JP5323244B2 - Contact mechanism and electromagnetic contactor using the same - Google Patents

Description

  The present invention relates to a contact mechanism including a fixed contact and a movable contact inserted in a current path and an electromagnetic contactor using the contact mechanism, and to an electromagnetic repulsive force that separates the movable contact from the fixed contact during energization. It is designed to generate a Lorentz force to resist.

  Conventionally, as a contact mechanism that opens and closes a current path, as a fixed contact that is applied to a switch that generates an arc when a current is interrupted, such as a circuit breaker or an electromagnetic contactor, the U-shaped fixed contact is viewed from the side. The fixed contact is formed in the folded part, and the movable contact of the movable contact is arranged on the fixed contact so that the movable contact can be contacted / separated, and the electromagnetic repulsive force acting on the movable contact when a large current is interrupted is increased. Has proposed a switch in which the opening speed is increased to rapidly stretch the arc (see, for example, Patent Document 1).

  Further, a contactor structure of an electromagnetic contactor that drives an arc by a magnetic field generated by a flowing current in a similar configuration has been proposed (see, for example, Patent Document 2).

JP 2001-210170 A JP-A-4-123719

  By the way, in the conventional example described in Patent Document 1, the electromagnetic repulsive force generated as a U-shape when the fixed contact is viewed from the side is increased, and a short circuit or the like is caused by this large electromagnetic repulsive force. The opening speed of the movable contact at the time of interrupting a large current that interrupts a large current by increasing the arc rapidly, and the fault current can be limited to a small value.

  However, an electromagnetic contactor that constitutes a circuit in combination with a fuse or a circuit breaker needs to prevent the movable contact from being opened by electromagnetic repulsion when energizing a large current that flows during a short circuit. In order to apply the conventional example described in No. 2, generally, the spring force of the contact spring that secures the contact pressure of the movable contact with the fixed contact is increased.

  When the contact pressure by the contact spring is increased in this way, it is necessary to increase the thrust generated by the electromagnet that drives the movable contact, and the overall configuration increases. Alternatively, it is necessary to combine with a fuse or a circuit breaker having a higher current limiting effect and an excellent breaking performance.

  Therefore, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and suppresses the electromagnetic repulsive force that opens the movable contact when energized without increasing the overall configuration. It is an object of the present invention to provide a contact mechanism that can be used and an electromagnetic contactor using the same.

  In order to achieve the above object, a first aspect of the contact mechanism according to the present invention is a contact mechanism having a movable contact and a fixed contact inserted in an energization path, wherein the movable contact is movable. A conductive plate portion supported by the portion, a U-shaped folded portion formed at both ends of the conductive plate portion, and a contact portion formed on a surface of the U-shaped folded portion facing the fixed contact. The fixed contact is arranged in parallel with the conductive plate portion so as to face the central portion of the U-shaped folded portion, and forms a contact portion that contacts the contact portion of the movable contact. A first conductive plate portion and a second conductive plate portion extending opposite to a side portion of the U-shaped folded portion from an inner end on the other fixed contact side of the pair of first conductive plate portions; A side portion of the U-shaped folded portion of the movable contact and the pair of fixed contacts that are opposed to each other when energized. The direction of the current flowing through the two conductive plate portions is the same direction, and a Lorentz force is generated on the movable contact that resists the electromagnetic repulsion force in the opening direction generated between the fixed contact and the movable contact. It has a fixed contact and a movable contact inserted in the current path.

  According to this configuration, the shape of at least one of the fixed contact and the movable contact is configured to generate a Lorentz force that resists the electromagnetic repulsion force in the opening direction that occurs between the fixed contact and the movable contact during energization. Therefore, it is possible to suppress the opening of the movable contact when a large current is applied.

  In addition, a U-shaped folded portion is formed on the movable contact side, and a current path in the U-shaped folded portion is used to make a conductive plate portion of the movable contact and a second conductive plate portion of the fixed contact A Lorentz force can be generated in a direction in which the movable contact is brought into contact with the fixed contact.

  Further, according to a second aspect of the contact mechanism of the present invention, the fixed contact has a pair of flat conductors, and the inner end of the pair of flat conductors on the other fixed contact side. A U-shaped groove that opens to the side is formed, and the inside of the U-shaped groove serves as the first conductive plate portion, and the outside of the U-shaped groove serves as the second conductive plate portion.

  Moreover, the 1st aspect of the electromagnetic contactor which concerns on this invention is equipped with the contact mechanism of the said 1st or 2nd aspect, the said movable contact is connected with the movable iron core of the electromagnet for operation, and the said fixed contact is It is connected to an external connection terminal.

  According to this configuration, the spring of the contact spring that makes the movable contact contact the fixed contact by generating a Lorentz force against the electromagnetic repulsion force that opens the gap between the movable contact and the fixed contact when the electromagnetic contactor is energized. The power can be reduced. Accordingly, the thrust of the electromagnet that drives the movable contact can also be reduced, and a small electromagnetic contactor can be provided.

  According to the present invention, a Lorentz that resists an electromagnetic repulsion force in the opening direction generated in a stationary contact and a movable contact when a large current is applied to a contact mechanism having a stationary contact and a movable contact inserted in a current path. Can generate power. For this reason, it is possible to reliably prevent the opening of the movable contact when energizing a large current without using a mechanical pressing force.

It is sectional drawing which shows embodiment at the time of applying this invention to an electromagnetic contactor. It is a figure which shows the reference form of the contact mechanism of this invention, Comprising: (a) is a perspective view, (b) is sectional drawing which shows the contact mechanism at the time of opening, (c) is sectional drawing which shows the contact mechanism at the time of closing (D) It is sectional drawing which shows the magnetic flux at the time of closing. It is a figure which shows the other reference form of the contact mechanism of this invention, Comprising: (a) is a perspective view, (b) is sectional drawing which shows the contact mechanism at the time of opening, (c) shows the contact mechanism at the time of closing It is sectional drawing. It is a figure which shows the other reference form of the contact mechanism of this invention, Comprising: (a) is a perspective view, (b) is sectional drawing which shows the contact mechanism at the time of opening, (c) is the contact mechanism at the time of closing. It is sectional drawing shown. It is a figure which shows embodiment of the contact mechanism of this invention, Comprising: (a) is a perspective view, (b) is sectional drawing which shows the contact mechanism at the time of opening, (c) is sectional drawing which shows the contact mechanism at the time of closing (D) is explanatory drawing which shows the electric current direction at the time of closing.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view showing an embodiment of an electromagnetic contactor according to the present invention, and FIG. 2 is a view showing a reference form of a contact mechanism.

  In FIG. 1, 1 is a main body case made of, for example, a synthetic resin. The main body case 1 has a two-part structure of an upper case 1a and a lower case 1b. The upper case 1a is provided with a contact mechanism CM. The contact mechanism CM includes a fixed contact 2 fixedly disposed on the upper case 1a, and a movable contactor 3 disposed so as to be able to contact and separate from the fixed contact 2.

  In the lower case 1b, an operation electromagnet 4 for driving the movable contact 3 is disposed. The electromagnet 4 for operation has a stationary iron core 5 formed of an E-shaped laminated steel plate and a movable iron core 6 formed of an E-shaped laminated steel plate facing each other.

  An electromagnetic coil 8 supplied with a single-phase alternating current wound around a coil holder 7 is fixed to the central leg 5a of the fixed iron core 5. Further, a return spring 9 for biasing the movable iron core 6 in the direction away from the fixed iron core 5 is disposed between the upper surface of the coil holder 7 and the root of the central leg 6 a of the movable iron core 6.

  Further, a shading coil 10 is embedded in the upper end surface of the outer leg portion of the fixed iron core 5. The shading coil 10 can suppress fluctuations in electromagnetic attraction, noise, and vibration due to changes in alternating magnetic flux in the single-phase AC electromagnet.

  A contact holder 11 is connected to the upper end of the movable iron core 6. The contact holder 11 is pressed downward into an insertion hole 11a formed in a direction perpendicular to the axis on the upper end side thereof so that the movable contact 3 obtains a predetermined contact pressure against the fixed contact 2 by the contact spring 12. Being held.

  As shown in an enlarged view in FIG. 2, the movable contact 3 is composed of an elongated bar-like conductive plate 3a whose central portion is pressed by a contact spring 12, and a movable contact portion 3b is formed on the lower surface of both ends of the conductive plate 3a. , 3c are formed.

  On the other hand, the fixed contact 2 supports a pair of fixed contact portions 2a and 2b facing the movable contact portions 3b and 3c of the movable contact 3 from below as shown in an enlarged view in FIG. The first conductive plate portions 2c and 2d facing outward in parallel and the upper ends of the first conductive plate portions 2c and 2d from the outer end portion outside the conductive plate 3a through the outside of the end portions of the conductive plate 3a L-shaped conductive plate portions 2g and 2h formed by second conductive plate portions 2e and 2f extending in the length direction. And as shown in FIG. 1, it connects with the external connection terminals 2i and 2j extended and fixed to the outer side of the upper case 1a at the upper end of these L-shaped electroconductive board parts 2g and 2h.

Next, the operation of the above embodiment will be described.
Now, in a state where the electromagnetic coil 8 of the operation electromagnet 4 is in a non-energized state, no electromagnetic attractive force is generated between the fixed iron core 5 and the movable iron core 6, and the movable iron core 6 is removed from the fixed iron core 5 by the return spring 9. The movable iron core 6 is urged in a direction away from the top, and the upper end of the movable iron core 6 abuts against the stopper 13 to be held at the current interruption position.

  In the state where the movable iron core 6 is in the current interruption position, the movable contact 3 is in contact with the bottom of the insertion hole 11a of the contact holder 11 by the contact spring 12, as shown in FIG. In this state, the movable contact portions 3b and 3c formed on both ends of the conductive plate 3a of the movable contact 3 are spaced upward from the fixed contact portions 2a and 2b of the fixed contact 2, and the contact mechanism CM is opened. It is in a state.

  When a single-phase alternating current is supplied to the electromagnetic coil 8 of the electromagnet 4 for operation from the opened state of the contact mechanism CM, an attractive force is generated between the fixed iron core 5 and the movable iron core 6, and the movable iron core 6 becomes the return spring 12. It is sucked down against. Thereby, the movable contact 3 supported by the contact holder 11 is lowered, and the movable contact portions 3b and 3c come into contact with the fixed contact portions 2a and 2b of the fixed contact 2 with the contact pressure of the contact spring 12, Closed state.

  In this closed state, for example, a large current of, for example, several tens of kA inputted from the external connection terminal 2i of the fixed contact 2 connected to a DC power source (not shown) is applied to the second conductive plate portion 2e, 1 is supplied to the movable contact portion 3b of the movable contact 3 through the conductive plate portion 2c and the fixed contact portion 2a. The large current supplied to the movable contact portion 3b is supplied to the fixed contact portion 2b through the conductive plate 3a and the movable contact portion 3c. The large current supplied to the fixed contact portion 2b is supplied to the first conductive plate portion 2d, the second conductive plate portion 2f, and the external connection terminal 2j to form an energization path that is supplied to an external load.

At this time, an electromagnetic repulsive force is generated between the fixed contact portions 2a and 2b of the fixed contact 2 and the movable contact portions 3b and 3c of the movable contact 3 in a direction to open the movable contact portions 3b and 3c.
However, as shown in FIG. 2, the fixed contact 2 has L-shaped conductive plate portions 2g and 2h formed by the first conductive plate portions 2c and 2d and the second conductive plate portions 2e and 2f. By forming the above-described current path, a magnetic field shown in FIG. 2D is formed for the current flowing through the movable contact 3. Therefore, according to Fleming's left-hand rule, a Lorentz force is applied to the conductive plate 3a of the movable contact 3 to resist the electromagnetic repulsion force in the opening direction that presses the movable contact portions 3b, 3c toward the fixed contact portions 2a, 2b. be able to.

  Therefore, even if an electromagnetic repulsive force in the direction to open the movable contact 3 is generated, a Lorentz force can be generated to resist this, so that the movable contact 3 is reliably prevented from opening. Can do. For this reason, the pressing force of the contact spring 12 that supports the movable contact 3 can be reduced, the thrust generated by the operation electromagnet 4 can be reduced accordingly, and the overall configuration can be downsized. Can do.

  In addition, in this case, it is only necessary to form the L-shaped conductive plate portions 2g and 2h on the stationary contact 2, the machining of the stationary contact 2 can be easily performed, and the electromagnetic repulsive force in the opening direction is separately provided. Since the member which generate | occur | produces the electromagnetic force or mechanical force to resist is not required, the number of parts does not increase and it can suppress that the whole structure enlarges.

Next, a reference form will be described with reference to FIG.
In this reference embodiment, a Lorentz force is generated against the electromagnetic repulsion force in the opening direction generated with respect to the stationary contact and the movable contact on the back side of the movable contact.

  That is, in the reference embodiment, as shown in FIG. 3, in the configuration of FIG. 2 in the reference embodiment of the present invention described above, the second conductive plate portions 2e, 2e in the L-shaped conductive plate portions 2g, 2h of the stationary contact 2 are provided. 2f is bent so as to cover the upper end side of the end portion of the conductive plate 3a of the movable contact 3, and third conductive plate portions 2m and 2n parallel to the conductive plate 3a are formed to form U-shaped conductive plate portions 2o, Except that 2p is formed, it has the same configuration as the reference embodiment of the present invention described above.

  According to this reference embodiment, in the state where the electromagnetic coil 8 of the operation electromagnet 4 is in a non-energized state, no attractive force acts between the fixed iron core 5 and the movable iron core 6, so that it is the same as the reference embodiment of the present invention described above. Further, the movable iron core 6 and the contact holder 11 are biased upward by the spring force of the return spring 9, and the contact mechanism CM is in an open state as shown in FIG.

  When a single-phase alternating current is applied to the electromagnetic coil 8 of the operation electromagnet 4 from the opened state of the contact mechanism CM, an attractive force is generated in the fixed iron core 5 and the movable iron core 6 is attracted downward against the return spring 9. Is done. As a result, as shown in FIG. 3C, the contact mechanism CM moves down the contact holder 11 so that the movable contact portions 3 b and 3 c of the movable contact 3 become the fixed contact portions 2 a and 2 b of the fixed contact 2. The contact spring 12 is brought into contact with the contact pressure to be closed.

  When the contact mechanism CM is in the closed state in this way, for example, a large current of about several tens kA, for example, input from the external connection terminal 2i of the fixed contact 2 connected to the DC power source (not shown) is third. The conductive plate portion 2m, the second conductive plate portion 2e, the first conductive plate portion 2c, and the fixed contact portion 2a are supplied to the movable contact portion 3b of the movable contact 3. The large current supplied to the movable contact portion 3b is supplied to the fixed contact portion 2b through the conductive plate 3a and the movable contact portion 3c. The large current supplied to the fixed contact portion 2b is supplied to the first conductive plate portion 2d, the second conductive plate portion 2f, the third conductive plate portion 2n, and the external connection terminal 2j, and is applied to an external load. A supplied energization path is formed.

At this time, an electromagnetic repulsive force is generated between the fixed contact portions 2a and 2b of the fixed contact 2 and the movable contact portions 3b and 3c of the movable contact 3 in a direction to open the movable contact portions 3b and 3c.
However, as shown in FIG. 3, the fixed contact 2 has a U-shaped conductive plate by the first conductive plate portions 2c and 2d, the second conductive plate portions 2e and 2f, and the third conductive plate portions 2m and 2n. Since the portions 2o and 2p are formed, a current in the reverse direction flows between the third conductive plate portions 2m and 2n of the fixed contact 2 and the conductive plate 3a of the movable contact 3 facing the third conductive plate portions 2m and 2n. For this reason, the conductive plate 3a of the movable contact 3 is determined by Fleming's left-hand rule from the relationship between the magnetic field formed by the third conductive plate portions 2m and 2ng of the fixed contact 2 and the current flowing through the conductive plate 3a of the movable contact 3. A Lorentz force that presses against the fixed contact portions 2 a and 2 b of the fixed contact 2 can be generated. This Lorentz force can resist the electromagnetic repulsion force in the opening direction generated between the fixed contact portions 2a and 2b of the fixed contact 2 and the movable contact portions 3b and 3c of the movable contact 3. It is possible to prevent the three movable contact portions 3b and 3c from opening.

  Even in this reference embodiment, the electromagnetic contact force in the opening direction generated between the fixed contact 2 and the movable contact 3 can be resisted with a simple configuration in which the U-shaped conductive plate portions 2o and 2p are formed on the fixed contact 2. Lorentz force can be generated, and the same effect as the above-described reference of the present invention can be obtained.

Next, still another reference embodiment of the present invention will be described with reference to FIG.
In this reference embodiment, a U-shaped folded portion is formed on the movable contact, contrary to the reference embodiment shown in FIG.

  That is, in this reference embodiment, as shown in FIGS. 4A to 4C, the first conductive plate portions 3d and 3e extending upward from both end sides of the conductive plate 3a of the movable contact 3 and The second conductive plate portions 3f and 3g extending inward from the upper ends of the first conductive plate portions 3d and 3e form U-shaped folded portions 3h and 3i that are folded upward on the conductive plate 3a. ing. Movable contact portions 3j and 3k are formed on the lower surfaces of the distal ends of the second conductive plate portions 3f and 3g of the U-shaped folded portions 3h and 3i.

  The fixed contact 2 faces the conductive plate 3a forming the U-shaped folded portions 3h, 3i of the movable contact 3 and the second conductive plate portions 3f, 3g in the opened state of the contact mechanism CM. Inwardly extending fourth conductive plate portions 2q, 2r and inner sides of the U-shaped folded portions 3h, 3i of the movable contact 3 upward from the inner ends of the fourth conductive plate portions 2q, 2r L-shaped conductive plate portions 2u and 2v are formed by the fifth conductive plate portions 2s and 2t extending upward through the inside of the end portion, and the fourth conductive plate portions 2q and 2r are movable. Fixed contact portions 2w and 2x are formed at positions facing the movable contact portions 3j and 3k of the contact 3.

  According to this reference embodiment, when the electromagnetic coil 8 of the operation electromagnet 4 is in a non-energized state, the movable iron core 6 is moved upward by the return spring 9 so that the contact holder 11 comes into contact with the stopper 13. At this time, in the contact mechanism CM, as shown in FIG. 4B, the conductive plate 3 a of the movable contact 3 is in contact with the bottom of the insertion hole 11 a by the contact spring 12. Then, the fourth conductive plate portions 2q and 2r of the fixed contact 2 are located at the intermediate portion between the conductive plate 3a and the second conductive plate portions 3f and 3g constituting the U-shaped folded portions 3h and 3i. The parts 2w and 2x are spaced apart from the movable contact parts 3j and 3k and are in an open state.

  When the movable iron core 6 is attracted by the fixed iron core 5 against the return spring 9 by applying a single-phase alternating current to the electromagnetic coil 8 of the operation electromagnet 4 from the opened state of the contact mechanism CM, the contact holder 11 is moved. Descend. For this reason, in the contact mechanism CM, as shown in FIG. 4C, the movable contact portions 3 j and 3 k of the movable contact 3 are in a closed state in which they are in contact with the fixed contact portions 2 w and 2 x of the fixed contact 2.

  When the contact mechanism CM is thus closed, for example, a large current of about several tens of kA, for example, input from the external connection terminal 2i of the fixed contact 2 connected to a DC power source (not shown) is the fifth. Are supplied to the movable contact portion 3j of the movable contact 3 through the conductive plate portion 2s, the fourth conductive plate portion 2q, and the fixed contact portion 2w. The large current supplied to the movable contact portion 3j includes the second conductive plate portion 3f, the first conductive plate portion 3d, the conductive plate 3a, the first conductive plate portion 3e, the second conductive plate portion 3g, and the movable contact point. It is supplied to the fixed contact portion 2x through the portion 3k. The large current supplied to the fixed contact portion 2x forms an energization path that is supplied to an external load through the fourth conductive plate portion 2r, the fifth conductive plate portion 2t, and the external connection terminal 2j.

At this time, an electromagnetic repulsive force is generated between the fixed contact portions 2w and 2x of the fixed contact 2 and the movable contact portions 3j and 3k of the movable contact 3 in a direction to open the movable contact portions 3j and 3k.
However, in the movable contact 3, as shown in FIG. 4, U-shaped folded portions 3h and 3i are formed by the conductive plate 3a, the first conductive plate portions 3d and 3e, and the second conductive plate portions 3f and 3g. Therefore, a reverse current flows through the conductive plate 3a of the movable contact 3 and the fourth conductive plate portions 2q and 2r of the fixed contact 2. For this reason, as shown in FIG. 4C, the conductive plate 3a is moved by the current flowing through the conductive plate 3a of the movable contact 3 and the magnetic field formed by the fourth conductive plate portions 2q and 2r of the fixed contact 2. Lorentz force that presses the movable contact portions 3j and 3k of the contact 3 against the fixed contact portions 2w and 2x of the fixed contact 2 can be generated. By this Lorentz force, it becomes possible to resist the electromagnetic repulsion force in the opening direction generated between the fixed contact portions 2w and 2x of the fixed contact 2 and the movable contact portions 3j and 3k of the movable contact 3, and a large current It is possible to prevent the movable contact portions 3j and 3k of the movable contact 3 from opening when energized.

  Furthermore, in this reference form, since the L-shaped conductive plate portions 2u and 2v are formed on the fixed contact 2, the L-shaped conductive plate portion is located above the second conductive plate portions 3f and 3g of the movable contact 3. Since the magnetic flux strengthening portion is formed by the second conductive plate portions 2s and 2t of 2u and 2v, the Lorentz force similar to that of the above-described reference embodiment of the present invention can be generated, and the movable contact 3 can be opened more strongly. The pole can be prevented.

Next, an embodiment of the contact mechanism according to the present invention will be described with reference to FIG.
In this embodiment, both the fixed contact and the movable contact are formed in parallel to generate a Lorentz force that resists the electromagnetic repulsion force in the opening direction.

  In other words, in the embodiment, as shown in FIGS. 5A to 5D, the fixed contact 2 and the movable contact 3 constituting the contact mechanism CM are both formed in parallel. The fixed contact 2 has flat plate conductors 21a and 21b that are rectangular when viewed from a plane arranged at a predetermined distance from each other. These flat conductors 21a and 21b are formed in line symmetry, and U-shaped grooves 22a and 22b whose open end surfaces are on the inner end surface side are located on the front and back at positions corresponding to the longitudinal ends of the movable contact 3. Fixed contact portions 24a and 24b are formed on the surfaces of the plate portions 23a and 23b that are formed so as to penetrate and are surrounded by the U-shaped grooves 22a and 22b.

  On the other hand, the movable contact 3 has rectangular through holes 31a and 31b separated from each other at positions facing the plate portions 23a and 23b surrounded by the U-shaped grooves 22a and 22b in the flat conductors 21a and 21b of the fixed contact 2. Is formed. Movable contact portions 32a and 32b are formed on the lower surface of the fixed contact 2 opposite to the fixed contact portions 24a and 24b at the outer end portions of the through holes 31a and 31b.

  According to this embodiment, when the electromagnetic coil 8 of the operation electromagnet 4 is in a non-energized state, the movable iron core 6 is at an upper position by the return spring 9 as in the above-described reference embodiment of the present invention. For this reason, since the contact holder 11 is located at the upper position as shown in FIG. 5B, the flat conductors 21a and 21b of the fixed contact 2 and the movable contact 3 are separated from each other, and the fixed contact portions of the both are fixed. 24a, 24b and the movable contact portions 32a, 32b are separated from each other, and the contact mechanism CM is in an open state.

  When single-phase alternating current is supplied to the electromagnetic coil 8 of the operation electromagnet 4 from the opened state of the contact mechanism CM, the movable iron core 6 is attracted to the fixed iron core 5 against the return spring 9, whereby the contact holder 11 Is lowered, and the fixed contact portions 24a and 24b of the fixed contact 2 of the contact mechanism CM and the movable contact portions 32a and 32b of the movable contact 3 come into contact with each other to be in a closed state.

  In the closed state of the contact mechanism CM, a large current from, for example, a DC power source input from the external connection terminal 2i is input to the flat conductor 21a on the left end side, and is fixed to the plate portion 23a surrounded by the U-shaped groove 22a. Since the portion 24a is formed, a large current input to the flat conductor 21a enters the plate portion 23a through the side plate portions 25a and 25b on both side surfaces of the U-shaped groove 22a and is movable from the fixed contact portion 24a. It is supplied to the movable contact portion 32 a of the contact 3.

  The large current supplied to the movable contact portion 32a passes through the side plate portions 33a and 33b on both side surfaces of the through hole 31a, passes through the side plate portions 34a and 34b on both side surfaces of the through hole 31b, and moves from the movable contact portion 32b. It is supplied to the fixed contact portion 24b of the flat conductor 21b.

  The large current supplied to the fixed contact portion 24b passes through the side plate portions 26a and 26b on both sides of the U-shaped groove 22b from the plate portion 23b, and passes through the external connection terminal 2j from the right end side of the flat conductor 21b. To be supplied.

  At this time, the direction of the current passing through the side plate portions 25a, 25b of the flat conductor 21a of the fixed contact 2 facing each other and the side plate portions 33a, 33b of the movable contact 3 becomes the same direction, and the movable contacts facing each other similarly. The direction of the current passing through the three side plate portions 34a and 34b and the side plate portions 26a and 26b of the flat conductor 21b of the fixed contact 2 is the same direction.

  For this reason, downward Lorentz force is generated in the side plate portions 33a, 33b and 34a, 34b of the movable contact 3 by Fleming's left-hand rule. This Lorentz force can suppress the electromagnetic repulsion force in the opening direction generated between the fixed contact portions 24a and 24b and the movable contact portions 32a and 32b, and can prevent the opening of the movable contact 3 as described above. The same effects as those of the embodiment of the present invention can be obtained.

  In the above embodiment, the case where the contact mechanism CM of the present invention is applied to an electromagnetic contactor has been described. However, the present invention is not limited to this and can be applied to any device such as a switch.

  DESCRIPTION OF SYMBOLS 1 ... Main body case, 1a ... Upper case, 1b ... Lower case, 2 ... Fixed contact, 2a, 2b ... Fixed contact part, 2c, 2d ... 1st conductive plate part, 2e, 2f ... 2nd conductive plate part, 2g, 2h ... L-shaped conductive plate portion, 2i, 2j ... external connection terminal, 2m, 2n ... third conductive plate portion, 2o, 2p ... U-shaped conductive plate portion, 2q, 2r ... fourth conductive plate , 2s, 2t ... fifth conductive plate, 2u, 2v ... L-shaped conductive plate, 2w, 2x ... fixed contact, 3 ... movable contact, 3a ... conductive plate, 3b, 3c ... movable contact , 3d, 3e ... first conductive plate, 3f, 3g ... second conductive plate, 3h, 3i ... U-shaped folded portion, 3j, 3k ... movable contact, 4 ... electromagnet for operation, 5 ... Fixed iron core, 6 ... movable iron core, 8 ... electromagnetic coil, 9 ... return spring, 11 ... contactor holder, 12 ... contact spring, 13 ... stock 21a, 21b ... Flat conductor, 22a, 22b ... U-shaped groove, 23a, 23b ... Plate, 24a, 24b ... Fixed contact, 31a, 32b ... Through hole, 41 ... Power line, 42 ... Lightning arrester, 43 ... U-shaped folded part

Claims (3)

A contact mechanism having a movable contact and a fixed contact inserted in a current path,
The movable contact is formed on an opposing surface of the conductive plate supported by the movable portion, U-shaped folded portions formed at both ends of the conductive plate, and the fixed contact of the U-shaped folded portion. A contact point formed,
The fixed contact is disposed in parallel with the conductive plate portion so as to face the central portion of the U-shaped folded portion, and a pair of first contact members that contact the contact portion of the movable contact are formed. A conductive plate portion; and a second conductive plate portion extending opposite to the side portion of the U-shaped folded portion from the inner end on the other fixed contact side of the pair of first conductive plate portions. ,
When energized, the direction of the current flowing through the side of the U-shaped folded portion of the movable contact facing each other and the second conductive plate of the pair of fixed contacts is the same direction, the movable contact A contact mechanism characterized by generating a Lorentz force against an electromagnetic repulsion force in the opening direction generated between a fixed contact and the movable contact.   Each of the pair of fixed contacts has a flat conductor, and a U-shaped groove that opens the inner end is formed at the inner end of the flat conductor on the other fixed contact side. The contact mechanism according to claim 1, wherein an inner side of the groove is the first conductive plate portion and an outer side of the U-shaped groove is the second conductive plate portion.   An electromagnetic contactor comprising the contact mechanism according to claim 1, wherein the movable contact is connected to a movable iron core of an operating electromagnet, and the fixed contact is connected to an external connection terminal. .