DC relay for short circuit protection

Abstract

To provide a DC relay for preventing short-circuit current in which volume of a product is small, contact pressure capable of countering electric reaction force due to the short-circuit current is provided, magnetic efficiency is high, and a magnetic circuit is hardly saturated.SOLUTION: A DC relay for preventing short-circuit current comprises two fixed contact lead-out ends, one movable contact 2, and one push rod member 3. An upper magnetic conductor 61 is mounted above the movable contact. A lower magnetic conductor 62 movable with the movable contact is mounted below the movable contact. At least one through hole is provided on the movable contact. The upper magnetic conductor and the lower magnetic conductor can be close to or in contact with each other through the through hole. The upper magnetic conductor and the lower magnetic conductor are configured to form, in a width direction of the movable contact, at least two independent magnetic circuits, and when fault current occurs, are configured to generate attraction force in a direction of contact pressure by using a magnetic pole surface formed at a position of the through hole by each magnetic circuit, to counter electric reaction force due to the fault current.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention claims priority based on six Chinese patent applications, including the Chinese patent application having application number 201811330771.1 filed on November 9, 2018, the Chinese patent application having application number 201811624114.8 filed on December 28, 2018, the Chinese patent application having application number 201811623949.1 filed on December 28, 2018, the Chinese patent application having application number 201811624058.8 filed on December 28, 2018, the Chinese patent application having application number 201811624113.3 filed on December 28, 2018, and the Chinese patent application having application number 201811623963.1 filed on December 28, 2018, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to the technical field of relays, and in particular to a DC relay for preventing short circuit currents. [Background technology]

[0003] In the prior art DC relay, a direct drive type magnetic circuit structure is used, in which two fixed contact drawers (i.e., two load drawers) are respectively mounted on a case, and fixed contacts are provided at the bottoms of the two fixed contact drawers. Current flows into one of the fixed contact drawers and flows out from the other fixed contact drawer. A movable spring and a push rod member are mounted inside the case. The movable spring uses a straight plate type movable contactor (also called a bridge type movable contactor). The movable contactor (movable spring sheet) is attached to the push rod member via a spring. The push rod member is connected to a direct drive type magnetic circuit, and the action of the direct drive type magnetic circuit moves the movable contactor upward to bring the movable contacts located at both ends of the movable contactor into contact with the fixed contacts located at the bottoms of the two fixed contact drawers, respectively, thereby realizing connection to the load. In such a DC relay in the prior art, when a short circuit current occurs due to a fault, an electric reaction force is generated between the moving contact and the fixed contact, which affects the stability of the contact between the moving contact and the fixed contact.

[0004] With the rapid development of the new energy industry, automobile factories and battery pack factories have increasingly higher requirements for current caused by fault short circuit, and thus a DC relay is required that has a short circuit prevention function while maintaining the characteristic of small volume, and provides auxiliary attraction force to counter the electric reaction force received by the movable spring when a large fault current occurs in the system. The typical input short circuit prevention required by the market at present is that it will not burn or explode when 8000A, 5ms, but the DC relay in the prior art cannot provide sufficient attraction force while maintaining the characteristic of small volume. That is, the contact pressure is insufficient to counter the electric reaction force received by the movable spring, making it difficult to meet the market demand. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made to solve the problems of the conventional technology, and has an object to provide a DC relay for preventing short-circuit currents which, while retaining the characteristic of a small product volume, can provide sufficient contact pressure to withstand the electric reaction force caused by the large short-circuit current acting on the movable spring, and which has the characteristics of high magnetic efficiency and a magnetic circuit that is not easily saturated. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention has the following configuration. A DC relay for preventing short circuit current includes two fixed contact drawers, one straight plate type movable contactor, and one push rod member. The movable contactor is attached to the push rod member, and the movable contacts located at both ends of the movable contactor and the fixed contacts located at the bottoms of the two fixed contact drawers are brought into contact with each other by the action of the push rod member, and a current flows into one of the fixed contact drawers, passes through the movable contactor, and flows out from the other fixed contact drawer. An upper magnetic conductor is attached above one of the predetermined positions of the movable contactor, and is distributed along the width direction of the movable contactor. A lower magnetic conductor is attached below the predetermined position of the movable contactor, and is distributed along the width direction of the movable contactor and movable together with the movable contactor. At least one through hole is provided at a predetermined position of the movable contactor, and the upper magnetic conductor and the lower magnetic conductor can approach, contact, or separate from each other through the through hole. In addition, the upper and lower magnetic conductors form at least two independent magnetic circuits in the width direction of the movable contact, and when a large fault current occurs in the movable contact, each magnetic circuit uses a magnet pole face added to the position of a corresponding through hole to generate an attractive force in the direction of the contact pressure, thereby countering the electrical reaction force caused by the fault current between the movable contact and the fixed contact pull-out end.

[0007] In one embodiment, the predetermined position is located between two movable contacts along the length of the movable contact.

[0008] In one embodiment, the upper magnetic conductor is at least one straight-shaped upper magnetic conductor, and the lower magnetic conductor is at least two U-shaped lower magnetic conductors, where one U-shaped lower magnetic conductor and the corresponding straight-shaped upper magnetic conductor form an independent magnetic circuit, and two adjacent U-shaped lower magnetic conductors forming two magnetic circuits are not in contact with each other.

[0009] In one embodiment, in at least two independent magnetic circuits, the linear upper magnetic conductor in at least one set of two adjacent magnetic circuits is a common one, and the two U-shaped lower magnetic conductors in the two adjacent magnetic circuits are each arranged below one linear upper magnetic conductor.

[0010] In one embodiment, in at least two independent magnetic circuits, all of the linear upper magnetic conductors in two adjacent magnetic circuits are independent, and the two U-shaped lower magnetic conductors in the two adjacent magnetic circuits are respectively arranged below the corresponding linear upper magnetic conductors.

[0011] In one embodiment, there are two magnetic circuits, the movable contactor is provided with a through hole, one side wall of each of the two U-shaped lower magnetic conductors is attached to the upper side of the movable contactor in the width direction, the other side wall of each of the two U-shaped lower magnetic conductors passes through the same through hole of the movable contactor, and there is a gap between the other side wall of each of the two U-shaped lower magnetic conductors.

[0012] In one embodiment, the other side walls of the two U-shaped lower magnetic conductors are arranged side by side along the length of the movable contactor within the same through hole of the movable contactor, thereby distributing the two magnetic circuits formed by the two U-shaped lower magnetic conductors side by side along the length of the movable contactor.

[0013] In one embodiment, the other side walls of the two U-shaped lower magnetic conductors are arranged in the same through hole of the movable contactor with a shift along the longitudinal direction of the movable contactor, so that the two magnetic circuits formed by the two U-shaped lower magnetic conductors are distributed with a shift along the longitudinal direction of the movable contactor.

[0014] In one embodiment, there are two magnetic circuits, the movable contactor is provided with two through holes, and the two through holes are arranged side by side along the longitudinal direction of the movable contactor. One side wall of each of the two U-shaped lower magnetic conductors is attached to the corresponding side edge in the width direction of the movable contactor, and the other side wall of each of the two U-shaped lower magnetic conductors is inserted into the two through holes of the movable contactor, thereby distributing the two magnetic circuits formed by the two U-shaped lower magnetic conductors side by side along the longitudinal direction of the movable contactor.

[0015] In one embodiment, there are two magnetic circuits, the movable contactor is provided with two through holes, and the two through holes are arranged with a shift along the longitudinal direction of the movable contactor. One side wall of each of the two U-shaped lower magnetic conductors is attached to the upper side of the movable contactor in the width direction, and the other side wall of each of the two U-shaped lower magnetic conductors is penetrated by the two through holes of the movable contactor, thereby distributing the two magnetic circuits formed in the two U-shaped lower magnetic conductors with a shift along the longitudinal direction of the movable contactor.

[0016] In one embodiment, the magnetic circuits are three, the movable contactor is provided with two through holes, and the three U-shaped lower magnetic conductors are sequentially arranged along the width direction of the movable contactor, where both side walls of one U-shaped lower magnetic conductor located in the center pass through two through holes of the movable contactor, one side wall of each of the two U-shaped lower magnetic conductors located on both sides is attached to the side of the movable contactor in the width direction, and the other side wall of each of the two U-shaped lower magnetic conductors located on both sides passes through two through holes of the movable contactor, and there is a gap between the two side walls of the movable contactor in the same through hole.

[0017] In one embodiment, the upper surface of the side wall of the U-shaped lower magnetic conductor is substantially flush with the upper surface of the movable contact.

[0018] In one embodiment, the upper magnetic conductor is an upper armature fixed to the push rod member, and the lower magnetic conductor is a lower armature fixed to the movable contact, the movable contact is attached to the push rod member via a spring, and when the movable contact of the movable contact is brought into contact with the fixed contact of the fixed contact pull-out end, a predetermined gap exists between the upper armature and the lower armature.

[0019] In one embodiment, the upper magnetic conductor is an upper yoke fixed to a case for mounting two fixed contact pull-out ends, and the lower magnetic conductor is a lower armature fixed to the movable contact, the movable contact is attached to the push rod member via a spring, and the upper yoke contacts the lower armature when the movable contact of the movable contact is brought into contact with the fixed contact of the fixed contact pull-out end.

[0020] In one embodiment, the push rod member includes a U-shaped holder, a spring seat, and a push rod. The tip of the push rod is fixed to the spring seat, the bottom of the U-shaped holder is fixed to the spring seat, and a movable spring block composed of the movable contact and two U-shaped lower magnetic conductors is mounted in the U-shaped holder via the spring. Here, the upper surface of the movable contact abuts against the upper yoke, the upper yoke is fixed to the inner wall of the top of the U-shaped holder, and the spring elastically abuts between the bottoms of the two U-shaped lower magnetic conductors and the upper surface of the spring seat.

[0021] In one embodiment, each of the bottoms of the two U-shaped lower magnetic conductors is further provided with a semicircular groove for positioning the spring, and the two semicircular grooves form a full circle in which the tip of the spring is positioned.

[0022] In one embodiment, each of the bottoms of the two U-shaped lower magnetic conductors is further provided with a positioning post for positioning the spring, and the positioning post is used to position the spring outside the tip of the spring.

[0023] In one embodiment, the movable contact further includes widened portions on both sides in the width direction corresponding to the positions of the through holes.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] According to the present invention, an upper magnetic conductor is attached above one predetermined position of the movable contact, and a lower magnetic conductor movable together with the movable contact is attached below a predetermined position of the movable contact, at least one through hole is provided at the predetermined position of the movable contact, the upper magnetic conductor and the lower magnetic conductor can approach or contact each other through the through hole, and the upper magnetic conductor and the lower magnetic conductor form at least two independent magnetic circuits in the width direction of the movable contact, when a large fault current occurs in the movable contact, the magnetic pole surface added at the position of the corresponding through hole by each magnetic circuit is used to increase the attractive force in the direction of the contact pressure, and the attractive force is superimposed on the contact pressure to counteract the electrical reaction force caused by the fault current between the movable contact and the fixed contact pull-out end, and the multiple independent magnetic circuits distribute the large short-circuit current almost evenly, resulting in high magnetic efficiency and a magnetic circuit that is not easily saturated.

[0026] Furthermore, according to the present invention, each independent magnetic circuit is formed by combining a straight-shaped upper magnetic conductor and a U-shaped lower magnetic conductor, so that the same material can be used, and the cost is low. Also, there is a gap between each U-shaped lower magnetic conductor. The straight-shaped upper magnetic conductor can be fixed to a push rod member or to a case for mounting two fixed contact lead ends. Each U-shaped lower magnetic conductor is fixed to the movable contactor by a crimping method, and the upper surface of the side wall of the U-shaped lower magnetic conductor is exposed to the upper surface of the movable contactor. According to such a structure of the present invention, a plurality of independent magnetic circuits are formed in the cross section of the movable contactor by the upper magnetic conductor and the lower magnetic conductor, so that when a fault current flows through the movable contactor, magnetic flux is generated in the plurality of magnetic circuits, and an attractive force is generated between the magnetic conductors of each magnetic circuit. This attractive force is in the direction of increasing contact pressure and is intended to counter the electrical reaction force between the contacts; since multiple magnetic circuits are used, the fault current allowed for each circuit is only Imax / n, making it difficult for the magnetic circuits to saturate; the higher the passing current, the greater the increase in contact pressure and the greater the attractive force generated by the magnetic circuits.

[0027] According to another aspect of the present invention, a DC relay with arc-extinguishing and short-circuit current prevention functions includes two fixed contact pull-out ends, one straight plate type movable contact, one push rod member, and four permanent magnets. The movable contact is attached to the push rod member, and the movable contacts located at both ends of the movable contact and the fixed contacts located at the bottoms of the two fixed contact pull-out ends are matched by the action of the push rod member. The four permanent magnets are respectively arranged at both sides of the movable contact facing the movable contact and the fixed contact, and the two permanent magnets facing the same pair of movable contact and fixed contact have opposite magnetic poles on one side facing the movable contact and the fixed contact, and the two permanent magnets located at the same side of the movable contact in the width direction also have opposite magnetic poles on one side facing the movable contact and the fixed contact, and a yoke clip is further connected between the two permanent magnets facing the same pair of movable contact and fixed contact. An upper magnetic conductor is attached above a position between the two movable contacts of the movable contactor and arranged along the width direction of the movable contactor, and a lower magnetic conductor is attached below the position and arranged along the width direction of the movable contactor and movable together with the movable contactor. At least one through hole is provided at the predetermined position of the movable contactor, and the upper magnetic conductor and the lower magnetic conductor can approach, contact, or separate from each other through the through hole. The upper magnetic conductor and the lower magnetic conductor form at least two independent magnetic circuits in the width direction of the movable contactor, and when a large fault current occurs in the movable contactor, each magnetic circuit uses a magnetic pole surface added at the position of the corresponding through hole to generate an attractive force in the direction of the contact pressure, thereby countering the electric reaction force caused by the fault current between the movable contactor and the drawn-out end of the fixed contact.

[0028] In one embodiment, the two permanent magnets facing the same pair of movable contacts and fixed contacts are provided at a biased position relative to the same pair of movable contacts and fixed contacts, and the two permanent magnets are arranged in an offset manner.

[0029] Compared with the prior art, the present invention has the following beneficial effects. According to the present invention, four permanent magnets are arranged at both sides of the movable contact facing the movable contact and the fixed contact in the width direction of the movable contactor, and the two permanent magnets facing the same pair of movable contact and the fixed contact are arranged with opposite magnetic poles on one side facing the movable contact and the fixed contact, and the two permanent magnets located on the same side in the width direction of the movable contactor are also arranged with opposite magnetic poles on one side facing the movable contact and the fixed contact. A yoke clip is further connected between the two permanent magnets facing the same pair of movable contact and the fixed contact. An upper magnetic conductor is attached above the position between the two movable contacts of the movable contactor, and a lower magnetic conductor movable together with the movable contactor is attached below the position between the two movable contacts of the movable contactor. At least one through hole is provided at the position of the movable contactor, and the upper magnetic conductor and the lower magnetic conductor can approach or contact or separate from each other through the through hole. The upper magnetic conductor and the lower magnetic conductor form at least two independent magnetic circuits in the width direction of the movable contactor. According to this structure of the present invention, arc extinction is achieved by four permanent magnets, and the magnetic pole faces added to the positions of the corresponding through holes by each magnetic circuit are used to increase the attractive force in the direction of the contact pressure when a large fault current occurs in the moving contact, and the attractive force is superimposed on the contact pressure to counter the electrical reaction force caused by the fault current between the moving contact and the fixed contact. Since the multiple independent magnetic circuits distribute the large short-circuit current almost evenly, the magnetic efficiency is high and the magnetic circuits are not easily saturated.

[0030] According to another aspect of the present invention, a DC relay with arc extinguishing and short circuit current prevention functions includes two fixed contact pull-out ends, one straight plate type movable contact, one push rod member, and two permanent magnets. The movable contact is attached to the push rod member, and the movable contacts located at both ends of the movable contact and the fixed contacts located at the bottoms of the two fixed contact pull-out ends are matched by the action of the push rod member. The two permanent magnets are arranged at both side positions in the width direction of the movable contact facing the movable contact and the fixed contact, respectively, and the movable contacts and fixed contacts corresponding to the two permanent magnets are different. A yoke clip is further connected to each of the two permanent magnets. The two yoke clips each have an L-shape, and one side of the L-shaped yoke clip is connected to one side opposite to one side of the permanent magnet facing the movable contact and the fixed contact, and the other side of the L-shaped yoke clip is located outside both ends in the length direction of the movable contact. An upper magnetic conductor is attached above a position between the two movable contacts of the movable contactor and arranged along the width direction of the movable contactor, and a lower magnetic conductor is attached below the position and arranged along the width direction of the movable contactor and movable together with the movable contactor. At least one through hole is provided at the position of the movable contactor, and the upper magnetic conductor and the lower magnetic conductor can approach, contact, or separate from each other through the through hole. The upper magnetic conductor and the lower magnetic conductor form at least two independent magnetic circuits in the width direction of the movable contactor. When a large fault current occurs in the movable contactor, an attractive force is generated in the direction of contact pressure by using a magnetic pole surface added at the position of the corresponding through hole by each magnetic circuit, thereby countering the electric reaction force caused by the fault current between the movable contactor and the fixed contact lead end.

[0031] In one embodiment, the two permanent magnets are disposed at positions facing the movable contact and the fixed contact, respectively.

[0032] In one embodiment, the two permanent magnets are arranged with the same magnetic poles on one side facing the movable contact and the fixed contact.

[0033] In one embodiment, the magnetic poles of the two permanent magnets facing the movable contact and the fixed contact are oppositely arranged.

[0034] Compared with the prior art, the present invention has the following beneficial effects. According to the present invention, two permanent magnets are arranged at both sides of the movable contactor in the width direction facing the movable contact and the fixed contact, respectively, and the two permanent magnets correspond to different movable contacts and fixed contacts. A yoke clip is further connected to each of the two permanent magnets. Each of the two yoke clips has an L-shape, and one side of the L-shaped yoke clip is connected to one side of the permanent magnet opposite to the surface facing the movable contact and the fixed contact, and the other side of the L-shaped yoke clip is located outside both ends in the length direction of the movable contactor. An upper magnetic conductor is attached above the position between the two movable contacts of the movable contactor, and a lower magnetic conductor movable together with the movable contactor is attached below the position between the two movable contacts of the movable contactor. At least one through hole is provided at the position of the movable contactor, and the upper magnetic conductor and the lower magnetic conductor can approach, contact, or separate from each other through the through hole. In addition, the upper and lower magnetic conductors form at least two independent magnetic circuits in the width direction of the movable contact. According to this structure of the present invention, after realizing arc extinction by two permanent magnets, when a large fault current occurs in the movable contact, each magnetic circuit uses a magnetic pole face added at the position of the corresponding through hole to increase the attractive force in the direction of the contact pressure, and the attractive force is superimposed on the contact pressure to counter the electric reaction force caused by the fault current between the movable contact and the fixed contact. Since the multiple independent magnetic circuits distribute the large short-circuit current almost evenly, the magnetic efficiency is high and the magnetic circuits are not easily saturated.

[0035] According to another aspect of the present invention, a DC relay with arc-extinguishing and short-circuit current prevention functions includes two fixed contact pull-out ends, one straight plate type movable contact, one push rod member, and four permanent magnets. The movable contact is attached to the push rod member, and the movable contacts located at both ends of the movable contact and the fixed contacts located at the bottoms of the two fixed contact pull-out ends are contacted by the action of the push rod member. The four permanent magnets are respectively arranged at both sides of the movable contact facing the movable contact and the fixed contact, and the two permanent magnets located at the same pair of movable contact and fixed contact have the same magnetic poles on one side facing the movable contact and the fixed contact, and a yoke clip is further connected between the two permanent magnets facing the same pair of movable contact and fixed contact. An upper magnetic conductor arranged along the width direction of the movable contact is attached above the position between the two movable contacts of the movable contact, and a lower magnetic conductor arranged along the width direction of the movable contact and movable together with the movable contact is attached below the position. At least one through hole is provided at the position of the movable contact, and the upper magnetic conductor and the lower magnetic conductor can approach, contact, or separate from each other through the through hole. The upper magnetic conductor and the lower magnetic conductor form at least two independent magnetic circuits in the width direction of the movable contact. When a large fault current occurs in the movable contact, each magnetic circuit uses a magnetic pole face added at the position of the corresponding through hole to generate an attractive force in the direction of contact pressure to counter the electric reaction force caused by the fault current between the movable contact and the fixed contact lead end.

[0036] In one embodiment, the four permanent magnets are disposed at positions facing the movable contact and the fixed contact, respectively.

[0037] In one embodiment, among the four permanent magnets, two permanent magnets located on the same side in the width direction of the movable contactor are arranged with the same magnetic poles on one side facing the movable contact and the fixed contact.

[0038] In one embodiment, among the four permanent magnets, two permanent magnets located on the same side in the width direction of the movable contactor are arranged with the magnetic poles of one side facing the movable contact and the fixed contact opposite to each other.

[0039] Compared with the prior art, the present invention has the following beneficial effects. According to the present invention, four permanent magnets are arranged at both sides of the movable contact facing the movable contact and the fixed contact, and the two permanent magnets facing the same pair of movable contact and the fixed contact are arranged with the same magnetic poles on one side facing the movable contact and the fixed contact, and a yoke clip is further connected between the two permanent magnets facing the same pair of movable contact and the fixed contact. An upper magnetic conductor is attached above the position between the two movable contacts of the movable contact, and a lower magnetic conductor movable together with the movable contact is attached below the position between the two movable contacts of the movable contact. At least one through hole is provided at the position of the movable contact, and the upper magnetic conductor and the lower magnetic conductor can approach, contact, or separate from each other through the through hole. The upper magnetic conductor and the lower magnetic conductor form at least two independent magnetic circuits in the width direction of the movable contact. According to this structure of the present invention, arc extinction is achieved by four permanent magnets, and the magnetic pole faces added to the positions of the corresponding through holes by each magnetic circuit are used to increase the attractive force in the direction of the contact pressure when a large fault current occurs in the moving contact, and the attractive force is superimposed on the contact pressure to counter the electrical reaction force caused by the fault current between the moving contact and the fixed contact. Since the multiple independent magnetic circuits distribute the large short-circuit current almost evenly, the magnetic efficiency is high and the magnetic circuits are not easily saturated.

[0040] According to another aspect of the present invention, a DC relay with arc extinguishing and short circuit current prevention functions includes two fixed contact pull-out ends, one straight plate type movable contactor, one push rod member, and two permanent magnets. The movable contactor is attached to the push rod member, and the movable contacts located at both ends of the movable contactor and the fixed contacts located at the bottoms of the two fixed contact pull-out ends are contacted by the action of the push rod member. The two permanent magnets are arranged at outer positions of both ends in the length direction of the movable contactor facing the movable contactor and the fixed contact, respectively, and the magnetic poles of the opposing sides of the two permanent magnets are oppositely arranged, and two yoke clips are further connected to the two permanent magnets. The two yoke clips further include yoke sections located at both sides in the width direction of the movable contactor facing at least the movable contactor and the fixed contact. An upper magnetic conductor arranged along the width direction of the movable contactor is attached above a position between the two movable contacts of the movable contactor, and a lower magnetic conductor arranged along the width direction of the movable contactor and movable together with the movable contactor is attached below the position. At least one through hole is provided at the position of the movable contact, and the upper magnetic conductor and the lower magnetic conductor can approach, contact, or separate from each other through the through hole. The upper magnetic conductor and the lower magnetic conductor form at least two independent magnetic circuits in the width direction of the movable contact. When a large fault current occurs in the movable contact, each magnetic circuit uses a magnetic pole face added at the position of the corresponding through hole to generate an attractive force in the direction of contact pressure to counter the electric reaction force caused by the fault current between the movable contact and the fixed contact lead end.

[0041] In one embodiment, the two permanent magnets are disposed at positions facing the movable contact and the fixed contact, respectively.

[0042] In one embodiment, the yoke clip has a U-shape, the bottom walls of the two U-shaped yoke clips are respectively connected to one side of the back surfaces of the two permanent magnets, and the ends of both side walls of the two U-shaped yoke clips respectively constitute corresponding yoke sections.

[0043] In one embodiment, the yoke clip has a U-shape, the bottom walls of the two U-shaped yoke clips are connected to one side of the back surfaces of the two permanent magnets, and the tips of both side walls of the two U-shaped yoke clips exceed both sides of the width direction of the movable contactor that faces the movable contact and the fixed contact, respectively. The both side walls of the two U-shaped yoke clips include the yoke section.

[0044] In one embodiment, the yoke clip has a U-shape, the bottom walls of the two U-shaped yoke clips are respectively arranged on both sides of the movable contactor in the width direction, and the tips of both side walls of the two U-shaped yoke clips are respectively connected to one side of the back surfaces of the two permanent magnets.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] According to the present invention, two permanent magnets are arranged at the outer positions of both ends in the length direction of the movable contactor facing the movable contact and the fixed contact, and the magnetic poles of the opposing faces of the two permanent magnets are arranged in opposite directions, and two yoke clips are further connected to the two permanent magnets. The two yoke clips further include yoke sections located at least at both sides in the width direction of the movable contactor facing the movable contact and the fixed contact. An upper magnetic conductor is attached above the position between the two movable contacts of the movable contactor, and a lower magnetic conductor movable together with the movable contactor is attached below the position between the two movable contacts of the movable contactor. At least one through hole is provided in the movable contactor at the above position, and the upper magnetic conductor and the lower magnetic conductor can approach, contact, or separate from each other through the through hole. The upper magnetic conductor and the lower magnetic conductor form at least two independent magnetic circuits in the width direction of the movable contactor. According to this structure of the present invention, after achieving arc extinction by two permanent magnets, when a large fault current occurs in the moving contact, the magnetic circuit utilizes the magnetic pole faces added at the corresponding through hole positions to increase the attractive force in the direction of the contact pressure, and the attractive force is superimposed on the contact pressure to counter the electrical reaction force caused by the fault current between the moving contact and the fixed contact. Since the multiple independent magnetic circuits distribute the large short-circuit current almost evenly, the magnetic efficiency is high and the magnetic circuits are not easily saturated.

[0047] According to another aspect of the present invention, a DC relay with arc extinguishing and short circuit current prevention functions using permanent magnets includes two fixed contact drawers, one straight plate type movable contactor, one push rod member, and four permanent magnets. The movable contactor is attached to the push rod member, and the movable contacts located at both ends of the movable contactor and the fixed contacts located at the bottoms of the two fixed contact drawers are contacted by the action of the push rod member. The four permanent magnets are respectively arranged at both sides of the movable contactor facing the movable contactor and the fixed contactor in the width direction, and the two permanent magnets facing the same pair of movable contactor and the fixed contactor have opposite magnetic poles on one side facing the movable contactor and the fixed contactor, and the two permanent magnets located on the same side of the movable contactor in the width direction have the same magnetic poles on one side facing the movable contactor and the fixed contactor, and a yoke clip is further connected between the two permanent magnets facing the same pair of movable contactor and the fixed contactor. An upper magnetic conductor is attached above a position between the two movable contacts of the movable contactor, and a lower magnetic conductor is attached below the position, and is arranged along the width direction of the movable contactor and movable together with the movable contactor. At least one through hole is provided at the position of the movable contactor, and the upper magnetic conductor and the lower magnetic conductor can approach, contact, or separate from each other through the through hole. The upper magnetic conductor and the lower magnetic conductor form at least two independent magnetic circuits in the width direction of the movable contactor. When a large fault current occurs in the movable contactor, magnetic pole faces added at the positions of the corresponding through holes by each magnetic circuit are used to generate an attractive force in the direction of the contact pressure to counter the electric reaction force caused by the fault current between the movable contactor and the fixed contact lead end.

[0048] In one embodiment, the four permanent magnets are disposed at positions facing the movable contact and the fixed contact, respectively.

[0049] In one embodiment, of the four permanent magnets, the two permanent magnets located on the left side of the moving contact in the direction of current flow have one magnetic pole facing the moving contact and the fixed contact set as the N pole. Effect of the Invention

[0050] Compared with the prior art, the present invention has the following beneficial effects. In the present invention, the four permanent magnets are disposed at both sides of the movable contact facing the movable contact and the fixed contact, and the two permanent magnets facing the same pair of movable contact and the fixed contact are arranged with opposite magnetic poles on one side facing the movable contact and the fixed contact, and the two permanent magnets located on the same side of the movable contact in the width direction are arranged with the same magnetic poles on one side facing the movable contact and the fixed contact, and a yoke clip is further connected between the two permanent magnets facing the same pair of movable contact and the fixed contact. In addition, an upper magnetic conductor is attached above the position between the two movable contacts of the movable contact, and a lower magnetic conductor movable together with the movable contact is attached below the position between the two movable contacts of the movable contact. At least one through hole is provided at the position of the movable contact, and the upper magnetic conductor and the lower magnetic conductor can approach or contact each other through the through hole. In addition, the upper magnetic conductor and the lower magnetic conductor form at least two independent magnetic circuits in the width direction of the movable contact. According to this structure of the present invention, after arc extinction is achieved by four permanent magnets, when a large fault current occurs in the moving contact, the magnetic circuits utilize the magnetic pole faces added at the corresponding through hole positions to increase the attractive force in the direction of the contact pressure, and the attractive force is superimposed on the contact pressure to counter the electrical reaction force caused by the fault current between the moving contact and the fixed contact. Since the multiple independent magnetic circuits distribute the large short-circuit current almost evenly, the magnetic efficiency is high and the magnetic circuits are not easily saturated.

[0051] The present invention will be described in more detail below with reference to the drawings and examples, but the DC relay for preventing short-circuit current of the present invention is not limited to the examples. [Brief description of the drawings]

[0052] [Figure 1] 1 is a cross-sectional view of a portion of the configuration (corresponding to a cross section along the length direction of a movable contact) according to a first embodiment of the present invention. [Diagram 2]1 is a cross-sectional view of a portion of the configuration (corresponding to a cross section along the width direction of a movable contact) according to a first embodiment of the present invention. [Diagram 3] 1 is a schematic diagram showing the connection between a movable contact, an upper magnetic conductor, a lower magnetic conductor, and a push rod member in a first embodiment of the present invention. FIG. [Figure 4] 2 is an exploded view of the coupling of a movable contact, an upper magnetic conductor, a lower magnetic conductor, and a push rod member in the first embodiment of the present invention. FIG. [Diagram 5] 1 is a schematic diagram showing the coupling of a movable contact, an upper magnetic conductor, and a lower magnetic conductor according to a first embodiment of the present invention. FIG. [Figure 6] 1 is a schematic diagram showing the coupling (inversion surface) of a movable contact, an upper magnetic conductor, and a lower magnetic conductor according to a first embodiment of the present invention. FIG. [Figure 7] 2 is a schematic diagram showing the connection between the U-shaped holder and the upper magnetic conductor of the push rod member in the first embodiment of the present invention. FIG. [Figure 8] 3 is a schematic diagram showing the coupling between the movable contact and the lower magnetic conductor according to the first embodiment of the present invention. FIG. [Figure 9] FIG. 2 is a schematic diagram of a dual magnetic circuit according to the first embodiment of the present invention. [Figure 10] FIG. 2 is a schematic diagram showing the arrangement of a fixed contact lead end and a movable contactor (contacts are separated) according to the first embodiment of the present invention. [Figure 11] FIG. 2 is a schematic diagram showing the arrangement (contact points) of a fixed contact drawn end and a movable contactor according to the first embodiment of the present invention. [Figure 12] FIG. 11 is a schematic diagram showing the arrangement of a fixed contact lead end and a movable contactor (contacts are separated) according to a second embodiment of the present invention. [Figure 13] FIG. 11 is a schematic diagram showing the arrangement (contact between the fixed contact drawn end and the movable contactor) according to the second embodiment of the present invention. [Figure 14] FIG. 11 is a perspective view of the coupling of an upper magnetic conductor, a lower magnetic conductor, and a movable contact in accordance with a third embodiment of the present invention. [Figure 15] 11 is a cross-sectional view of the coupling of an upper magnetic conductor, a lower magnetic conductor, and a movable contact in accordance with a third embodiment of the present invention. FIG. [Figure 16] FIG. 11 is a schematic diagram showing the structure of a movable contact according to a third embodiment of the present invention. [Figure 17] FIG. 13 is a schematic diagram of a partial configuration according to a fourth embodiment of the present invention. [Figure 18] FIG. 11 is a schematic diagram of a permanent magnet arrangement according to a fourth embodiment of the present invention. [Figure 19] 13 is a schematic diagram of an arc-extinguishing structure using a permanent magnet according to a fourth embodiment of the present invention (yoke clip not shown). FIG. [Figure 20] 13 is a schematic diagram of an arc-extinguishing structure using a permanent magnet according to a fourth embodiment of the present invention, rotated at a certain angle (yoke clip not shown). FIG. [Figure 21] FIG. 13 is a schematic diagram of a partial configuration according to a fifth embodiment of the present invention. [Figure 22] FIG. 13 is a schematic diagram of permanent magnet distribution according to a fifth embodiment of the present invention. [Diagram 23] 13 is a schematic diagram of an arc-extinguishing structure using a permanent magnet according to a fifth embodiment of the present invention (yoke clip not shown). FIG. [Figure 24] FIG. 13 is a schematic diagram of another arrangement of permanent magnets according to the fifth embodiment of the present invention. [Diagram 25] FIG. 13 is a schematic diagram of a partial configuration according to a sixth embodiment of the present invention. [Figure 26] FIG. 13 is a schematic diagram showing the distribution of permanent magnets according to the sixth embodiment of the present invention. [Figure 27] 13 is a schematic diagram of an arc-extinguishing structure using a permanent magnet according to a sixth embodiment of the present invention (yoke clip not shown). FIG. [Figure 28] FIG. 13 is another schematic diagram of the distribution of permanent magnets according to the sixth embodiment of the present invention. [Figure 29] 13 is a schematic diagram of an arc-extinguishing structure using another permanent magnet according to the sixth embodiment of the present invention (yoke clip not shown). FIG. [Diagram 30] FIG. 13 is a schematic diagram of a partial configuration according to a seventh embodiment of the present invention. [Diagram 31] FIG. 13 is a schematic diagram of a permanent magnet arrangement according to a seventh embodiment of the present invention. [Diagram 32]13 is a schematic diagram of an arc-extinguishing structure using a permanent magnet according to a seventh embodiment of the present invention (yoke clip is not shown). FIG. [Diagram 33] FIG. 13 is a schematic diagram of a partial configuration according to an eighth embodiment of the present invention. [Diagram 34] FIG. 13 is a schematic diagram of a permanent magnet arrangement according to an eighth embodiment of the present invention. [Diagram 35] 13 is a schematic diagram of an arc-extinguishing structure using a permanent magnet according to an eighth embodiment of the present invention (yoke clip not shown). FIG. [Diagram 36] FIG. 13 is a schematic diagram of an arc-extinguishing structure using another permanent magnet according to the eighth embodiment of the present invention (yoke clip not shown). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0053] Hereinafter, exemplary embodiments will be described more fully with reference to the drawings. However, the exemplary embodiments may be implemented in many different forms and are not limited to the embodiments described herein. In this specification, relative terms such as "above" and "below" are used to describe the relative relationship between one structure and another structure shown in the drawings, but these terms are used merely for convenience and are based on the exemplary orientation shown in the drawings. If the device shown in the drawings is inverted and turned upside down, it can be understood that the structure located "above" becomes the structure located "below". Other relative terms such as "top" and "bottom" have similar meanings. When a structure is located "above" another structure, it can mean that the structure is integrally formed on the other structure, that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure by another structure.

[0054] The terms "a," "an," "the," and "said" are used to indicate the presence of one or more elements / components etc. The terms "comprise" and "comprise" are used in an open-ended manner and mean to include additional elements / components etc. other than the listed elements / components etc. The terms "first," "second," etc. are used for descriptive purposes only and do not limit the number of their objects.

[0055] Example 1 1 to 11, the DC relay for preventing short circuit current according to the present invention includes a fixed contact drawn end 11 for current inflow, a fixed contact drawn end 12 for current outflow, one straight plate type movable contactor 2, and one push rod member 3 for moving the movable contactor 2 to realize contact or separation between the movable contacts located at both ends of the movable contactor 2 and the fixed contacts located at the bottom of the fixed contact drawn end. The two fixed contact drawn ends 11 and 12 are attached to a case 4, respectively. The movable contactor 2 and a part of the push rod member 3 are housed in the case 4. The push rod member 3 is also connected to a movable iron core 5 in a magnetic circuit structure. The push rod member 3 moves the movable contactor 2 upward by the action of the magnetic circuit, thereby bringing the movable contacts located at both ends of the movable contactor 2 into contact with the fixed contacts located at the bottoms of the two fixed contact drawn ends 11 and 12, respectively. In this way, connection to a load is realized. The movable contact 2 is attached to the push rod member 3 via a spring 31, thereby realizing the movable contact 2 being movable relative to the push rod member 3 (realizing overtravel of the contact). An upper magnetic conductor 61 is attached above a predetermined position of the movable contact 2. In this embodiment, the upper magnetic conductor 61 is an upper armature. A lower magnetic conductor 62 movable together with the movable contact 2 is attached below a predetermined position of the movable contact 2. In this embodiment, the lower magnetic conductor 62 is a lower armature. In this embodiment, the upper magnetic conductor 61 is fixed to the push rod member 3, and the lower magnetic conductor 62 is fixed to the movable contact 2. At least one through hole 22 is provided at the predetermined position of the movable contact 2, and the upper magnetic conductor 61 and the lower magnetic conductor 62 can approach each other or contact and separate from each other via the through hole 22. The upper magnetic conductor 61 and the lower magnetic conductor 62 can form at least two independent magnetic circuits in the width direction of the movable contact 2. Since each magnetic circuit forms a magnetic pole face at the position of the corresponding through hole 22, when a large fault current occurs in the movable contact 2, an attractive force is generated in the direction of the contact pressure, thereby making it possible to counter the electric reaction force caused by the fault current between the movable contact 2 and the fixed contact lead ends 11, 12.Here, the upper magnetic conductor 61 and the lower magnetic conductor 62 can be made of materials such as iron, cobalt, nickel, and alloys thereof.

[0056] The two independent magnetic circuits refer to the fact that the two magnetic circuits do not interfere with each other, that is, the magnetic fluxes do not cancel each other out.

[0057] The predetermined position is located between two movable contacts in the length direction of the movable contactor 2. In this embodiment, the predetermined position is approximately the middle 21 of the movable contactor 2 in the length direction.

[0058] In this embodiment, as shown in Figures 10 and 11, when the upper magnetic conductor 61 is fixed to the push rod member 3, the lower magnetic conductor 62 is fixed to the movable contact 2, the movable contact 2 is attached to the push rod member 3 via a spring 31, and the movable contact of the movable contact 2 contacts the fixed contacts at the fixed contact pull-out ends 11 and 12, a predetermined gap exists between the upper magnetic conductor 61 and the lower magnetic conductor 62, and therefore a magnetic gap exists in the magnetic circuit.

[0059] The upper magnetic conductor 61 is at least one straight-shaped upper magnetic conductor, and the lower magnetic conductor 62 is at least two U-shaped lower magnetic conductors, where one U-shaped lower magnetic conductor and the corresponding straight-shaped upper magnetic conductor form an independent magnetic circuit, and the two U-shaped lower magnetic conductors 62 of two adjacent magnetic circuits do not contact each other.

[0060] In this embodiment, there are two magnetic circuits. Each of the two magnetic circuits is formed by combining one straight-shaped upper magnetic conductor 61 and one U-shaped lower magnetic conductor 62. The two straight-shaped upper magnetic conductors 61 are fixed to the push rod member 3 by crimping or welding. The two U-shaped lower magnetic conductors 62 are fixed to the movable contact 2 by crimping, and the upper surfaces of the side walls of the two U-shaped lower magnetic conductors 62 are both exposed to the upper surface of the movable contact 2.

[0061] In this embodiment, the through hole 22 of the movable contact 2 is disposed so that the side walls of the two U-shaped lower magnetic conductors 62 pass through it.

[0062] In this embodiment, there are two magnetic circuits, namely, magnetic circuit Φ1 and magnetic circuit Φ2 (as shown in FIG. 9). The two linear upper magnetic conductors 61 are fixed to the push rod member 3, and there is a certain gap between the two linear upper magnetic conductors 61. One side wall 621 of each of the two U-shaped lower magnetic conductors 62 is attached to the corresponding side in the width direction of the movable contact 2. The other side wall 622 of each of the two U-shaped lower magnetic conductors 62 passes through the same through hole 22 of the movable contact 2, and there is a gap between the other side wall 622 of each of the two U-shaped lower magnetic conductors 62, so that the magnetic fluxes of the two magnetic circuits are not offset by each other.

[0063] In this embodiment, the upper surface of the side wall of the U-shaped lower magnetic conductor 62 is approximately flush with the upper surface of the movable contact 2. That is, the upper surfaces of the side walls 621 and 622 of the U-shaped lower magnetic conductor 62 are approximately flush with the upper surface of the movable contact 2.

[0064] In this embodiment, the movable contact 2 is further provided with widened portions 23 on both sides in the width direction corresponding to the installation positions of the through holes 22.

[0065] 9, the present invention has two or more magnetic circuits, so that the upper surfaces of a total of four side walls (i.e., two side walls 621 and two side walls 622) of the two U-shaped lower magnetic conductors 62 are combined with the upper magnetic conductor 61, i.e., the two U-shaped lower magnetic conductors 62 have a total of four magnetic pole faces. Compared with the situation of having only one magnetic circuit (having only two magnetic pole faces), the magnetic efficiency is improved and the attractive force is improved by adding two magnetic pole faces (corresponding to adding two magnetic pole faces at the installation position of the through hole 22) while maintaining the structural features of the lower magnetic conductor 62. When a large fault current occurs in the movable contact 2, the attractive force F is generated by the magnetic circuit Φ1 and the magnetic circuit Φ2, which are two independent magnetic circuits, and counters the electric reaction force caused by the fault current between the movable contact 2 and the fixed contact lead ends 11 and 12, so that the short circuit current (fault current) prevention ability of the present invention can be greatly improved.

[0066] Due to the structural limitations, the cross-sectional area of ​​the magnetic circuit is insufficient, and the magnetic circuit is easily saturated by the fault current, so that the attractive force does not increase. The two magnetic circuits in the embodiment of the present invention are equivalent to dividing the current flow direction into two cross-sectional areas, each cross-sectional area corresponds to a shunted current, and the shunted current is basically half of the fault current, so that the magnetic circuit does not become magnetically saturated, the magnetic flux is increased, and the attractive force formed is also increased. Thus, the two magnetic circuits of the present invention can be increased by one compared with one magnetic circuit in the prior art. According to the level of the fault current of the system and the cross-sectional area of ​​the magnetic circuit, N magnetic circuits can be arranged. For example, three magnetic circuits are shown in FIG. 14.

[0067] The push rod member 3 includes a U-shaped holder 32, a spring seat 33, and a push rod 34. The tip of the push rod 34 is fixed to the spring seat 33. The bottom of the push rod 34 is connected to the movable iron core 5. The bottom of the U-shaped holder 32 is fixed to the spring seat 33. The U-shaped holder 32 and the spring seat 33 form a frame. The movable spring block 20 (see FIG. 8) composed of the movable contact 2 and two U-shaped lower magnetic conductors 62 is attached to the frame composed of the U-shaped holder 32 and the spring seat 33 via the spring 31. Here, the upper surface of the movable contact 2 abuts against the inner wall of the top of the U-shaped holder 32. The spring 31 elastically abuts between the bottoms of the two U-shaped lower magnetic conductors 62 and the upper end of the spring seat 33.

[0068] In this embodiment, a positioning post 623 is further provided at each bottom of the two U-shaped lower magnetic conductors 62 for positioning the spring 31. The positioning post 623 (see FIG. 8) is used to position the spring 31 outside the tip of the spring 31. The spring seat 33 is provided with an annular positioning groove 331 for positioning the bottom of the spring 31 (see FIG. 4).

[0069] Of course, the positioning structure for the tip of the spring 31 may be configured such that a semicircular groove for positioning the spring 31 is further provided at each of the bottoms of the two U-shaped lower magnetic conductors 62, and the two semicircular grooves form a full circle so that the tip of the spring 31 is positioned.

[0070] In this embodiment, the two U-shaped lower magnetic conductors 62 are arranged side by side in the length direction of the movable contact 2. Of course, the two U-shaped lower magnetic conductors 62 may be arranged offset from each other in the length direction of the movable contact 2.

[0071] When the push rod member 3 is not moved upward, the upper surface of the movable contact 2 is abutted against the bottom surface of the straight-shaped upper magnetic conductor 61 by the action of the spring 31. When the push rod member 3 is moved to an appropriate position, the movable contacts located at both ends of the movable contact 2 are respectively contacted with the two fixed contact lead ends 11, 12. After that, when the push rod member 3 continues to move upward, the straight-shaped upper magnetic conductor 61 also continues to move upward together with the push rod member 3. The movable contact 2 cannot continue to move upward because it is in contact with the bottoms of the two fixed contact lead ends 11, 12. This realizes the overtravel of the contact. The spring 31 provides contact pressure and forms a certain gap between the bottom of the straight-shaped upper magnetic conductor 61 and the upper surface of the movable contact 2, thereby forming a magnetic gap between the bottom surface of the straight-shaped upper magnetic conductor 61 and the upper surface of the U-shaped lower magnetic conductor 62.

[0072] In the DC relay for preventing short circuit current of the present invention, an upper magnetic conductor 61 is attached above a predetermined position of the movable contact 2, and a lower magnetic conductor 62 movable together with the movable contact 2 is attached below the predetermined position of the movable contact 2. The upper magnetic conductor 61 is fixed to the push rod member 3, and the lower magnetic conductor 62 is fixed to the movable contact 2. At least one through hole 22 is provided at the predetermined position of the movable contact 2, and the upper magnetic conductor 61 and the lower magnetic conductor 62 can approach, contact, or separate from each other via the through hole 22. The upper magnetic conductor 61 and the lower magnetic conductor 62 form at least two independent magnetic circuits in the width direction of the movable contact 2. As a result, when a large fault current occurs in the movable contact 2, the magnetic circuit utilizes the magnetic pole faces added to the corresponding through holes 22 to increase the attractive force in the direction of the contact pressure, and by superimposing the attractive force and the contact pressure, it counteracts the electrical reaction force caused by the fault current between the movable contact and the fixed contact, and the large short-circuit current is distributed almost evenly by the multiple independent magnetic circuits, resulting in high magnetic efficiency and the magnetic circuits being less likely to become saturated.

[0073] In the DC relay for preventing short circuit current of the present invention, each independent magnetic circuit is formed by combining a straight-shaped upper magnetic conductor 61 and a U-shaped lower magnetic conductor 62, so that the same material can be used and the cost can be reduced. In addition, there is a gap between each U-shaped lower magnetic conductor 62. The straight-shaped upper magnetic conductor 61 is fixed to the push rod member 3. Specifically, there are two magnetic circuits in this embodiment, that is, the magnetic circuit includes two straight-shaped upper magnetic conductors 61 and two U-shaped lower magnetic conductors 62. There is a gap between the two straight-shaped upper magnetic conductors 61, and there is also a gap between the two U-shaped lower magnetic conductors 62. Since each of the side walls 622 of the two U-shaped lower magnetic conductors 62 is inserted into the through hole 22 of the movable contact 2, it is necessary to form a gap between the side walls 622 of the two U-shaped lower magnetic conductors 62 in the through hole 22 of the movable contact 2. Each of the straight-shaped upper magnetic conductors 61 is fixed to the push rod member 3 by crimping or welding, and each of the U-shaped upper magnetic conductors 62 is fixed to the movable contact 2 by crimping. The upper surface of the side wall of the U-shaped lower magnetic conductor 62 is exposed to the upper surface of the movable contact 2, which increases the magnetic pole surface and improves the attractive force. According to this structure of the present invention, by dividing the movable contact 2 into multiple cross-sectional areas, when a fault current flows through the movable contact 2, magnetic flux is generated in multiple magnetic circuits, and an attractive force is generated between the magnetic conductors of each magnetic circuit. This attractive force is in the direction of increasing the contact pressure and is intended to counter the electric reaction force between the contacts. Since multiple magnetic circuits are used, the fault current allowed for each circuit is only Imax / n, which makes it difficult for the magnetic circuit to be saturated, and the larger the passing current, the greater the contact pressure and the greater the attractive force by the magnetic circuit.

[0074] Example 2 12 and 13, in the DC relay for preventing short-circuit current of the present invention, the upper magnetic conductor 61 is an upper yoke fixed to the case 4 for mounting the two fixed contact lead-out ends 11 and 12, so that when the movable contact of the movable contactor 2 is not in contact with the fixed contact of the fixed contact lead-out ends 11 and 12 (i.e., when the contacts are separated), a predetermined gap exists between the upper magnetic conductor (upper yoke) 61 and the lower magnetic conductor (lower armature) 62. On the other hand, when the movable contact of the movable contactor 2 is in contact with the fixed contact of the fixed contact lead-out ends 11 and 12, the upper magnetic conductor 61 comes in contact with the lower magnetic conductor 62, i.e., there is almost no gap between the upper magnetic conductor 61 and the lower magnetic conductor 62, which is different from the first embodiment.

[0075] Example 3 14 to 16, the DC relay for preventing short circuit current of the present invention has three magnetic circuits. The movable contactor 2 is provided with two through holes 22. The three U-shaped lower magnetic conductors 62 are sequentially arranged along the width direction of the movable contactor 2. Here, both side walls 621, 622 of one U-shaped lower magnetic conductor 62 located in the center pass through two through holes 22 of the movable contactor 2, respectively, and one side wall 621 of each of the two U-shaped lower magnetic conductors 62 located on both sides is attached to the corresponding side edge in the width direction of the movable contactor 2. The other side wall 622 of each of the two U-shaped lower magnetic conductors 62 located on both sides passes through two through holes 22 of the movable contactor 2, respectively, and is configured to have a gap between the side walls 622 of the two U-shaped lower magnetic conductors 62 in the same through hole 22 of the movable contactor 2, which is different from the first embodiment.

[0076] Example 4 17 to 20, the DC relay with arc extinguishing and short circuit current prevention functions of the present invention includes a fixed contact lead end 11 for current inflow, a fixed contact lead end 12 for current outflow, one straight plate type movable contactor 2, one push rod member 3 for moving the movable contactor 2 to realize contact or separation between the movable contacts located at both ends of the movable contactor 2 and the fixed contacts located at the bottoms of the fixed contact lead ends 11 and 12, and four permanent magnets 71. The two fixed contact lead ends 11 and 12 are respectively attached to a case 4. A part of the movable contactor 2 and the push rod member 3 (see FIG. 4) are housed in the case 4. The push rod member 3 is also connected to a movable iron core 5 in a magnetic circuit structure. The push rod member 3 moves the movable contactor 2 upward by the action of the magnetic circuit, thereby bringing the movable contacts located at both ends of the movable contactor 2 into contact with the fixed contacts located at the bottoms of the two fixed contact lead ends 11 and 12, respectively. In this way, connection to the load is realized. The movable contactor 2 is attached to the push rod member 3 via the spring 31, thereby realizing the movable contactor 2 being movable relative to the push rod member 3 (realizing overtravel of the contacts). The four permanent magnets 71 are located outside the case 4, and are arranged at positions facing the movable contact and the fixed contact on both sides in the width direction of the movable contactor 2. In addition, for the same pair of movable contact and fixed contact, the magnetic poles of one surface of the two permanent magnets 71 facing the movable contact and the fixed contact are set to be opposite. The magnetic poles of one surface of the two permanent magnets 71 positioned on the same side in the width direction of the movable contactor 2 facing the movable contact and the fixed contact are also set to be opposite. A yoke clip 72 is further connected between the two permanent magnets 71 facing the same pair of movable contact and fixed contact. In this embodiment, a current flows into the fixed contact drawn end 11 and flows out from the fixed contact drawn end 12. In the movable contactor 2, a current flows from one end close to the fixed contact drawn end 11 to the other end close to the fixed contact drawn end 12.As shown in FIG. 18, of the four permanent magnets 71, the two permanent magnets 71 located on the left side in the direction of current flow of the movable contact 2, the permanent magnet 71 located on the side closer to the fixed contact drawn end 11 has one surface facing the movable contact and fixed contact as an N pole; the permanent magnet 71 located on the side closer to the fixed contact drawn end 12 has one surface facing the movable contact and fixed contact as an S pole. Of the two permanent magnets 71 located on the right side in the direction of current flow of the movable contact 2, the permanent magnet 71 located on the side closer to the fixed contact drawn end 11 has one surface facing the movable contact and fixed contact as an S pole, and the permanent magnet 71 located on the side closer to the fixed contact drawn end 12 has one surface facing the movable contact and fixed contact as an N pole. The two permanent magnets 71 facing the same pair of movable contacts and fixed contacts are provided at positions offset from the same pair of movable contacts and fixed contacts and are arranged in a shifted manner. The yoke clip 72 is approximately U-shaped. The bottom wall of the U-shaped yoke clip 72 corresponds to the outside of the corresponding ends located at both ends in the length direction of the movable contact 2, and both side walls of the U-shaped yoke clip 72 are connected to the back surface opposite to the surface facing the movable contact and the fixed contact of two permanent magnets 71 facing the same pair of movable contact and fixed contact. An upper magnetic conductor 61 is attached above a position between the two movable contacts of the movable contact 2 (almost the middle position of the movable contact 2). In this embodiment, the upper magnetic conductor 61 is an upper armature. A lower magnetic conductor 62 movable together with the movable contact 2 is attached below a position between the two movable contacts of the movable contact 2. In this embodiment, the lower magnetic conductor 62 is a lower armature. In this embodiment, the upper magnetic conductor 61 is fixed to the push rod member 3, and the lower magnetic conductor 62 is fixed to the movable contact 2. At least one through hole 22 is provided between the two movable contacts of the movable contactor 2, and the upper magnetic conductor 61 and the lower magnetic conductor 62 can approach, contact, or separate from each other via the through hole 22. In addition, the upper magnetic conductor 61 and the lower magnetic conductor 62 form at least two independent magnetic circuits in the width direction of the movable contactor 2.As a result, by utilizing the magnetic pole faces added by each magnetic circuit at the position of the corresponding through hole 22, when a large fault current occurs in the movable contact 2, an attractive force is generated in the direction of the contact pressure (the upper magnetic conductor 61 is relatively fixed, but the lower magnetic conductor 62 is relatively movable, so an upward attractive force is generated), which counters the electric reaction force caused by the fault current between the movable contact 2 and the fixed contact pull-out ends 11, 12. Here, the upper magnetic conductor 61 and the lower magnetic conductor 62 can be made of materials such as iron, cobalt, nickel and alloys thereof.

[0077] In this embodiment, the magnetic field formed by the combination of four permanent magnets 71 and two yoke clips 72 can form a magnetic blow force in the direction shown by the arrow in FIG. 18. The magnetic blow forces in the two directions perform arc extinguishing processing on two pairs of movable contacts and fixed contacts, respectively. The magnetic blow forces are all directed diagonally upward in the same direction, so they do not interfere with each other. The magnetic field formed by the combination of four permanent magnets 71 and two yoke clips 72 is also applied to the movable contactor 2, so that an upward acting force is formed at one end of the movable contactor 2 and a downward force is formed at the other end of the movable contactor 2. This creates a friction effect between the movable contactor and the fixed contactor, which serves to prevent the contacts from adhering.

[0078] Such a DC relay of the present invention has no polarity requirement for the load, and has the same arc-extinguishing capability in both the forward and reverse directions.

[0079] In the present invention, the so-called two independent magnetic circuits refer to the fact that there is no interference between the two magnetic circuits, that is, the magnetic fluxes do not cancel each other out.

[0080] In this embodiment 4, the structures other than the four permanent magnets 71 and the two yoke clips 72, such as the push rod member 3, the movable contact 2, the upper magnetic conductor 61, and the lower magnetic conductor 62, may be the same as those in the embodiments 1, 2, and 3, and therefore detailed explanations will be omitted here.

[0081] The DC relay with arc-extinguishing and short-circuit current prevention functions of the present invention has four permanent magnets 71 arranged at positions facing the movable contact and the fixed contact on both sides in the width direction of the movable contactor 2, and the two permanent magnets facing the same pair of movable contacts and fixed contacts are arranged with opposite magnetic poles on one side facing the movable contact and the fixed contact; the two permanent magnets located on the same side in the width direction of the movable contactor 2 are also arranged with opposite magnetic poles on one side facing the movable contact and the fixed contact; and a yoke clip 72 is further connected between the two permanent magnets facing the same pair of movable contacts and the fixed contact. An upper magnetic conductor 61 is attached above the position between the two movable contacts of the movable contactor 2, and a lower magnetic conductor 62 movable together with the movable contactor 2 is attached below the position between the two movable contacts of the movable contactor 2. The upper magnetic conductor 61 is fixed to the push rod member 3, and the lower magnetic conductor 62 is fixed to the movable contactor 2. At least one through hole 22 is provided between the two movable contacts of the movable contactor 2, and the upper magnetic conductor 61 and the lower magnetic conductor 62 can approach, contact, or separate from each other through the through hole 22. The upper magnetic conductor 61 and the lower magnetic conductor 62 form at least two independent magnetic circuits in the width direction of the movable contactor 2. According to this structure of the present invention, after realizing arc extinction by the four permanent magnets 71, the magnetic pole faces added to the positions of the corresponding through holes 22 by each magnetic circuit are used to increase the attractive force in the direction of the contact pressure when a large fault current occurs in the movable contactor 2, and the attractive force is superimposed on the contact pressure to counter the electric reaction force caused by the fault current between the movable contactor and the fixed contactor. Since the multiple independent magnetic circuits distribute the large short-circuit current almost evenly, the magnetic efficiency is high and the magnetic circuit is not easily saturated.

[0082] Example 5 As shown in Figs. 21 to 23, the DC relay with arc extinguishing and short circuit current prevention functions of the present invention includes a fixed contact lead end 11 for current inflow, a fixed contact lead end 12 for current outflow, one straight plate type movable contactor 2, one push rod member 3 for moving the movable contactor 2 to realize contact or separation between the movable contacts located at both ends of the movable contactor 2 and the fixed contacts located at the bottoms of the fixed contact lead ends 11 and 12, and two permanent magnets. The two fixed contact lead ends 11 and 12 are attached to a case 4, respectively. A part of the movable contactor 2 and the push rod member 3 are housed in the case 4. The push rod member 3 is also connected to a movable core 5 in a magnetic circuit structure. The push rod member 3 moves the movable contactor 2 upward by the action of the magnetic circuit, thereby bringing the movable contacts located at both ends of the movable contactor 2 into contact with the fixed contacts located at the bottoms of the two fixed contact lead ends 11 and 12, respectively. In this way, connection to a load is realized. The movable contact 2 is attached to the push rod member 3 via a spring 31, thereby realizing the movable contact 2 relative to the push rod member 3 (realizing overtravel of the contact). The two permanent magnets 71 are located outside the case 4, and are arranged at positions facing the movable contact and the fixed contact on both sides in the width direction of the movable contact 2, respectively. The two permanent magnets 71 face different movable contacts and fixed contacts. That is, one permanent magnet 71 faces the fixed contact drawn end 11 side, and the other permanent magnet 71 faces the fixed contact drawn end 12 side. A yoke clip 72 is further connected between the two permanent magnets 71. Each of the two yoke clips 72 has an L-shape. One side 721 of the L-shaped yoke clip 72 is connected to one side of the permanent magnet 71 opposite to the one side facing the movable contact and the fixed contact. The other side 722 of the L-shaped yoke clip 72 is located outside both ends in the length direction of the movable contact 2. In this embodiment, current flows into the fixed contact drawn-out end 11 and flows out from the fixed contact drawn-out end 12. In the movable contactor 2, current flows from one end close to the fixed contact drawn-out end 11 to the other end close to the fixed contact drawn-out end 12. Two permanent magnets 71 are disposed in positions facing the movable contact and the fixed contact, respectively.As shown in FIG. 22, of the two permanent magnets 71, one permanent magnet 71 located on the fixed contact pull-out end 11 side has one surface facing the movable contact and the fixed contact set to an N pole; one permanent magnet 71 located on the fixed contact pull-out end 12 side has one surface facing the movable contact and the fixed contact set to an N pole. That is, the magnetic poles of the two permanent magnets 71 facing the movable contact and the fixed contact are set to the same pole. An upper magnetic conductor 61 is attached above a position between the two movable contacts of the movable contactor 2 (almost at the middle position of the movable contactor 2). In this embodiment, the upper magnetic conductor 61 is an upper armature. A lower magnetic conductor 62 movable together with the movable contactor 2 is attached below a position between the two movable contacts of the movable contactor 2. In this embodiment, the lower magnetic conductor 62 is a lower armature. In this embodiment, the upper magnetic conductor 61 is fixed to the push rod member 3, and the lower magnetic conductor 62 is fixed to the movable contact 2. At least one through hole 22 (see FIG. 5) is provided between the two movable contacts of the movable contact 2, and the upper magnetic conductor 61 and the lower magnetic conductor 62 can approach, contact, or separate from each other through the through hole 22. The upper magnetic conductor 61 and the lower magnetic conductor 62 form at least two independent magnetic circuits in the width direction of the movable contact 2. In this way, when a large fault current occurs in the movable contact 2, an attractive force is generated in the direction of the contact pressure by using the magnetic pole surface added to the position of the corresponding through hole 22 by each magnetic circuit (the upper magnetic conductor 61 is relatively fixed, but the lower magnetic conductor 62 is relatively movable, so an upward attractive force is generated.) to counter the electric reaction force caused by the fault current between the movable contact 2 and the fixed contact lead ends 11 and 12. Here, the upper magnetic conductor 61 and the lower magnetic conductor 62 can be made of materials such as iron, cobalt, nickel, and alloys thereof.

[0083] In this embodiment, the magnetic field formed by combining two permanent magnets 71 and two yoke clips 72 can form a magnetic blow force in the direction shown by the arrow in FIG. 22. The magnetic blow forces in the two directions perform arc extinguishing processing on two pairs of movable contacts and fixed contacts, respectively. The magnetic blow forces are all directed diagonally upward in the same direction, so they do not interfere with each other. The magnetic field formed by combining two permanent magnets 71 and two yoke clips 72 is also applied to the movable contactor 2, so that an upward acting force is formed at one end of the movable contactor 2 and a downward force is formed at the other end of the movable contactor 2. This creates a friction effect between the movable contactor and the fixed contactor, which serves to prevent the contacts from adhering.

[0084] Such a DC relay of the present invention has no polarity requirement for the load, and has the same arc-extinguishing capability in both the forward and reverse directions.

[0085] In the present invention, the so-called two independent magnetic circuits refer to the fact that there is no interference between the two magnetic circuits, that is, the magnetic fluxes do not cancel each other out.

[0086] Referring to FIG. 24, the magnetic poles of the two permanent magnets 71 facing the movable contacts and fixed contacts are set to opposite sides. Specifically, of the two permanent magnets 71, one permanent magnet 71 located on the fixed contact pull-out end 11 side has the magnetic pole of one side facing the movable contacts and fixed contacts set to N pole; one permanent magnet 71 located on the fixed contact pull-out end 12 side has the magnetic pole of one side facing the movable contacts and fixed contacts set to S pole. In this embodiment, the magnetic field formed by the combination of the two permanent magnets 71 and the two yoke clips 72 can form a magnetic blow force in the direction shown by the arrow in FIG. 24. The magnetic blow forces in the two directions respectively perform an arc-extinguishing process on two pairs of movable contacts and fixed contacts. The direction of one magnetic blow force is diagonally upward, and the direction of the other magnetic blow force is diagonally downward. When both magnetic blow forces are directed outward, they do not interfere with each other. When both magnetic blow forces are directed inward, they interfere to a certain extent.

[0087] In this embodiment 5, the structures other than the four permanent magnets 71 and the two yoke clips 72, such as the push rod member 3 (see Figure 4), the movable contact 2, the upper magnetic conductor 61 and the lower magnetic conductor 62, may be the same as those in the embodiments 1, 2 and 3, and therefore detailed explanations will be omitted here.

[0088] In the DC relay with arc extinguishing and short circuit current prevention functions of the present invention, two permanent magnets 71 are arranged at positions on both sides in the width direction of the movable contactor 2 facing the movable contact and the fixed contact. In addition, the movable contact and the fixed contact that the two permanent magnets 71 face are different. One yoke clip 72 is further connected to each of the two permanent magnets 71. Each of the two yoke clips 72 has an L-shape. One side of the L-shaped yoke clip 72 is connected to the surface of the permanent magnet 71 on the side opposite to the movable contact and the fixed contact. The other side of the L-shaped yoke clip 72 is located outside both ends in the length direction of the movable contactor 2. In addition, an upper magnetic conductor 61 is attached above the position between the two movable contacts of the movable contactor 2. In addition, a lower magnetic conductor 62 that is movable together with the movable contactor 2 is attached below the position between the two movable contacts of the movable contactor 2. In addition, the upper magnetic conductor 61 is fixed to the push rod member 3. The lower magnetic conductor 62 is fixed to the movable contact 2. At least one through hole 22 (see FIG. 5) is provided between the two movable contacts of the movable contact 2, and the upper magnetic conductor 61 and the lower magnetic conductor 62 can approach, contact, or separate from each other through the through hole 22. In addition, the upper magnetic conductor 61 and the lower magnetic conductor 62 form at least two independent magnetic circuits in the width direction of the movable contact 2. According to such a structure of the present invention, after realizing arc extinction by the two permanent magnets 71, when a large fault current occurs in the movable contact 2, the magnetic circuit uses the magnetic pole surface added at the position of the corresponding through hole 22 to increase the attractive force in the direction of the contact pressure, and the attractive force is superimposed on the contact pressure to counter the electric reaction force caused by the fault current between the movable contact and the fixed contact, and the multiple independent magnetic circuits distribute the large short-circuit current almost evenly, so that the magnetic efficiency is high and the magnetic circuit is not easily saturated.

[0089] Example 6 As shown in Figs. 25 to 27, the DC relay with arc extinguishing and short circuit current prevention functions of the present invention includes a fixed contact lead end 11 for current inflow, a fixed contact lead end 12 for current outflow, one straight plate type movable contactor 2, one push rod member 3 for moving the movable contactor 2 to realize contact or separation between the movable contacts located at both ends of the movable contactor 2 and the fixed contacts located at the bottoms of the fixed contact lead ends 11 and 12, and four permanent magnets 71. The two fixed contact lead ends 11 and 12 are attached to a case 4, respectively. A part of the movable contactor 2 and the push rod member 3 are housed in the case 4. The push rod member 3 (see Fig. 4) is also connected to the movable core 5 (see Fig. 2) in the magnetic circuit structure. The push rod member 3 moves the movable contactor 2 upward by the action of the magnetic circuit, thereby bringing the movable contacts located at both ends of the movable contactor 2 into contact with the fixed contacts located at the bottoms of the two fixed contact lead ends 11 and 12, respectively. This realizes connection to the load. The movable contactor 2 is attached to the push rod member 3 via a spring 31, thereby realizing the movable contactor 2 being movable relative to the push rod member 3 (realizing overtravel of the contacts). The four permanent magnets 71 are located outside the case 4, and are arranged at positions facing the movable contact and the fixed contact (i.e., corresponding movable contact and fixed contact) on both sides in the width direction of the movable contactor 2. In addition, the two permanent magnets 71 facing the same pair of movable contact and fixed contact are installed with the same magnetic pole on one side facing the movable contact and the fixed contact. A yoke clip 72 is further connected between the two permanent magnets facing the same pair of movable contact and fixed contact. In this embodiment, a current flows into the fixed contact drawn end 11 and flows out from the fixed contact drawn end 12. In the movable contactor 2, a current flows from one end close to the fixed contact drawn end 11 to the other end close to the fixed contact drawn end 12. The four permanent magnets 71 are arranged at positions facing the movable contact and the fixed contact, respectively.As shown in FIG. 26, among the four permanent magnets 71, the two permanent magnets 71 located on the left side of the current flow direction of the movable contact 2 have one surface facing the movable contact and fixed contact set as N poles; the two permanent magnets 71 located on the right side of the current flow direction of the movable contact 2 also have one surface facing the movable contact and fixed contact set as N poles. The yoke clip 72 is substantially U-shaped. The bottom wall of the U-shaped yoke clip 72 is located outside both ends in the length direction of the movable contact 2; both side walls of the U-shaped yoke clip 72 are connected to one surface of the two permanent magnets 71 facing the same pair of movable contacts and fixed contacts, the one surface being opposite the movable contact and fixed contact. The upper magnetic conductor 61 is attached above the position between the two movable contacts of the movable contact 2 (approximately the middle position of the movable contact 2). In this embodiment, the upper magnetic conductor 61 is an upper armature. A lower magnetic conductor 62 movable together with the movable contact 2 is attached below a position between the two movable contacts of the movable contactor 2. In this embodiment, the lower magnetic conductor 62 is a lower armature. In this embodiment, the upper magnetic conductor 61 is fixed to the push rod member 3, and the lower magnetic conductor 62 is fixed to the movable contactor 2. At least one through hole 22 (see FIG. 5) is provided between the two movable contacts of the movable contactor 2, and the upper magnetic conductor 61 and the lower magnetic conductor 62 can approach, contact, or separate from each other via the through hole 22. In addition, the upper magnetic conductor 61 and the lower magnetic conductor 62 form at least two independent magnetic circuits in the width direction of the movable contactor 2. As a result, by utilizing the magnetic pole faces added by each magnetic circuit at the position of the corresponding through hole 22, when a large fault current occurs in the movable contact 2, an attractive force is generated in the direction of the contact pressure (the upper magnetic conductor 61 is relatively fixed, but the lower magnetic conductor 62 is relatively movable, so an upward attractive force is generated) to counter the electric reaction force caused by the fault current between the movable contact 2 and the fixed contact pull-out ends 11, 12. Here, the upper magnetic conductor 61 and the lower magnetic conductor 62 can be made of materials such as iron, cobalt, nickel and alloys thereof.

[0090] In this embodiment, the magnetic field formed by the combination of four permanent magnets 71 and two yoke clips 72 can generate a magnetic blow force in the direction shown by the arrow in Fig. 26. The magnetic blow forces in the two directions perform an arc-extinguishing process on two pairs of movable contacts and fixed contacts, respectively. The magnetic blow forces all face outward (i.e., diagonally upward in Fig. 26), so they do not interfere with each other. The magnetic field formed by the combination of four permanent magnets 71 and two yoke clips 72 also acts on the movable contactor 2, but the acting forces cancel each other out, so they have almost no effect.

[0091] 28 and 29, of the four permanent magnets 71, two permanent magnets 71 located on the same side in the width direction of the movable contactor 2 have opposite magnetic poles on one side facing the movable contacts and fixed contacts. Specifically, of the two permanent magnets 71 located on the left side of the current flow direction of the movable contactor 2, the permanent magnet 71 located on the side closer to the fixed contact drawn end 11 has one magnetic pole facing the movable contacts and fixed contacts as the N pole; the permanent magnet 71 located on the side closer to the fixed contact drawn end 12 has one magnetic pole facing the movable contacts and fixed contacts as the S pole. Of the two permanent magnets 71 located on the right side of the current flow direction of the movable contactor 2, the permanent magnet 71 located on the side closer to the fixed contact drawn end 11 has one magnetic pole facing the movable contacts and fixed contacts as the N pole; the permanent magnet 71 located on the side closer to the fixed contact drawn end 12 has one magnetic pole facing the movable contacts and fixed contacts as the S pole.

[0092] The magnetic field formed by the combination of four permanent magnets 71 and two yoke clips 72 can generate a magnetic blow force in the direction shown by the arrow in Fig. 28. The magnetic blow forces in the two directions perform an arc-extinguishing process on two pairs of movable contacts and fixed contacts, respectively. The magnetic blow forces are all directed outward (i.e., diagonally upward and downward in Fig. 28), so they do not interfere with each other. The magnetic field formed by the combination of four permanent magnets 71 and two yoke clips 72 also acts on the movable contactor 2, but the acting forces cancel each other out, so they have almost no effect.

[0093] Such a DC relay of the present invention has no polarity requirement for the load, and has the same arc-extinguishing capability in both the forward and reverse directions.

[0094] In this Example 6, the structures other than the four permanent magnets 71 and the two yoke clips 72, such as the push rod member 3, the movable contact 2, the upper magnetic conductor 61, and the lower magnetic conductor 62, may be the same as those in Examples 1, 2, and 3, and therefore detailed explanations will be omitted here.

[0095] In the DC relay with arc extinguishing and short circuit current prevention functions of the present invention, four permanent magnets 71 are arranged at both sides of the movable contact 2 facing the movable contact and the fixed contact. In addition, the two permanent magnets 71 facing the same pair of movable contact and fixed contact are arranged with the same magnetic poles on one side facing the movable contact and the fixed contact; the two permanent magnets located on the same side in the width direction of the movable contact 2 are also arranged with the same magnetic poles on one side facing the movable contact and the fixed contact. A yoke clip 72 is further connected between the two permanent magnets facing the same pair of movable contact and the fixed contact. In addition, an upper magnetic conductor 61 is attached above the position between the two movable contacts of the movable contact 2. In addition, a lower magnetic conductor 62 movable together with the movable contact 2 is attached below the position between the two movable contacts of the movable contact 2. In addition, the upper magnetic conductor 61 is fixed to the push rod member 3, and the lower magnetic conductor 62 is fixed to the movable contact 2. At least one through hole 22 (see FIG. 5) is provided between the two movable contacts of the movable contactor 2, and the upper magnetic conductor 61 and the lower magnetic conductor 62 can approach, contact, or separate from each other through the through hole 22. The upper magnetic conductor 61 and the lower magnetic conductor 62 form at least two independent magnetic circuits in the width direction of the movable contactor 2. According to this structure of the present invention, after realizing arc extinction by the four permanent magnets 71, the magnetic pole faces added to the positions of the corresponding through holes 22 by each magnetic circuit are used to increase the attractive force in the direction of the contact pressure when a large fault current occurs in the movable contactor 2, and the attractive force is superimposed on the contact pressure to counter the electric reaction force caused by the fault current between the movable contactor and the fixed contactor. Since the multiple independent magnetic circuits distribute the large short-circuit current almost evenly, the magnetic efficiency is high and the magnetic circuits are not easily saturated.

[0096] Example 7 As shown in Figs. 30 to 32, the DC relay with arc extinguishing and short circuit current prevention functions of the present invention includes a fixed contact lead end 11 for current inflow, a fixed contact lead end 12 for current outflow, one straight plate type movable contactor 2, one push rod member 3 for moving the movable contactor 2 to realize contact or separation between the movable contacts located at both ends of the movable contactor 2 and the fixed contacts located at the bottoms of the fixed contact lead ends 11 and 12, and two permanent magnets 71. The two fixed contact lead ends 11 and 12 are attached to a case 4, respectively. A part of the movable contactor 2 and the push rod member 3 are housed in the case 4. The push rod member 3 is also connected to a movable iron core 5 in a magnetic circuit structure. The push rod member 3 moves the movable contactor 2 upward by the action of the magnetic circuit, thereby bringing the movable contacts located at both ends of the movable contactor 2 into contact with the fixed contacts located at the bottoms of the two fixed contact lead ends 11 and 12, respectively. This realizes connection to a load. The movable contact 2 is attached to the push rod member 3 via a spring 31, thereby realizing the movable contact 2 relative to the push rod member 3 (realizing overtravel of the contact). The two permanent magnets 71 are located outside the case 4, and are arranged at positions facing the movable contact and the fixed contact on the outside of both ends of the movable contact 2 in the longitudinal direction. In addition, the magnetic poles of the opposing surfaces of the two permanent magnets 71 are installed in opposite directions. Two yoke clips 72 are further connected to the two permanent magnets 71. The two yoke clips 72 further include a yoke section 721 located at a position facing the movable contact and the fixed contact at least on both sides in the width direction of the movable contact 2. In this embodiment, a current flows into the fixed contact drawn end 11 and flows out from the fixed contact drawn end 12. In the movable contact 2, a current flows from one end close to the fixed contact drawn end 11 to the other end close to the fixed contact drawn end 12. The two permanent magnets 71 are arranged at positions facing the movable contact and the fixed contact, respectively.As shown in FIG. 31, of the two permanent magnets 71, one permanent magnet 71 located on the fixed contact pull-out end 11 side has a magnetic pole on one side facing the movable contact and the fixed contact as an N pole; one permanent magnet 71 located on the fixed contact pull-out end 12 side has a magnetic pole on one side facing the movable contact and the fixed contact as an S pole. An upper magnetic conductor 61 is attached above a position between the two movable contacts of the movable contactor 2 (almost the middle position of the movable contactor 2). In this embodiment, the upper magnetic conductor 61 is an upper armature. A lower magnetic conductor 62 movable together with the movable contactor 2 is attached below a position between the two movable contacts of the movable contactor 2. In this embodiment, the lower magnetic conductor 62 is a lower armature. In this embodiment, the upper magnetic conductor 61 is fixed to the push rod member 3, and the lower magnetic conductor 62 is fixed to the movable contactor 2. At least one through hole 22 (see FIG. 5) is provided between the two movable contacts of the movable contactor 2, and the upper magnetic conductor 61 and the lower magnetic conductor 62 can approach, contact, or separate from each other through the through hole 22. The upper magnetic conductor 61 and the lower magnetic conductor 62 form at least two independent magnetic circuits in the width direction of the movable contactor 2. As a result, when a large fault current occurs in the movable contactor 2, an attractive force is generated in the direction of the contact pressure by using the magnetic pole surface added to the position of the corresponding through hole 22 by each magnetic circuit (the upper magnetic conductor 61 is relatively fixed, but the lower magnetic conductor 62 is relatively movable, so an attractive force facing upward is generated.) to counter the electric reaction force caused by the fault current between the movable contactor 2 and the fixed contact lead ends 11 and 12. Here, the upper magnetic conductor 61 and the lower magnetic conductor 62 can be made of materials such as iron, cobalt, nickel, and alloys thereof.

[0097] In this embodiment, both of the two yoke clips 72 are U-shaped. The bottom walls 722 of the two U-shaped yoke clips 72 are connected to the surfaces opposite the two permanent magnets 71, respectively. That is, one yoke clip 72 is connected to one permanent magnet 71. The tips of both side walls 723 of the two U-shaped yoke clips exceed the positions of both side edges in the width direction of the movable contactor 2 that face the movable contact and the fixed contact, respectively. The both side walls 723 of the two U-shaped yoke clips 72 include the yoke section 721.

[0098] Of course, the length of both side walls 723 of the U-shaped yoke clip 72 can be shortened. For example, the ends of both side walls 723 of the U-shaped yoke clip 72 can be formed in the yoke section 721 .

[0099] Of course, each yoke clip 72 may be connected to two permanent magnets 71, that is, the bottom walls 722 of the two U-shaped yoke clips 72 may be arranged on both widthwise sides of the movable contactor 2, and the tips of both side walls 723 of the two U-shaped yoke clips 72 may be connected to one side opposite the two permanent magnets 71.

[0100] In this embodiment, the magnetic field formed by combining two permanent magnets 71 and two yoke clips 72 can generate a magnetic blow force in the direction shown by the arrow in FIG. 31. The magnetic blow forces in the two directions perform arc-extinguishing processing on two pairs of movable contacts and fixed contacts, respectively. The directions of the magnetic blow forces are all directed diagonally outward, so they do not interfere with each other. The magnetic field formed by combining two permanent magnets 71 and two yoke clips 72 also acts on the movable contact 2, but the acting forces cancel each other out, so they have almost no effect.

[0101] In this embodiment 7, the structures other than the four permanent magnets 71 and the two yoke clips 72, such as the push rod member 3, the movable contact 2, the upper magnetic conductor 61 and the lower magnetic conductor 62, may be the same as those in the embodiments 1, 2 and 3, and therefore detailed explanations thereof will be omitted here.

[0102] Such a DC relay of the present invention has no requirement for polarity with respect to the load, and has the same arc-extinguishing capability in the forward and reverse directions.

[0103] In the DC relay with arc extinguishing and short circuit current prevention functions of the present invention, two permanent magnets 71 are arranged at outer positions on both ends of the length direction of the movable contactor 2 facing the movable contact and the fixed contact. In addition, the magnetic poles of the opposing sides of the two permanent magnets 71 are arranged in opposite directions. The two permanent magnets 71 are further connected to two yoke clips 72. The two yoke clips 72 further include a yoke section 721 located at a position facing the movable contact and the fixed contact at least on both sides in the width direction of the movable contactor 2. In addition, an upper magnetic conductor 61 is attached above a position between the two movable contacts of the movable contactor 2. A lower magnetic conductor 62 movable together with the movable contactor 2 is attached below a position between the two movable contacts of the movable contactor 2. In addition, the upper magnetic conductor 61 is fixed to the push rod member 3, and the lower magnetic conductor 62 is fixed to the movable contactor 2. At least one through hole 22 (see FIG. 5) is provided between the two movable contacts of the movable contactor 2, and the upper magnetic conductor 61 and the lower magnetic conductor 62 can approach, contact, or separate from each other through the through hole 22. The upper magnetic conductor 61 and the lower magnetic conductor 62 form at least two independent magnetic circuits in the width direction of the movable contactor 2. According to this structure of the present invention, after realizing arc extinction by the four permanent magnets 71, when a large fault current occurs in the movable contactor 2, the magnetic circuit uses the magnetic pole surface added at the position of the corresponding through hole 22 to increase the attractive force in the direction of the contact pressure, and the attractive force is superimposed on the contact pressure to counter the electric reaction force caused by the fault current between the movable contactor and the fixed contactor. Since the multiple independent magnetic circuits distribute the large short-circuit current almost evenly, the magnetic efficiency is high and the magnetic circuit is not easily saturated.

[0104] Example 8 33 to 35, the DC relay with arc extinguishing and short circuit current prevention functions by permanent magnets of the present invention includes a fixed contact drawn end 11 for current inflow, a fixed contact drawn end 12 for current outflow, one straight plate type movable contactor 2, one push rod member 3 for moving the movable contactor 2 to realize contact or separation between the movable contacts located at both ends of the movable contactor 2 and the fixed contacts located at the bottoms of the fixed contact drawn ends 11 and 12, and four permanent magnets 71. The two fixed contact drawn ends 11 and 12 are respectively attached to a case 4. A part of the movable contactor 2 and the push rod member 3 is housed in the case 4. The push rod member 3 is further connected to a movable iron core 5 in a magnetic circuit structure. The push rod member 3 moves the movable contactor 2 upward by the action of the magnetic circuit, thereby bringing the movable contacts located at both ends of the movable contactor 2 into contact with the fixed contacts located at the bottoms of the two fixed contact drawn ends 11 and 12, respectively. This realizes connection to a load. The movable contactor 2 is attached to the push rod member 3 via a spring 31, thereby realizing the movable contactor 2 being movable relative to the push rod member 3 (realizing overtravel of the contacts). Four permanent magnets 71 are located outside the case 4, and are arranged at both sides of the width of the movable contactor 2 facing the movable contact and the fixed contact (i.e., the corresponding movable contact and the fixed contact). In addition, two permanent magnets facing the same pair of movable contact and fixed contact are installed with opposite magnetic poles on one side facing the movable contact and the fixed contact; two permanent magnets located on the same side in the width of the movable contactor 2 are installed with the same magnetic poles on one side facing the movable contact and the fixed contact. A yoke clip 72 is further connected between the two permanent magnets 71 facing the same pair of movable contact and the fixed contact. In this embodiment, a current flows into the fixed contact drawn end 11 and flows out from the fixed contact drawn end 12. In the movable contactor 2, a current flows from one end close to the fixed contact drawn-out end 11 to the other end close to the fixed contact drawn-out end 12. The four permanent magnets 71 are disposed in positions facing the movable contact and the fixed contact, respectively.As shown in FIG. 34, among the four permanent magnets 71, the two permanent magnets 71 located on the left side of the current flow direction of the movable contact 2 have one surface facing the movable contact and fixed contact set as N poles; the two permanent magnets 71 located on the right side of the current flow direction of the movable contact 2 have one surface facing the movable contact and fixed contact set as S poles. The yoke clip 72 is approximately U-shaped. The bottom wall of the U-shaped yoke clip 72 is located outside both ends of the movable contact 2 in the length direction; both side walls of the U-shaped yoke clip 72 are connected to one surface of the two permanent magnets 71 facing the same pair of movable contacts and fixed contacts, the one surface being opposite the movable contact and fixed contact. The upper magnetic conductor 61 is attached above the position between the two movable contacts of the movable contact 2 (approximately the middle position of the movable contact 2). In this embodiment, the upper magnetic conductor 61 is an upper armature. A lower magnetic conductor 62 movable together with the movable contact 2 is attached below a position between the two movable contacts of the movable contactor 2. In this embodiment, the lower magnetic conductor 62 is a lower armature. In this embodiment, the upper magnetic conductor 61 is fixed to the push rod member 3, and the lower magnetic conductor 62 is fixed to the movable contactor 2. At least one through hole 22 (see FIG. 5) is provided between the two movable contacts of the movable contactor 2, and the upper magnetic conductor 61 and the lower magnetic conductor 62 can approach, contact, or separate from each other through the through hole 22. In addition, the upper magnetic conductor 61 and the lower magnetic conductor 62 form at least two independent magnetic circuits in the width direction of the movable contactor 2. As a result, by utilizing the magnetic pole faces added by each magnetic circuit at the position of the corresponding through hole 22, when a large fault current occurs in the movable contact 2, an attractive force is generated in the direction of the contact pressure (the upper magnetic conductor 61 is relatively fixed, but the lower magnetic conductor 62 is relatively movable, so an upward attractive force is generated) to counter the electric reaction force caused by the fault current between the movable contact 2 and the fixed contact pull-out ends 11, 12. Here, the upper magnetic conductor 61 and the lower magnetic conductor 62 can be made of materials such as iron, cobalt, nickel and alloys thereof.

[0105] In this embodiment, the magnetic field formed by the combination of four permanent magnets 71 and two yoke clips 72 can generate a magnetic blow force in the direction shown by the arrow in FIG. 34. The magnetic blow forces in the two directions perform arc extinguishing processing on two pairs of movable contacts and fixed contacts, respectively. Since the directions of the magnetic blow forces are both outward, they do not interfere with each other. The magnetic field formed by the combination of four permanent magnets 71 and two yoke clips 72 is also applied to the movable contactor 2, forming a downward force (as shown in FIG. 35) at the contact position, which may result in insufficient contact pressure. Therefore, the attractive force formed by the magnetic circuit must also counter the downward force generated by the magnetic field action of the four permanent magnets 71 and two yoke clips 72.

[0106] Such a structure in this embodiment is applied to a user who has a requirement to break an arc.

[0107] In the four permanent magnets 71 shown in FIG. 36, the two permanent magnets 71 located on the left side of the current flow direction of the movable contact 2 are installed with the magnetic poles facing the movable contact and fixed contact as S poles; the two permanent magnets 71 located on the right side of the current flow direction of the movable contact 2 are installed with the magnetic poles facing the movable contact and fixed contact as N poles. In this way, the magnetic field directions are reversed, so that the magnetic blow forces are all directed inward. The arc is interfered with to some extent by the magnetic blow. This structure of the present embodiment can be applied to users who do not require the arc to be broken. When the magnetic field formed by the combination of the four permanent magnets 71 and the two yoke clips 72 acts on the movable contact 2, an upward force is formed at the contact position, increasing the contact pressure. That is, the attraction force by the magnetic circuit, together with the upward force by the magnetic field action of the four permanent magnets 71 and the two yoke clips 72, can counter the electric reaction force by the fault current between the movable contact 2 and the fixed contact lead ends 11, 12.

[0108] The DC relay with arc extinguishing and short circuit current prevention functions using a permanent magnet according to the present invention has requirements regarding polarity with respect to the load, and there is a large difference in arc extinguishing capability between the forward and reverse directions.

[0109] In this Example 8, the structures other than the four permanent magnets 71 and the two yoke clips 72, such as the push rod member 3, the movable contact 2, the upper magnetic conductor 61 and the lower magnetic conductor 62, may be the same as those in Examples 1, 2 and 3, and therefore detailed explanations will be omitted here.

[0110] In the DC relay with arc extinguishing and short circuit current prevention functions using permanent magnets according to the present invention, four permanent magnets 71 are arranged at both sides of the movable contact 2 facing the movable contact and the fixed contact in the width direction. In addition, two permanent magnets facing the same pair of movable contact and fixed contact are installed with opposite magnetic poles on one side facing the movable contact and the fixed contact. Two permanent magnets located on the same side in the width direction of the movable contact 2 are installed with the same magnetic poles on one side facing the movable contact and the fixed contact. A yoke clip 72 is further connected between the two permanent magnets facing the same pair of movable contact and the fixed contact. In addition, an upper magnetic conductor 61 is attached above the position between the two movable contacts of the movable contact 2. In addition, a lower magnetic conductor 62 movable together with the movable contact 2 is attached below the position between the two movable contacts of the movable contact 2. In addition, the upper magnetic conductor 61 is fixed to the push rod member 3, and the lower magnetic conductor 62 is fixed to the movable contact 2. At least one through hole 22 (see FIG. 5) is provided between the two movable contacts of the movable contactor 2, and the upper magnetic conductor 61 and the lower magnetic conductor 62 can approach, contact, or separate from each other through the through hole 22. The upper magnetic conductor 61 and the lower magnetic conductor 62 form at least two independent magnetic circuits in the width direction of the movable contactor 2. According to this structure of the present invention, after realizing arc extinction by the four permanent magnets 71, when a large fault current occurs in the movable contactor 2, the magnetic circuit uses the magnetic pole surface added at the position of the corresponding through hole 22 to increase the attractive force in the direction of the contact pressure, and the attractive force is superimposed on the contact pressure to counter the electric reaction force caused by the fault current between the movable contactor and the fixed contactor. Since the multiple independent magnetic circuits distribute the large short-circuit current almost evenly, the magnetic efficiency is high and the magnetic circuit is not easily saturated.

[0111] It should be understood that the present invention is not limited in its application to the detailed construction and arrangement of the parts described herein. The present invention has other embodiments and can be realized and carried out in various ways. Such variations and modifications are included within the scope of the present invention. It should be understood that the present invention as disclosed and limited herein extends to all alternative combinations of two or more individual features mentioned or apparent in the specification and / or drawings. All of these different combinations constitute multiple alternative aspects of the invention. The embodiments described herein illustrate the most preferred modes known for implementing the invention and enable those skilled in the art to utilize the invention.

Claims

1. A DC relay including two fixed contact leads, one straight plate type movable contact, one push rod member, and four permanent magnets, and having an arc extinguishing and short circuit current prevention function by the permanent magnets, The movable contactor is attached to a push rod member, and the movable contacts located at both ends of the movable contactor are brought into contact with the fixed contacts located at the bottoms of the two fixed contact pull-out ends by the action of the push rod member. The four permanent magnets are disposed at both side positions in the width direction of the movable contactor facing the movable contacts and the fixed contacts, respectively. The two permanent magnets facing the same pair of movable contacts and fixed contacts have opposite magnetic poles on one side facing the movable contacts and the fixed contacts, and the two permanent magnets located on the same side in the width direction of the movable contactor have the same magnetic poles on one side facing the movable contacts and the fixed contacts. A yoke clip is further connected between the two permanent magnets facing the same pair of movable contacts and fixed contacts, and above the position between the two movable contacts of the movable contactor. an upper magnetic conductor arranged along the width direction of the movable contact is attached to the movable contact, and a lower magnetic conductor arranged along the width direction of the movable contact and movable together with the movable contact is attached below said position, and at least one through hole is provided at said position of the movable contact, and the upper magnetic conductor and the lower magnetic conductor can approach, contact, or separate from each other through said through hole, and the upper magnetic conductor and the lower magnetic conductor form at least two independent magnetic circuits in the width direction of the movable contact, and when a large fault current occurs in the movable contact, each magnetic circuit utilizes a magnetic pole surface added at the position of the corresponding through hole to generate an attractive force in the direction of contact pressure to counteract the electric reaction force caused by the fault current between the movable contact and the fixed contact pull-out end. A DC relay characterized by:

2. The four permanent magnets are disposed at positions facing the movable contact and the fixed contact, respectively.

2. A DC relay according to claim 1.

3. Of the four permanent magnets, the two permanent magnets located on the left side of the moving contact in the direction of current flow are set with the magnetic poles on one side facing the moving contact and the fixed contact as N poles.

3. A DC relay according to claim 1 or 2.

4. The upper magnetic conductor is at least one straight-shaped upper magnetic conductor, and the lower magnetic conductor is at least two U-shaped lower magnetic conductors, where one U-shaped lower magnetic conductor and the corresponding straight-shaped upper magnetic conductor form an independent magnetic circuit, and the two U-shaped lower magnetic conductors forming the two adjacent magnetic circuits are not in contact with each other.

2. A DC relay according to claim 1.

5. In at least two independent magnetic circuits, the straight-shaped upper magnetic conductor in at least one pair of two adjacent magnetic circuits is a common one, and the two U-shaped lower magnetic conductors in the two adjacent magnetic circuits are each disposed below one straight-shaped upper magnetic conductor.

5. A DC relay according to claim 4.

6. In at least two independent magnetic circuits, all of the linear upper magnetic conductors in two adjacent magnetic circuits are independent, and the two U-shaped lower magnetic conductors in the two adjacent magnetic circuits are respectively disposed below the corresponding linear upper magnetic conductors.

5. A DC relay according to claim 4.

7. The magnetic circuits are two, the movable contactor is provided with one through hole, one side wall of each of the two U-shaped lower magnetic conductors is attached to the widthwise side of the movable contactor, the other side wall of each of the two U-shaped lower magnetic conductors passes through the same through hole of the movable contactor, and there is a gap between the other side wall of each of the two U-shaped lower magnetic conductors.

5. A DC relay according to claim 4.

8. The other side walls of the two U-shaped lower magnetic conductors are arranged side by side or offset along the length direction of the movable contactor in the same through hole of the movable contactor, so that the two magnetic circuits formed by the two U-shaped lower magnetic conductors are distributed side by side or offset along the length direction of the movable contactor.

8. A DC relay as claimed in claim 7.

9. The number of magnetic circuits is two, the movable contactor is provided with two through holes, and the two through holes are arranged side by side or offset along the length direction of the movable contactor. One side wall of each of the two U-shaped lower magnetic conductors is attached to a corresponding side edge in the width direction of the movable contactor, and the other side wall of each of the two U-shaped lower magnetic conductors is inserted into the two through holes of the movable contactor, thereby distributing the two magnetic circuits formed by the two U-shaped lower magnetic conductors side by side or offset along the length direction of the movable contactor.

5. A DC relay according to claim 4.

10. The magnetic circuits are three in number, the movable contactor is provided with two through holes, the three U-shaped lower magnetic conductors are sequentially arranged along the width direction of the movable contactor, both side walls of one central U-shaped lower magnetic conductor pass through the two through holes of the movable contactor, one side wall of each of the two U-shaped lower magnetic conductors located on both sides is attached to the side edge of the movable contactor in the width direction, and the other side wall of each of the two U-shaped lower magnetic conductors located on both sides passes through the two through holes of the movable contactor, and a gap exists between the two side walls of the movable contactor within the same through hole.

5. A DC relay according to claim 4.

11. The upper magnetic conductor is an upper armature fixed to the push rod member, and the lower magnetic conductor is a lower armature fixed to the movable contact. The movable contact is attached to the push rod member via a spring. When the movable contact of the movable contact is brought into contact with the fixed contact at the fixed contact pull-out end, a predetermined gap exists between the upper armature and the lower armature, thereby further countering the electrical reaction force.

2. A DC relay according to claim 1.

12. The upper magnetic conductor is an upper yoke fixed to a case for mounting two fixed contact lead-out ends, and the lower magnetic conductor is a lower armature fixed to the movable contact. The movable contact is attached to the push rod member via a spring, and the upper yoke comes into contact with the lower armature when the movable contact of the movable contact is brought into contact with the fixed contact of the fixed contact lead-out end.

2. A DC relay according to claim 1.

13. The push rod member includes a U-shaped holder, a spring seat, and a push rod, the tip of the push rod is fixed to the spring seat, the bottom of the U-shaped holder is fixed to the spring seat, a movable spring block composed of the movable contact and two U-shaped lower magnetic conductors is attached in the U-shaped holder via the spring, the upper surface of the movable contact abuts against the upper yoke, the upper yoke is fixed to the inner wall of the top of the U-shaped holder, and the spring elastically abuts between the bottoms of the two U-shaped lower magnetic conductors and the upper surface of the spring seat.

13. A DC relay as claimed in claim 12.

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