A DC relay capable of improving the short-circuit current resistance

Abstract

The present invention discloses a DC relay capable of improving the short-circuit current resistance ability, which includes two static contact lead-out terminals, a straight sheet-shaped moving reed, and a push rod component; the moving reed is assembled in the push rod component through at least one elastic member, so that under the action of the push rod component, both ends of the moving reed are respectively in contact with the bottom ends of the two static contact lead-out terminals, realizing that current flows in from one static contact lead-out terminal and flows out from the other static contact lead-out terminal after passing through the moving reed; in the moving reed, on both sides of the center line of the length of the moving reed, corresponding to the distance between the center line of the length of the moving reed and the contact position of the moving reed with the static contact lead-out terminal, at least one magnetic conduction ring surrounding the moving reed along the width direction of the moving reed is respectively provided, so as to form at least two series magnetic conduction loops in the length direction of the moving reed. The present invention can improve the short-circuit current resistance ability of the product and reduce the influence of the assembly difference of the moving reed on the short-circuit current resistance ability of the product.

Description

Technical Field

[0001] The present invention relates to the technical field of relays, and particularly to a DC relay capable of improving the short-circuit current resistance ability. Background Art

[0002] A DC relay of the prior art adopts a direct-acting magnetic circuit structure. Two static contact leads (i.e., two load leads) are respectively installed on the housing. The bottom ends of the two static contact leads are set as static contacts. The current of one static contact lead flows in, and the current of the other static contact lead flows out. A moving reed and a push rod component are installed in the housing. The moving reed adopts a straight-piece moving reed (also called a bridge-type moving reed). The two ends of the moving reed are set as moving contacts. The middle of the moving reed is installed in the push rod component through a spring. The push rod component is connected to the direct-acting magnetic circuit. Under the action of the direct-acting magnetic circuit, the push rod component drives the moving reed to move upward, so that the two ends of the moving reed respectively contact the bottom ends of the two static contact leads, thereby realizing the connection of the load. For this DC relay of the prior art, when a fault short-circuit current occurs, an electro-dynamic repulsive force will be generated between the moving and static contacts, affecting the contact stability between the moving and static contacts.

[0003] In order to improve the short-circuit current resistance ability of the DC relay, the prior art is to install a short-circuit resistance ring in the middle of the moving reed, that is, at the support position of the spring on the moving reed. Figure 1 Namely, it is a partial structure schematic diagram of a DC relay capable of resisting short-circuit current in the prior art. Figure 2 It is a front view of a partial structure of a DC relay capable of resisting short-circuit current in the prior art. As Figure 1 、 Figure 2 shown, this DC relay includes two static contact leads 101, 102, a straight-piece moving reed 103, and a push rod component (not shown in the figure). The middle of the moving reed 103 is installed in the push rod component through a spring 104, so as to realize the contact between the two ends (i.e., the moving contacts) of the moving reed 103 and the bottom ends (i.e., the static contacts) of the two static contact leads 101, 102 under the action of the push rod component, and realize the current flowing in from one static contact lead 101 and flowing out from the other static contact lead 102 after passing through the moving reed 103; a magnetic conduction ring 105 surrounding the width of the moving reed is installed in the middle of the moving reed 103, that is, at the support position of the spring 104. The magnetic conduction ring 105 is composed of an upper magnetic conductor 106 and a lower magnetic conductor 107. For this DC relay with such a structure, after actual short-circuit resistance tests, the tested samples are disassembled and analyzed, and it is found that most of the samples are single-sided bonding of the moving reed, that is, a single-sided bouncing and bonding phenomenon occurs after being subjected to the electro-dynamic repulsive force. Analyzing the reason, it is related to the misalignment of the forces on both ends of the moving reed 103 relative to the fulcrum. When a fault short-circuit current occurs, the two ends of the moving reed 103 are subjected to an electro-dynamic repulsive force F HFunction, at the middle of the moving reed 103, i.e., the spring 104 support position, receives the support force F provided by the push rod component through the spring 104 K and the suction force F in the contact pressure direction generated by the short-circuit ring E , during the actual production and assembly process, due to the fact that the moving reed 103 has a certain degree of freedom after assembly, the distances L1 and L2 between the contact points at the left and right ends (as moving contacts) relative to the fulcrum (spring 104 position) will be different. When L1 > L2, the electric repulsive force F H of the resultant moment M FH (1) will make the right side of the moving reed easier to bounce off, resulting in the failure of the right-side bonding; the greater the difference between L1 and L2, the more obvious this phenomenon is, thus affecting the anti-short-circuit current effect. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a DC relay capable of improving the anti-short-circuit current ability. Through structural improvement, the anti-short-circuit current ability of the product can be improved, and the influence of the assembly difference of the moving reed on the anti-short-circuit current ability of the product can be reduced.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a DC relay capable of improving the anti-short-circuit current ability, including two static contact lead-out terminals, a straight-piece moving reed, and a push rod component; the moving reed is assembled in the push rod component through at least one elastic member so that the two ends of the length of the moving reed can respectively contact the bottom ends of the two static contact lead-out terminals under the action of the push rod component, realizing the current flowing in from one static contact lead-out terminal and flowing out from the other static contact lead-out terminal after passing through the moving reed; in the moving reed, on both sides of the center line of the length of the moving reed, corresponding to the position between the center line of the length of the moving reed and the contact position of the moving reed with the static contact lead-out terminal, at least one magnetic conduction ring is respectively provided around the moving reed along the width direction of the moving reed, so as to form at least two series-connected magnetic conduction loops in the length direction of the moving reed, so as to utilize the suction force in the contact pressure direction generated by the magnetic conduction rings on both sides of the center line of the length of the moving reed to increase the support for the moving reed and resist the electric repulsive force generated between the moving reed and the static contact lead-out terminal due to the fault current.

[0006] The elastic member is a spring, and there is one spring, and the one spring supports at the position of the center line of the length of the moving reed.

[0007] The elastic member is a spring, and there are at least two springs, and the at least two springs are respectively distributed on both sides of the center line of the length of the moving reed.

[0008] The at least two springs are respectively supported under the magnetic conductive rings on both sides of the center line of the length of the moving reed piece, and the number of the springs ≤ the number of the magnetic conductive rings.

[0009] In the moving reed piece, the magnetic conductive rings arranged on both sides of the center line of the length of the moving reed piece are symmetrically distributed with respect to the center line of the length of the moving reed piece.

[0010] The magnetic conductive rings arranged on both sides of the center line of the length of the moving reed piece are biased towards the contact position between the moving reed piece and the static contact lead-out end.

[0011] In the moving reed piece, there is one magnetic conductive ring on each side of the center line of the length of the moving reed piece, and the two magnetic conductive rings are of the same size, and the distances from the two magnetic conductive rings to the center line of the length of the moving reed piece are the same.

[0012] The magnetic conductive ring is composed of an upper magnetic conductor and a lower magnetic conductor. The upper magnetic conductor is fixed in the push rod component or at a preset position, and the lower magnetic conductor is fixed on the moving reed piece.

[0013] The upper magnetic conductor is of a linear structure, and the lower magnetic conductor is of a U-shaped structure; the two ends of the linear structure of the upper magnetic conductor respectively correspond to the two upper ends of the U-shaped structure of the lower magnetic conductor.

[0014] The upper magnetic conductors of the magnetic conductive rings arranged on both sides of the center line of the length of the moving reed piece are connected into one body.

[0015] The DC relay includes a housing. The two static contact lead-out ends are respectively installed at the top wall of the housing. The bottom ends of the two static contact lead-out ends and the moving reed piece are respectively accommodated in the housing. The preset position is the bottom end of the convex part extending downward from the top wall of the housing.

[0016] The DC relay includes a yoke iron plate. The yoke iron plate is equipped with an inverted U-shaped bracket. The preset position is the inner side of the top wall of the U-shaped bracket.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. In the present invention, in the moving contact spring piece, on both sides of the center line of the length of the moving contact spring piece, corresponding to the position between the center line of the length of the moving contact spring piece and the contact position with the static contact lead-out end, at least one magnetic conduction ring that wraps around the moving contact spring piece along the width direction of the moving contact spring piece is respectively provided, so as to form at least two series-connected magnetic conduction loops in the length direction of the moving contact spring piece, and the suction force in the direction of the contact pressure generated by the magnetic conduction rings on both sides of the center line of the length of the moving contact spring piece is used to increase the support for the moving contact spring piece and resist the electro-dynamic repulsion force generated by the fault current between the moving contact spring piece and the static contact lead-out end. With this structure of the present invention, the suction force in the same direction as the contact pressure of the magnetic conduction rings on both sides of the center line of the length of the moving contact spring piece is used to increase the support for the moving contact spring piece, so that the original support at only one spring position becomes multiple supports (the support formed by the spring position support and the suction force of the magnetic conduction ring), making the support more stable, capable of improving the short-circuit current resistance ability of the product, and reducing the influence of the assembly difference of the moving contact spring piece on the short-circuit current resistance ability of the product.

[0019] 2. In the present invention, the magnetic conduction rings provided on both sides of the center line of the length of the moving contact spring piece are biased towards the contact position between the moving contact spring piece and the static contact lead-out end. With this structure of the present invention, the magnetic conduction rings are closer to the contact point. In this way, the closer the force arms of the electro-dynamic repulsion force and the suction force of the magnetic conduction ring are, the better the effect of reducing the influence of the assembly difference of the moving contact spring piece on the short-circuit current resistance ability of the product.

[0020] 3. In the present invention, the upper magnetic conduction bodies of the magnetic conduction rings provided on both sides of the center line of the length of the moving contact spring piece are connected into one body. With this structure of the present invention, the area of the upper magnetic conduction body is larger than the combined area of the upper magnetic conduction bodies of each individual magnetic conduction ring. When a short-circuit current passes through, the upper magnetic conduction body also has an upward suction force on the moving contact spring piece. The larger the area of the upper magnetic conduction body, the greater the suction force of the upper magnetic conduction body on the moving contact spring piece. This structure can maximize the suction force of the upper magnetic conduction body on the moving contact spring piece, and the moving contact spring piece will also receive a part of the upward Lorentz force, which can further improve the short-circuit resistance performance of the product.

[0021] The present invention will be further described in detail below in conjunction with the drawings and embodiments; however, a DC relay capable of improving the short-circuit current resistance ability of the present invention is not limited to the embodiments. Description of the Drawings

[0022] Figure 1 is a schematic diagram of a partial structure of a DC relay capable of resisting short-circuit current in the prior art;

[0023] Figure 2 is a front view of a partial structure of a DC relay capable of resisting short-circuit current in the prior art;

[0024] Figure 3 is an exploded schematic diagram of a partial structure of Embodiment 1 of the present invention;

[0025] Figure 4 is the front view of the partial structure of the first embodiment of the present invention (the moving and static contacts are not in contact);

[0026] Figure 5 is the front view of the partial structure of the first embodiment of the present invention (the moving and static contacts are in contact);

[0027] Figure 6 is the front view of the partial structure of the first embodiment of the present invention (the moving and static contacts are not in contact, and the push rod component is removed);

[0028] Figure 7 is the front view of the partial structure of the first embodiment of the present invention (the moving and static contacts are in contact, and the push rod component is removed);

[0029] Figure 8 is the schematic diagram of the cooperation between the moving reed and the magnetic conductive ring in the first embodiment of the present invention;

[0030] Figure 9 is the schematic diagram of the effect of anti - short - circuit current in the first embodiment of the present invention;

[0031] Figure 10 is the front view of the partial structure of the second embodiment of the present invention (the moving and static contacts are not in contact, and the push rod component is removed);

[0032] Figure 11 is the exploded schematic diagram of the partial structure of the third embodiment of the present invention;

[0033] Figure 12 is the schematic diagram of the cooperation between the moving reed and the magnetic conductive ring in the third embodiment of the present invention;

[0034] Figure 13 is the front view of the partial structure of the fourth embodiment of the present invention (the moving and static contacts are not in contact, and the push rod component is removed). Detailed implementation manners

[0035] Embodiment 1

[0036] See Figures 3 to 9As shown in the figure, a DC relay capable of improving the short-circuit current resistance ability of the present invention includes two static contact leads 11, 12, a straight-shaped moving reed 2, and a push rod component 3; the elastic member in this embodiment is a spring, and there is one spring 4, and one spring 4 is supported at the position of the center line of the length of the moving reed 2. The middle of the moving reed 2 is assembled in the push rod component 3 through the spring 4, so that the two ends of the moving reed (as moving contacts) are respectively in contact with the bottoms of the two static contact leads 11, 12 (as static contacts) under the action of the push rod component 3, realizing that current flows in from one static contact lead and flows out from the other static contact lead after passing through the moving reed; the push rod component 3 includes a U-shaped basket 31, a fixing piece 32, a push rod 33, and a spring seat 34. The fixing piece 32 and the push rod 33 form an integral part through the spring seat 34 formed by injection molding. The two ends of the U-shaped basket 31 are respectively connected to the fixing piece 32. The lower end of the spring 4 is matched with the spring seat 34, and the upper end of the spring 4 pushes the moving reed 2 against the inner side of the upper wall of the U-shaped basket 31; in the moving reed 2, on both sides of the spring support position, corresponding to the position between the spring support position and the contact position of the moving reed with the static contact lead, at least one magnetic conduction ring 5 that wraps around the moving reed in the width direction of the moving reed is respectively provided, so as to form at least two series-connected magnetic conduction loops in the length direction of the moving reed 2, so as to utilize the suction force F E , to increase the support for the moving reed 2 and resist the electro-magnetic repulsive force F H .

[0037] In this embodiment, in the moving reed 2, there is one magnetic conduction ring 5 on each side of the spring support position, and the two magnetic conduction rings 5 are of the same size, and the distances from the two magnetic conduction rings 5 to the spring support position are the same.

[0038] In this embodiment, the magnetic conduction rings 5 provided on both sides of the spring support position are as close as possible to the contact position of the moving reed with the static contact lead (i.e., the contact position of the static and moving contacts).

[0039] In this embodiment, the magnetic conduction ring 5 is composed of an upper magnetic conductor 51 and a lower magnetic conductor 52. The upper magnetic conductor 51 is fixed in the push rod component 3, and the lower magnetic conductor 52 is fixed on the moving reed 2.

[0040] Of course, the fixing position of the upper magnetic conductor can also be in other ways. For example, it can be installed on the housing of a DC relay. At this time, the two static contact terminals are respectively installed at the top wall of the housing. The bottom ends of the two static contact terminals and the moving reed are respectively accommodated in the housing, and the preset position is the bottom end of the convex part extending downward from the top wall of the housing. For another example, it can also be installed on the yoke iron plate of the DC relay. At this time, the yoke iron plate is equipped with an inverted U-shaped bracket, and the preset position is the inner side of the top wall of the U-shaped bracket.

[0041] In this embodiment, the upper magnetic conductor 51 has a straight structure, and the lower magnetic conductor 52 has a U-shaped structure; the two ends of the straight structure of the upper magnetic conductor 51 respectively correspond to the two upper ends of the U-shaped structure of the lower magnetic conductor 52. The magnetic conduction ring 5 of the present invention wraps around the moving reed along the width direction of the moving reed, which can be a complete wrap or an incomplete wrap. In this embodiment, a straight upper magnetic conductor 51 and a U-shaped lower magnetic conductor 52 are used to achieve wrapping around the moving reed, which belongs to a complete wrap. When the lower magnetic conductor also has a straight structure, the side of the width of the moving reed is not wrapped, and this situation belongs to an incomplete wrap.

[0042] A DC relay capable of improving the short-circuit current resistance ability of the present invention adopts at least one magnetic conduction ring 5 that wraps around the moving reed along the width direction of the moving reed on both sides of the spring support position in the moving reed 2, corresponding to the position from the spring support position to the contact position with the static contact terminal, so as to form at least two series magnetic conduction loops in the length direction of the moving reed 2, so as to utilize the suction force F in the direction of the contact pressure generated by the magnetic conduction ring 5 on both sides of the spring support position. E to form a support for the moving reed 2 and resist the electric repulsive force FH generated by the fault current between the moving reed and the static contact terminal. With this structure of the present invention, the suction force F in the same direction as the contact pressure of the magnetic conduction rings 5 on both sides of the spring support position of the moving reed 2 E is used to form a support for the moving reed, so that the original support at only one spring position becomes three supports (the support force F at the spring position K support and the suction force F of the magnetic conduction ring E formed support), making the support more stable. When the three support forces are not enough to resist the electric repulsive force and unilateral bounce occurs, it can also quickly close the bounced side, as Figure 9As shown, at the moment when the moving reed 2 is elastically pushed open unilaterally by the electro-dynamic repulsive force (for convenience of description, the angles in the figure are enlarged), the original bilateral contact becomes unilateral contact, that is, it rotates around one contact point, and the conduction of the conductor on the pushed-open side changes to arc conduction. At this time, the electro-dynamic repulsive force decreases rapidly, while the electromagnetic suction force Fe between the short-circuit rings generates an upward torque on the moving reed, causing the pushed-open side to close quickly. Subsequently, due to the high temperature of the arc, the lead-out end and the moving reed are welded together. The greater the upward torque of the electromagnetic suction force Fe on the moving reed 2, the shorter the pushing-open time, the smaller the influence of the arc, and the smaller the risk of ceramic cavity damage; and torque = force x force arm; Me = Fe1xL1 + Fe2xL2. It can be seen from this that compared with the middle single short-circuit ring in the present invention, the torque Me of the series short-circuit ring is greater, and whether it is pushed open on the left or the right, the effect is the same. Thus, the present invention can improve the short-circuit current resistance ability of the product and reduce the influence of the assembly difference of the moving reed on the short-circuit current resistance ability of the product.

[0043] A DC relay capable of improving the short-circuit current resistance ability according to the present invention adopts a structure in which the magnetic conductive rings 5 provided on both sides of the spring support position are biased towards the contact position between the moving reed and the static contact lead-out end. With this structure of the present invention, the magnetic conductive rings are closer to the contact point. In this way, the force arms of the electro-dynamic repulsive force and the suction force of the magnetic conductive rings are closer, and the better the effect of reducing the influence of the assembly difference of the moving reed on the short-circuit current resistance ability of the product.

[0044] Embodiment 2

[0045] See Figure 10 As shown, a DC relay capable of improving the short-circuit current resistance ability according to the present invention is different from that in Embodiment 1 in that there are two springs 4, and the two springs 4 are respectively distributed on both sides of the center line of the length of the moving reed 2 and supported under the magnetic conductive rings 5 on both sides of the center line of the length of the moving reed, and the number of springs = the number of magnetic conductive rings.

[0046] When two springs are used, the two springs 4 can also be respectively distributed under the contact position of the moving and static contacts.

[0047] Embodiment 3

[0048] See Figures 11 to 12 As shown, a DC relay capable of improving the short-circuit current resistance ability according to the present invention is different from that in Embodiment 1 in that the upper magnetic conductors 51 of the magnetic conductive rings 5 provided on both sides of the spring support position are connected into one body.

[0049] A DC relay capable of improving the short-circuit current resistance ability of the present invention adopts a structure in which the upper magnetic conductors 51 of the magnetic conduction rings arranged on both sides of the spring support position are connected into one body. With this structure of the present invention, the area of the upper magnetic conductor is larger than the combined area of the upper magnetic conductors of each individual magnetic conduction ring. When a short-circuit current passes through, the upper magnetic conductor also has an upward suction force on the moving reed. The larger the area of the upper magnetic conductor, the greater the suction force of the upper magnetic conductor on the moving reed. This structure can maximize the suction force of the upper magnetic conductor on the moving reed, and the moving reed will also receive a part of the upward Lorentz force, which can further improve the short-circuit resistance performance of the product.

[0050] Embodiment 4

[0051] See Figure 13 As shown, a DC relay capable of improving the short-circuit current resistance ability of the present invention is different from that of Embodiment 3 in that there are two springs 4, and the two springs 4 are respectively distributed on both sides of the center line of the length of the moving reed 2 and supported under the magnetic conduction rings 5 on both sides of the center line of the length of the moving reed, and the number of springs = the number of magnetic conduction rings.

[0052] The above are only the preferred embodiments of the present invention and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent equivalent embodiment, without departing from the scope of the technical solution of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of the protection of the technical solution of the present invention.

Claims

1. A DC relay capable of improving the short-circuit current resistance ability, comprising two static contact terminals, a straight piece-shaped moving reed, and a push rod component; the moving reed is assembled in the push rod component through at least one elastic member, so that when the push rod component acts, both ends of the length of the moving reed are respectively in contact with the bottom ends of the two static contact terminals, realizing that current flows in from one static contact terminal and flows out from the other static contact terminal after passing through the moving reed; Characterized in that: In the moving reed, on both sides of the center line of the length of the moving reed, corresponding to the distance between the center line of the length of the moving reed and the contact position of the moving reed with the static contact terminal, at least one magnetic conduction ring surrounding the moving reed along the width direction of the moving reed is respectively provided, so as to form at least two series magnetic conduction loops in the length direction of the moving reed, and the suction force in the contact pressure direction generated by the magnetic conduction rings on both sides of the center line of the length of the moving reed is used to increase the support for the moving reed and resist the electro-dynamic repulsive force generated between the moving reed and the static contact terminal due to the fault current.

2. The DC relay capable of improving the short-circuit current resistance ability according to claim 1, Characterized in that: The elastic member is a spring, and there is one spring, and the one spring is supported at the position of the center line of the length of the moving reed.

3. The DC relay capable of improving the short-circuit current resistance ability according to claim 1, Characterized in that: The elastic member is a spring, and there are at least two springs, and the at least two springs are respectively distributed on both sides of the center line of the length of the moving reed.

4. The DC relay capable of improving the short-circuit current resistance ability according to claim 3, Characterized in that: The at least two springs are respectively supported under the magnetic conduction rings on both sides of the center line of the length of the moving reed, and the number of springs ≤ the number of magnetic conduction rings.

5. The DC relay capable of improving the short-circuit current resistance ability according to claim 1, Characterized in that: In the moving reed, the magnetic conduction rings arranged on both sides of the center line of the length of the moving reed are symmetrically distributed with respect to the center line of the length of the moving reed.

6. The DC relay capable of improving the short-circuit current resistance ability according to claim 1, Characterized in that: The magnetic conduction rings arranged on both sides of the center line of the length of the moving reed are biased towards the contact position of the moving reed with the static contact terminal.

7. The DC relay capable of improving the short-circuit current resistance ability according to claim 1, Characterized in that: In the moving reed, there is one magnetic conduction ring on each side of the center line of the length of the moving reed, and the two magnetic conduction rings are of the same size, and the distances from the two magnetic conduction rings to the center line of the length of the moving reed are the same.

8. The DC relay capable of improving the short-circuit current resistance ability according to claim 1 or 5 or 6 or 7, Characterized in that: The magnetic conduction ring is composed of an upper magnetic conductor and a lower magnetic conductor, the upper magnetic conductor is fixed in the push rod component or a preset position, and the lower magnetic conductor is fixed on the moving reed.

9. The DC relay capable of improving the short-circuit current resistance ability according to claim 8, Characterized in that: The upper magnetic conductor is of a linear structure, and the lower magnetic conductor is of a U-shaped structure; the two ends of the linear structure of the upper magnetic conductor respectively correspond to the two upper ends of the U-shaped structure of the lower magnetic conductor.

10. The DC relay capable of improving the short-circuit current resistance ability according to claim 7, characterized in that: The upper magnetic conductors of the magnetic conduction rings arranged on both sides of the center line of the length of the moving reed are connected into one body.

11. The DC relay capable of improving the short-circuit current resistance ability according to claim 8, characterized in that: The DC relay includes a cover shell, the two static contact lead-out ends are respectively installed at the top wall of the cover shell, the bottom ends of the two static contact lead-out ends and the moving reed are respectively accommodated in the cover shell, and the preset position is the bottom end of the convex part extending downward from the top wall of the cover shell.

12. The DC relay capable of improving the short-circuit current resistance ability according to claim 8, characterized in that: The DC relay includes a yoke iron plate, the yoke iron plate is equipped with an inverted U-shaped bracket, and the preset position is the inner side of the top wall of the U-shaped bracket.

Images