  is a cross-section diagram taken along line A-A in  FIG. 17 ; 
         FIG. 19  is an exploded perspective view of an electromagnetic relay according to a sixth embodiment; 
         FIG. 20  is a diagram illustrating the assembly structure of the electromagnetic relay; 
         FIG. 21  is a cross-section diagram taken along line A-A in  FIG. 20 ; 
         FIG. 22  is an exploded perspective view of an electromagnetic relay according to a seventh embodiment; 
         FIG. 23  is a cross-section diagram taken along line A-A in  FIG. 22 ; 
         FIG. 24  is an exploded perspective view of an electromagnetic relay according to an eighth embodiment; 
         FIG. 25  is a diagram illustrating the assembly structure of the electromagnetic relay; 
         FIG. 26  is a cross-section diagram taken along line A-A in  FIG. 25 ; 
         FIG. 27  is an exploded perspective view of an electromagnetic relay according to a ninth embodiment; and 
         FIG. 28  is a cross-section diagram taken along line B-B in  FIG. 27 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     In an electromagnetic relay disclosed in Japanese Laid-open Patent Publication No. 2012-142210, the vibration propagates to a spring member, and hence an effect of the noise reduction is insufficient. 
     A description will now be given of embodiments according to the present invention with reference to drawings. 
     (FIRST EMBODIMENT)  FIG. 1  is an exploded perspective view of an electromagnetic relay according to a first embodiment.  FIG. 2  is a diagram illustrating the assembly structure of the electromagnetic relay.  FIGS. 3A and 3B  are cross-section diagrams of springs for pressing the electromagnetic relay.  FIG. 4  is a cross-section diagram taken along line A-A in  FIG. 2 . In the following, a front direction, a rear direction, a right direction, a left direction, an up direction, and a down direction are defined as illustrated in  FIG. 1  for convenience of explanation. 
     An electromagnetic relay  1 A (hereinafter referred to as “a relay”) according to a first embodiment includes an outer cover  11 , a relay body  14 , a base  12 , as illustrated in  FIG. 1 . That is, the silent type relay  1 A is formed by covering the relay body  14  with the outer cover  11  and the base  12 . The outer cover  11  and the base  12  constitute an outer case. As illustrated in  FIG. 4 , grooves  101  as a first groove are formed on an inner wall of the outer cover  11 . 
     The relay body  14  includes an electromagnet not shown, a movable contact not shown, a fixed contact not shown, coil terminals  17  and contact terminals  18  (see  FIG. 4 ). The coil terminals  17  and the contact terminals  18  serve as a first terminal. The relay body  14  may be a so-called hinge type relay or a plunger type relay. As illustrated in  FIG. 1 , grooves  15  as a second groove are formed on a housing  14 A of the relay body  14 . 
     The coil terminals  17  and the contact terminals  18  are bent, and include flat portions  17 A and  18 A (an example of a first flat portion) in parallel with a bottom surface of the housing  14 A of the relay body  14 , as illustrated in  FIG. 4 . The flat portions  17 A and  18 A are provided outside the housing  14 A of the relay body  14 . 
     The base  12  includes external terminals  16  as a second terminal supporting the relay body  14 . Each of the external terminals  16  includes a leg portion  16 A that is connected to an external device, not shown, and extends perpendicularly from the base  12 , and a flat portion  16 B (an example of a second flat portion) that is bent from an upper end of the leg portion  16 A, and is in parallel with an upper surface of the base  12  or the bottom surface of the housing  14 A of the relay body  14 . The flat portion  16 B comes into surface contact with the flat portions  17 A and  18 A in assembling, as illustrated in  FIG. 4 . In the example of  FIGS. 1 and 4 , there are four external terminals  16 , two coil terminals  17  and two contact terminals  18 . The number of external terminals  16 , coil terminals  17  and contact terminals  18  does not have limitation. 
     In  FIG. 1 , the outer cover  11  is transparent. Elastic members, plate springs  13  in  FIG. 1 , are attached to the inner wall of the outer cover  11 . The plate springs  13  include a plate spring  13 A and a plate spring  13 B which have an uneven cross section, as illustrated in  FIGS. 3A and 3B . Specifically, the plate spring  13 A has a substantially V-shaped cross section, and the plate spring  13 B has a substantially W-shaped cross section. 
     First engaging portions  130  that engage with the grooves  101  formed on the inner wall of the outer cover  11  are formed on both ends of the plate springs  13 A and  13 B. Moreover, second engaging portions  131  that engage with the grooves  15  formed on the housing  14 A are formed on a center of the plate spring  13 A and two tops of the plate spring  13 B which are a middle portion of the plate spring  13  and contact with the housing  14 A of the relay body  14 . 
     When the outer cover  11  to which the plate springs  13 A and  13 B are attached covers the relay body  14  arranged on the base  12 , the second engaging portions  131  of the plate springs  13 A and  13 B engage with the grooves  15  formed on the housing  14 A of the relay body  14 , and hence the position of the relay body  14  is fixed. Here, the outer cover  11  is fixed on the base  12  with an adhesive. Moreover, the base  12  may be fixed to the outer cover  11  by press fit. 
     A force of the plate springs  13 A and  13 B for pressing the relay body  14 , which is generated by the second engaging portions  131  contacting the housing  14 A, presses the flat portions  17 A and  18 A against the flat portions  16 B. At this time, a vibration generated in the relay body  14  is attenuated by a friction generated between the flat portions  17 A and  18 A and the flat portions  16 B, and it is restrained to propagate the vibration to the outside of the relay. 
     In the first embodiment, the plate springs  13  arc provided on the front, the rear, the right, the left and the upper sides of the inner wall of the outer cover  11 . However, if the vibration generated in the relay body  14  can be restricted, the plate springs  13  may be provided on only a part of the inner wall of the outer cover  11 . For example, the plate springs  13 B may be provided on only the right and the left sides of the inner wall of the outer cover  11 . Alternatively, the plate springs  13 B may be provided on only the upper side of the inner wall of the outer cover  11 . Alternatively, the plate springs  13 A may be provided on only the front and the rear sides of the inner wall of the outer cover  11 . 
     (SECOND EMBODIMENT)  FIG. 5  is an exploded perspective view of an electromagnetic relay according to a second embodiment.  FIG. 6  is a diagram illustrating the assembly structure of the electromagnetic relay.  FIG. 7  is a cross-section diagram of a spring for pressing the electromagnetic relay.  FIG. 8  is a cross-section diagram taken along line B-B in  FIG. 6 .  FIG. 9  is a cross-section diagram taken along line A-A in  FIG. 6 . Elements corresponding to those of the first embodiment are designated by identical reference numerals, and a description thereof is omitted. In the following, the front direction, the rear direction, the right direction, the left direction, the up direction, and the down direction are defined as illustrated in  FIG. 5  for convenience of explanation. 
     As illustrated in  FIG. 5 , a relay  1 B according to a second embodiment includes the outer cover  11 , the relay body  14  and the base  12 . Receiving portions  20  for attaching plate springs  21  are formed on the inner wall of the outer cover  11 , as illustrated in  FIG. 9 . In  FIGS. 5 and 6 , the receiving portions  20  are omitted. 
     As illustrated in  FIG. 5 , two rod-like projections  22  (an example of a fitted portion) extending parallel are formed on each surface (except a bottom surface) of the housing  14 A of the relay body  14 . An interval between the two projections  22  is the same as a width “w” of the plate spring  21 , as illustrated in  FIGS. 6 and 8 . The plate spring  21  is fitted between the two projections  22 . 
     In  FIGS. 5 and 6 , the outer cover  11  is transparent. The plate springs  21 , an example of an elastic member, are attached to the inner wall of the outer cover  11 . Moreover, bending portions  211  to be fitted into the receiving portions  20  formed on the inner wall of the outer cover  11  are formed on both ends of each plate spring  21 , as illustrated in  FIG. 7 . A flat portion  212 , as a third flat portion, is formed on the center of the plate spring  21 . When the plate spring  21  is attached to the receiving portions  20  and the plate spring  21  is compressed as illustrated in  FIG. 7 , the flat portion  212  curves in a bending direction of the bending portions  211  illustrated in  FIG. 7 , and the plate spring  21  curves so as to contact the housing  14 A of the relay body  14  illustrated in  FIG. 9 . A part of the curved flat portion  212  is fitted between the projections  22 , as illustrated in  FIGS. 8 and 9 . When the outer cover  11  in which the plate spring  21  is fitted into the receiving portions  20  covers the relay body  14  arranged on the base  12 , the part of the flat portion  212  of the plate spring  21  is fitted between the projections  22  formed on the housing  14 A of the relay body  14 , and the position of the relay body  14  is fixed. Here, the outer cover  11  is fixed to the base  12  with an adhesive. Moreover, the base  12  may be fixed to the outer cover  11  by press fit. 
     A force of the plate springs  21  for pressing the relay body  14 , which is generated by contacting the housing  14 A, presses the flat portions  17 A and  18 A against the flat portions  16 B. At this time, a vibration generated in the relay body  14  is attenuated by a friction generated between the flat portions  17 A and  18 A and the flat portions  16 B, and it is restrained to propagate the vibration to the outside of the relay. 
     In the second embodiment, the plate springs  21  are provided on each inner wall of the outer cover  11 . However, the plate springs  21  may be provided on only a part of the inner wall of the outer cover  11 . For example, the plate springs  21  may be provided on only the front and rear sides of the inner wall of the outer cover  11 . Alternatively, the plate springs  21  may be provided on only the right and left sides of the inner wall of the outer cover  11 . Alternatively, the plate springs  21  may be provided on only the upper side of the inner wall of the outer cover  11 . 
     (THIRD EMBODIMENT)  FIG. 10  is an exploded perspective view of an electromagnetic relay according to a third embodiment.  FIG. 11  is a diagram illustrating the structure of the outer cover as viewed from below. Elements corresponding to those of the second embodiment are designated by identical reference numerals, and a description thereof is omitted. In the following, the front direction, the rear direction, the right direction, the left direction, the up direction, and the down direction are defined as illustrated in  FIG. 10  for convenience of explanation. 
     As illustrated in  FIG. 10 , a relay  1 C according to a third embodiment includes the outer cover  11 , the relay body  14  and the base  12 . The outer cover  11  is divided into a first outer cover  11 A and a second outer cover  11 B, as illustrated in  FIGS. 10 and 11 . Here, the outer cover  11  is divided into two, and may be divided into “n (n=3 or more)”. 
     The receiving portions  20  for attaching plate springs  21  are formed on the inner wall of the first outer cover  11 A and the second outer cover  11 B. Recess portions  23  and claw portions  24  as a third engaging portion are formed on an edge of the first outer cover  11 A to be coupled with the second outer cover  11 B. Similarly, the recess portions  23  and the claw portions  24  are formed on an edge of the second outer cover  11 B to be coupled with the first outer cover  11 A. The claw portions  24  of the second outer cover  11 B engage with the recess portions  23  of the first outer cover  11 A, and the claw portions  24  of the first outer cover  11 A engage with the recess portions  23  of the second outer cover  11 B. The first outer cover  11 A and the second outer cover  11 B are coupled with each other so as not to generate a gap by the recess portions  23  and the claw portions  24 . In the third embodiment, the outer cover  11  can be divided, and therefore the plate springs  21  are easily attached to the first outer cover  11 A and the second outer cover  11 B. 
     In the third embodiment, the plate springs  21  are provided on the inner wall (i.e., the front, the rear, the right, the left and the upper sides of the inner wall) of the first outer cover  11  A and the second outer cover  11 B. However, the plate springs  21  need not be provided on all of the inner wall of the first outer cover  11  A and the second outer cover  11 B. For example, the plate springs  21  may be provided on only the front and the rear sides of the inner wall of the first outer cover  11 A and the second outer cover  11 B. Alternatively, the plate springs  21  may be provided on only the right and the left sides of the inner wall of the first outer cover  11 A and the second outer cover  11 B. Alternatively, the plate springs  21  may be provided on only the upper side of the inner wall of the first outer cover  11 A and the second outer cover  11 B. 
     (FOURTH EMBODIMENT)  FIG. 12  is a perspective view of an electromagnetic relay according to a fourth embodiment before an elastic member is inserted.  FIG. 13  is a perspective view of the electromagnetic relay according to the fourth embodiment after the elastic member is inserted.  FIG. 14A  is a diagram illustrating a shape of the elastic member, and  FIG. 14B  is a diagram illustrating a shape of the elastic member before insertion.  FIG. 15  is a cross-section diagram taken along line A-A in  FIG. 12 . Elements corresponding to those of the first embodiment are designated by identical reference numerals, and a description thereof is omitted. In the following, the front direction, the rear direction, the right direction, the left direction, the up direction, and the down direction are defined as illustrated in  FIG. 12  for convenience of explanation. 
     As illustrated in  FIG. 12 , a relay  1 D according to a fourth embodiment includes the outer cover  11 , the relay body  14  and the base  12 . 
     In  FIGS. 12 and 13 , the outer cover  11  is transparent. A through-hole  25  for inserting an elastic member  26  is formed on the center of each surface of the outer cover  11 . The elastic member  26  is made of a rubber, a spring or the like, and has a Y-shape in a natural state. The elastic member  26  includes a body portion  26 A and a forked portion  26 B. The dimension D 1  of the body portion  26 A is smaller than the through-hole  25 . Therefore, the body portion  26 A can pass the through-hole  25 . On the other hand, a width W 2  of the forked portion  26 B in a widely spread condition is larger than the through-hole  25 , as illustrated in  FIG. 14A . Therefore, the forked portion  26 B in the widely spread condition cannot pass the through-hole  25 . To pass the elastic member  26  through the through-hole  25 , a force is applied to the forked portion  26 B, and the forked portion  26 B is temporarily transformed into a rod shape, as illustrated in  FIG. 14B . Then, the elastic member  26  is inserted into the through-hole  25 . When the forked portion  26 B passes through the through-hole  25  and enters in the inside of the outer cover  11 , the forked portion  26 B spreads naturally as illustrated in  FIG. 13  and returns to the shape of  FIG. 14A . 
     When the forked portion  26 B of the elastic member  26  inserted into the through-hole  25  returns to an original shape, a force in which the forked portion  26 B presses the relay body  14  presses the flat portions  17 A and  18 A against the flat portions  16 B. At this time, it is restrained that a vibration generated in the relay body  14  propagates to the outside of the relay by a friction generated between the flat portions  17 A and  18 A and the flat portions  16 B. 
     Here, the shape of the elastic member  26  is not limited to the shape of  FIG. 14A . For example, the forked portion  26 B may be formed on both ends of the elastic member  26 . 
     In the fourth embodiment, the through-hole  25  is formed on the center of each surface of the outer cover  11 , and the elastic member  26  is inserted into the through-hole  25 . However, the through-hole  25  need not be formed on all surfaces of the outer cover  11 , and the elastic members  26  need not be inserted into all through-holes  25  of the outer cover  11 . For example, the through-holes  25  may be provided on only the front and the rear surfaces of the outer cover  11 . Alternatively, the through-holes  25  may be provided on only the right and the left surfaces of the outer cover  11 . Alternatively, the through-hole  25  may be provided on only the upper surface of the outer cover  11 . For example, the elastic members  26  may be inserted into only the through-holes  25  of the front and the rear surfaces of the outer cover  11 . Alternatively, the elastic members  26  may be inserted into only the through-holes  25  of the right and the left surfaces of the outer cover  11 . Alternatively, the elastic member  26  may be inserted into only the through-hole  25  of the upper surface of the outer cover  11 . 
     (FIFTH EMBODIMENT)  FIG. 16  is an exploded perspective view of an electromagnetic relay according to a fifth embodiment.  FIG. 17  is a diagram illustrating the assembly structure of the electromagnetic relay.  FIG. 18  is a cross-section diagram taken along line A-A in  FIG. 17 . Elements corresponding to those of the first embodiment are designated by identical reference numerals, and a description thereof is omitted. In the following, the front direction, the rear direction, the right direction, the left direction, the up direction, and the down direction are defined as illustrated in  FIG. 16  for convenience of explanation. 
     As illustrated in  FIG. 16 , a relay  1 E according to a fifth embodiment includes the outer cover  11 , the relay body  14 , the base  12  and an elastic member  27 . The elastic member  27  is made of an elastomer, for example. As illustrated in  FIGS. 17 and 18 , the elastic member  27  has a case structure without a bottom surface, as with the outer cover  11 . The elastic member  27  covers the relay body  14  so as to contact the housing  14 A, and contacts the inner cover of the outer cover  11 . 
     When the outer cover  11  covers the relay body  14  to which the elastic member  27  is attached, a force in which the elastic member  27  contacting the housing  14 A presses the relay body  14  presses the flat portions  17 A and  18 A against the flat portions  16 B. At this time, it is restrained that the vibration generated in the relay body  14  propagates to the outside of the relay by the friction generated between the flat portions  17 A and  18 A and the flat portions  16 B. 
     (SIXTH EMBODIMENT)  FIG. 19  is an exploded perspective view of an electromagnetic relay according to a sixth embodiment.  FIG. 20  is a diagram illustrating the assembly structure of the electromagnetic relay.  FIG. 21  is a cross-section diagram taken along line A-A in  FIG. 20 . Elements corresponding to those of the first embodiment are designated by identical reference numerals, and a description thereof is omitted. In the following, the front direction, the rear direction, the right direction, the left direction, the up direction, and the down direction are defined as illustrated in  FIG. 19  for convenience of explanation. 
     As illustrated in  FIG. 19 , a relay  1 F according to a sixth embodiment includes the outer cover  11 , the relay body  14 , the base  12  and an elastic member  28 . The elastic member  28  is a substantially U-shaped plate spring, and is an integrated structure having waveform springs  29  (an example of a waveform portion) and flat springs  30  (an example of fourth portion). As illustrated in  FIG. 21 , the waveform springs  29  contact the inner wall of the outer cover  11 , and the front surface, the rear surface and the upper surface of the relay body  14 . The flat springs  30  have plate shapes along the front surface, the rear surface and the upper surface of the relay body  14 , and do not contact the inner wall of the outer cover  11 . Moreover, formed on both ends of the elastic member  28  are projections  31  that engage with grooves  32  provided on lower ends of the front and the rear surfaces of the relay body  14 . The relay body  14  is covered with the elastic member  28  and the projections  31  are fitted in the grooves  32 , so that the elastic member  28  can be easily attached to the relay body  14 . 
     Although the grooves  32  are formed on the front surface and the rear surface of the relay body  14 , the grooves  32  may be formed on the right surface and the left surface of the relay body  14 . Alternatively, the grooves  32  may be formed on all side surfaces of the relay body  14 . At this time, an attachment position of the elastic member  28  to the relay body  14  can be changed according to the size of the elastic member  28 . 
     When the outer cover  11  covers the relay body  14  to which the elastic member  28  is attached, as illustrated in  FIGS. 20 and 21 , each of the waveform springs  29  contacts the outer cover  11  and the housing  14 A and a force in which the elastic member  28  presses the relay body  14  presses the flat portions  17 A and  18 A against the flat portions  16 B. At this time, it is restrained that the vibration generated in the relay body  14  propagates to the outside of the relay by the friction generated between the flat portions  17 A and  18 A and the flat portions  16 B. 
     In the elastic member  28  illustrated in  FIG. 19 , the waveform springs  29  are formed at positions opposite to the front surface, the rear surface and the upper surface of the housing  14 A. However, if the vibration generated in the relay body  14  can be restricted, the waveform springs  29  need not be formed at all positions opposite to all surfaces of the housing  14 A. For example, the waveform springs  29  may be formed at only positions opposite to the front and the rear surfaces of the housing  14 A. Alternatively, the waveform spring  29  may be formed at only a position opposite to the upper surface of the housing  14 A. 
     (SEVENTH EMBODIMENT)  FIG. 22  is an exploded perspective view of an electromagnetic relay according to a seventh embodiment.  FIG. 23  is a cross-section diagram taken along line A-A in  FIG. 22 . Elements corresponding to those of the first embodiment are designated by identical reference numerals, and a description thereof is omitted. 
     As illustrated in  FIG. 22 , a relay  1 G according to a seventh embodiment includes the outer cover  11 , the relay body  14 , the base  12  and a plurality of elastic members  33 . Each elastic member  33  is made of a box-like rubber or the like, for example. The elastic members  33  are stuck on the inner wall of the outer cover  11  or the surfaces of the housing  14 A of the relay body  14  with an adhesive. Here, the number of elastic members  33  is not limited to the example of  FIGS. 22 and 23 . For example, at least one elastic member  33  may be arranged between a single surface of the housing  14 A of the relay body  14  and the inner wall of the outer cover  11  opposite to the single surface. 
     When the outer cover  11  covers the relay body  14  to which the elastic members  33  are attached or the outer cover  11  to which the elastic members  33  are attached covers the relay body  14 , a force in which the elastic members  33  press the relay body  14  presses the flat portions  17 A and  18 A against the flat portions  16 B. At this time, it is restrained that the vibration generated in the relay body  14  propagates to the outside of the relay by the friction generated between the flat portions  17 A and  18 A and the flat portions  16 B. 
     In the seventh embodiment, the elastic members  33  are provided on the front surface, the rear surface, the right surface, the left surface and the upper surface of the housing  14 A or on the each inner wall of the outer cover  11 . However, the elastic members  33  need not be provided on all surfaces of the housing  14 A or on all the inner wall of the outer cover  11 . For example, the elastic members  33  may be provided on only the right surface and the left surface of the housing  14 A or only the right and left surfaces of the inner wall of the outer cover  11 . Alternatively, the elastic members  33  may be provided on only the upper surface of the housing  14 A or only the upper surface of the inner wall of the outer cover  11 . The elastic members  33  may be provided on only the front surface and the rear surface of the housing  14 A or only the front and rear surfaces of the inner wall of the outer cover  11 . 
     (EIGHTH EMBODIMENT)  FIG. 24  is an exploded perspective view of an electromagnetic relay according to an eighth embodiment.  FIG. 25  is a diagram illustrating the assembly structure of the electromagnetic relay.  FIG. 26  is a cross-section diagram taken along line A-A in  FIG. 25 . Elements corresponding to those of the first embodiment are designated by identical reference numerals, and a description thereof is omitted. In the following, the front direction, the rear direction, the right direction, the left direction, the up direction, and the down direction are defined as illustrated in  FIG. 24  for convenience of explanation. 
     A relay  1 H according to an eighth embodiment includes the outer cover  11 , the relay body  14  and the base  12 , as with the relay  1  A according to the first embodiment. In the eighth embodiment, the grooves  15  are formed on the inner wall of the outer cover  11 , and the grooves  101  which engage with the first engaging portions  130  of the plate springs  13 A and  13 B are formed on the housing  14 A of the relay body  14 , as illustrated in  FIG. 26 . In  FIGS. 24 and 25 , the outer cover  11  is transparent. Elastic members, the plate springs  13 A and  13 B in  FIGS. 24 and 25 , are attached to the housing  14 A of the relay body  14 . The shapes of the plate springs  13 A and  13 B are the same as the shapes illustrated in  FIGS. 3A and 3B . 
     When the relay body  14  to which the plate springs  13 A and  13 B are attached is arranged on the base  12  and the outer cover  11  covers the relay body  14 , the second engaging portions  131  of the plate springs  13 A and  13 B engage with the grooves  15  formed on the inner walls of the outer cover  11 , and hence the position of the relay body  14  to the outer cover  11  is fixed. Here, the outer cover  11  is fixed on the base  12  with an adhesive. Moreover, the base  12  may be fixed to the outer cover  11  by press fit. 
     When a force in which the plate springs  13 A and  13 B press the flat portions  17 A and  18 A against the flat portions  16 B. At this time, it is restrained that the vibration generated in the relay body  14  propagates to the outside of the relay by the friction generated between the flat portions  17 A and  18 A and the flat portions  16 B. 
     In the eighth embodiment, the plate springs  13 A and  13 B are provided on the front surface, the rear surface, the right surface, the left surface and the upper surface of the housing  14 A. However, if the vibration generated in the relay body  14  can be restricted, the plate springs  13  may be provided on only a part of the surfaces of the housing  14 A. For example, the plate springs  13 B may be provided on only the right and the left surfaces of the housing  14 A. Alternatively, the plate springs  13 B may be provided on only the upper surface of the housing  14 A. Alternatively, the plate springs  13 B may be provided on only the front and the rear surfaces of the housing  14 A. 
     (NINTH EMBODIMENT)  FIG. 27  is an exploded perspective view of an electromagnetic relay according to a ninth embodiment.  FIG. 28  is a cross-section diagram taken along line B-B in  FIG. 27 . Elements corresponding to those of the first embodiment and the sixth embodiment are designated by identical reference numerals, and a description thereof is omitted. In the following, the front direction, the rear direction, the right direction, the left direction, the up direction, and the down direction are defined as illustrated in  FIG. 27  for convenience of explanation.  100821  As illustrated in  FIG. 27 , a relay II according to a ninth embodiment includes the outer cover  11 , the relay body  14 , the base  12  and the elastic member  28 . 
     The elastic member  28  is a substantially U-shaped plate spring, and is the integrated structure having the waveform springs  29  and the flat springs  30 . 
     As illustrated in  FIG. 28 , the waveform springs  29  contact the inner wall of the outer cover  11  opposite to the upper surface of the relay body  14 , and two projections  35  extending parallel are formed on the inner wall of the outer cover  11  opposite to the upper surface of the relay body  14  to prevent the deviation of the elastic member  28  in a width direction. The waveform springs  29  are arranged between the projections  35 . Here, the projections  35  may be formed on the inner wall of the outer cover  11  opposite to the side surfaces of the relay body  14 . 
     When the outer cover  11  covers the relay body  14  to which the elastic member  28  is attached, the waveform springs  29  enter between the projections  35 . 
     Then, a force in which the elastic member  28  presses the relay body  14  presses the coil terminals  17  and the contact terminals  18  of the relay body  14  against the external terminals  16  of the base  12 . At this time, it is restrained that the vibration generated in the relay body  14  propagates to the outside of the relay by the friction generated between the flat portions  17 A and  18 A and the flat portions  16 B. Moreover, the projections  35  prevent the deviation of the elastic member  28  in the width direction. 
     In the first to the ninth embodiments, the plate spring, the rubber or the elastomer is used as the elastic member, but a coil spring may be used as the elastic member. 
     As described above, according to the first to the ninth embodiments, the electromagnetic relay ( 1 A- 1 I) includes: the relay body  14  that includes the coil terminals  17  and the contact terminals  18 ; the base  12  that includes the external terminals  16  which contact the coil terminals  17  and the contact terminals  18  and support the relay body  14 ; the outer cover  11  that covers the relay body  14  along with the base  12 ; and the elastic member (the plate springs  13 A and  13 B, the plate spring  21  or the elastic member  26 ,  27 ,  28  or  33 ) that is attached between the relay body  14  and the outer cover  11 . The force in which the elastic member presses the relay body  14  presses the coil terminals  17  and the contact terminals  18  of the relay body  14  against the external terminals  16  of the base  12 . Therefore, it can be restrained that the vibration generated in the relay body  14  propagates to the outside of the relay by the friction generated between the external terminals  16 , and the coil terminals  17  and the contact terminals  18 . 
     All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various change, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.