JP2014197549A - Contact arrangement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contact arrangement capable of efficiently eliminating a contact repulsive force while preventing reduction of contact pressure acting on the contact points.SOLUTION: The contact arrangement includes: a fixed terminal 33 having fixed contact points 32; a movable contact 35 having movable contact points 34 which come into contact with and separate away from the fixed contact point 32; and a yoke 53. The yoke 53 is formed in a generally U shape in section having a base portion 53a facing to a plane on which the movable contact points 34 are formed on the movable contact 35, and a pair of extensions 53b which extend from both ends of the base portion 53a. The movable contact 35 is positioned between the pair of extensions 53b and each of the pair of extensions 53b is positioned in the vicinity of the movable contact 35.

Description

  The present invention relates to a contact device.

  Conventionally, as shown in FIG. 9, a fixed terminal 33 having a fixed contact 32, a movable contact 34 having a movable contact 34 contacting and separating from the fixed contact 32, and having an insertion hole 35b, and the insertion hole A movable shaft 37 having a shaft portion 37b that is movably inserted into the shaft 35b and a contact portion 37a that is provided at one end of the shaft portion 37b and restricts the movement of the movable contact 35 toward the fixed contact 32; A contact device composed of a contact pressure spring 36 that urges the child 35 toward the fixed contact 32 and an electromagnet block (drive means) 2 that drives the movable shaft 37 so that the movable contact 34 contacts and separates from the fixed contact 32. It has been known. Hereinafter, the description will be made with reference to the vertical and horizontal directions in FIG.

  The movable contact 35 is formed in a substantially rectangular shape, and a movable contact 34 is fixed to both left and right ends, and an insertion hole 35b is formed in a substantially center.

  The movable contact 35 whose movement to the fixed contact 32 side is regulated by the contact portion 37a of the movable shaft 37 moves toward the fixed contact 32 by the biasing force of the contact pressure spring 36 when the movable shaft 37 moves upward. The movable contact 34 comes into contact with the fixed contact 32, and the contacts are electrically connected.

  Here, in the above contact device, the movable contact 35 is repelled by the influence of the magnetic field generated from the fixed terminal 33 when the contacts are conducted or when a large current such as a short-circuit current flows between the contacts. Receives force in the direction (downward). Then, the contact pressure between the contacts decreases, and there is a possibility that the contacts are welded due to heat generated by the energization current.

  Further, when the movable contact 35 receives a larger contact repulsive force, the contact may open and abnormal heat may be generated.

  Therefore, as shown in FIG. 10, the yoke 46 is fixed to substantially the center of the upper surface of the movable contact 35 so that the yoke 46 and the movable contact 35 are integrated, and works between the movable contact 35 and the fixed contact 32. Some attempt to reduce the contact repulsion force (see, for example, Patent Document 1).

  More specifically, the movable contact 35 to which the yoke 46 is fixed is attracted in the diagonally upper right direction from the fixed terminal 33 on the right side as indicated by the arrow in FIG. The left fixed terminal 33 receives a suction force in the diagonally upward left direction.

  Therefore, the downward contact repulsive force acting on the movable contact 35 by the two diagonally upward suction forces is reduced.

JP 59-87711 A

  However, when the yoke 46 is fixed to the movable contact 35 as described above, since the attractive force acting on the movable contact 35 is an obliquely upward force, it is efficient to cancel the contact repulsive force (downward force). Unfortunately, there is a possibility that sufficient suction force cannot be obtained with respect to the contact repulsion force.

  The present invention has been made in view of the above reasons, and an object of the present invention is to provide a contact device that can efficiently cancel a contact repulsive force and prevent a decrease in contact pressure acting between the contacts.

  The invention of claim 1 includes a fixed terminal having a fixed contact, a movable contact having a movable contact contacting and separating from the fixed contact, and a yoke, and the yoke is provided with the movable contact in the movable contact. The movable portion is formed in a substantially U-shaped cross section from a base portion facing the formed surface and a pair of extended portions extending from both ends of the base portion, and the movable contact between the pair of extended portions. There is a child, and each of the pair of extending portions is close to the movable contact.

  According to a second aspect of the present invention, in the first aspect of the invention, a case for preventing the yoke from rotating is provided.

  According to a third aspect of the present invention, in the first aspect of the present invention, a case abutting on the outer periphery of the yoke is provided.

  The invention of claim 4 is the invention according to any one of claims 1 to 3, wherein a shaft portion inserted into an insertion hole formed in the movable contact, and one end of the shaft portion is provided on one end of the movable contact. And a contact portion for restricting movement toward the fixed contact side.

  According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the yoke is formed integrally with the shaft portion so as to serve as the contact portion.

  According to a sixth aspect of the invention, there is provided the contact pressure spring according to any one of the first to fifth aspects, wherein the movable contact is urged toward the fixed contact, and the contact pressure spring is not interposed through the yoke. The movable contact is biased.

  Another first invention of the present application relates to a fixed terminal having a fixed contact, a movable contact having a movable contact contacting and separating from the fixed contact, and a magnetic flux generated in the movable contact to attract to the movable contact. A yoke disposed so as to cancel the contact repulsive force that acts; and a contact pressure spring that urges the movable contact toward the fixed contact; and the contact pressure spring does not pass through the yoke. The yoke is formed into a flat plate shape.

  According to another second invention of the present application, a fixed terminal having a fixed contact, a movable contact contacting and separating from the fixed contact, a movable contact in which an insertion hole is formed, and the insertion hole are movably inserted. A movable shaft having an abutting portion that is provided at one end of the shaft portion and the shaft portion and restricts movement of the movable contact toward the fixed contact; a contact pressure spring that biases the movable contact toward the fixed contact; A driving means for driving the movable shaft so that the movable contact is in contact with and away from the fixed contact; and a yoke disposed opposite to the surface of the movable contact where the movable contact is provided. It also serves as a contact portion, and at least the movable contact and the yoke are accommodated in the case, and at least a part of the outer periphery of the yoke contacts the inner wall of the case.

  According to this invention, the yoke that is separate from the movable contact is provided so as to face the surface of the movable contact on which the movable contact is provided. An upward electromagnetic force that presses against the fixed contact side is generated, and a decrease in contact pressure between the contacts can be prevented. Further, according to the present invention, the number of parts can be reduced because one part serves as the function of the yoke and the function of the contact portion. Further, according to the present invention, it is not necessary to provide a separate part for stopping the rotation of the yoke, and an increase in the number of parts can be prevented.

  In the second aspect of the invention, the yoke is preferably formed in a flat plate shape.

  According to the present invention, since the yoke is formed in a flat plate shape, the distance from each point to the movable contact on the surface of the yoke facing the movable contact becomes substantially constant, and the electromagnetic acting on the movable contact The force can be made uniform.

  In the second aspect of the invention, the yoke has a substantially cross-section from a flat plate-like base portion facing the movable contact and a pair of extending portions extending from the end of the base toward the movable contact. It is preferably formed in a substantially U-shape.

  According to this invention, the upward electromagnetic force that presses the movable contact toward the fixed contact can be further increased, and a decrease in contact pressure between the contacts can be further prevented.

  In the second aspect of the invention, it is preferable that the yoke is formed integrally with the shaft portion so as to serve as a contact portion of the movable shaft.

  According to the present invention, the number of parts can be reduced because one part serves as the function of the yoke, the function of the contact part, and the function of the shaft part.

  Another third invention of the present application includes a fixed terminal having a fixed contact, a movable contact that contacts and separates from the fixed contact, a movable contact formed with an insertion hole, and is movably inserted into the insertion hole. A movable shaft having an abutting portion that is provided at one end of the shaft portion and the shaft portion and restricts movement of the movable contact toward the fixed contact; a contact pressure spring that biases the movable contact toward the fixed contact; And a drive means for driving the movable shaft so that the movable contact is in contact with and away from the fixed contact, and a yoke disposed to face the surface of the movable contact on which the movable contact is provided, at least the movable contact and the yoke Is housed in the case, and the yoke is characterized in that at least a part of the outer periphery abuts against the inner wall of the case.

  According to this invention, the yoke that is separate from the movable contact is provided so as to face the surface of the movable contact on which the movable contact is provided. An upward electromagnetic force that presses against the fixed contact side is generated, and a decrease in contact pressure between the contacts can be prevented. Further, according to the present invention, it is not necessary to provide a separate part for stopping the rotation of the yoke, and an increase in the number of parts can be prevented.

  As described above, in the present invention, when the contacts are conducted, a vertically upward electromagnetic force that presses the movable contact toward the fixed contact is generated, and a decrease in contact pressure between the contacts can be prevented. effective.

The perspective view of the contact device in Embodiment 1 is shown. The principal part enlarged view of the contact apparatus in the same as the above, and a general example are shown. Sectional drawing of the electromagnetic relay provided with the contact apparatus in the same as the above is shown. The external view of the case of the electromagnetic relay provided with the contact device in the same as above is shown. The disassembled perspective view of the electromagnetic relay provided with the contact apparatus in the same as the above is shown. The principal part sectional drawing of the electromagnetic relay provided with the contact apparatus in the same as the above is shown. The perspective view of the contact apparatus in Embodiment 2 is shown. The principal part enlarged view of the contact apparatus in the same as the above is shown. The front view of the contact device in a prior art example is shown. The front view of another form of the contact apparatus in a prior art example is shown.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
The contact device of this embodiment is demonstrated using FIG. However, the structure common to the prior art shown in FIG. Note that the description will be made with reference to the vertical and horizontal directions in FIG.

  The difference between the contact device in the present embodiment and the contact device of the conventional example shown in FIG. 10 is that the contact portion 52 in the movable shaft 5 of the present embodiment is formed from soft iron. That is, the contact part 52 has the function of the contact part and the function of the yoke. Hereinafter, the contact portion 52 is referred to as a yoke contact portion 52.

  Here, as shown in FIG. 2A, when a current flows through a conductor (movable contact 35) that is generally not provided with a yoke in the vicinity, the magnetic flux is concentrically formed with the center of the conductor as the center of the magnetic field. Occur. Therefore, in FIG. 2A, the number of magnetic fluxes from right to left in the conductor is substantially equal to the number of magnetic fluxes from left to right in the conductor, and no electromagnetic force is generated in the conductor.

  However, in the contact device of the present embodiment, when the contacts are conducted, as shown in FIG. 2B, the movable contact 35 is affected by the influence of the yoke contact portion 52 adjacent to the upper surface of the movable contact 35. The balance of the magnetic field generated around the child 35 is lost. More specifically, in FIG. 2 (b), most of the magnetic flux from right to left is attracted to the yoke contact portion 52, and the yoke is brought close to the movable contact 35 as shown in FIG. 2 (a). Compared with the case where it is not provided, the number of magnetic fluxes from the right to the left in the movable contact 35 decreases.

  On the other hand, in FIG. 2B, the magnetic flux from the left to the right moves upward as a whole, as compared with the case where the yoke is not provided near the movable contact 35 as shown in FIG. Thus, the number of magnetic fluxes from the left to the right in the movable contact 35 increases.

  Then, the upward electromagnetic force acting on the movable contact 35 by the magnetic flux from the left to the right in the movable contact 35 acts on the movable contact 35 by the magnetic flux in the movable contact 35 from the right to the left. It becomes larger than the downward electromagnetic force, and an upward electromagnetic force (attraction force) acts on the movable contact 35. That is, the movable contact 35 is subjected to a suction force toward the fixed contact 32 that is substantially parallel to the displacement direction of the movable contact 35 (vertically upward).

  Here, since the vertically upward suction force acting on the movable contact 35 is a force in the opposite direction to the contact repulsive force (downward force) generated on the movable contact 35, the contact repulsive force is It is the force that works in the direction of the most efficient cancellation.

  Therefore, in the contact device according to the present embodiment, the contact repulsive force can be efficiently canceled by the suction force, and the decrease in the contact pressure between the contacts can be reduced.

  Further, in the present embodiment, the yoke contact portion 52 has both functions of the yoke and the contact portion, and the yoke contact portion 52 and the shaft portion 51 are integrally molded to constitute the movable shaft 5. Is done. Therefore, one component (movable shaft 5) can function as a yoke, a contact portion, and a shaft portion, thereby reducing the number of components.

  In this embodiment, the yoke contact portion 52 and the shaft portion 51 are integrally molded. However, after the yoke contact portion 52 and the shaft portion 51 are separately molded, the yoke contact portion 52 is connected to the shaft portion. It may be formed integrally by inserting 51 or the like.

  The contact device of the present embodiment is used for an electromagnetic relay as shown in FIG. 3, for example.

  As shown in FIGS. 3 (a), 3 (b), 4 (a), 4 (b), and 5 (a) to 5 (c), the electromagnetic relay includes an electromagnetic block in a hollow box type case 4. (Drive means) The internal unit block 1 configured by integrally combining the contact block 2 and the contact block 3 is accommodated. In the following, the direction perpendicular to the up / down / left / right direction is defined as the front / rear direction with reference to the up / down / left / right direction in FIG.

  The electromagnet block 2 is formed of an insulating material and is fixed to a hollow cylindrical coil bobbin 21 around which the excitation winding 22 is wound, a coil terminal 23 connected to both ends of the excitation winding 22, and the coil bobbin 21 in the cylinder. The fixed iron core 24 magnetized by the energized excitation winding 22 and the fixed iron core 24 are arranged in the cylinder of the coil bobbin 21 so as to oppose each other in the axial direction of the coil bobbin 21 and according to whether the energization winding 22 is turned on or off. A movable iron core 25 that is attracted to the fixed iron core 24 and moves in the axial direction of the coil bobbin 21, a yoke 26 made of a magnetic material and surrounding the coil bobbin 21, and a movable iron core disposed in the cylinder of the coil bobbin 21. A return spring 27 that biases 25 downward is provided.

  The contact block 3 includes a sealing container 31 formed in a hollow box shape whose bottom surface is opened from an insulating material, and is formed in a substantially columnar shape and penetrates the top surface of the sealing container 31 so that the fixed contact 32 is provided on the bottom surface. A fixed terminal 33 provided with a movable contact 34 having a movable contact 34 that contacts and separates from the fixed contact 32, and a movable contact 35 that is in contact with the lower surface of the movable contact 35. The movable contact 35 is connected to the upper end of the contact pressure spring 36 for urging 35 toward the fixed contact 32, and the movable shaft 5 is connected to the movable iron core 25 at the lower end to interlock with the movement of the movable iron core 25.

  The coil bobbin 21 is formed of a resin material in a hollow cylindrical shape having flanges 21a and 21b formed at the upper and lower ends, and an excitation winding 22 is wound around the outer periphery of the cylindrical portion 21c. The inner diameter on the lower end side of the cylindrical portion 21c is larger than the inner diameter on the upper end side.

  As shown in FIG. 5 (c), the excitation winding 22 is connected to a pair of terminal portions 121 provided on the flange portion 21 a of the coil bobbin 21, and ends thereof are connected via lead wires 122 connected to the terminal portion 121. A pair of coil terminals 23 are connected to each other.

  The coil terminal 23 is formed of a conductive material such as copper, and is formed of a base portion 23a connected to the lead wire 122 by solder or the like, and a terminal portion 23b extending substantially vertically from the base portion 23a.

  As shown in FIG. 5B, the yoke 26 has a substantially rectangular plate-shaped first yoke plate 26 </ b> A disposed on the upper end side of the coil bobbin 21 and a substantially rectangular plate disposed on the lower end side of the coil bobbin 21. A plate-shaped second yoke plate 26B and a pair of third yokes 26C extending upward from the left and right ends of the second yoke plate 26B and connected to the first yoke plate 26A. Is done.

  And the recessed part 26a is formed in the upper surface side approximate center of the 1st yoke plate 26A, and the penetration hole 26c is formed in the approximate center of the said recessed part 26a. And the bottomed cylindrical cylindrical member 28 in which the collar part 28a is formed in the upper end is penetrated by the said insertion hole 26c, and the collar part 28a is joined to the recessed part 26a. Here, on the lower end side in the cylindrical portion 28b of the cylindrical member 28, the movable iron core 25 formed in a substantially columnar shape from a magnetic material is disposed, and further, the cylindrical portion 28b is formed in a substantially columnar shape from a magnetic material. The fixed iron core 24 is inserted, and the fixed iron core 24 and the movable iron core 25 are arranged to face each other.

  Further, on the upper surface of the first yoke plate 26A, a peripheral portion is fixed to the first yoke plate 26A, and a convex portion that forms a space for accommodating the flange portion 24a formed at the upper end of the fixed iron core 24 at the approximate center. A cap member 45 made of a metal provided with 45 a is provided, and the cap member 45 prevents the fixed iron core 24 from coming off.

  A cylindrical bush 26D made of a magnetic material is fitted into a gap formed between the inner peripheral surface on the lower end side of the coil bobbin 21 and the outer peripheral surface of the cylindrical member 28, and the yoke 26 and A magnetic circuit is formed together with the fixed iron core 24 and the movable iron core 25.

  The return spring 27 is inserted through an insertion hole 24 b formed in the axial direction of the fixed iron core 24, the lower end is in contact with the upper surface of the movable iron core 25, and the upper end is in contact with the lower surface of the cap member 45. Further, the return spring 27 is provided in a compressed state between the movable iron core 25 and the cap member 45, and elastically biases the movable iron core 25 downward.

  The movable shaft 5 includes a shaft portion 51 formed in the shape of a long round bar that is vertically long from a nonmagnetic material, and a hook-shaped contact portion 52 that is integrally formed with the shaft portion 51 at the upper end of the shaft portion 51. Consists of

  The shaft portion 51 is inserted through the insertion hole 45 b formed at the approximate center of the convex portion 45 a of the cap member 45 and the return spring 27, and the screw portion 51 a formed at the lower end portion is formed in the axial direction of the movable core 25. The movable iron core 25 is connected by being screwed into the screw hole 25a.

  The contact part 52 is formed in a substantially rectangular flat plate shape from soft iron, and restricts the movement of the movable contact 35 toward the fixed contact 32. That is, the contact portion 52 has a function of a contact portion that restricts the movement of the movable contact 35 and a function of a yoke. Hereinafter, the contact portion 52 is referred to as a yoke contact portion 52.

  In the movable contact 35, the movable shaft 5 is inserted into an insertion hole 35b formed in a substantially center with the movable contact 34 fixed to the left and right ends of the main body 35a formed in a substantially rectangular shape.

  The fixed terminal 33 is formed in a substantially cylindrical shape using a conductive material such as copper, a flange 33a is formed at the upper end, and a fixed contact 32 facing the movable contact 34 is fixed to the lower surface. A screw hole 33b is formed in the axial direction from the upper surface of the fixed terminal 33, and a screw portion such as an external load (not shown) is screwed into the screw hole 33b to be connected.

  The sealing container 31 is formed in a hollow box shape whose bottom surface is opened from a heat-resistant material such as ceramic, and two through holes 31a through which the fixed terminals 33 are provided are arranged in parallel on the top surface. And the fixed terminal 33 is penetrated by the through-hole 31a in the state which made the collar part 33a protruded from the upper surface of the sealing container 31, and is joined by brazing. 5A, one end of the flange 38 is joined to the opening periphery of the sealing container 31 by brazing. The sealed container 31 is sealed by joining the other end of the flange 38 to the first yoke plate 26A by brazing.

  Furthermore, an insulating member 39 for insulating an arc generated between the fixed contact 32 and the movable contact 34 from the joint between the sealing container 31 and the flange 38 is provided at the opening of the sealing container 31. ing.

  The insulating member 39 is formed in a substantially hollow rectangular parallelepiped shape having an upper surface opened from an insulating material such as ceramic or synthetic resin, and a convex portion 45a of the cap member 45 is formed in a concave portion in a rectangular frame 39a formed at a substantially central portion of the lower surface. Mated. Further, since the upper end side of the peripheral wall of the insulating member 39 is in contact with the inner surface of the peripheral wall of the sealing container 31, it is possible to join the sealing container 31 and the flange part 38 from the contact part including the fixed contact 32 and the movable contact 34. Insulating parts.

  Further, a circular frame 39c having an inner diameter substantially the same size as the inner diameter of the contact pressure spring 36 is formed at the approximate center of the inner bottom surface of the insulating member 39, and the movable shaft 5 is inserted through the approximate center of the circular frame 39c. An insertion hole 39b is formed. And the displacement of the contact pressure spring 36 is prevented by fitting the lower end portion of the contact pressure spring 36 through which the movable shaft 5 is inserted into the recess in the circular frame 39c.

  In addition, the contact spring 36 is provided in a compressed state between the insulating member 39 and the movable contact 35 with its upper end abutting against the lower surface of the movable contact 35, so that the movable contact 35 is placed on the fixed contact 32 side. It is elastically biased to the back.

  The case 4 is formed of a resin material in a substantially rectangular box shape, and includes a hollow box-type case main body 41 having an open upper surface, and a hollow box-type cover 42 covering the opening of the case main body 41.

  The case main body 41 is provided with a protrusion 141 formed with an insertion hole 141a used for fixing the electromagnetic relay to the mounting surface by screwing at the front ends of the left and right side walls. Further, a step portion 41 a is formed at the opening periphery of the upper end side of the case body 41, and the outer periphery is smaller than the lower end side. A pair of slits 41b into which the terminal portion 23b of the coil terminal 23 is fitted is formed on the front surface above the step portion 41a. Further, a pair of concave portions 41c are arranged in the left-right direction on the rear surface above the step portion 41a.

  The cover 42 is formed in a hollow box shape with an open bottom surface, and a pair of protrusions 42 a that fit into the recesses 41 c of the case body 41 when assembled to the case body 41 are formed on the rear surface. A partition 42c is formed on the upper surface of the cover 42 to divide the upper surface into two substantially right and left, and a pair of insertion holes 42b through which the fixed terminals 33 are inserted are formed on the upper surface divided into two by the partition 42c. It is formed.

  As shown in FIG. 5 (c), when the inner unit block 1 including the electromagnet block 2 and the contact block 3 is stored in the case 4, the flange 21 b at the lower end of the coil bobbin 21 and the bottom surface of the case main body 41 A substantially rectangular lower cushion rubber 43 is interposed between the upper cushion rubber 44 and an insertion hole 44a through which the flange 33a of the fixed terminal 33 is inserted between the sealing container 31 and the cover 42. Interpose.

  In the electromagnetic relay configured as described above, since the return spring 27 has a higher spring coefficient than the contact pressure spring 36, the movable iron core 25 slides downward by the urging force of the return spring 27, and accordingly the movable shaft 5 also moves downward. As a result, the movable contact 35 moves downward as the contact portion 52 of the movable shaft 5 moves, so that the movable contact 34 is provided in a state of being separated from the fixed contact 32 in the initial state.

  When the exciting winding 22 is energized, the movable iron core 25 is attracted to the fixed iron core 24 and slides upward, so that the movable shaft 5 connected to the movable iron core 25 also moves upward in conjunction with it. As a result, the contact portion 52 of the movable shaft 5 moves to the fixed contact 32 side, and the movable contact 35 also moves to the fixed contact 32 side by the biasing force of the contact pressure spring 36, so that it is fixed to the movable contact 35. The movable contact 34 is brought into contact with the fixed contact 32 so that the contacts are electrically connected.

  Here, in the electromagnetic relay, the yoke contact portion 52 of the movable shaft 5 comes close to the upper surface of the movable contact 35 when the contacts are conducted. Then, as described in FIG. 2B, the balance of the magnetic field generated around the movable contact 35 is lost, and the movable contact 35 has a vertically upward direction substantially parallel to the displacement direction of the movable contact 35. The suction force works.

  Therefore, even when a contact repulsive force acts between the contacts, the movable contact 35 has a suction force in the direction opposite to the contact repulsive force by 180 degrees, so that the contact repulsive force can be canceled out efficiently. A decrease in contact pressure can be prevented.

  Further, since the yoke contact portion 52 is formed in a substantially flat plate shape, the distance from each point on the surface of the yoke contact portion 52 facing the movable contact 35 to the movable contact 35 becomes substantially constant. The suction force acting on the movable contact 35 can be made substantially uniform.

  When the energization of the excitation winding 22 is turned off, the movable iron core 25 slides downward by the urging force of the return spring 27, and the movable shaft 5 also moves downward accordingly. Therefore, the abutting portion 52 moves downward and the movable contact 35 also moves downward, so that the fixed contact 32 and the movable contact 34 are separated from each other, and the contact is interrupted.

  As shown in FIG. 6, the abutting portion 52 is provided with its front end and rear end abutting against the inner wall of the case 4, thereby receiving a rotational force in the winding direction of the contact pressure spring 36. Even in this case, rotation is prevented without providing additional parts. Here, in the present embodiment, the front end and the rear end of the contact portion 52 are in contact with the inner wall of the case 4, but only a part of the contact portion 52 is in contact with the inner wall of the case 4. May be prevented from rotating.

  In the present embodiment, the contact portion 52 is made of soft iron and is used as a yoke contact portion having both functions of the contact portion and the yoke. A yoke may be provided separately from a nonmagnetic material. In that case, the yoke is provided substantially at the center of the pair of fixed terminals 33 and substantially opposite to the axis of the movable shaft.

(Embodiment 2)
The contact device of this embodiment will be described with reference to FIG. The contact device according to the present embodiment and the contact device according to the first embodiment are different only in the shape of the yoke contact portion 53 of the movable shaft 5, and the structures common to the first embodiment are denoted by the same reference numerals. Description is omitted. The description will be made with reference to the vertical and horizontal directions in FIG.

  As shown in FIG. 7, the yoke contact portion 53 of the present embodiment includes a substantially rectangular flat plate-like base portion 53a and a pair of extending portions 53b extending downward from both front and rear ends of the base portion 53a. It is formed in a substantially U-shaped cross section.

  When the contacts are conducted, the lower surface of the base 53a of the yoke contact portion 53 is close to the upper surface of the movable contact 35, and the pair of extending portions 53b are the front end and the rear end of the movable contact 35, respectively. Proximity to.

  Then, as shown in FIG. 8, the balance of the magnetic field generated around the movable contact 35 is lost due to the influence of the yoke contact portion 53 adjacent to the upper surface and the front and rear ends of the movable contact 35. More specifically, in FIG. 8, most of the magnetic flux from the right to the left in the movable contact 35 is attracted to the yoke contact portion 53, and the flat yoke contact portion shown in FIG. Compared with the case where 52 is provided in the vicinity of the movable contact 35, the number of magnetic fluxes from the right to the left in the movable contact 35 is further reduced.

  On the other hand, in FIG. 8, the magnetic flux from the left to the right inside the movable contact 35 moves upward as a whole, and the flat yoke contact portion 52 shown in FIG. The number of magnetic fluxes from the left to the right in the movable contact 35 is further increased compared to the case where the magnetic flux is provided in the vicinity of.

  Then, an upward electromagnetic force acting on the movable contact 35 by the magnetic flux moving from left to right in the movable contact 35 acts on the movable contact 35 by the magnetic flux moving from right to left in the movable contact 35. Compared with the downward electromagnetic force, the movable contact 35 is subjected to a large vertically upward electromagnetic force (attraction force) substantially parallel to the displacement direction of the movable contact 35.

  Here, since the vertically upward suction force acting on the movable contact 35 is a force in the opposite direction to the contact repulsive force (downward force) generated on the movable contact 35, the contact repulsive force is It is the force that works in the direction of the most efficient cancellation.

  Therefore, in the contact device of the present embodiment, a larger upward suction force is generated in the movable contact 35 than in the first embodiment, and the decrease in the contact pressure between the contacts can be further prevented.

  In the present embodiment, the yoke contact portion 53 has both functions of the yoke and the contact portion, and the yoke contact portion 53 and the shaft portion 51 are integrally formed so that the movable shaft 5 is formed. Composed. Therefore, one component (movable shaft 5) can function as a yoke, a contact portion, and a shaft portion, thereby reducing the number of components.

  As shown in FIG. 7, the contact portion 53 is provided with a pair of extending portions 53 b in contact with the inner wall of the case 4, so that the rotational force of the contact pressure spring 36 in the winding direction of the spring, etc. Even if it receives, rotation is prevented without providing a separate component. In the present embodiment, the pair of extending portions 53b are both in contact with the inner wall of the case 4, but only one of the extending portions 53b is in contact with the inner wall of the case 4 so that the contact portion 53 rotates. It may be prevented.

  In the present embodiment, the yoke contact portion 53 and the shaft portion 51 are integrally molded. However, after the yoke contact portion 53 and the shaft portion 51 are separately molded, the yoke contact portion 53 has a shaft portion. It may be formed integrally by inserting 51 or the like.

  In the present embodiment, the yoke contact portion 53 is made of soft iron and is used as a yoke contact portion having both functions of the contact portion and the yoke. May be formed from a non-magnetic material and a yoke may be provided separately. In that case, the yoke is provided substantially at the center of the pair of fixed terminals 33 and substantially opposite to the axis of the movable shaft.

2 Electromagnet block (drive means)
4 Case 5 Movable shaft 32 Fixed contact 33 Fixed terminal 34 Movable contact 35 Movable contact 35b Insertion hole 36 Contact pressure spring 51 Shaft portion 52 Contact portion (Yoke contact portion)

Claims (6)

A fixed terminal having a fixed contact;
A movable contact having a movable contact contacting and separating from the fixed contact;
With a yoke,
The yoke is formed in a substantially U-shaped cross section from a base portion that faces the surface of the movable contact on which the movable contact is provided and a pair of extended portions that extend from both ends of the base portion. The contact device is characterized in that the movable contact is between the pair of extending portions, and each of the pair of extending portions is close to the movable contact.   The contact device according to claim 1, further comprising a case for preventing the yoke from rotating.   The contact device according to claim 1, further comprising a case that contacts the outer periphery of the yoke.   A shaft portion that is inserted through an insertion hole formed in the movable contact, and a contact portion that is provided at one end of the shaft portion and restricts movement of the movable contact toward the fixed contact. The contact device according to claim 1.   The contact device according to claim 4, wherein the yoke is formed integrally with the shaft portion also serving as the contact portion. A contact pressure spring that biases the movable contact toward the fixed contact;
The contact device according to claim 1, wherein the contact pressure spring biases the movable contact without passing through the yoke.

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