DC relay for preventing short-circuit current

Abstract

To provide a DC relay for preventing short-circuit current in which contact pressure is provided so as to be able to counter electric reaction force due to the short-circuit current while maintaining a feature of a small volume of a product, 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, and one push rod member. An upper magnetic conductor is mounted above the movable contact. A lower magnetic conductor 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.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention claims priority based on a total of six Chinese patent applications, namely the Chinese patent application with application number 201811330771.1 filed on November 9, 2018, the Chinese patent application with application number 201811624114.8 filed on December 28, 2018, the Chinese patent application with application number 201811623949.1 filed on December 28, 2018, the Chinese patent application with application number 201811624058.8 filed on December 28, 2018, the Chinese patent application with application number 201811624113.3 filed on December 28, 2018, and the Chinese patent application with application number 201811623963.1 filed on December 28, 2018, and incorporates all the contents of these Chinese patent applications into this application.

[0002] This invention relates to the technical field of relays, and particularly to a DC relay for preventing short-circuit current.

Background Art

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

[0004] With the rapid development of the new energy industry, the requirements for current against fault short circuits in each automobile factory and battery pack factory are also increasing. There is a need for a DC relay that has a short-circuit prevention function while maintaining the characteristic of a small volume, and can provide an auxiliary suction force so as to counteract the electric reaction force received by the movable spring when a large fault current occurs in the system. Currently, for the typical prevention against input short circuits required in the market, it is required not to burn or explode in the case of 8000A and 5ms. However, the DC relays in the prior art cannot provide sufficient suction force while maintaining the characteristic of a small volume. That is, the contact pressure is insufficient to counteract the electric reaction force received by the movable spring, so it is difficult to meet the market requirements.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention is for solving the problems of the prior art. While maintaining the feature of a small product volume, it can provide sufficient contact pressure so as to be able to resist the large electric reaction force due to the short - circuit current received by the movable spring, and has the features of high magnetic efficiency and being difficult for the magnetic circuit to be saturated, aiming to provide a DC relay for preventing short - circuit current.

Means for Solving the Problems

[0006] In order to solve the above - mentioned problems, the present invention has the following configuration. The DC relay for preventing short - circuit current includes two fixed contact terminals, one straight - type movable contact and one push - rod member. The movable contact is attached to the push - rod member, so that by the action of the push - rod member, the contact between the movable contacts located at both ends of the movable contact and the fixed contacts located at the bottom of the two fixed contact terminals is realized. The current flows into one of the fixed contact terminals, passes through the movable contact, and then flows out from the other fixed contact terminal. Above a predetermined position of the movable contact, an upper magnetic conductor distributed along the width direction of the movable contact is attached. Below the predetermined position of the movable contact, a lower magnetic conductor distributed along the width direction of the movable contact and movable together with the movable contact is attached. At least one through - hole is provided at the predetermined 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. Also, 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 utilizes the additional magnet pole face at the position of the corresponding through - hole to generate an attractive force in the direction of the contact pressure, so as to counteract the electric reaction force due to the fault current between the movable contact and the fixed contact terminal.

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

[0008] In one embodiment, the upper magnetic conductor is at least one straight upper magnetic conductor, and the lower magnetic conductor is at least two U-shaped lower magnetic conductors. Here, one U-shaped lower magnetic conductor and the corresponding straight upper magnetic conductor form an independent magnetic circuit, and there is no contact between the two U-shaped lower magnetic conductors that form two adjacent magnetic circuits.

[0009] In one embodiment, in at least two independent magnetic circuits, among at least one pair of two adjacent magnetic circuits, the straight upper magnetic conductors are one in common, and the two U-shaped lower magnetic conductors in the two adjacent magnetic circuits are respectively arranged below one straight upper magnetic conductor.

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

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

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

[0013] In one embodiment, the other side walls of the two U-shaped lower magnetic conductors are respectively arranged to be displaced along the length direction of the movable contact in the same through holes of the movable contact, so as to distribute the two magnetic circuits formed by the two U-shaped lower magnetic conductors along the length direction of the movable contact in a displaced manner.

[0014] In one embodiment, there are two magnetic circuits. The movable contact is provided with two through holes, and the two through holes are arranged side by side along the length direction of the movable contact. One side wall of each of the two U-shaped lower magnetic conductors is respectively attached to the corresponding side in the width direction of the movable contact, and the other side wall of each of the two U-shaped lower magnetic conductors is respectively inserted into the two through holes of the movable contact, so as to distribute the two magnetic circuits formed by the two U-shaped lower magnetic conductors side by side along the length direction of the movable contact.

[0015] In one embodiment, there are two magnetic circuits. The movable contact is provided with two through holes, and the two through holes are arranged to be displaced along the length direction of the movable contact. One side wall of each of the two U-shaped lower magnetic conductors is respectively attached to the side in the width direction of the movable contact, and the other side wall of each of the two U-shaped lower magnetic conductors penetrates through the two through holes of the movable contact, so as to distribute the two magnetic circuits formed by the two U-shaped lower magnetic conductors along the length direction of the movable contact in a displaced manner.

[0016] In one embodiment, there are three magnetic circuits. The movable contact is provided with two through holes, and the three U-shaped lower magnetic conductors are sequentially arranged along the width direction of the movable contact. Here, both side walls of the one U-shaped lower magnetic conductor located in the center pass through the two through holes of the movable contact. One side wall of the two U-shaped lower magnetic conductors located on both sides is respectively attached to the side in the width direction of the movable contact, and the other side wall of the two U-shaped lower magnetic conductors located on both sides passes through the two through holes of the movable contact, and there is a gap between the two side walls of the movable contact 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, 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 point of the movable contact contacts the fixed contact point of the fixed contact point lead-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 attaching two fixed contact point lead-out ends, 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 point of the movable contact contacts the fixed contact point of the fixed contact point lead-out end.

[0020] In one embodiment, the push rod member includes a U-shaped holder, a spring sheet, and a push rod. The tip of the push rod is fixed to the spring sheet, the bottom of the U-shaped holder is fixed to the spring sheet, and a movable spring block composed of the movable contact and two U-shaped lower magnetic conductors is attached into 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 sheet.

[0021] In one embodiment, each of the bottoms of the two U-shaped lower magnetic conductors is further provided with a semi-circular groove for positioning the spring, and the two semi-circular grooves form a complete circle such that the tip of the spring is disposed therein.

[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 spring is positioned outside the tip of the spring by using the positioning post.

[0023] In one embodiment, the movable contact is further provided with widened portions on both sides in the width direction corresponding to the installation 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 a predetermined position of the movable contact, a lower magnetic conductor movable together with the movable contact is attached below the 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, each magnetic circuit utilizes the additional magnetic pole surface 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 counteract the electric reaction force caused by the fault current between the movable contact and the fixed contact lead-out end. Since the plurality of independent magnetic circuits distribute a large short-circuit current substantially evenly, it has the characteristics of high magnetic efficiency and difficulty in saturation of the magnetic circuit.

[0026] Furthermore, according to the present invention, each independent magnetic circuit is formed by the combination of a straight upper magnetic conductor and a U-shaped lower magnetic conductor, so the same members can be used, resulting in lower costs. Also, there is a gap between each U-shaped lower magnetic conductor. The straight upper magnetic conductor can be fixed to the push rod member or can be fixed to a case for attaching two fixed contact lead-out terminals. Each U-shaped lower magnetic conductor is fixed to the movable contact by caulking respectively, and the upper surface of the side wall of the U-shaped lower magnetic conductor is exposed on the upper surface of the movable contact. According to such a structure of the present invention, by forming a plurality of independent magnetic circuits in the cross-section of the movable contact by the upper magnetic conductor and the lower magnetic conductor, when a fault current flows through the movable contact, magnetic fluxes are 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 the contact pressure and is for counteracting the electrical repulsive force between the contacts. Since a plurality of 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 larger the passing current, the greater the contact pressure increases, and the greater the attractive force generated by the magnetic circuits.

[0027] According to another aspect of the present invention, a DC relay with an arc extinguishing and short-circuit current prevention function includes two fixed contact terminals, 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 cooperation between the movable contacts located at both ends of the movable contact and the fixed contacts located at the bottom of the two fixed contact terminals is realized by the action of the push rod member. The four permanent magnets are respectively arranged at the positions of both sides in the width direction of the movable contact facing the movable contact and the fixed contact, and for the two permanent magnets facing the same pair of movable contacts and fixed contacts, the magnetic poles on the surface facing the movable contact and the fixed contact are installed oppositely, and for the two permanent magnets located on the same side in the width direction of the movable contact, the magnetic poles on the surface facing the movable contact and the fixed contact are also installed oppositely. A yoke clip is further connected between the two permanent magnets facing the same pair of movable contacts and fixed contacts. 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 predetermined 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. Further, 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 utilizes the additional magnetic pole surface added at the position of the corresponding through hole to generate an attractive force in the direction of the contact pressure to counteract the electrical reaction force caused by the fault current between the movable contact and the fixed contact terminal.

[0028] In one embodiment, the two permanent magnets facing the same pair of the movable contacts and the fixed contacts are provided at positions offset with respect to the same pair of the movable contacts and the fixed contacts, and the two permanent magnets are arranged in a displaced manner.

[0029] Compared with the prior art, the present invention has the following beneficial effects. According to the present invention, each of the four permanent magnets is arranged at positions on both sides in the width direction of the movable contactor facing the movable contact and the fixed contact, and the two permanent magnets facing the same pair of movable contact and fixed contact are installed with opposite magnetic poles on the surface 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 are also installed with opposite magnetic poles on the surface 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 fixed contact. In addition, 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. Further, 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 such a structure of the present invention, arc extinction is realized by the four permanent magnets, and when a large fault current occurs in the movable contactor by using the magnetic pole surfaces added at the positions of the corresponding through holes by each magnetic circuit, the attractive force is increased in the direction of the contact pressure, and the attractive force is superimposed on the contact pressure to counteract the electric reaction force caused by the fault current between the movable contact and the fixed contact. The plurality of independent magnetic circuits distribute the large short-circuit current almost evenly, so it has the characteristics of high magnetic efficiency and being difficult for the magnetic circuit to saturate.

[0030] According to another aspect of the present invention, a DC relay with arc extinction and short-circuit current prevention functions includes two fixed contact terminals, 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 cooperation between the movable contacts located at both ends of the movable contact and the fixed contacts located at the bottom of the two fixed contact terminals is realized by the action of the push rod member. The two permanent magnets are respectively arranged at both sides in the width direction of the movable contact facing the movable contact and the fixed contact, and the corresponding movable contacts and fixed contacts of the two permanent magnets are different. One yoke clip is further connected to each of the two permanent magnets. The two yoke clips each have an L-shaped shape. One side of the L-shaped yoke clip is connected to one side opposite to the surface 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. Above the position between the two movable contacts of the movable contact, an upper magnetic conductor arranged along the width direction of the movable contact is attached. Below the position, a lower magnetic conductor arranged along the width direction of the movable contact and movable together with the movable contact is attached. 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. Further, the upper magnetic conductor and the lower magnetic conductor form at least two independent magnetic circuits in the width direction of the movable contact. By utilizing the additional magnetic pole surfaces added at the positions of the corresponding through holes by each magnetic circuit, when a large fault current occurs in the movable contact, an attractive force is generated in the direction of the contact pressure, thereby counteracting the electric reaction force caused by the fault current between the movable contact and the fixed contact terminal.

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

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

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

[0034] Compared with the prior art, the present invention has the following beneficial effects. According to the present invention, each of the two permanent magnets is arranged at positions on both sides in the width direction of the movable contactor facing the movable contact and the fixed contact, and the corresponding movable contact and fixed contact of the two permanent magnets are different. One yoke clip is further connected to each of the two permanent magnets. The two yoke clips each have an L-shaped configuration. One side of the L-shaped yoke clip is connected to a surface opposite to the surface 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 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. Also, 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 such a structure of the present invention, arc extinction is realized by the two permanent magnets. When a large fault current occurs in the movable contactor, by utilizing the additional magnetic pole surfaces added at the positions of the corresponding through holes by each magnetic circuit, the attractive force is increased 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. The plurality of independent magnetic circuits distribute a large short-circuit current almost evenly, so it has the characteristics of high magnetic efficiency and being difficult for the magnetic circuit to saturate.

[0035] According to another aspect of the present invention, a DC relay with an arc extinguishing and short-circuit current prevention function includes two fixed contact terminals, 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 by the action of the push rod member, the contact between the movable contacts located at both ends of the movable contact and the fixed contacts located at the bottom of the two fixed contact terminals is realized. The four permanent magnets are respectively arranged at both sides in the width direction of the movable contact facing the movable contact and the fixed contact, and for the two permanent magnets located at the same pair of movable contacts and fixed contacts, the magnetic poles on the surface facing the movable contact and the fixed contact are set to be the same. A yoke clip is further connected between the two permanent magnets facing the same pair of movable contacts and fixed contacts. Above the position between the two movable contacts of the movable contact, an upper magnetic conductor arranged along the width direction of the movable contact is attached. Below the position, a lower magnetic conductor arranged along the width direction of the movable contact and movable together with the movable contact is attached. 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. Also, 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 utilizes the additional magnetic pole surface added at the position of the corresponding through hole to generate an attractive force in the direction of the contact pressure to counteract the electric reaction force caused by the fault current between the movable contact and the fixed contact terminal.

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

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

[0038] In one embodiment, among the four permanent magnets, for the two permanent magnets located on the same side in the width direction of the movable contact, the magnetic poles of the surfaces facing the movable contact and the fixed contact are installed oppositely.

[0039] Compared with the prior art, the present invention has the following beneficial effects. According to the present invention, each of the four permanent magnets is arranged at positions on both sides in the width direction of the movable contact facing the movable contact and the fixed contact, and for the two permanent magnets facing the same pair of movable contact and fixed contact, the magnetic poles of the surfaces facing the movable contact and the fixed contact are installed the same. Between the two permanent magnets facing the same pair of movable contact and fixed contact, a yoke clip is further connected. Also, above the position between the two movable contacts of the movable contact, an upper magnetic conductor is attached, and below the position between the two movable contacts of the movable contact, a lower magnetic conductor movable together with the movable contact is attached. 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. Further, the upper magnetic conductor and the lower magnetic conductor form at least two independent magnetic circuits in the width direction of the movable contact. With such a structure of the present invention, after arc extinction is realized by the four permanent magnets, when a large fault current occurs in the movable contact, by utilizing the additional magnetic pole surfaces added at the positions of the corresponding through holes by each magnetic circuit, the attractive force is increased in the direction of the contact pressure, and the attractive force is superimposed on the contact pressure to counteract the electric reaction force caused by the fault current between the movable contact and the fixed contact. Since the plurality of independent magnetic circuits distribute a large short-circuit current almost evenly, it has the characteristics of high magnetic efficiency and being difficult for the magnetic circuit to saturate.

[0040] According to another aspect of the present invention, a DC relay with an arc extinguishing and short-circuit current prevention function includes two fixed contact terminals, 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 action of the push rod member realizes the contact between the movable contacts located at both ends of the movable contact and the fixed contacts located at the bottom of the two fixed contact terminals. The two permanent magnets are respectively arranged at the outer positions of both ends in the length direction of the movable contact facing the movable contact and the fixed contact, and the magnetic poles of the opposing surfaces of the two permanent magnets are installed in opposite directions. Two yoke clips are further connected to the two permanent magnets. The two yoke clips further include yoke sections located at least on both sides in the width direction of the movable contact facing the movable contact and the fixed contact. Above the position between the two movable contacts of the movable contact, an upper magnetic conductor arranged along the width direction of the movable contact is attached, and below the position, a lower magnetic conductor arranged along the width direction of the movable contact and movable together with the movable contact is attached. 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. Further, 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 utilizes the additional magnetic pole surface added at the position of the corresponding through hole to generate an attractive force in the direction of the contact pressure to counteract the electric reaction force caused by the fault current between the movable contact and the fixed contact terminal.

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

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

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

[0044] In one embodiment, the yoke clip has a U-shaped configuration. The bottom walls of the two U-shaped yoke clips are respectively arranged on both sides in the width direction of the movable contactor. The tips of the two side walls of the two U-shaped yoke clips are respectively connected to one surface of the back 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, each of the two permanent magnets is arranged at a position outside both ends in the longitudinal direction of the movable contact facing the movable contact and the fixed contact, and the magnetic poles of the opposing surfaces of the two permanent magnets are installed oppositely. Two yoke clips are further connected to the two permanent magnets. The two yoke clips further include yoke sections located at least on both sides in the width direction of the movable contact facing the movable contact and the fixed contact. Also, 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 in the movable contact 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. Further, 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 such a structure of the present invention, arc extinction is realized by the two permanent magnets. When a large fault current occurs in the movable contact, the additional magnetic pole surfaces at the positions of the corresponding through holes by each magnetic circuit are utilized 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 electric reaction force due to the fault current between the movable contact and the fixed contact. The plurality of independent magnetic circuits distribute a large short-circuit current almost evenly, so it has the characteristics of high magnetic efficiency and difficulty in saturation of the magnetic circuit.

[0047] According to another aspect of the present invention, a DC relay having an arc extinguishing and short-circuit current prevention function by a permanent magnet includes two fixed contact terminals, one straight plate-shaped movable contact, one push rod member, and four permanent magnets. The movable contact is attached to the push rod member, and by the action of the push rod member, contact between the movable contacts located at both ends of the movable contact and the fixed contacts located at the bottom of the two fixed contact terminals is realized. The four permanent magnets are respectively arranged at positions on both sides in the width direction of the movable contact facing the movable contact and the fixed contact, and for the two permanent magnets facing the same pair of movable contacts and fixed contacts, the magnetic poles on the surface facing the movable contact and the fixed contact are installed oppositely, and for the two permanent magnets located on the same side in the width direction of the movable contact, the magnetic poles on the surface facing the movable contact and the fixed contact are installed the same. A yoke clip is further connected between the two permanent magnets facing the same pair of movable contacts and fixed contacts. Above the position between the two movable contacts of the movable contact, an upper magnetic conductor arranged along the width direction of the movable contact is attached, and below the position, a lower magnetic conductor arranged along the width direction of the movable contact and movable together with the movable contact is attached. 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. Further, 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 utilizes the additional magnetic pole surface added at the position of the corresponding through hole to generate an attractive force in the direction of the contact pressure to counteract the electric reaction force caused by the fault current between the movable contact and the fixed contact terminal.

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

[0049] In one embodiment, among the four permanent magnets, the two permanent magnets located on the left side in the current flow direction of the movable contact are installed with the magnetic poles on the surface facing the movable contact and the fixed contact as N poles.

Advantages 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 respectively arranged at positions on both sides in the width direction of the movable contactor facing the movable contact and the fixed contact, and for the two permanent magnets facing the same pair of movable contact and fixed contact, the magnetic poles on the surface facing the movable contact and the fixed contact are installed oppositely, and for the two permanent magnets located on the same side in the width direction of the movable contactor, the magnetic poles on the surface facing the movable contact and the fixed contact are installed the same. A yoke clip is further connected between the two permanent magnets facing the same pair of movable contact and fixed contact. Also, 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 each other through the through hole. Further, 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 such a structure of the present invention, arc extinguishing is realized by the four permanent magnets. When a large fault current occurs in the movable contactor, the additional magnetic pole surfaces at the positions of the corresponding through holes are utilized by each magnetic circuit 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 electric reaction force caused by the fault current between the movable contact and the fixed contact. The plurality of independent magnetic circuits distribute the large short-circuit current almost evenly, so it has the characteristics of high magnetic efficiency and being difficult for the magnetic circuit to saturate.

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

Brief Description of the Drawings

[0052]

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Figure 36

Mode for Carrying Out the Invention

[0053] Hereinafter, exemplary embodiments will be described more comprehensively with reference to the drawings. However, the exemplary embodiments can be implemented in various forms and are not limited to the embodiments described herein. In this specification, relative terms such as "upper" and "lower" are used to explain the relative relationship between one configuration shown in the drawings and another configuration. These terms are for convenience only and, for example, are based on the exemplary directions shown in the drawings. It can be understood that when the device shown in the drawings is inverted and its top and bottom are reversed, the configuration located "above" becomes the configuration located "below". Other relative terms such as "top" and "bottom" have the same meaning. When one structure is located "above" another structure, it may mean that one structure is integrally formed above another structure, one structure is "directly" arranged above another structure, or one structure is "indirectly" arranged on another structure by another structure.

[0054] The terms "one", "a", "said", and "the foregoing" are used to indicate that there is one or more elements / components, etc. The terms "comprising" and "including" mean being inclusively included and further including elements / components, etc. other than the recited elements / components, etc. The terms "first", "second", etc. are used only for notation and do not limit the number of the object.

[0055] Example 1 Referring to FIGS. 1 to 11, the DC relay for preventing short-circuit current according to the present invention includes a fixed contact lead-out terminal 11 for current inflow, a fixed contact lead-out terminal 12 for current outflow, one straight plate-type movable contact 2, and a push rod member 3 for realizing contact or separation between the movable contacts located at both ends of the movable contact 2 and the fixed contacts located at the bottom of the fixed contact lead-out terminals by moving the movable contact 2. The two fixed contact lead-out terminals 11 and 12 are respectively attached to the case 4. A part of the movable contact 2 and the push rod member 3 is accommodated in the case 4. The push rod member 3 is also connected to the movable iron core 5 in the magnetic circuit structure. The push rod member 3 moves the movable contact 2 upward by the action of the magnetic circuit, so that the movable contacts located at both ends of the movable contact 2 are respectively brought into contact with the fixed contacts located at the bottom of the two fixed contact lead-out terminals 11 and 12. In this way, connection to the load is realized. The movable contact 2 is attached to the push rod member 3 via a spring 31, thereby realizing the ability to move relative to the push rod member 3 (realizing the 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, contact, or separate from each other through 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 surface at the position of the corresponding through hole 22, when a large fault current occurs in the movable contact 2, by generating an attractive force in the direction of the contact pressure, it is possible to counteract the electric reaction force due to the fault current between the movable contact 2 and the fixed contact lead-out terminals 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 their alloys.

[0056] The two independent magnetic circuits mean 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 the two movable contacts in the length direction of the movable contact 2. In this embodiment, the predetermined position is the substantially middle 21 in the length direction of the movable contact 2.

[0058] In this embodiment, as shown in FIGS. 10 and 11, 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 when the movable contacts of the movable contact 2 contact the fixed contacts of the fixed contact lead-out ends 11 and 12, since there is a predetermined gap between the upper magnetic conductor 61 and the lower magnetic conductor 62, there is a magnetic gap in the magnetic circuit.

[0059] The upper magnetic conductor 61 is at least one straight upper magnetic conductor, and the lower magnetic conductor 62 is at least two U-shaped lower magnetic conductors. Here, one U-shaped lower magnetic conductor and the corresponding straight upper magnetic conductor constitute 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. The two magnetic circuits are both formed by the combination of one straight upper magnetic conductor 61 and one U-shaped lower magnetic conductor 62. The two straight upper magnetic conductors 61 are respectively fixed to the push rod member 3 by caulking or welding methods. The two U-shaped lower magnetic conductors 62 are respectively fixed to the movable contact 2 by caulking methods, and the upper surfaces of the side walls of the two U-shaped lower magnetic conductors 62 are both exposed on the upper surface of the movable contact 2.

[0061] In this embodiment, the through hole 22 of the movable contact 2 is installed such 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 walls 622 of the two U-shaped lower magnetic conductors 62, so that the magnetic fluxes of the two magnetic circuits are not offset from each other.

[0063] In this embodiment, the upper surface of the side wall of the U-shaped lower magnetic conductor 62 is substantially flush with the upper surface of the movable contact 2. That is, the upper surfaces of the side wall 621 and the side wall 622 of the U-shaped lower magnetic conductor 62 are substantially 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] Referring to FIG. 9, since the present invention has two or more magnetic circuits, the upper surfaces of the total four side walls (i.e., two side walls 621 and two side walls 622) of the two U-shaped lower magnetic conductors 62 are fitted to the upper magnetic conductor 61. That is, the two U-shaped lower magnetic conductors 62 have a total of four magnetic pole faces and have only one magnetic circuit (only two magnetic pole faces). Compared with the situation of having only one magnetic circuit (only two magnetic pole faces), when the structural characteristics of the lower magnetic conductor 62 are maintained as they are, by adding two magnetic pole faces (which corresponds to adding two magnetic pole faces at the installation positions of the through holes 22), the magnetic efficiency is improved and the suction force is improved. When a large fault current occurs in the movable contact 2, the magnetic circuits Φ1 and Φ2, which are two independent magnetic circuits, generate a suction force F, and by countering the electric reaction force caused by the fault current between the movable contact 2 and the fixed contact leads 11 and 12, the ability of the present invention to prevent short-circuit current (fault current) can be greatly improved.

[0066] Due to structural limitations, the cross-sectional area of the magnetic circuit is insufficient, and the magnetic circuit is prone to saturation due to the fault current, so the suction force does not increase. The two magnetic circuits of the embodiment of the present invention correspond to dividing the current flow direction into two cross-sectional regions. Each cross-sectional region corresponds to the shunted current, and the shunted current is basically half of the fault current. Therefore, the magnetic circuit does not suffer from magnetic saturation, the magnetic flux is increased, and the formed suction force is also increased. Thus, the two magnetic circuits of the present invention can be increased by a factor of one compared with one magnetic circuit of 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, FIG. 14 shows three magnetic circuits.

[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 shape. The movable spring block 20 (see FIG. 8) composed of the movable contact 2 and the 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, positioning posts 623 for positioning the spring 31 are further provided at the bottoms of the two U-shaped lower magnetic conductors 62 respectively. The spring 31 is positioned outside the tip of the spring 31 by using the positioning posts 623 (see FIG. 8). An annular positioning concave groove 331 for positioning the bottom of the spring 31 is provided on the spring seat 33 (see FIG. 4).

[0069] Of course, the positioning structure for the tip of the spring 31 may be configured such that semi-circular grooves for positioning the spring 31 are further provided at the bottoms of the two U-shaped lower magnetic conductors 62 respectively, and the two semi-circular grooves form a full circle so that the tip of the spring 3 is disposed.

[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 can also be installed so as to be displaced in the length direction of the movable contact 2.

[0071] When the push rod member 3 has not moved upward, the upper surface of the movable contact 2 abuts against the bottom surface of the U-shaped upper magnetic conductor 61 due to the action of the spring 31. When the push rod member 3 moves to an appropriate position, the movable contacts located at both ends of the movable contact 2 come into contact with the two fixed contact leads 11 and 12 respectively. Thereafter, when the push rod member 3 continues to move upward, the U-shaped upper magnetic conductor 61 also continues to move upward together with the push rod member 3. Since the movable contact 2 is in contact with the bottoms of the two fixed contact leads 11 and 12, it cannot continue to move upward. Thereby, overtravel of the contacts is realized. The spring 31 provides contact pressure and forms a certain gap between the bottom surface of the U-shaped upper magnetic conductor 61 and the upper surface of the U-shaped lower magnetic conductor 62 by forming a certain gap between the bottom surface of the U-shaped upper magnetic conductor 61 and the upper surface of the movable contact 2, thereby forming a magnetic gap.

[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. Further, 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 through the through hole 22. Further, 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. Thereby, when a large fault current occurs in the movable contact 2, by utilizing the additional magnetic pole surfaces added to the positions of the corresponding through holes 22 by each magnetic circuit, the attractive force is increased in the direction of the contact pressure, and by superimposing the attractive force and the contact pressure, it counteracts the electric reaction force due to the fault current between the movable contact and the fixed contact, and a plurality of independent magnetic circuits distribute a large short-circuit current almost evenly, so it has the characteristics of high magnetic efficiency and difficulty in saturation of the magnetic circuit.

[0073] The DC relay for preventing short-circuit current of the present invention has each independent magnetic circuit formed by the combination of a linear upper magnetic conductor 61 and a U-shaped lower magnetic conductor 62, so the same members can be used and the cost can be reduced. Also, there is a gap between each of the U-shaped lower magnetic conductors 62. The linear upper magnetic conductor 61 is fixed to the push rod member 3. Specifically, there are two magnetic circuits in this embodiment, that is, it includes two linear upper magnetic conductors 61 and two U-shaped lower magnetic conductors 62. There is a gap between the two linear upper magnetic conductors 61, and there is also a gap between the two U-shaped lower magnetic conductors 62. Each side wall 622 of the two U-shaped lower magnetic conductors 62 is inserted into the through hole 22 of the movable contact 2. Therefore, in 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. Each of the linear upper magnetic conductors 61 is fixed to the push rod member 3 by caulking or welding, and each of the U-shaped upper magnetic conductors 62 is fixed to the movable contact 2 by caulking. Also, the upper surface of the side wall of the U-shaped lower magnetic conductor 62 is exposed on the upper surface of the movable contact 2, increasing the magnetic pole surface and improving the attractive force. According to such a structure of the present invention, by dividing the movable contact 2 into a plurality of cross-sectional regions, when a fault current flows through the movable contact 2, magnetic fluxes are generated in a 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 in which the contact pressure increases and is for countering the electrical reaction force between the contacts. Since a plurality of magnetic circuits are used, the fault current allowed in each circuit is only Imax / n. As a result, it is difficult for the magnetic circuit to become saturated. The greater the passing current, the greater the contact pressure increases, and the greater the attractive force by the magnetic circuit also becomes.

[0074] Embodiment 2 Referring to FIGS. 12 to 13, in the DC relay for preventing short-circuit current of the present invention, since the upper magnetic conductor 61 is an upper yoke fixed to the case 4 for attaching the two fixed contact terminals 11 and 12, when the movable contact of the movable contactor 2 is not in contact with the fixed contacts of the fixed contact terminals 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 contacts of the fixed contact terminals 11 and 12, the upper magnetic conductor 61 is in contact with the lower magnetic conductor 62, that is, it is different from the first embodiment in that there is almost no gap between the upper magnetic conductor 61 and the lower magnetic conductor 62.

[0075] Embodiment 3 Referring to FIGS. 14 to 16, the DC relay for preventing short-circuit current of the present invention has three magnetic circuits. Two through holes 22 are provided in the movable contactor 2. 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 and 622 of one U-shaped lower magnetic conductor 62 located in the center pass through the two through holes 22 of the movable contactor 2, 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 in the width direction of the movable contactor 2. The other one side wall 622 of each of the two U-shaped lower magnetic conductors 62 located on both sides passes through the two through holes 22 of the movable contactor 2, and is configured to have a gap between the side wall 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] Embodiment 4 Referring to FIGS. 17 to 20, the DC relay with an arc extinguishing and short-circuit current prevention function according to the present invention includes a fixed contact lead-out terminal 11 for current inflow, a fixed contact lead-out terminal 12 for current outflow, one straight plate-shaped movable contact 2, and by moving the movable contact 2, a push rod member 3 for realizing contact or separation between the movable contacts located at both ends of the movable contact 2 and the fixed contacts located at the bottoms of the fixed contact lead-out terminals 11 and 12, and four permanent magnets 71. The two fixed contact lead-out terminals 11 and 12 are respectively attached to the case 4. A part of the movable contact 2 and the push rod member 3 (see FIG. 4) is accommodated in the case 4. The push rod member 3 is also connected to the movable iron core 5 in the magnetic circuit structure. The push rod member 3 moves the movable contact 2 upward by the action of the magnetic circuit, so that the movable contacts located at both ends of the movable contact 2 are respectively brought into contact with the fixed contacts located at the bottoms of the two fixed contact lead-out terminals 11 and 12. In this way, connection to the load is realized. The movable contact 2 is attached to the push rod member 3 via a spring 31, thereby realizing the ability to move relative to the push rod member 3 (realizing the overtravel of the contact). The four permanent magnets 71 are located outside the case 4 and are respectively arranged at positions facing the movable contacts and the fixed contacts on both sides in the width direction of the movable contact 2. Also, for the same pair of movable contacts and fixed contacts, the magnetic poles on one surface of the two permanent magnets 71 facing the movable contacts and the fixed contacts are installed in opposite directions. The two permanent magnets 71 located on the same side in the width direction of the movable contact 2 also have the magnetic poles on one surface facing the movable contacts and the fixed contacts installed in opposite directions. A yoke clip 72 is further connected between the two permanent magnets 71 facing the same pair of movable contacts and fixed contacts. In this embodiment, the current flows into the fixed contact lead-out terminal 11 and flows out from the fixed contact lead-out terminal 12. The current flows through the movable contact 2 from one end close to the fixed contact lead-out terminal 11 to the other end close to the fixed contact lead-out terminal 12.As shown in Fig. 18, among the four permanent magnets 71, for the two permanent magnets 71 located on the left side in the current flow direction of the movable contact 2, the permanent magnet 71 located closer to the fixed contact lead-out terminal 11 has the magnetic pole on the side facing the movable contact and the fixed contact set as the N pole; the permanent magnet 71 located closer to the fixed contact lead-out terminal 12 has the magnetic pole on the side facing the movable contact and the fixed contact set as the S pole. For the two permanent magnets 71 located on the right side in the current flow direction of the movable contact 2, the permanent magnet 71 located closer to the fixed contact lead-out terminal 11 has the magnetic pole on the side facing the movable contact and the fixed contact set as the S pole, and the magnetic pole on the side facing the movable contact and the fixed contact of the permanent magnet 71 located closer to the fixed contact lead-out terminal 12 is set as the N pole. The two permanent magnets 71 facing the same pair of movable contacts and fixed contacts are provided at offset positions with respect to the same pair of the movable contacts and fixed contacts and are arranged in a displaced manner. The yoke clip 72 is substantially 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 the two side walls of the U-shaped yoke clip 72 are respectively connected to the back surfaces opposite to the sides facing the movable contact and the fixed contact in the two permanent magnets 71 facing the same pair of movable contacts and fixed contacts. Above the position between the two movable contacts of the movable contact 2 (substantially the middle position of the movable contact 2), an upper magnetic conductor 61 is attached. In this embodiment, the upper magnetic conductor 61 is the upper armature. Below the position between the two movable contacts of the movable contact 2, a lower magnetic conductor 62 movable together with the movable contact 2 is attached. In this embodiment, the lower magnetic conductor 62 is the 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 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. Also, 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.Thus, when a large fault current occurs in the movable contact 2, by utilizing the magnetic pole surfaces added at the positions of the corresponding through holes 22 by each magnetic circuit, an attractive force is generated in the direction of the contact pressure (since the upper magnetic conductor 61 is relatively fixed, while the lower magnetic conductor 62 is relatively movable, an upward attractive force is formed), to counteract the electrical reaction force caused by the fault current between the movable contact 2 and the fixed contact leads 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 their alloys.

[0077] In this embodiment, the magnetic field formed by the combination of the four permanent magnets 71 and the two yoke clips 72 can form a magnetic blowing force in the direction indicated by the arrow in FIG. 18. The magnetic blowing 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 blowing forces are both obliquely upward in the same direction, they do not interfere with each other. The magnetic field formed by the combination of the four permanent magnets 71 and the two yoke clips 72 also acts on the movable contact 2, so that an upward acting force is formed at one end of the movable contact 2 and a downward force is formed at the other end of the movable contact 2. Thereby, a frictional effect is formed between the movable contact and the fixed contact, which serves to prevent the contacts from adhering.

[0078] Such a DC relay of the present invention has no requirement for the polarity of the load, and the arc extinguishing capabilities in the positive and reverse directions are the same.

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

[0080] In Example 4, other structures except for the four permanent magnets 71 and the two yoke clips 72, for example, the push rod member 3, the movable contact 2, the upper magnetic conductor 61, the lower magnetic conductor 62, etc. may be the same as those in Example 1, Example 2, and Example 3, so detailed description is omitted here.

[0081] The DC relay with arc extinguishing and short-circuit current prevention functions of the present invention arranges four permanent magnets 71 at positions facing the movable contacts and fixed contacts on both sides in the width direction of the movable contact 2, respectively. For the two permanent magnets facing the same pair of movable contacts and fixed contacts, the magnetic poles on the side facing the movable contacts and fixed contacts are installed oppositely; for the two permanent magnets located on the same side in the width direction of the movable contact 2, the magnetic poles on the side facing the movable contacts and fixed contacts are also installed oppositely; between the two permanent magnets facing the same pair of movable contacts and fixed contacts, a yoke clip 72 is further connected. Above the position between the two movable contacts of the movable contact 2, an upper magnetic conductor 61 is attached, and below the position between the two movable contacts of the movable contact 2, a lower magnetic conductor 62 movable together with the movable contact 2 is attached. Also, 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 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. Also, 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 arc extinguishing is realized by the four permanent magnets 71, when a large fault current occurs in the movable contact 2 by using the additional magnetic pole surfaces added to the positions of the corresponding through holes 22 by each magnetic circuit, the attractive force is increased in the direction of the contact pressure, and by superimposing the attractive force on the contact pressure, it counteracts the electric reaction force caused by the fault current between the movable contact and the fixed contact. Since the plurality of independent magnetic circuits distribute a large short-circuit current almost evenly, it has the characteristics of high magnetic efficiency and being difficult for the magnetic circuit to saturate.

[0082] Example 5 As shown in FIGS. 21 to 23, the DC relay with an arc extinguishing and short-circuit current prevention function of the present invention includes a fixed contact lead-out terminal 11 for current inflow, a fixed contact lead-out terminal 12 for current outflow, one straight plate type movable contact 2, and by moving the movable contact 2, one push rod member 3 for realizing contact or separation between the movable contacts located at both ends of the movable contact 2 and the fixed contacts located at the bottoms of the fixed contact lead-out terminals 11 and 12, and two permanent magnets. The two fixed contact lead-out terminals 11 and 12 are respectively attached to the case 4. A part of the movable contact 2 and the push rod member 3 is accommodated in the case 4. The push rod member 3 is also connected to the movable iron core 5 in the magnetic circuit structure. The push rod member 3 moves the movable contact 2 upward by the action of the magnetic circuit, so that the movable contacts located at both ends of the movable contact 2 are respectively brought into contact with the fixed contacts located at the bottoms of the two fixed contact lead-out terminals 11 and 12. In this way, connection to the load is realized. The movable contact 2 is attached to the push rod member 3 via a spring 31, thereby realizing that the movable contact 2 is movable with respect to the push rod member 3 (realizing the overtravel of the contact). The two permanent magnets 71 are located outside the case 4 and are respectively arranged at positions facing the movable contacts and the fixed contacts on both sides in the width direction of the movable contact 2. Also, the movable contacts and the fixed contacts facing each other of the two permanent magnets 71 are different. That is, one permanent magnet 71 faces the fixed contact lead-out terminal 11 side, and the other permanent magnet 71 faces the fixed contact lead-out terminal 12 side. One yoke clip 72 is further connected between the two permanent magnets 71 respectively. The two yoke clips 72 each have an L-shaped shape. One side 721 of the L-shaped yoke clip 72 is connected to one surface of the permanent magnet 71 opposite to the surface 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, the current flows into the fixed contact lead-out terminal 11 and flows out from the fixed contact lead-out terminal 12. The current flows in the movable contact 2 from one end close to the fixed contact lead-out terminal 11 to the other end close to the fixed contact lead-out terminal 12. The two permanent magnets 71 are respectively arranged at positions facing the movable contacts and the fixed contacts.As shown in Fig. 22, among the two permanent magnets 71, one permanent magnet 71 located on the side of the fixed contact lead-out terminal 11 has the magnetic pole on the side facing the movable contact and the fixed contact set as the N pole; one permanent magnet 71 located on the side of the fixed contact lead-out terminal 12 also has the magnetic pole on the side facing the movable contact and the fixed contact set as the N pole. That is, the magnetic poles on one side of the two permanent magnets 71 facing the movable contact and the fixed contact are set to be the same. Above the position between the two movable contacts of the movable contactor 2 (substantially the middle position of the movable contactor 2), an upper magnetic conductor 61 is attached. In this embodiment, the upper magnetic conductor 61 is the upper armature. Below the 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. In this embodiment, the lower magnetic conductor 62 is the 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. Also, 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. In this way, when a large fault current occurs in the movable contactor 2, by utilizing the additional magnetic pole surfaces added at the positions of the corresponding through holes 22 by each magnetic circuit, an attractive force is generated in the direction of the contact pressure (since the upper magnetic conductor 61 is relatively fixed, but the lower magnetic conductor 62 is relatively movable, an upward attractive force is formed), to counteract the electric reaction force due to the fault current between the movable contactor 2 and the fixed contact lead-out terminals 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 their alloys.

[0083] 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 blowing force in the direction indicated by the arrow in FIG. 22. The magnetic blowing forces in the two directions respectively perform arc extinguishing processing on the two pairs of movable contacts and fixed contacts. Since the directions of the magnetic blowing forces are both obliquely upward in the same direction, they do not interfere with each other. The magnetic field formed by the combination of the two permanent magnets 71 and the two yoke clips 72 also acts on the movable contact 2, so that an upward acting force is formed at one end of the movable contact 2, and a downward force is formed at the other end of the movable contact 2. Thereby, a frictional effect is formed between the movable contact and the fixed contact, which plays a role in preventing the contacts from adhering.

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

[0085] In the present invention, the so-called two independent magnetic circuits mean that the two magnetic circuits do not interfere with each other, that is, the magnetic fluxes do not cancel each other out.

[0086] Referring to FIG. 24, the magnetic poles on one side of the two permanent magnets 71 facing the movable contact and the fixed contact are installed oppositely. Specifically, among the two permanent magnets 71, one permanent magnet 71 located on the fixed contact lead-out end 11 side installs the magnetic pole on the side facing the movable contact and the fixed contact as the N pole; one permanent magnet 71 located on the fixed contact lead-out end 12 side also installs the magnetic pole on the side facing the movable contact and the fixed contact as the 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 blowing force in the direction indicated by the arrow in FIG. 24. The magnetic blowing forces in the two directions respectively perform arc extinguishing processing on the two pairs of movable contacts and fixed contacts. The direction of one magnetic blowing force is obliquely upward, and the direction of the other magnetic blowing force is obliquely downward. When both of the two magnetic blowing forces are directed outward, they do not interfere with each other. When both of the two magnetic blowing forces are directed inward, they interfere to a certain extent.

[0087] In the present Example 5, other structures other than the four permanent magnets 71 and the two yoke clips 72, for example, the push rod member 3 (see FIG. 4), the movable contact 2, the upper magnetic conductor 61, and the lower magnetic conductor 62 may be the same as those in the first, second, and third embodiments, and thus detailed description thereof will be omitted here.

[0088] The DC relay with arc extinguishing and short-circuit current prevention functions of the present invention has two permanent magnets 71 respectively arranged at positions on both sides in the width direction of the movable contact 2 facing the movable contact and the fixed contact. Also, the movable contact and the fixed contact facing each other of the two permanent magnets 71 are different. One yoke clip 72 is further connected to each of the two permanent magnets 71. The two yoke clips 72 each have an L-shaped configuration. 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 contact 2. Also, an upper magnetic conductor 61 is attached above the position between the two movable contacts of the movable contact 2. 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. Also, 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. Also, 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 arc extinguishing is realized by the two permanent magnets 71, when a large fault current occurs in the movable contact 2, the additional magnetic pole surfaces at the positions of the corresponding through holes 22 by each magnetic circuit are utilized 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 due to the fault current between the movable contact and the fixed contact. The plurality of independent magnetic circuits distribute a large short-circuit current almost evenly, so it has the characteristics of high magnetic efficiency and being difficult for the magnetic circuit to saturate.

[0089] Example 6 As shown in FIGS. 25 to 27, the DC relay having the arc extinguishing and short-circuit current preventing functions of the present invention includes a fixed contact lead-out terminal 11 for current inflow, a fixed contact lead-out terminal 12 for current outflow, one straight plate-shaped movable contact 2, and by moving the movable contact 2, one push rod member 3 for realizing the contact or separation between the movable contacts located at both ends of the movable contact 2 and the fixed contacts located at the bottoms of the fixed contact lead-out terminals 11 and 12, and four permanent magnets 71. The two fixed contact lead-out terminals 11 and 12 are respectively attached to the case 4. A part of the movable contact 2 and the push rod member 3 is accommodated in the case 4. The push rod member 3 (see FIG. 4) is also connected to the movable iron core 5 (see FIG. 2) in the magnetic circuit structure. The push rod member 3 moves the movable contact 2 upward by the action of the magnetic circuit, so that the movable contacts located at both ends of the movable contact 2 are respectively brought into contact with the fixed contacts located at the bottoms of the two fixed contact lead-out terminals 11 and 12. Thereby, connection to the load is realized. The movable contact 2 is attached to the push rod member 3 via a spring 31, thereby realizing that the movable contact 2 is movable with respect to the push rod member 3 (realizing the overtravel of the contact). The four permanent magnets 71 are located outside the case 4 and are respectively arranged at positions facing the movable contacts and the fixed contacts (that is, the corresponding movable contacts and fixed contacts) on both sides in the width direction of the movable contact 2. Also, the two permanent magnets 71 facing the same pair of movable contacts and fixed contacts are installed with the magnetic poles on the surface facing the movable contacts and the fixed contacts being the same. A yoke clip 72 is further connected between the two permanent magnets facing the same pair of movable contacts and fixed contacts. In this embodiment, the current flows into the fixed contact lead-out terminal 11 and flows out from the fixed contact lead-out terminal 12. The current flows in the movable contact 2 from one end close to the fixed contact lead-out terminal 11 to the other end close to the fixed contact lead-out terminal 12. The four permanent magnets 71 are respectively arranged at positions facing the movable contacts and the fixed contacts.As shown in Fig. 26, among the four permanent magnets 71, the two permanent magnets 71 located on the left side in the current flow direction of the movable contact 2 have the N pole set as the magnetic pole on the side facing the movable contact and the fixed contact; the two permanent magnets 71 located on the right side in the current flow direction of the movable contact 2 also have the N pole set as the magnetic pole on the side facing the movable contact and the fixed contact. The yoke clip 72 has a substantially U-shaped configuration. The bottom wall of the U-shaped yoke clip 72 is located outside both ends in the length direction of the movable contact 2; the two side walls of the U-shaped yoke clip 72 are respectively connected to one surface on the side opposite to the movable contact and the fixed contact in the two permanent magnets 71 facing the same pair of movable contacts and fixed contacts. Above the position between the two movable contacts of the movable contact 2 (substantially the middle position of the movable contact 2), an upper magnetic conductor 61 is attached. In this embodiment, the upper magnetic conductor 61 is an upper armature. Below the position between the two movable contacts of the movable contact 2, a lower magnetic conductor 62 movable together with the movable contact 2 is attached. 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. Also, 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. Thereby, when a large fault current occurs in the movable contact 2, by utilizing the additional magnetic pole surface added at the position of the corresponding through hole 22 by each magnetic circuit, an attractive force is generated in the direction of the contact pressure (since the upper magnetic conductor 61 is relatively fixed, but the lower magnetic conductor 62 is relatively movable, an upward attractive force is formed), to counteract the electric reaction force due to the fault current between the movable contact 2 and the fixed contact leads 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 their alloys.

[0090] In this embodiment, the magnetic field formed by the combination of the four permanent magnets 71 and the two yoke clips 72 can form a magnetic blowing force in the direction indicated by the arrow in FIG. 26. The magnetic blowing forces in the two directions perform arc extinguishing processing on the two pairs of movable contacts and fixed contacts respectively. Since the directions of the magnetic blowing forces are both outward (i.e., diagonally upward in FIG. 26), they do not interfere with each other. The magnetic field formed by the combination of the four permanent magnets 71 and the two yoke clips 72 also acts on the movable contact 2, but since the acting forces cancel each other out, it hardly acts.

[0091] Referring to FIGS. 28 and 29, among the four permanent magnets 71, the two permanent magnets 71 located on the same side in the width direction of the movable contact 2 are installed with opposite magnetic poles on the side facing the movable contact and the fixed contact. Specifically, among the two permanent magnets 71 located on the left side in the current flowing direction of the movable contact 2, the permanent magnet 71 located closer to the fixed contact lead-out end 11 is installed with the magnetic pole on the side facing the movable contact and the fixed contact as the N pole; the permanent magnet 71 located closer to the fixed contact lead-out end 12 is installed with the magnetic pole on the side facing the movable contact and the fixed contact as the S pole. Among the two permanent magnets 71 located on the right side in the current flowing direction of the movable contact 2, the permanent magnet 71 located closer to the fixed contact lead-out end 11 is installed with the magnetic pole on the side facing the movable contact and the fixed contact as the N pole; the permanent magnet 71 located closer to the fixed contact lead-out end 12 is installed with the magnetic pole on the side facing the movable contact and the fixed contact as the S pole.

[0092] The magnetic field formed by the combination of the four permanent magnets 71 and the two yoke clips 72 can form a magnetic blowing force in the direction indicated by the arrow in FIG. 28. The magnetic blowing forces in the two directions perform arc extinguishing processing on the two pairs of movable contacts and fixed contacts respectively. Since the directions of the magnetic blowing forces are both outward (i.e., diagonally upward and diagonally downward in FIG. 28), they do not interfere with each other. The magnetic field formed by the combination of the four permanent magnets 71 and the two yoke clips 72 also acts on the movable contact 2, but since the acting forces cancel each other out, it hardly acts.

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

[0094] In this Example 6, other structures except for the four permanent magnets 71 and the two yoke clips 72, for example, the push rod member 3, the movable contact 2, the upper magnetic conductor 61, the lower magnetic conductor 62, etc. may be the same as those in Example 1, Example 2, and Example 3, so detailed description is omitted here.

[0095] The DC relay with arc extinguishing and short-circuit current prevention functions of the present invention has four permanent magnets 71 respectively arranged at positions on both sides in the width direction of the movable contact 2 facing the movable contact and the fixed contact. Also, the two permanent magnets 71 facing the same pair of movable contact and fixed contact are installed with the magnetic poles on one side facing the movable contact and the fixed contact being the same; the two permanent magnets located on the same side in the width direction of the movable contact 2 are also installed with the magnetic poles on one side facing the movable contact and the fixed contact being the same. A yoke clip 72 is further connected between the two permanent magnets facing the same pair of movable contact and fixed contact. Also, an upper magnetic conductor 61 is attached above the position between the two movable contacts of the movable contact 2. 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. Also, 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. Also, 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 arc extinguishing is realized by the four permanent magnets 71, when a large fault current occurs in the movable contact 2 by using the magnetic pole surfaces added at the positions of the corresponding through holes 22 by each magnetic circuit, the attractive force is increased in the direction of the contact pressure, and by superimposing the attractive force on the contact pressure, it counteracts the electric reaction force due to the fault current between the movable contact and the fixed contact, and the plurality of independent magnetic circuits distribute the large short-circuit current almost evenly, so it has the characteristics of high magnetic efficiency and being difficult for the magnetic circuit to saturate.

[0096] Example 7 As shown in FIGS. 30 to 32, the DC relay having the arc extinguishing and short-circuit current prevention functions of the present invention includes a fixed contact lead-out terminal 11 for current inflow, a fixed contact lead-out terminal 12 for current outflow, one straight plate-shaped movable contact 2, and by moving the movable contact 2, a push rod member 3 for realizing the contact or separation between the movable contacts located at both ends of the movable contact 2 and the fixed contacts located at the bottoms of the fixed contact lead-out terminals 11 and 12, and two permanent magnets 71. The two fixed contact lead-out terminals 11 and 12 are respectively attached to the case 4. A part of the movable contact 2 and the push rod member 3 is accommodated in the case 4. The push rod member 3 is also connected to the movable iron core 5 in the magnetic circuit structure. The push rod member 3 moves the movable contact 2 upward by the action of the magnetic circuit, so that the movable contacts located at both ends of the movable contact 2 are respectively brought into contact with the fixed contacts located at the bottoms of the two fixed contact lead-out terminals 11 and 12. Thereby, the connection to the load is realized. The movable contact 2 is attached to the push rod member 3 via a spring 31, thereby realizing that the movable contact 2 is movable with respect to the push rod member 3 (realizing the overtravel of the contact). The two permanent magnets 71 are located outside the case 4 and are respectively arranged at positions facing the movable contacts and the fixed contacts on the outer sides of both ends in the longitudinal direction of the movable contact 2. Also, the magnetic poles of the opposing surfaces of the two permanent magnets 71 are installed oppositely. Two yoke clips 72 are further connected to the two permanent magnets 71. The two yoke clips 72 further include yoke sections 721 located at positions facing the movable contacts and the fixed contacts at least on both sides in the width direction of the movable contact 2. In this embodiment, the current flows into the fixed contact lead-out terminal 11 and flows out from the fixed contact lead-out terminal 12. The current flows from one end of the movable contact 2 close to the fixed contact lead-out terminal 11 to the other end close to the fixed contact lead-out terminal 12 in the movable contact 2. The two permanent magnets 71 are respectively arranged at positions facing the movable contacts and the fixed contacts.As shown in FIG. 31, among the two permanent magnets 71, one permanent magnet 71 located on the fixed contact lead-out terminal 11 side has the magnetic pole on the side facing the movable contact and the fixed contact set as the N pole; one permanent magnet 71 located on the fixed contact lead-out terminal 12 side has the magnetic pole on the side facing the movable contact and the fixed contact set as the S pole. Above the position between the two movable contacts of the movable contactor 2 (substantially the middle position of the movable contactor 2), an upper magnetic conductor 61 is attached. In this embodiment, the upper magnetic conductor 61 is an upper armature. Below the 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. 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. Also, 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. Thereby, when a large fault current occurs in the movable contactor 2, by utilizing the magnetic pole surfaces added to the positions of the corresponding through holes 22 by each magnetic circuit, an attractive force is generated in the direction of the contact pressure (since the upper magnetic conductor 61 is relatively fixed, but the lower magnetic conductor 62 is relatively movable, an attractive force facing upward is formed.), to counteract the electric reaction force caused by the fault current between the movable contactor 2 and the fixed contact lead-out terminals 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 their alloys.

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

[0098] Of course, the lengths of the two side walls 723 of the U-shaped yoke clip 72 can also be set to be short. For example, the ends of the two 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 can also be connected to the two permanent magnets 71. That is, the bottom walls 722 of the two U-shaped yoke clips 72 are respectively arranged on both sides in the width direction of the movable contact 2, and the tips of the two side walls 723 of the two U-shaped yoke clips 72 are respectively connected to one surface on the opposite side of the two permanent magnets 71. Such a configuration may also be adopted.

[0100] 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 blowing force in the direction indicated by the arrow in FIG. 31. The magnetic blowing forces in the two directions respectively perform arc extinguishing treatment on the two pairs of movable contacts and fixed contacts. Since the directions of the magnetic blowing forces are all directed obliquely outward, they do not interfere with each other. The magnetic field formed by the combination of the two permanent magnets 71 and the two yoke clips 72 also acts on the movable contact 2, but since the acting forces cancel each other out, it hardly acts.

[0101] In Embodiment 7, other structures except for 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 Embodiment 1, Embodiment 2, and Embodiment 3. Therefore, detailed descriptions are omitted here.

[0102] Such a DC relay of the present invention has no polarity requirement for the load, and the arc extinguishing capabilities in the forward and reverse directions are the same.

[0103] In the DC relay with arc extinguishing and short-circuit current prevention functions of the present invention, each of the two permanent magnets 71 is arranged at positions outside both ends in the longitudinal direction of the movable contact 2 facing the movable contact and the fixed contact. Also, the magnetic poles on the opposing surfaces of the two permanent magnets 71 are installed in opposite directions. The two permanent magnets 71 are further connected to two yoke clips 72. The two yoke clips 72 further include yoke sections 721 located at positions facing the movable contact and the fixed contact at least on both sides in the width direction of the movable contact 2. Also, an upper magnetic conductor 61 is attached above the position between the two movable contacts of the movable contact 2. 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. Also, 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. Also, 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 arc extinguishing is realized by the four permanent magnets 71, when a large fault current occurs in the movable contact 2, the additional magnetic pole surfaces at the positions of the corresponding through holes 22 are utilized by each magnetic circuit to increase the attractive force in the direction of the contact pressure, and by superimposing the attractive force on the contact pressure, it counteracts the electrical reaction force due to the fault current between the movable contact and the fixed contact, and the plurality of independent magnetic circuits distribute the large short-circuit current almost evenly, so it has the characteristics of high magnetic efficiency and being difficult for the magnetic circuit to saturate.

[0104] Example 8 Referring to FIGS. 33 to 35, a DC relay having an arc extinguishing and short-circuit current preventing function by a permanent magnet of the present invention includes a fixed contact lead-out terminal 11 for current inflow, a fixed contact lead-out terminal 12 for current outflow, one straight plate-type movable contact 2, and by moving the movable contact 2, a push rod member 3 for realizing contact or separation between the movable contacts located at both ends of the movable contact 2 and the fixed contacts located at the bottoms of the fixed contact lead-out terminals 11 and 12, and four permanent magnets 71. The two fixed contact lead-out terminals 11 and 12 are respectively attached to the case 4. A part of the movable contact 2 and the push rod member 3 is accommodated in the case 4. The push rod member 3 is further connected to the movable iron core 5 in the magnetic circuit structure. The push rod member 3 moves the movable contact 2 upward by the action of the magnetic circuit, so that the movable contacts located at both ends of the movable contact 2 are respectively brought into contact with the fixed contacts located at the bottoms of the two fixed contact lead-out terminals 11 and 12. Thereby, connection to the load is realized. The movable contact 2 is attached to the push rod member 3 via a spring 31, so that the movable contact 2 can move relative to the push rod member 3 (realizing overtravel of the contact). The four permanent magnets 71 are located outside the case 4 and are respectively arranged at positions on both sides in the width direction of the movable contact 2 facing the movable contact and the fixed contact (i.e., the corresponding movable contact and fixed contact). Also, for the two permanent magnets facing the same pair of movable contact and fixed contact, the magnetic poles on the surface facing the movable contact and the fixed contact are installed oppositely; for the two permanent magnets located on the same side in the width direction of the movable contact 2, the magnetic poles on the surface facing the movable contact and the fixed contact are installed the same. 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, the current flows into the fixed contact lead-out terminal 11 and flows out from the fixed contact lead-out terminal 12. The current flows from one end of the movable contact 2 close to the fixed contact lead-out terminal 11 to the other end close to the fixed contact lead-out terminal 12 in the movable contact 2. The four permanent magnets 71 are respectively arranged at positions facing the movable contact and the fixed contact.As shown in FIG. 34, among the four permanent magnets 71, the two permanent magnets 71 located on the left side in the current flow direction of the movable contact 2 have the magnetic poles on the side facing the movable contact and the fixed contact set as N poles; the two permanent magnets 71 located on the right side in the current flow direction of the movable contact 2 have the magnetic poles on the side facing the movable contact and the fixed contact set as S 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; the two side walls of the U-shaped yoke clip 72 are respectively connected to one side opposite to the movable contact and the fixed contact on the two permanent magnets 71 facing the same pair of movable contacts and fixed contacts. Above the position between the two movable contacts of the movable contact 2 (substantially the middle position of the movable contact 2), an upper magnetic conductor 61 is attached. In this embodiment, the upper magnetic conductor 61 is an upper armature. Below the position between the two movable contacts of the movable contact 2, a lower magnetic conductor 62 movable together with the movable contact 2 is attached. 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. Also, 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. Thereby, when a large fault current occurs in the movable contact 2, by utilizing the additional magnetic pole surfaces added at the positions of the corresponding through holes 22 by each magnetic circuit, an attractive force is generated in the direction of the contact pressure (since the upper magnetic conductor 61 is relatively fixed, but the lower magnetic conductor 62 is relatively movable, an upward attractive force is formed), to counteract the electrical reaction force due to the fault current between the movable contact 2 and the fixed contact leads 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 their alloys.

[0105] In this embodiment, the magnetic field formed by the combination of the four permanent magnets 71 and the two yoke clips 72 can form a magnetic blowing force in the direction indicated by the arrow in FIG. 34. The magnetic blowing 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 blowing forces are both outward, they do not interfere with each other. The magnetic field formed by the combination of the four permanent magnets 71 and the two yoke clips 72 also acts on the movable contact 2, thereby forming a downward force (as shown in FIG. 35) at the contact position, so the contact pressure may be insufficient. Therefore, it is also necessary for the attractive force formed by the magnetic circuit to counteract the downward force generated by the magnetic field action of the four permanent magnets 71 and the two yoke clips 72.

[0106] Such a structure of this embodiment is applicable to users who have a requirement for arc interruption.

[0107] Among 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 have the magnetic poles on the side facing the movable contact and the fixed contact set as S poles; the two permanent magnets 71 located on the right side of the current flow direction of the movable contact 2 have the magnetic poles on the side facing the movable contact and the fixed contact set as N poles. In this way, since the direction of the magnetic field is reversed, the directions of the magnetic blowing forces are both inward. The arc is interfered to a certain extent by the magnetic blowing. Such a structure of this embodiment can be applied to users who do not have a requirement for arc interruption. 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 to increase the contact pressure. That is, the attractive force by the magnetic circuit can counteract the electric reaction force by the fault current between the movable contact 2 and the fixed contact leads 11 and 12 together with the upward force by the magnetic field action of the four permanent magnets 71 and the two yoke clips 72.

[0108] The DC relay with an arc extinguishing and short-circuit current prevention function by the permanent magnet according to the present invention has a requirement for the polarity of the load, and there is a large difference in the arc extinguishing ability between the positive direction and the negative direction.

[0109] In the present Example 8, the structures other than the four permanent magnets 71 and the two yoke clips 72, for example, 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 above-described Example 1, Example 2, and Example 3, and thus the detailed description thereof is omitted here.

[0110] The DC relay with an arc extinguishing and short-circuit current prevention function by permanent magnets of the present invention is configured such that each of the four permanent magnets 71 is disposed at positions on both sides in the width direction of the movable contact 2 facing the movable contact and the fixed contact. Also, for the two permanent magnets facing the same pair of movable and fixed contacts, the magnetic poles on the surface facing the movable and fixed contacts are installed in opposite directions. For the two permanent magnets located on the same side in the width direction of the movable contact 2, the magnetic poles on the surface facing the movable and fixed contacts are installed in the same direction. A yoke clip 72 is further connected between the two permanent magnets facing the same pair of movable and fixed contacts. Also, an upper magnetic conductor 61 is attached above the position between the two movable contacts of the movable contact 2. 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. Further, 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. Also, 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 arc extinguishing is achieved by the four permanent magnets 71, when a large fault current occurs in the movable contact 2, the additional magnetic pole surfaces added at the positions of the corresponding through holes 22 by each magnetic circuit are utilized 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 due to the fault current between the movable contact and the fixed contact. The plurality of independent magnetic circuits distribute a large short-circuit current almost evenly, so it has the characteristics of high magnetic efficiency and low susceptibility to magnetic circuit saturation.

[0111] It should be understood that the application of the present invention is not limited to the detailed structure and arrangement of the members described herein. The present invention has other embodiments and can be implemented and executed in various ways. The above-mentioned deformations and modifications are included within the scope of the present invention. It should be understood that the present invention disclosed and limited herein extends to all alternative combinations of two or more distinct features mentioned in this specification and / or the drawings or that are obvious. All of these different combinations constitute multiple alternative aspects of the present invention. The embodiments described herein illustrate the best-known preferred mode for carrying out the present invention and enable those skilled in the art to utilize the present invention.

Claims

1. A DC relay comprising two fixed contact terminals, one straight-type movable contact, one push rod member, and four permanent magnets, and having an arc extinguishing and short-circuit current prevention function, wherein the movable contact is attached to the push rod member, and by the action of the push rod member, the contact or separation between the movable contacts located at both ends of the movable contact and the fixed contacts located at the bottom of the two fixed contact terminals is realized; the four permanent magnets are respectively arranged at positions on both sides in the width direction of the movable contact facing the movable contact and the fixed contact, and for the two permanent magnets facing the same pair of movable contacts and fixed contacts, the magnetic poles on the surface facing the movable contact and the fixed contact are installed oppositely; for the two permanent magnets located on the same side in the width direction of the movable contact, the magnetic poles on the surface facing the movable contact and the fixed contact are also installed oppositely; a yoke clip is further connected between the two permanent magnets facing the same pair of movable contacts and fixed contacts; above the position between the two movable contacts of the movable contact, an upper magnetic conductor arranged along the width direction of the movable contact is attached; below the position, a lower magnetic conductor arranged along the width direction of the movable contact and movable together with the movable contact is attached; at a predetermined position of the movable contact, at least one through hole is provided, and the upper magnetic conductor and the lower magnetic conductor can approach, contact or separate from each other through the through hole; also, 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 utilizes the additional magnetic pole surface added at the position of the corresponding through hole to generate an attractive force in the direction of the contact pressure to counteract the electric reaction force caused by the fault current between the movable contact and the fixed contact terminal. A DC relay characterized by the above.

2. The two permanent magnets facing the same pair of the movable contacts and the fixed contacts are provided at positions biased with respect to the same pair of the movable contacts and the fixed contacts, and the two permanent magnets are arranged offset. The DC relay according to claim 1, characterized by the above.

3. The upper magnetic conductor is at least one linear upper magnetic conductor, and the lower magnetic conductor is at least two U-shaped lower magnetic conductors. One U-shaped lower magnetic conductor and the corresponding linear upper magnetic conductor form an independent magnetic circuit, and there is no contact between two adjacent U-shaped lower magnetic conductors that form two adjacent magnetic circuits. The DC relay according to claim 1, characterized in that.

4. In at least two independent magnetic circuits, at least one set of adjacent two magnetic circuits has one common linear upper magnetic conductor, and the two U-shaped lower magnetic conductors in the adjacent two magnetic circuits are respectively arranged below one linear upper magnetic conductor. The DC relay according to claim 3, characterized in that.

5. In at least two independent magnetic circuits, all of the linear upper magnetic conductors in the adjacent two magnetic circuits are two independent ones, and the two U-shaped lower magnetic conductors in the adjacent two magnetic circuits are respectively arranged below the corresponding linear upper magnetic conductors. The DC relay according to claim 3, characterized in that.

6. There are two magnetic circuits, and the movable contact is provided with one through hole. One side wall of each of the two U-shaped lower magnetic conductors is attached to the side of the movable contact in the width direction, and the other one side wall of the two U-shaped lower magnetic conductors passes through the same through hole of the movable contact respectively, and there is a gap between the other one side walls of the two U-shaped lower magnetic conductors. The DC relay according to claim 3, characterized in that.

7. The other one side walls of the two U-shaped lower magnetic conductors are arranged side by side or offset along the length direction of the movable contact in the same through hole of the movable contact, 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 contact. The DC relay according to claim 6, characterized in that.

8. There are two of the magnetic circuits. The movable contact has two through holes provided therein, and the two through holes are arranged side by side or offset along the length direction of the movable contact. One side wall of each of the two U-shaped lower magnetic conductors is attached to the corresponding side in the width direction of the movable contact, 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 contact, 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 contact. The DC relay according to claim 3, characterized in that.

9. There are three of the magnetic circuits. The movable contact has two through holes provided therein. The three U-shaped lower magnetic conductors are sequentially arranged along the width direction of the movable contact. Both side walls of the one U-shaped lower magnetic conductor located in the center pass through the two through holes of the movable contact respectively. One side wall of each of the two U-shaped lower magnetic conductors located on both sides is attached to the side in the width direction of the movable contact respectively. 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 contact respectively, and a gap exists between the two side walls of the movable contact within the same through hole. The DC relay according to claim 3, characterized in that.

10. The upper magnetic conductor is an upper armature fixed to the push rod member, 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 touches the fixed contact of the fixed contact lead-out end, a predetermined gap exists between the upper armature and the lower armature, so as to further counteract the electric reaction force. The DC relay according to claim 1, characterized in that.

11. The upper magnetic conductor is an upper yoke fixed to a case for attaching two fixed contact lead-out ends, 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 touches the lower armature when the movable contact of the movable contact touches the fixed contact of the fixed contact lead-out end. The DC relay according to claim 1, characterized in that.

12. The push rod member includes a U-shaped holder, a spring sheet, and a push rod. The tip of the push rod is fixed to the spring sheet, and the bottom of the U-shaped holder is fixed to the spring sheet. The 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. The upper surface of the movable contact abuts against the upper yoke, and the upper yoke is fixed to the inner wall of the top of the U-shaped holder. The spring elastically abuts between the bottoms of the two U-shaped lower magnetic conductors and the upper surface of the spring sheet. The DC relay according to claim 11, characterized in that.

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