Patent Publication Number: US-6903638-B2

Title: Complex electromagnetic relay

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to an electromagnetic relay and, more particularly, to a complex electromagnetic relay including a plurality of relay structures, accommodated in a common housing, which are configured respectively as electromagnetic relays functionally independent of each other. 
   2. Description of the Related Art 
   There is known a complex electromagnetic relay including a plurality of relay structures accommodated in a single common housing in a side-by-side arrangement, wherein the respective relay structures are configured as electromagnetic relays functionally independent of each other and wherein each relay structure includes an electromagnet assembly and a contact section acting to open or close in accordance with the operation of the electromagnet assembly. This type of complex electromagnetic relay can be used in a control circuit frequently switching the operation of a motor or a solenoid between normal and reverse directions. Also, due to the provision of the common housing, the complex electromagnetic relay exhibits an effect of reducing a relay mount space, in comparison with a configuration using a plurality of electromagnetic relays having respective housings independent of each other, and, therefore, is effectively applicable to a control circuit where circuit components must be mounted in a narrow space, e.g., a control circuit for a vehicle-mounted electric-powered appliance such as a power window. particularly, a complex electromagnetic relay, in which a plurality of relay structures are configured as electromagnetic relays mechanically independent of each other in a common housing, makes it possible to control plural electric-powered appliances individually and in a timely fashion by a single complex electromagnetic relay, in contrast to another type of complex electromagnetic relay in which a pair of relay structures share a certain part of contact sections thereof with each other by, e.g., sharing a terminal member having a stationary terminal (i.e., a stationary contact member). 
   Japanese Unexamined patent publication (Kokai) No. 2003-59383 (JP-A-2003-59383) discloses a complex electromagnetic relay, in which plural (or a pair of) relay structures independent of each other are accommodated in a single housing so as to be oriented reversely to each other with the contact sections thereof being located alternately at opposing sides. In such an arrangement that the plural relay structures are placed to be inverted relative to each other as described in JP-A-2003-59383, coil-terminal pairs provided in the respective relay structures are arranged so as to protrude from the housing at positions spaced away from each other and, therefore, it is possible to advantageously facilitate the formation of a circuit pattern in an electromagnetic-relay mount board. 
   In the complex electromagnetic relay disclosed in JP-A-2003-59383, a pair of relay structures, each of which is configured as an independent electromagnetic relay, are mounted in a mutually inverted orientation onto a base block acting as a common holding member, and a box-like cover is attached to the base block so as to form the housing accommodating the relay structures. In this arrangement, problems may arise due to the presence of the base block, in that the dimension of the complex electromagnetic relay is increased especially in a height direction, and that the numbers of parts and of assembling steps are increased. Further, in this arrangement, it may be difficult to reduce the dimension of a housing while ensuring a desired insulation distance or clearance between the relay structures disposed side-by-side or, in particular, between armatures as actuating elements, in the respective electromagnet assemblies. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a complex electromagnetic relay including a plurality of relay structures accommodated in a common housing, which are configured respectively as electromagnetic relays independent of each other, in a mutually inverted orientation with the contact sections thereof being located alternately at opposing sides, wherein it is possible to reduce the dimension in a height direction as well as the numbers of parts and assembling steps, and wherein it is possible to ensure a desired insulation distance between the relay structures disposed side-by-side. 
   To accomplish the above object, the present invention provides a complex electromagnetic relay comprising a plurality of relay structures configured respectively as relays independent of each other, each relay structure including an electromagnet assembly and a contact section acting to open or close in accordance with an operation of the electromagnet assembly; and a housing accommodating the relay structures in a mutually inverted orientation with contact sections of the relay structures being located alternately at opposing sides; wherein electromagnet assemblies in the plurality of relay structures are provided, individually, with bobbins supporting coils; wherein the housing includes an enclosing wall enclosing the plurality of relay structures in an envelope-like manner and a partition wall arranged between the relay structures disposed side-by-side to separate the relay structures from each other; and wherein the bobbins of the electromagnet assemblies are fixedly attached to the enclosing wall as well as to the partition wall. 
   In the above complex electromagnetic relay, the housing may define a plurality of receptacles between the enclosing wall and the partition wall; and the complex electromagnetic relay may further comprise locating elements provided respectively in the plurality of receptacles of the housing, for constraining the relay structures into an mutually inverted orientation in the receptacles. 
   In this arrangement, the locating elements may comprise protrusions protruding in the plurality of receptacles of the housing in a mutually opposing positional relationship. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects, features and advantages of the present invention will become more apparent from the following description of preferred embodiments in connection with the accompanying drawings, wherein: 
       FIG. 1  is an exploded perspective view showing a complex electromagnetic relay according to an embodiment of the present invention, as viewed from a bottom side; 
       FIG. 2  is an exploded perspective view showing the electromagnetic relay of  FIG. 1 , as viewed from a top side; 
       FIG. 3  is a sectional view, taken along a line III—III in  FIG. 4 , showing the electromagnetic relay of  FIG. 1  in an assembled state; 
       FIG. 4  is a sectional view showing the electromagnetic relay taken along a line IV—IV in  FIG. 3 ; 
       FIG. 5  is a sectional view showing the electromagnetic relay taken along a line V—V in  FIG. 4 ; 
       FIG. 6  is a plan view showing a housing provided in the electromagnetic relay of  FIG. 1 , as viewed from an opening side thereof; 
       FIG. 7  is a perspective view showing the housing of  FIG. 6 , as viewed in a direction of an arrow VII; 
       FIG. 8  is a perspective view showing the housing of  FIG. 6 , as viewed in a direction of an arrow VIII; and 
       FIG. 9  is a perspective view showing the housing of  FIG. 6 , as viewed in a direction of an arrow IX. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The embodiments of the present invention are described below in detail, with reference to the accompanying drawings. In the drawings, the same or similar components are denoted by common reference numerals. 
   Referring to the drawings,  FIG. 1  is an exploded perspective view showing a complex electromagnetic relay  10 , according to one embodiment of the present invention, as viewed from the bottom side thereof;  FIG. 2  is an exploded perspective view showing the complex electromagnetic relay  10  as viewed from the top side thereof; and  FIGS. 3  to  5  are sectional views of the complex electromagnetic relay  10 . AS shown in  FIGS. 1 and 2 , the complex electromagnetic relay  10  includes a pair of relay structures  16  configured respectively as electromagnetic relays independent of each other, each relay structure including an electromagnet assembly  12  and a contact section  14  acting to open or close in accordance with the operation of the electromagnet assembly  12 ; and a housing  18  accommodating the relay structures  16  in a mutually inverted orientation with the contact sections  14  of the relay structures  16  being located alternately at opposing sides. 
   The electromagnet assembly  12  of each relay structure  16  includes an electromagnet  20  and an armature  22  driven by the electromagnet  20 . As shown in  FIG. 3 , the electromagnet  20  includes a bobbin  24 , a coil  26  wound and supported on the bobbin  24 , and an iron core  28  attached to the bobbin  24  along a center axis  26   a  of the coil  26 . The bobbin  24  is formed of an electrically insulating resinous molded article, and is provided with a hollow body  24   a  having a predetermined length for carrying the coil  26  and a pair of annular rectangular flanges  24   b ,  24   c  integrally joined to the opposite longitudinal ends of the body  24   a.    
   The coil  26  is formed by tightly winding a required length of a conductive wire on the body  24   a  of the bobbin  24 , and is securely held between the flanges  24   b ,  24   c  of the bobbin  24 . The core  28  is a columnar member made of, e.g., a magnetic steel, and a generally cylindrical major part  28   a  thereof is securely received inside the body  24   a  of the bobbin  24  in an arrangement coaxial with the center axis  26   a  of the coil  26 . The core  28  is provided integrally at one axial end thereof with a head  28   b  having a flat end face generally perpendicular to the coil center axis  26   a , with the head  28   b  being exposed on the outside surface of the one (or upper, in the drawing) flange  24   b  of the bobbin  24 . 
   In the other (or lower, in the drawing) flange  24   c  of the bobbin  24 , a pair of coil terminals  30 , made of a good electrically conductive material, is fixedly attached to one peripheral region of the flange  24   c . The opposite ends of the conductive wire forming the coil  26  are joined respectively to the coil terminals  30 . Each coil terminal  30  is integrally provided with an entwining portion  30   a  at one longitudinal end, to which the wire end of the coil  26  is entwined, and a terminal portion  30   b  at the other longitudinal end, and is fixed to the flange  24   c  so that the terminal portion  30   b  extends downward from the flange  24   c  at a side away from the coil  26 . 
   The iron core  28  of the electromagnet  20  protrudes from the flange  24   c  of the bobbin  24 , at a longitudinal end  28   c  at a side opposite to the head  28   b , and a yoke  32  is fixedly connected to the core end  28   c  by, e.g., caulking, to form a magnetic path around the coil  26 . The yoke  32  is an L-shaped plate-like rigid member made of, e.g., magnetic steel, wherein one flat plate part  32   a thereof extends along the flange  24   c  of the bobbin  24  and the other flat plate part  32   b  thereof is laterally spaced from the coil  26  to extend substantially parallel to the coil center axis  26   a . The flange  24   c  of the bobbin  24  is provided, in the other peripheral region apart from the coil terminal  30 , with a through-hole  34  having a generally convex contour, and the flat plate part  32   b  of the yoke  32  is inserted into the through-hole  34 . The flat plate part  32   b  of the yoke  32  extends so that the distal end  32   c  thereof reaches a position in close proximity to the head  28   b  of the iron core  28 , and the armature  22  is supported on the yoke  32  to be adjacent to the distal end  32   c  in a rockable manner. 
   The armature  22  is a flat plate-like rigid member made of, e.g., a magnetic steel, and is resiliently supported on the yoke  32  of the electromagnet  20  in a relatively displaceable manner at a position oppositely facing the core head  28   b , through a movable spring contact member provided in the contact section  14  as described later. The armature  22  cooperates with the iron core  28  and the yoke  32  of the electromagnet  20  to form a magnetic circuit by means of the coil  26 . As described later, when the electromagnet  20  is not excited, the armature  22  is stationarily held in its returned or released position in which the major surface  22   a  thereof is spaced from the head  28   b  of the core  28  by a predetermined distance (FIG.  3 ). When the electromagnet  20  is excited, the armature  22  moves, due to the magnetic attractive force, in such a direction that the major surface  22   a  moves toward the core head  28   b.    
   The contact section  14  of each relay structure  16  includes a first stationary contact member  38  having a make stationary contact  36 , a movable contact spring member  42  having a movable contact  40 , and a second stationary contact member  46  having a break stationary contact  44 . The first stationary contact member  38  is formed by stamping an electrically conductive sheet-metal material into a predetermined shape and bending it into an L-shape, and includes a support plate portion  38   a  at one longitudinal end, for carrying the make stationary contact  36 , a joint plate portion  38   b  at an intermediate length, extending generally perpendicular to the support plate portion  38   a , and a terminal portion  38   c  at the other longitudinal end, extending like a pin from the joint plate portion  38   b  (FIG.  4 ). The make stationary contact  36  is made of a desired contact material, and is secured to the support plate portion  38   a  so as to protrude at a side away from the joint plate portion  38   b  by, e.g., caulking. The second stationary contact member  46  is formed by stamping an electrically conductive sheet-metal material into a predetermined shape and bending it into an L-shape, and includes a support plate portion  46   a  at one longitudinal end, for carrying the break stationary contact  44 , a joint plate portion  46   b  at an intermediate length, extending generally perpendicular to the support plate portion  46   a , and a terminal portion  46   c  at the other longitudinal end, extending like a pin from the joint plate portion  46   b  (FIG.  4 ). The break stationary contact  44  is made of a desired contact material and is secured to the support plate portion  46   a  so as to protrude at a side close to the joint plate portion  46   b  by, e.g., caulking. 
   The first and second stationary contact members  38 ,  46  are securely attached to the flanges  24   b ,  24   c  of the bobbin  24  of the electromagnet  20 . In this connection, the joint plate portion  46   b  of the second stationary contact member  46  is longer than the joint plate portion  38   b  of the first stationary contact member  38  (FIG.  4 ). Therefore, in a condition where the stationary contact members  38 ,  46  are properly attached to the bobbin  24 , the make stationary contact  36  and the break stationary contact  44  are disposed at mutually opposing positions, so as to be spaced from each other in a direction parallel to the coil center axis  26   a  of the electromagnet  20  (or in a vertical direction, in the drawing) and to fixedly maintain a certain space therebetween. 
   The movable contact spring member  42  is an electrically conductive thin plate member that is formed by stamping a thin plate made of, e.g., phosphor bronze, into a predetermined shape and bending it into an L-shape, and integrally includes a support plate portion  42   a  at one longitudinal end, for supporting the movable contact  40 , a first attachment portion  42   b  extending from the support plate portion  42   a  in generally parallel thereto, an elastic hinge portion  42   c  at a longitudinal center, extending from the first attachment portion  42   b  to be bent in an L-shape, a second attachment portion  42   d  extending from the elastic hinge portion  42   c  in a direction generally perpendicular to the first attachment portion  42   b  at a side opposite to the first attachment portion  42   b , and a terminal portion  42   e  at the other longitudinal end, extending like a pin from the second attachment portion  42   d  (FIG.  3 ). The movable contact spring member  42  is supported on the electromagnet assembly  12  in a state where the first attachment portion  42   b  is secured to the armature  22  by, e.g., caulking, and the second attachment portion  42   d  is secured to the yoke  32  by, e.g., caulking. In this state, the terminal portion  42   e  of the movable contact spring member  42  is inserted, together with the flat plate part  32   b  of the yoke  32 , into the through-hole  34  formed in the flange  24   c  of the bobbin  24 , and extends downward from the flange  24   c  in a direction away from the yoke  32 . 
   The movable contact  40  is made of a desired contact material, and is secured to the support plate portion  42   a  so as to protrude at both sides of the support plate portion  42   a  by, e.g., caulking. In a condition where the movable contact spring member  42  is properly supported on the electromagnet assembly  12 , the movable contact  40  is disposed between the make stationary contact  36  and the break stationary contact  44 , so as to be displaceable in a direction generally parallel to the coil center axis  26   a  of the electromagnet  20 , and is allowed to alternately contact with the stationary contacts  36 ,  44 . 
   The elastic hinge portion  42   c  of the movable contact member  42  exerts a spring effect between the armature  22  and the yoke  32  so as to urge or bias the armature  22  in a direction away from the head  28   b  of the core  28 . Therefore, when the electromagnet  20  is not excited, the armature  22  is stationarily held in its returned or released position in which the major surface  22   a  thereof is spaced away from the head  28   b  of the core  28  by a predetermined distance (FIG.  3 ), under the spring effect of the movable contact spring member  42 , while one end (the left end in  FIG. 3 ) of the armature  22  is disposed close to the yoke distal end  32   c . In this state, the movable contact  40  of the movable contact spring member  42  comes into contact with the break stationary contact  44  of the second stationary contact member  46  under a pressing force. When the electromagnet  20  is excited, the armature  22  moves from the released position, due to the magnetic attractive force about one end thereof disposed close to the yoke distal end  32   c , in a direction toward the core head  28   b  and against the spring force of the movable contact spring member  42 . Then, the movable contact  40  of the movable contact spring member  42  comes into contact with the make stationary contact  36  of the first stationary contact member  38  under a pressing force, so as to close a make contact. 
   The complex electromagnetic relay  10  according to the present invention has a characteristic configuration wherein the housing  18  accommodating a pair of relay structures  16  in a mutually inverted orientation includes an enclosing wall  48  for enclosing the pair of relay structures  16  in an envelope-like manner, and a partition wall  50  arranged between the relay structures  16  disposed side-by-side to separate the relay structures  16  from each other. The enclosing wall  48  includes a flat plate-like top wall portion  48   a  having a generally rectangular shape in a plan view, and two pairs of opposing lateral wall portions  48   b ,  48   c , each having a flat plate shape and extending integrally from the respective four edges of the top wall portion  48   a  to be perpendicular to the top wall portion  48   a . The enclosing wall  48  opens at a side opposite to the top wall portion  48   a  along bottom edges of the opposing lateral walls  48   b ,  48   c . The flat plate-like partition wall  50  is integrally and perpendicularly joined to the top wall portion  48   a  and one pair of opposing lateral wall portions  48   b  of the enclosing wall  48 , and extends from the top wall portion  48   a  to the proximity of the bottom edges of the opposing lateral wall portions  48   b , at a location dividing each of the top wall portion  48   a  and the pair of opposing lateral wall portions  48   b  in half. The housing  18  having the above configuration may be integrally formed from an electrically insulating material such as a synthetic resin. 
   The housing  18  defines a pair of receptacles  52 , having generally rectangular cross-sectional shape substantially identical to each other, between the enclosing wall  48  and the partition wall  50 . The pair of relay structures  16  are individually accommodated in the receptacles  52  in the mutually inverted orientation as described above. In a state where each relay structure  16  is properly accommodated in the corresponding receptacle  52  of the housing  18 , the bobbin  24  of the electromagnet assembly  12  in the relay structure  16  is disposed in such a manner that the lower flange  24   c  supporting the coil terminals  30  is located adjacent to the bottom edges of the enclosing wall  48  and partition wall  50  so as to substantially close the opening of the housing  18 . Also, in this state, the pair of coil terminals  30 , the first and second stationary contact members  38 ,  46 , and the movable contact spring member  42 , which are provided in each relay structure  16 , are placed so that the respective terminal portions  30   b ,  38   c ,  46   c  and  42   e  thereof protrude outside the housing  18 . In this arrangement, an adhesive  54  is applied so as to cover the back surfaces (or exposed surfaces) of the bobbin flanges  24   c  of the relay structures  16  properly accommodated in the housing  18  (FIGS.  3  and  4 ). The adhesive  54  seals all clearances between the relay structures  16  and the housing  18 , that may be otherwise exposed outside the housing  18 , and fixedly attaches the bobbins  24  of the respective electromagnet assemblies  12  to the enclosing wall  48  as well as to the partition wall  50 . 
   In the complex electromagnetic relay  10  configured as described above, a pair of relay structures  16 , independent of each other, is disposed in a mutually inverted orientation with the contact sections  14  thereof being located alternately at opposing sides in the common housing  18 , so that the pairs of the coil terminals  30  provided in the respective relay structures  16  are arranged in such a manner that the terminal portions  30   b  of the respective pairs protrude from the housing  18  at positions spaced from each other (FIG.  1 ). Similarly, the first and second stationary contact members  38 ,  46  and the movable contact spring member  42 , which are provided in the respective relay structures  16 , are arranged in such a manner that the respective terminal portions  38   c ,  46   c  and  42   e  protrude from the housing  18  at positions spaced from each other. Therefore, an advantage is obtained in that a circuit pattern on a mount board (not shown) for the complex electromagnetic relay  10  can be easily formed. Moreover, the complex electromagnetic relay  10  is configured in such a manner that the relay structures  16  are fixedly supported on the housing  18  by the adhesive  54  for fixedly attaching the bobbins  24  of the respective electromagnet assemblies  12  to the enclosing wall  48  and the partition wall  50 , so that, in comparison with the related-art configuration wherein a housing is constructed by attaching a box-like cover to a common base block on which a pair of relay structures is mounted, it is possible to eliminate the base block and, as a result, to reduce the height dimension of the complex electromagnetic relay  10  as well as the number of parts and the number of assembling steps. Furthermore, the complex electromagnetic relay  10  is configured in such a manner that the partition wall  50  of the housing  18  lies between the pair of relay structures  16  arranged side-by-side or, in particular, between the armatures  22  as actuating elements in the respective electromagnet assemblies  12 , so that it is possible to readily ensure a desired insulation distance or clearance between the relay structures  16  arranged side-by-side. 
   In the complex electromagnetic relay  10  described above, it is advantageous that locating elements  56  are provided in the pair of receptacles  52  defined between the enclosing wall  48  and the partition wall  50  of the housing  18  (FIGS.  4  and  5 ), for constraining the respective relay structures  16  into the mutually inverted orientation in the receptacles  52 . The locating elements  56  have a polarizing function for mechanically preventing each relay structure  16  from being accommodated in the receptacle  52  with the contact section  14  thereof being oriented reverse to a proper orientation when each relay structure  16  is attached to the housing  18 . In the illustrated embodiment, the locating elements  56  include at least one pair of protrusions  58  protruding in the pair of receptacles  52  of the housing  18  in a mutually opposing positional relationship. 
   As shown in  FIGS. 6  to  9 , each receptacle  52  of the housing  18  is provided, adjacent to the top wall portion  48   a  of the enclosing wall  48  at respective joint regions (or corners) between one lateral wall portion  48   b  and the other lateral wall portion  48   c  as well as the partition wall  50 , with a pair of L-shaped protrusions  58   a , and, at mutually opposing positions on the lateral wall portion  48   c  and the partition wall  50 , with a pair of flat plate-shaped protrusions  58   b . The protrusions  58   a ,  58   b  have predetermined shapes and dimensions such that, when the relay structure  16  is inserted into each receptacle  52  in a proper orientation, the protrusions  58   a ,  58   b  do not obstruct certain components of the relay structure  16  but eliminate a useless space between the relay structure  16  and the enclosing wall  48  or the partition wall  50 , and that, when the relay structure  16  is erroneously inserted into each receptacle  52  in an orientation reverse to the proper orientation, the protrusions  58   a ,  58   b  collide with certain components of the relay structure  16  so as to inhibit the complete insertion of the relay structure  16 . Therefore, the protrusions  58   a ,  58   b  function not only to improve mechanical strength of the complex electromagnetic relay  10  in an assembled state against an external force, but also to eliminate unstableness of the relay structures  16  incorporated in the complex electromagnetic relay  10 . The protrusions  58   a ,  58   b  may be formed integrally with the enclosing wall  48  and the partition wall  50  in a die for molding the housing  18 , for example. 
   The complex electromagnetic relay according to the present invention may be used in, e.g., a control circuit frequently switching the operation of a motor or a solenoid between normal and reverse directions, and is particularly usable in an application wherein plural electric-powered appliances are individually and in a timely fashion controlled by a single complex electromagnetic relay. Also, the complex electromagnetic relay according to the present invention is effectively applicable to such a control circuit that circuit components should be mounted in a narrow space, such as a control circuit for a vehicle-mounted electric-powered appliance. 
   While the invention has been described with reference to specific preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made thereto without departing from the spirit and scope of the appended claims. For example, the characteristic configuration of the complex electromagnetic relay according to the present invention may also be adopted in a complex electromagnetic relay including three or more relay structures arranged side-by-side and completely independent of each other.