Patent Publication Number: US-2023162936-A1

Title: Relay device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority to Korean Patent Application No. 10-2021-0164791, filed on Nov. 25, 2021 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The disclosure relates to a relay device, and more particularly, to a relay device capable for permitting or cutting off electricity in response to application of a control power. 
     BACKGROUND 
     In general, a Direct Current (DC) relay is a device that uses the principle of an electromagnet to mechanically drive or transmit a current signal. A relay device is also called a magnetic switch, and is generally classified as an electrical circuit switch device. 
     Such a relay device includes a fixed contact point and a movable contact. The fixed contact point is connected to an external power source and a load so as to be energized. The movable contact point may be operated to contact or separate from the fixed contact point in response to the application of a control power. To move the movable contact point, the relay device is provided with a fixed core, a shaft passing through the fixed core and connected to the movable contact point, and a movable core coupled to the shaft to move toward the fixed core together with the shaft. The shaft is fixed to the movable core by welding while penetrating the movable core and slidably connected through the fixed core. 
     More specifically, when a control power is applied to a coil assembly disposed to surround the fixed core and the movable core, an electromagnetic field is formed to magnetize the fixed core, so that an attractive force is generated between the fixed core and the movable core. At this time, because the fixed core is provided in a fixed state, the movable core is moved toward the fixed core. In other words, the shaft moving together with the movable core allows the movable contact point to be contacted with the fixed contact point, so that the relay device may be energized with an external power source and a load. 
     When manufacturing such a relay device, a distance in which a movable core may be moved, that is, a stroke gap, is formed between a movable core and a fixed core, so that assembly is performed. For example, in the relay device, the stroke gap is required to turn the relay device on/off while the movable core moves. To form the stroke gap, a separate jig or a gap gauge is used. In other words, after the jig is disposed between the movable core and the fixed core or between the movable core and a plate, a shaft is fixed to the movable core by welding or the like. 
     However, in order to form the stroke gap, a process of fixing the movable core to the separate jig or positioning the stroke gap gauge between the fixed core and the movable core is required, which causes disadvantages of manufacturing as well as a cost increase due to an increase in the manufacturing process. 
     SUMMARY 
     An aspect of the disclosure is to provide a relay device capable of uniformly forming a stroke gap without a separate jig or a gap gauge by forming a step for adjusting the stroke gap on a shaft. 
     Additional aspects of the disclosure will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosure. 
     In accordance with an aspect of the disclosure, a relay device includes a fixed terminal having a pair of fixed contact points, a movable contact portion positioned adjacent to a lower side of the fixed terminal and configured to allow or block energization by being in contact with or spaced apart from the pair of fixed contact points, a fixed core disposed at a predetermined interval below the movable contact portion and configured to be magnetized when control power is applied, a movable core positioned adjacent to a lower side of the fixed core and configured to move toward the fixed core when the control power is applied, and a shaft that passes through the fixed core to connect to the movable contact portion, the shaft being is coupled to the movable core to move together with the movable core. The shaft is supported by a step portion formed in the movable core to form a stroke gap between the fixed core and the movable core. 
     A plunger for connecting to the movable contact portion may be coupled to an upper portion of the shaft, and a length of the shaft exposed to a lower portion of the plunger corresponds to the sum of the lengths of the fixed core, the movable core, and the stroke gap. 
     The shaft may include an upper shaft passing through the fixed core, and a lower shaft having a diameter smaller than the upper shaft and coupled to the movable core, and a stepped portion positioned between the upper shaft and the lower shaft. 
     A movable through-hole may be formed in the movable core in a longitudinal direction, and the step portion may be provided in the movable through-hole to support the stepped portion in a state in which the lower shaft and the movable core are assembled. 
     The movable through-hole may include an upper movable through-hole having a diameter larger than a diameter of the upper shaft, and a lower movable through-hole having a diameter smaller than the diameter of the upper shaft, and the lower shaft is inserted and fixed to the lower movable through-hole. 
     A fixed through-hole may be formed in the fixed core in a longitudinal direction, and the fixed through-hole may include an upper fixed through-hole through which the upper shaft passes, and a lower fixed through-hole having a larger diameter than that of the upper fixed through-hole. 
     The relay device may further include a return spring interposed in the lower movable through-hole and the upper movable through-hole. 
     The relay device may further include a coil assembly surrounding the fixed core and the movable core and configured to form an electromagnetic field when the control power is applied, and the fixed core is configured to be magnetized by the electromagnetic field formed by the coil assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       These and/or other aspects of the disclosure will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG.  1    is a perspective view illustrating a relay device according to an embodiment of the disclosure; 
         FIG.  2    is a cross-sectional view taken along line II-II′ of  FIG.  1   ; 
         FIG.  3    is a bottom perspective view illustrating a coupling state between a fixed core and a movable core provided in a relay device according to an embodiment of the disclosure; 
         FIG.  4    is a cross-sectional view illustrating a state in which a fixed core and a movable core provided in the relay device are coupled to the shaft according to an embodiment of the disclosure; and 
         FIG.  5    is a cross-sectional view illustrating an operation state of a relay device according to an embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, the embodiments of the disclosure will be described in detail with reference to accompanying drawings. It should be understood that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the disclosure on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation. Therefore, the description proposed herein is just a preferable example for the purpose of illustrations only, not intended to limit the scope of the disclosure, so it should be understood that other equivalents and modifications could be made thereto without departing from the spirit and scope of the disclosure. 
       FIG.  1    is a perspective view illustrating a relay device according to an embodiment of the disclosure,  FIG.  2    is a cross-sectional view taken along line II-II′ of  FIG.  1   ,  FIG.  3    is a bottom perspective view illustrating a coupling state between a fixed core and a movable core provided in a relay device according to an embodiment of the disclosure,  FIG.  4    is a cross-sectional view illustrating a state in which a fixed core and a movable core provided in the relay device are coupled to the shaft according to an embodiment of the disclosure, and  FIG.  5    is a cross-sectional view illustrating an operation state of a relay device according to an embodiment of the disclosure. 
     Referring to  FIGS.  1  to  5   , a relay device  1  according to an embodiment of the disclosure may include a housing  100 , a fixed terminal  200 , a movable unit  300 , and a coil assembly  400 . 
     The housing  100  has an internal space to safely accommodate main components, and forms the exterior of the relay device  1 . For example, the housing  100  may be provided in a substantially rectangular box shape, but the shape thereof may be freely deformed according to the place to be installed or other conditions. The housing  100  may be formed of an insulating material such as a synthetic resin to prevent the inside and outside of the housing  100  from being arbitrarily energized. 
     Furthermore, the housing  100  is divided into an upper housing  110  and a lower housing  120 , and may include an insulating plate  130  and a support plate  140 . 
     The upper housing  110  and the lower housing  120  are formed such that the surfaces facing each other are open, and the open facing surfaces are coupled to each other to form an inner space therebetween. The insulating plate  130  and the support plate  140  are installed in the inner space. 
     The insulating plate  130  and the support plate  140  are installed in a vicinity of the center of the housing  100 , and electrically and physically separate upper and lower spaces based on the insulating plate  130  and the support plate  140 . In other words, any energization between the fixed terminal  200  provided in the upper space, and a movable contact portion  350  to be described later and cores  320  and  330  provided in the lower space may be prevented. 
     The insulating plate  130  may be formed of an insulating material such as a synthetic resin to electrically separate the upper housing  110  and the lower housing  120  from each other. 
     The support plate  140  may be provided to physically separate the upper housing  110  and the lower housing  120 . As shown in drawings, the support plate  140  may be provided to support the insulating plate  130 . The support plate  140  may be formed of a magnetic material. Accordingly, the support plate  140  may form a magnetic circuit together with the fixed core  320  and a yoke  430  when a control power is applied to the coil assembly  400  to be described later. In other words, a driving force for moving the movable core  330  toward the fixed core  320  may be formed by a magnetic path. 
     A through-hole is formed in a center of the insulating plate  130  and the support plate  140 . A plunger  360  coupled to a shaft  310  to be described later is movably coupled to the through-hole in a vertical direction. Therefore, when the movable core  330  moves in the direction toward or away from the fixed core  320 , the shaft  310  and the plunger  360  move together, and thus the movable contact portion  350  connected to the plunger  360  may also be moved together in the same direction. Operation of the movable contact portion  350  according to operation of the movable core  330  and a coupling structure with the shaft  310  will be described again below. 
     The fixed terminal  200  may be provided as a pair and be fixedly mounted to the housing  100 . For example, the fixed terminals  200  may include a first fixed terminal  201  and a second fixed terminal  202 , and may be arranged side by side at a predetermined interval. As shown in drawings, the first and second fixed terminals  201  and  202  are installed on an upper side of the upper housing  110  and are physically separated from each other. However, when the movable contact portion  350 , which will be described later, comes into contact with the first and second fixed terminals  201  and  202 , the first and second fixed terminals  201  and  202  may be in an electrically energizable state. In other words, according to the position of the movable contact portion  350 , whether electricity is energized between the first and second fixed terminals  201  and  202  may be determined. Accordingly, a pair of fixed contact points P 1  are provided at a lower side of the fixed terminals  200 , and the corresponding movable contact portion  350  is provided with movable contact points P 2  in contact with the fixed contact points P 1 . 
     The movable unit  300  is provided to serve to move the movable contact portion  350  so that the movable contact points P 2  and the fixed contact points P 1  come into contact with each other. In this case, the movable unit  300  may be operated by an electromagnetic field generated through the coil assembly  400 . 
     More specifically, the movable unit  300  may include the shaft  310 , the fixed core  320 , the movable core  330 , the plunger  360 , a return spring  340 , and the movable contact portions  350 . The shaft  310  may be coupled passing through the fixed core  320  and the movable core  330 . The fixed core  320 , the movable core  330 , and the return spring  340  are arranged in a lower space of the housing  100 , and the plunger  360  and the movable contact portion  350  may be disposed in an upper space of the housing  100 . 
     The shaft  310  has a predetermined length, and is divided into an upper shaft  311  passing through the fixed core  320  in a longitudinal direction and a lower shaft  312  having a diameter smaller than that of the upper shaft  311  and coupled to the movable core  330 . Accordingly, a stepped portion  313  may be provided between the upper shaft  311  and the lower shaft  312 . At this time, the upper shaft  311  may pass through the fixed core  320  and be movably coupled from the fixed core  320 , and the upper end thereof protrudes from the upper portion of the fixed core  320  to be coupled with the plunger  360 . Furthermore, because the lower shaft  312  is coupled to the movable core  330 , the shaft  310  is provided to move together with the movable core  330  when the movable core  330  is operated. 
     The fixed core  320  is installed on the support plate  140  to restrict a movement thereof, and is magnetized by a magnetic field generated by the coil assembly  400  to generate electromagnetic attraction. Accordingly, the movable core  330  is moved toward the fixed core  320  by the electromagnetic attraction. The fixed core  320  may be provided in any shape capable of generating electromagnetic force by being magnetized by a magnetic field. For example, the fixed core  320  may be provided with a permanent magnet or an electromagnet. 
     Furthermore, a fixed through-hole  321  is formed in a center of the fixed core  320 . The shaft  310  may be vertically movable through the fixed through-hole  321 . In other words, the shaft  310  may be connected to the movable contactor  350  through the fixed through-hole  321 . The fixed through-hole  321  may include an upper fixed through-hole  321   a  through which the upper shaft  311  of the shaft  310  passes, and a lower fixed through-hole  321   b  having a diameter larger than that of the upper shaft  311 . An upper portion of a return spring  340 , which will be described later, is inserted into the lower fixed through-hole  321   b  so that the upper end thereof may be supported. 
     The movable core  330  may be positioned to be spaced apart from the fixed core  320  by a predetermined distance. Therefore, a distance at which the movable core  330  and the fixed core  320  are spaced apart and the movable core  330  may move toward the fixed core  320  may be defined as a stroke gap G. In other words, as the movable core  320  moves by the stroke gap G, the on/off of the relay device  1  is controlled. 
     A movable through-hole  332  is formed in the movable core  330  in a longitudinal direction. The movable through-hole  332  may include an upper movable through-hole  332   a  having a diameter larger than that of the upper shaft  311  and a lower movable through-hole  332   b  having a diameter smaller than that of the upper shaft  311 . Accordingly, a step portion  333  is formed between the upper movable through-hole  332   a  and the lower movable through-hole  332   b.  As a result, in a state in which the lower shaft  312  and the movable core  330  are assembled, the stepped portion  313  may be provided to be supported by the step portion  333 . 
     A lower portion of the return spring  340 , which will be described later, is inserted into the upper movable through-hole  332   a  so that the lower end thereof may be supported. 
     The lower movable through-hole  332   b  may have a diameter corresponding to that of the lower shaft  312 , and the lower shaft  312  may be inserted into the lower movable through-hole  332   b  to be fixed by welding or the like. 
     As described above, an upper portion of the shaft  310  is provided to penetrate the fixed core  320  so as to be coupled with the plunger  360  to be connected to the movable contact portion  350 . Accordingly, the length of the shaft  310  exposed to the lower portion of the plunger  360  may be provided to have a length corresponding to the sum of the lengths of the fixed core  320 , the movable core  330 , and the stroke gap G. In other words, because the stepped portion  313  of the lower shaft  312  is coupled in a supported state to the step portion  333  of the movable core  330 , the stroke gap G may be easily formed without using a separate jig or gap gauge. 
     When power is applied to the coil assembly  400  in a state in which the shaft  310  is coupled to the fixed core  320  and the movable core  330 , the fixed core  320  is magnetized such that the movable core  330  is moved upward by the stroke gap G, and the return spring  340  is compressed and the elastic restoring force is stored. Accordingly, when the application of the control power is released and then the magnetization of the fixed core  320  is terminated, the movable core  330  may be returned by moving downward by the stroke gap G again by the elastic restoring force. 
     The movable contact portion  350  is disposed in the upper space of the housing  100 , and is provided to be spaced apart from the fixed terminals  200  by a predetermined interval. The movable contact points P 2  of the movable contact portion  350  is provided to face the fixed contact points P 1  of the fixed terminals  200 . 
     The lower side of the movable contact portion  350  is elastically supported by a compression spring  352  so that the movable contact portion  350  moves in association with operation of the movable core  330 . At this time, the compression spring  352  may elastically support the movable contact portion  350  in a compressed state by a predetermined distance so that the movable contact portion  350  does not move arbitrarily downward. Here, the compression spring  352  may be provided in a compressed state by a predetermined distance by a cover  353  coupled between the plunger  360  and the movable contact portion  350 . 
     As shown in drawings, an upper end of the compression spring  352  may be elastically supported by the movable contact portion  350 , and a lower end thereof may be elastically supported by an upper end of the plunger  360 . Furthermore, a retainer  354  may be installed at a lower end of the movable contact portion  350  so that the compression spring  352  is stably maintained, and the upper end of the compression spring  352  may be installed in the retainer  354 . 
     As such, when the shaft  310  moves upward in response to the operation of the movable core  330  in a state in which the movable contact portion  350  and the shaft  310  are connected, the plunger  360  coupled to the upper end of the shaft  310  and the movable contact portion  350  connected to the plunger  360  move together, so that the fixed contact points P 1  and the movable contact points P 2  come into contact with each other. At this time, when the fixed contact points P 1  and the movable contact points P 2  are in contact, the movable contact portion  350  tends to be spaced apart from the fixed terminals  200  by electromagnetic repulsive force. However, because the compression spring  352  is compressed by a predetermined distance to elastically support the movable contact portion  350  in a state in which the elastic restoring force is stored, even if the electromagnetic repulsive force is generated between the movable contact portion  350  and the fixed terminals  200 , the movable contact portion  350  is not moved arbitrarily, thereby maintaining a stable contact state. 
     The coil assembly  400  is provided in a cylindrical shape with a hollow central passage and is disposed to surround the fixed core  320  and the movable core  330 . The coil assembly  400  may be configured to form an electromagnetic field when the control power is applied. In other words, the fixed core  320  and the movable core  330  may be arranged along the hollow central passage of the coil assembly  400 . 
     The coil assembly  400  includes a bobbin  410 , a coil  420 , and a yoke  430 . The coil  420  is wound around the bobbin  410 , and the bobbin  410  is accommodated in the yoke  430 . 
     The yoke  430  is accommodated in the lower housing  120 . In other words, the yoke  430 , the coil  420 , and the bobbin  410  on which the coil  420  is wound are sequentially arranged in a direction from an outer circumference of the lower housing  120  to the inside thereof. The yoke  430  forms a magnetic path when the control power is applied. Accordingly, the yoke  430  may be formed of a conductive material capable of conducting electricity. The magnetic path formed by the yoke  430  may be configured to control a direction of the electromagnetic field formed by the coil  420 . Accordingly, when the control power is applied to the coil  420 , the coil  420  forms the electromagnetic field in a direction in which the movable core  330  moves toward the fixed core  320 . Furthermore, the fixed core  320  is magnetized by the electromagnetic field, so that the attractive force may be applied to the movable core  330 . 
     The coil assembly  400  is a well-known technology, and a detailed description thereof will be omitted. 
     As described above, in the relay device  1  according to an embodiment of the disclosure, when the shaft  310  is coupled between the movable core  330  and the fixed core  320 , the stepped portions  313  of the shaft  310  is coupled to be supported by the step portion  333  of the movable core  330 , so that the stroke gap G of the movable core  330  may be easily secured, leading to improving assembly. 
     As is apparent from the above, the embodiment of the disclosure may provide the relay device capable of providing ease of manufacture by forming the stroke gap without a separate jig or a gap gauge in order to form the stroke gap of the movable core, as well as reducing manufacturing cost by shortening the manufacturing process. 
     As described above, although a few embodiments of the disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.