Abstract:
The present invention discloses a horizontal-deflection prevention mechanism for an HVDC relay, comprising a moving contact assembly which comprises a moving reed and moving contacts arranged at left and right ends of the moving reed; an upper section of a pushrod is located above a yoke plate and fixed with the moving reed; a positioning plate is provided on the yoke plate; and a left return spring is connected between a left end of the moving reed and the positioning plate, and a right return spring is connected between a right end of the moving reed and the positioning plate. In the present invention, by the arrangement of a left return spring and a right return spring at the left and right ends of the moving reed at which moving contacts are provided, on one hand, a breaking force can be provided, which allows the moving contacts to quickly separate from the stationary contacts when the moving contacts and the stationary contacts are to be separated from each other, so that the relay makes a response quickly. On the other hand, the left return spring and the right return spring always provide an acting force which prevents the moving reed from rotating horizontally, so as to ensure that the moving contacts and the stationary contacts can come into contact precisely and to thus prevent the occurrence of faults due to the contact between the moving reed and other components.

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present invention relates to a high voltage direct current (HVDC) relay, and in particular to a horizontal-deflection prevention mechanism for an HVDC relay, which is configured to prevent a moving reed inside the HVDC relay from deflecting. 
       BACKGROUND OF THE INVENTION 
       [0002]    In HVDC relays, a pushrod is driven to move upward and downward by a moving iron core, so that the moving contacts and the stationary contacts on a moving reed at the upper end of the pushrod are contacted or separated with or from each other. In the prior art, since the pushrod connecting the moving iron core and the moving reed is guided only in the axial direction without any position limit in the circumferential direction of the pushrod, the pushrod might rotate upward in the circumferential direction when moving upward and downward, leading to the deflection of the moving reed fixed with the pushrod in the horizontal direction. As a result, the moving contacts and the stationary contacts cannot be precisely aligned, and the reliability of the relay is affected. 
       SUMMARY OF THE INVENTION 
       [0003]    An object of the present invention is to provide a horizontal-deflection prevention mechanism for an HVDC relay, which is capable of preventing a moving reed from deflecting horizontally, ensuring the precise contact between the moving contacts and the stationary contacts of the relay, and improving the reliability of the relay. 
         [0004]    To achieve the purpose mentioned above, the present invention adopts the following technical solution. A horizontal-deflection prevention mechanism for an HVDC relay is provided, comprising a moving contact assembly which comprises a moving reed and moving contacts arranged at left and right ends of the moving reed; an upper section of a pushrod is located above a yoke plate and fixed with the moving reed; a positioning plate is provided on the yoke plate; and a left return spring is connected between a left end of the moving reed and the positioning plate, and a right return spring is connected between a right end of the moving reed and the positioning plate. 
         [0005]    In the present invention, by the arrangement of a left return spring and a right return spring at the left and right ends of the moving reed at which moving contacts are provided. On one hand, a breaking force can be provided, which allows the moving contacts to quickly separate from the stationary contacts when the moving contacts and the stationary contacts are to be separated from each other as the left return spring and the right return spring directly act on the moving reed, so that the relay makes a response quickly. On the other hand, since the two ends of the moving reed are tensioned and act on the positioning plate, the left return spring and the right return spring always provide an acting force which prevents the moving reed from rotating horizontally, so as to ensure that the moving contacts and the stationary contacts can come into contact precisely and to thus prevent the occurrence of faults due to the contact between the moving reed and other components. Wherein, the positioning plate is made of insulating material, for example, plastics. 
         [0006]    Preferably, a spring fixing plate extending upward is respectively formed on the positioning plate at a position below and corresponding to the left end of the moving reed and at a position below and corresponding to the right end of the moving reed; a lower spring fixing hole is formed on the spring fixing plate; and a protection ring is matched on an inner wall of the lower spring fixing hole. Wherein, the protection ring can be made of material with certain stiffness, for example, an iron ring, so as to prevent the spring fixing plate of the positioning plate from being broken by the left return spring and the right return spring, and thus the reliability of the relay is guaranteed. 
         [0007]    Preferably, both an axis of the left return spring and an axis of the right return spring are parallel to an axis of the pushrod; and both a connecting point between the left return spring and the moving reed and a connecting point between the right return spring and the moving reed are located between the two moving contacts and are close to an inner side of the moving contacts. Since both the axis of the left return spring and the axis of the right return spring are parallel to the axis of the pushrod, the moving reed can become more stable in the horizontal direction. 
         [0008]    Preferably, the connecting point between the left return spring and the moving reed and the connecting point between the right return spring and the moving reed are separately located on different sides of the moving reed, i.e., a front side and a rear side. Wherein, the connecting point between the left return spring and the moving reed and the connecting point between the right return spring and the moving reed are, respectively, arranged on the front side and the rear side of the moving reed, so that the anti-deflection force of the left return spring and the right return spring against the moving reed is further increased. 
         [0009]    Preferably, both the connecting point between the left return spring and the moving reed and the connecting point between the right return spring and the moving reed are located on a front side of the moving reed or on a rear side of the moving reed. The positions of the left return spring and the right return spring can be selected as desired. Wherein, when the left return spring and the right return spring are arranged on the same side, the moving reed will be inclined; and there will be rubbing actions when the moving contacts and the stationary contacts are contacted or separated with or from each other, so as to ensure the contact between the moving contacts and the stationary contacts. 
         [0010]    Preferably, the connecting point between the left return spring and the moving reed and the connecting point between the right return spring and the moving reed are located in a front-rear symmetric centerline of the moving reed. 
         [0011]    Preferably, an upper spring fixing hole is respectively provided on two ends of the moving reed; the spring fixing plate comprises a left spring fixing plate and a right spring fixing plate; and a lower spring fixing hole is formed on the left spring fixing plate, and a lower spring fixing hole is formed on the right spring fixing plate. 
         [0012]    Preferably, both the left return spring and the right return spring are S-shaped extension springs. The above arrangement can ensure the stability of the present invention. 
         [0013]    Preferably, a magnetic metal clip having an enclosed structure and an insulating plate are provided on the yoke plate; the yoke plate and the insulating plate are fixed by a fastener so that the magnetic metal clip is defined between the yoke plate and the insulating plate; a chamber for accommodating a stationary contact assembly and a moving contact assembly is formed by the insulating plate, the magnetic metal clip and the yoke plate; the stationary contact assembly comprises a leading-out end and stationary contacts fixed on the leading-out end, and the leading-out end is fixed with the insulating plate; and an upper end surface of the positioning plate resists against the magnetic metal clip, and a lower end surface of the positioning plate resists against the yoke plate. The above arrangement is configured to fix the positioning plate, and the positioning plate is tightly clamped between the magnetic metal clip and the yoke plate. 
         [0014]    Preferably, there is a positioning frame extending upward from the positioning plate, and the magnetic metal clip is sleeved on the outer periphery of the positioning frame. The arrangement of the positioning frame can promise no deflection of the magnetic metal clip in the horizontal direction. 
         [0015]    The present invention has the advantages of preventing a moving reed from deflecting horizontally, ensuring the precise contact between the moving contacts and the stationary contacts of the relay, improving the reliability of the relay, and the like. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a first structure diagram according to Embodiment 1 of the present invention; 
           [0017]      FIG. 2  is a second structure diagram according to Embodiment 1 of the present invention; 
           [0018]      FIG. 3  is a third structure diagram according to Embodiment 1 of the present invention; 
           [0019]      FIG. 4  is a sectional view of  FIG. 3 ; 
           [0020]      FIG. 5  is a top plan view of  FIG. 3 ; 
           [0021]      FIG. 6  is a first structure diagram according to Embodiment 2 of the present invention; 
           [0022]      FIG. 7  is a second structure diagram according to Embodiment 2 of the present invention; 
           [0023]      FIG. 8  is a third structure diagram according to Embodiment 2 of the present invention; 
           [0024]      FIG. 9  is a fourth structure according to Embodiment 2 of the present invention; 
           [0025]      FIG. 10  is a first structure diagram according to Embodiment 3 of the present invention; 
           [0026]      FIG. 11  is a second structure diagram according to Embodiment 3 of the present invention; and 
           [0027]      FIG. 12  is a third structure diagram according to Embodiment 3 of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiment 1 
       [0028]    As shown in  FIG. 1 ,  FIG. 2 ,  FIG. 3 ,  FIG. 4  and  FIG. 5 , the present invention provides a horizontal-deflection prevention mechanism for an HVDC relay, comprising a moving contact assembly which comprises a moving reed  1  and moving contacts arranged at left and right ends of the moving reed  1 ; an upper section of a pushrod  3  fixed with a moving iron core  2  is located above a yoke plate  4  and fixed with the moving reed  1 ; a main spring  5  is sleeved on the pushrod  3 ; a positioning plate  6  made of insulating plastic is provided on the yoke plate  4 ; a left return spring  13  is connected between a left end of the moving reed  1  and the positioning plate  6 , and a right return spring  14  is connected between a right end of the moving reed  1  and the positioning plate  6 ; and both the left return spring  13  and the right return spring  14  are S-shaped extension springs. A boss  21  is formed on an upper section of the pushrod  3  located above the yoke plate  4 ; and a lower end of the main spring  5  resists against the boss  21 , and an upper end of the main spring  5  resists against the moving reed  1 . 
         [0029]    Both an axis of the left return spring  13  and an axis of the right return spring  14  are parallel to an axis of the pushrod  3 ; and both a connecting point between the left return spring  13  and the moving reed  1  and a connecting point between the right return spring  14  and the moving reed  1  are located between the two moving contacts and are close to an inner side of the moving contacts. 
         [0030]    An upper spring fixing hole  11  is provided at a left end of the moving reed, and an upper spring fixing hole  11  is provided at a right end of the moving reed; and an upper end of the left return spring  13  is located inside the upper spring fixing hole at the left end, and an upper end of the right return spring  14  is located inside the upper spring fixing hole at the right end. The moving contacts comprise a left moving contact  15  and a right moving contact  16 ; and the upper spring fixing hole  11  at the left end of the moving reed is located on the inner side of the left moving contact  15 , and the upper spring fixing hole  11  at the right end of the moving reed is located on the inner side of the right moving contact  16 . 
         [0031]    A spring fixing plate extending upward is respectively formed on the positioning plate  6  at a position below and corresponding to the left end of the moving reed  1  and at a position below and corresponding to the right end of the moving reed; a lower spring fixing hole  12  is formed on the spring fixing plate; and a protection ring is matched on an inner wall of the lower spring fixing hole  12 , and the protection ring is an iron ring. The spring fixing plate comprises a left spring fixing plate  17  located on the left side and a right fixing plate  18  located on the right side; and a lower spring fixing hole  12  is formed on each of the left spring fixing plate  17  and the right spring fixing plate  18 . 
         [0032]    The connecting point between the left return spring  13  and the moving reed  1  and the connecting point between the right return spring  14  and the moving reed  1  are separately located on different sides of the moving reed  1 , i.e., a front side and a rear side. The upper spring fixing hole of the left return spring  13  is located on the front side of the moving reed, and the upper spring fixing hole of the right return spring  14  is located on the rear side of the moving reed. Cross-sections of the left spring fixing plate  17  and the right spring fixing plate  18  are arranged in a T-shape. Each of the left spring fixing plate and the right spring fixing plate comprises a first portion and a second portion, so that the cross-section of the right spring fixing plate is T-shaped; the lower spring fixing hole is arranged on the first portion; and the first portion of the left spring fixing plate is arranged to be parallel to the first portion of the right spring fixing plate, and the second portion of the left spring fixing plate is arranged to be parallel to the second portion of the right spring fixing plate. 
         [0033]    As shown in  FIG. 1 , a magnetic metal clip  7  having an enclosed structure and an insulating plate  8  made of ceramic are provided on an upper side of the yoke plate  4 ; the yoke plate  4  and the insulating plate  8  are fixed by a fastener so that the magnetic metal clip  7  is defined between the yoke plate  4  and the insulating plate  8 ; a chamber for accommodating a stationary contact assembly and a moving contact assembly is formed by the insulating plate  8 , the magnetic metal clip  7  and the yoke plate  4 ; the stationary contact assembly comprises a leading-out end  10  and stationary contacts  9  fixed on the leading-out end, and the leading-out end  10  and the insulating plate  8  are brazed or fixed by threads; an upper end surface of the positioning plate resists against the lower end of the magnetic metal clip, and a lower end surface of the positioning plate resists against the yoke plate; and the positioning plate  6  is tightly clamped between the magnetic metal clip  7  and the yoke plate  4 . There is a positioning frame  22  extending upward from the positioning plate  6 , and the magnetic metal clip  7  is sleeved on the outer periphery of the positioning frame so as to promise no deflection of the magnetic metal clip in the horizontal direction. 
         [0034]    As shown in  FIG. 1  and  FIG. 2 , both the insulating plate  8  and the yoke plate  4  are square structures. A first fixing hole is formed at each of the four corners of the insulating plate  8 ; a second fixing hole  20  is formed at each of the four corners of the yoke plate  4 ; and retreating gaps for the second fixing holes  20  are formed at the four corners of the positioning plate  6 . The fastener is a bolt  19 . One bolt  19  is fitted inside each first fixing hole. The first fixing holes and the second fixing holes correspond one by one in terms of position. The bolt  19 , after passing through the first fixing hole, is fixed by threads with the second fixing hole so that a lower end of the bolt  19  is fixed with the yoke plate and the head portion of the bolt  19  compacts the insulating plate  8 . 
       Embodiment 2 
       [0035]    As shown in  FIG. 6 ,  FIG. 7 ,  FIG. 8  and  FIG. 9 , the present invention provides a horizontal-deflection prevention mechanism for an HVDC relay, including a moving contact assembly which comprises a moving reed  1  and moving contacts arranged at left and right ends of the moving reed  1 ; an upper section of a pushrod  3  fixed with a moving iron core  2  is located above a yoke plate  4  and fixed with the moving reed  1 ; a main spring  5  is sleeved on the pushrod  3 ; a positioning plate  6  made of insulating plastic is provided on the yoke plate  4 ; a left return spring  13  is connected between a left end of the moving reed  1  and the positioning plate  6 , and a right return spring  14  is connected between a right end of the moving reed  1  and the positioning plate  6 ; and both the left return spring  13  and the right return spring  14  are S-shaped extension springs. A boss  21  is formed on an upper section of the pushrod  3  located above the yoke plate  4 ; and a lower end of the main spring  5  resists against the boss  21 , and an upper end of the main spring  5  resists against the moving reed  1 . 
         [0036]    Both an axis of the left return spring  13  and an axis of the right return spring  14  are parallel to an axis of the pushrod  3 ; and both a connecting point between the left return spring  13  and the moving reed  1  and a connecting point between the right return spring  14  and the moving reed  1  are located between the two moving contacts and are close to an inner side of the moving contacts. 
         [0037]    An upper spring fixing hole  11  is provided at a left end of the moving reed, and an upper spring fixing hole  11  is provided at a right end of the moving reed; and an upper end of the left return spring  13  is located inside the upper spring fixing hole at the left end, and an upper end of the right return spring  14  is located inside the upper spring fixing hole at the right end. The moving contacts comprise a left moving contact  15  and a right moving contact  16 ; and the upper spring fixing hole  11  at the left end of the moving reed is located on the inner side of the left moving contact  15 , and the upper spring fixing hole  11  at the right end of the moving reed is located on the inner side of the right moving contact  16 . 
         [0038]    A spring fixing plate extending upward is respectively formed on the positioning plate  6  at a position below and corresponding to the left end of the moving reed  1  and at a position below and corresponding to the right end of the moving reed; a lower spring fixing hole  12  is formed on the spring fixing plate; and a protection ring is matched on an inner wall of the lower spring fixing hole  12 , and the protection ring is an iron ring. The spring fixing plate comprises a left spring fixing plate  17  located on the left side and a right fixing plate  18  located on the right side; and a lower spring fixing hole  12  is formed on each of the left spring fixing plate  17  and the right spring fixing plate  18 . 
         [0039]    Both the connecting point between the left return spring  13  and the moving reed  1  and the connecting point between the right return spring  14  and the moving reed  1  are located on the front side of the moving reed  1 . The upper spring fixing hole of the left return spring  13  is located on the front side of the moving reed, and the upper spring fixing hole of the right return spring  14  is also located on the front side of the moving reed. 
         [0040]    A magnetic metal clip  7  having an enclosed structure and an insulating plate  8  made of ceramic are provided on an upper side of the yoke plate  4 ; the yoke plate  4  and the insulating plate  8  are fixed by a fastener so that the magnetic metal clip  7  is defined between the yoke plate  4  and the insulating plate  8 ; a chamber for accommodating a stationary contact assembly and a moving contact assembly is formed by the insulating plate  8 , the magnetic metal clip  7  and the yoke plate  4 ; the stationary contact assembly comprises a leading-out end  10  and stationary contacts  9  fixed on the leading-out end, and the leading-out end  10  and the insulating plate  8  are brazed or fixed by threads; an upper end surface of the positioning plate resists against the lower end of the magnetic metal clip, and a lower end surface of the positioning plate resists against the yoke plate; and the positioning plate  6  is tightly clamped between the magnetic metal clip  7  and the yoke plate  4 . There is a positioning frame  22  extending upward from the positioning plate  6 , and the magnetic metal clip  7  is sleeved on the outer periphery of the positioning frame so as to promise no deflection of the magnetic metal clip in the horizontal direction. 
         [0041]    Both the insulating plate  8  and the yoke plate  4  are square structures. A first fixing hole is formed at each of the four corners of the insulating plate  8 ; a second fixing hole  20  is formed at each of the four corners of the yoke plate  4 ; and retreating gaps for the second fixing holes  20  are formed at four corners of the positioning plate  6 . The fastener is a bolt  19 . One bolt  19  is matched inside each first fixing hole. The first fixing holes and the second fixing holes correspond one by one in terms of position. The bolt  19 , after passing through the first fixing hole, is fixed by threads with the second fixing hole so that a lower end of the bolt  19  is fixed with the yoke plate and the head portion of the bolt  19  compacts the insulating plate  8 . 
       Embodiment 3 
       [0042]    As shown in  FIG. 10 ,  FIG. 11  and  FIG. 12 , the present invention provides a horizontal-deflection prevention mechanism for an HVDC relay, including a moving contact assembly which comprises a moving reed  1  and moving contacts arranged at left and right ends of the moving reed  1 ; an upper section of a pushrod  3  fixed with a moving iron core  2  is located above a yoke plate  4  and fixed with the moving reed  1 ; a main spring  5  is sleeved on the pushrod  3 ; a positioning plate  6  made of insulating plastic is provided on the yoke plate  4 ; a left return spring  13  is connected between a left end of the moving reed  1  and the positioning plate  6 , and a right return spring  14  is connected between a right end of the moving reed  1  and the positioning plate  6 ; and both the left return spring  13  and the right return spring  14  are S-shaped extension springs. A boss  21  is formed on an upper section of the pushrod  3  located above the yoke plate  5 ; and a lower end of the main spring  5  resists against the boss  21 , and an upper end of the main spring  5  resists against the moving reed  1 .Both an axis of the left return spring  13  and an axis of the right return spring  14  are parallel to an axis of the pushrod  3 . 
         [0043]    An upper spring fixing hole  11  is provided at a left end of the moving reed, an upper spring fixing hole  11  is provided at a right end of the moving reed; and an upper end of the left return spring  13  is located inside the upper spring fixing hole at the left end, and an upper end of the right return spring  14  is located inside the upper spring fixing hole at the right end. The moving contacts comprise a left moving contact  15  and a right moving contact  16 ; and the upper spring fixing hole  11  at the left end of the moving reed is located on an outer side of the left moving contact  15 , and the upper spring fixing hole  11  at the right end of the moving reed is located on an outer side of the right moving contact  16 . 
         [0044]    A spring fixing plate extending upward is respectively formed on the positioning plate  6  at a position below and corresponding to the left end of the moving reed  1  and at a position below and corresponding to the right end of the moving reed; a lower spring fixing hole  12  is formed on the spring fixing plate; and a protection ring is matched on an inner wall of the lower spring fixing hole  12 , and the protection ring is an iron ring. The spring fixing plate comprises a left spring fixing plate  17  located on the left side and a right fixing plate  18  located on the right side; and a lower spring fixing hole  12  is formed on each of the left spring fixing plate  17  and the right spring fixing plate  18 . 
         [0045]    Both the connecting point between the left return spring  13  and the moving reed  1  and the connecting point between the right return spring  14  and the moving reed  1  are located in a front-rear symmetric centerline of the moving reed  1 . That is, the upper spring fixing hole of the left return spring  13  and the upper spring fixing hole of the right return spring  14  are located in a front-rear symmetric centerline of the moving reed. The left spring fixing plate  17  and the right spring fixing plate  18  are symmetrically arranged on the positioning plate  6 . An axis of the lower spring fixing hole  11  of the left spring fixing plate  17  and an axis of the lower spring fixing hole  11  of the right spring fixing plate  18  are located in a same straight line. 
         [0046]    As shown in  FIG. 10 , a magnetic metal clip  7  having an enclosed structure and an insulating plate  8  made of ceramic are provided on an upper side of the yoke plate  4 ; the yoke plate  4  and the insulating plate  8  are fixed by a fastener so that the magnetic metal clip  7  is defined between the yoke plate  4  and the insulating plate  8 ; a chamber for accommodating a stationary contact assembly and a moving contact assembly is formed by the insulating plate  8 , the magnetic metal clip  7  and the yoke plate  4 ; the stationary contact assembly comprises a leading-out end  10  and stationary contacts  9  fixed on the leading-out end, and the leading-out end  10  and the insulating plate  8  are brazed or fixed by threads; an upper end surface of the positioning plate resists against the lower end of the magnetic metal clip, and a lower end surface of the positioning plate resists against the yoke plate; and the positioning plate  6  is tightly clamped between the magnetic metal clip  7  and the yoke plate  4 . There is a positioning frame  22  extending upward from the positioning plate  6 , and the magnetic metal clip  7  is sleeved on the outer periphery of the positioning frame so as to promise no deflection of the magnetic metal clip in the horizontal direction. 
         [0047]    As shown in  FIG. 10  and  FIG. 12 , both the insulating plate  8  and the yoke plate  4  are square structures. A first fixing hole is formed at each of the four corners of the insulating plate  8 ; a second fixing hole  20  is formed at each of the four corners of the yoke plate  4 ; and retreating gaps for the second fixing holes  20  are formed at four corners of the positioning plate  6 . The fastener is a bolt  19 . One bolt  19  is matched inside each first fixing hole. The first fixing holes and the second fixing holes correspond one by one in terms of position. The bolt  19 , after passing through the first fixing hole, is fixed by threads with the second fixing hole so that a lower end of the bolt  19  is fixed with the yoke plate and the head portion of the bolt  19  compresses the insulating plate  8 . 
         [0048]    The horizontal-deflection prevention mechanism of the present invention is used in HVDC relays and has the advantages of preventing a moving reed from deflecting horizontally, ensuring the precise contact between the moving contacts and the stationary contacts of the relay, improving the reliability of the relay, and the like.