JP7613090B2 - Contact opening/closing mechanism and electromagnetic relay equipped with same - Google Patents

Description

The present invention relates to a contact opening and closing mechanism and an electromagnetic relay, particularly a power relay, that is equipped with this contact opening and closing mechanism.

Conventionally, electromagnetic relays have been used that include, for example, the following (1) to (4): (1) an electromagnet block; (2) a movable iron piece (armature) that swings in response to the excitation and de-excitation of the electromagnet block; (3) a leaf-spring-like movable contact piece that swings in response to the oscillation of the movable iron piece, a movable contact located on the free end side of the movable contact piece; and (4) a fixed terminal member that has, at one end, a fixed contact with which the movable contact comes into contact and is separated in response to the oscillation.

In particular, electromagnetic relays are used that have a pair of movable contacts (a pair of left and right contacts) on the free end of one movable contact piece, or on the free ends of two movable contact pieces driven by one movable iron piece. The pair of left and right movable contacts simultaneously make contact with and separate from the corresponding pair of left and right fixed contacts, thereby turning the output circuit on and off.

Typically, a pair of left and right movable contacts are electrically connected to each other through a movable terminal member that includes at least a part of the movable contact piece. These movable contacts are then pressed against and contacted with the corresponding fixed contacts, thereby electrically connecting the pair of left and right fixed terminal members to each other. In other words, when a pair of left and right contact opening/closing parts arranged close to each other are simultaneously in a contact (closed) state, the output side circuit of the electromagnetic relay is turned on.

The left-right direction here refers to the left-right direction when, for example, the contact opening/closing part is located on the front side (forward side) and the axis of the swinging movement of the movable iron piece is horizontal. In this case, the electromagnet block is located on the rear side.

In such electromagnetic relays, efforts have been made to suppress the arc that occurs when the movable contact is separated from the fixed contact.

For example, there is a contact opening and closing mechanism in which a protruding piece is formed on either the left or right end of a leaf spring-shaped movable contact piece to terminate the extension of the arc (see, for example, Patent Document 3). Another contact opening and closing mechanism is one in which an arc runner conductor is attached to a fixed terminal member, and a protrusion is further provided on this arc runner conductor, so that the arc generated between the movable contact and the fixed contact when the contacts are separated (opened) is diverted between the tip of the movable contact piece and the protrusion (see, for example, Patent Document 4).

These conventional techniques have problems in that the width of the electromagnetic relay in the left-right direction increases (Patent Document 3) or the material cost of the fixed terminal member increases (Patent Document 4). Therefore, it has been proposed to provide a space for arc elimination behind the contact opening and closing part (Patent Document 1). Specifically, a pair of left and right movable contact pieces are connected to one movable iron piece, and a pair of left and right movable contacts are provided at the free end (movable terminal part) of each movable contact piece. Since fixed contacts are provided corresponding to these movable contacts, a total of four contact opening and closing parts are provided aligned in the left-right direction. And the space for arc elimination (corresponding to reference symbol 19 in Figure 1 of this application) is provided only behind each of the two contact opening and closing parts located on the outside in the left-right direction.

On the other hand, it has been proposed to extend the free end of the movable contact piece beyond the movable contact and then bend it towards the fixed contact, so that the arc is extinguished early through the bent tip (corresponding to reference symbol 7D in Figures 7 to 9 of this application) (Patent Document 2). Here, the movable contact piece and the fixed terminal member are both supported in close proximity by a resin support member (base). The free end of the movable contact piece is then pressed from the movable iron piece side, bringing the movable contact into contact with the fixed contact.

Patent No. 6365684 (PCT/JP2015/071277) Japanese Patent No. 5923932 (JP 2013-98126 A) JP 2006-196372 A JP 2010-170876 A

While the inventors were diligently studying ways to reduce the occurrence of arcs, they noticed that restrikes could occur immediately after the drive input to the electromagnet block was stopped and the contact opening/closing section was opened (opened; separated), and they investigated the cause of this. They discovered that the force of the free end of the movable contact piece separating from the fixed contact and returning to its original position causes an overshoot, swing back, or bounce, which results in the pair of left and right movable contacts approaching the corresponding fixed contacts again.

The present invention was made based on the discovery of one such mechanism of arc generation and the discovery of this new problem, and aims to suppress the occurrence of restrike that occurs when the contact switching mechanism is switched to the OFF state.

In a preferred embodiment, the contact opening and closing mechanism includes: (1) a drive transmission section whose position and posture (at least one of the position and posture) is switched in accordance with whether the actuator is driven or not; (2) a spring-like movable contact piece or a movable terminal section that receives a spring force, whose position and posture is switched in accordance with the switching of the position and posture of the drive transmission section; (3) a pair of left and right movable contacts that are located on the free end side of the movable contact piece or on the movable terminal section, are electrically connected to each other, and are arranged in close proximity to each other; (4) a pair of left and right fixed contacts that come into contact with and separate from each other in accordance with the switching of the position and posture of the movable contact piece; (5) fixed terminal sections on which the left and right fixed contacts are respectively arranged; and (6) a step generating mechanism that causes one of the left and right movable contacts and the other of the left and right movable contacts to be stepped in terms of distance from the corresponding fixed contact when the actuator is switched to the off state and the pair of left and right movable contacts move away from the pair of left and right fixed contacts and approach the pair of left and right fixed contacts again by bouncing or swinging back. In a preferred embodiment, the electromagnetic relay includes such a contact opening and closing mechanism and an electromagnetic actuator.

In a preferred embodiment, the step generating mechanism is a stopper provided on the opposite side of the movable contacts from the fixed contacts. In other words, it is a fixed member that is arranged so that it can abut against the movable contacts to regulate the distance that the pair of left and right movable contacts can move away from the pair of left and right fixed contacts when the actuator is switched to the off state. This stopper is arranged so that it can abut against the pair of left and right movable contacts at positions that are spaced apart from the pair of left and right fixed contacts by different distances.

The stopper may be positioned so that it abuts only one of the movable contacts, the left or right (pair). Also, instead of making the position of the abutment surface of the stopper (the distance from the fixed contact) different between the left and right (between the left and right of the pair), or in addition to making them different between the left and right, the protruding dimension of the part of the movable contact piece that abuts against the stopper towards the stopper may be made different between the left and right. Furthermore, the mass of the part of the movable contact piece near the movable contact, or the support structure for the part near the movable contact, may be made different between the left and right.

In a preferred embodiment, the stopper and/or the protruding portion on the side of the movable contact piece (i.e., at least one of these) has spring properties or cushioning properties that absorb vibrations.

In a preferred embodiment, the actuator is made up of an electromagnet block and a movable iron piece that swings in response to the excitation and de-excitation of the electromagnet block. The drive transmission unit is made up of the movable iron piece, a generally flat resin member (spacer/retaining member) that is superimposed on the movable iron piece, and a metal leaf spring-like movable contact piece that is assembled to the resin member. Here, the movable iron piece is provided with a spring for returning it to the de-excited position/posture. In addition, a movable terminal portion is provided near the free end of the movable contact piece.

In another preferred embodiment, the actuator is a plunger type actuator that uses a solenoid or a piezoelectric element. In this case, the plunger forms the drive transmission part, and a pair of movable contacts is provided on a single movable terminal member in the form of a flat, elongated piece. A coil-shaped return spring can be provided on the side of this movable terminal member opposite the fixed contacts.

When multiple movable contact pieces are driven by one actuator and a pair of left and right movable contacts are arranged at the free end of each movable contact piece, the distances of each of the multiple pairs of movable contacts from the corresponding fixed contact can be made to be different from each other.

When the movable contact and the fixed contact are separated, i.e., when the contact opening/closing part is open (open; separated), it is possible to prevent or suppress restrike.

1A and 1B are a perspective view and a cutaway perspective view of the electromagnetic relay of the first embodiment, showing the appearance and main parts of the electromagnetic relay when a cover is removed; FIG. 2 is a horizontal cross-sectional perspective view of a main part of the electromagnetic relay of the first embodiment. 2A to 2C are a series of schematic horizontal cross-sectional views of essential parts for explaining the key points of the operating mode of the electromagnetic relay of the first embodiment. 1A to 1C are a series of schematic horizontal cross-sectional views of essential parts for explaining in more detail the operating mode of the electromagnetic relay of the first embodiment in comparison with that of the prior art. 3A to 3C are a series of horizontal cross-sectional views of essential parts, each of which is a schematic view of modified embodiments 1 to 7, similar to FIG. 2A. 2A to 2C are a series of horizontal cross-sectional views of essential parts of modified embodiments 8 to 11, each of which is shown in a schematic manner similar to FIG. FIG. 11 is a schematic side view of an electromagnetic relay according to a second embodiment. FIG. 11 is a perspective view showing a movable contact piece of an electromagnetic relay according to a second embodiment. FIG. 11 is a perspective view showing a contact opening and closing portion of an electromagnetic relay according to a second embodiment. 5 is a schematic horizontal cross-sectional view (left half) of a main part similar to FIG. 2 and a schematic vertical cross-sectional view (right half) of a main part for explaining the main points of the operating mode of an electromagnetic relay of embodiment 2. FIG. FIG. 12 is a schematic horizontal cross-sectional view of a main portion similar to FIG. 2, for explaining the main points of the operation mode of a modified embodiment (modified embodiment 12) from embodiment 2. 11 is a schematic horizontal cross-sectional view (left half) of a main portion similar to FIG. 2 and a schematic vertical cross-sectional view (right half) of a main portion for explaining the main points of the operating mode of an electromagnetic relay of embodiment 3. FIG. FIG. 11 is a schematic cutaway side view showing a more detailed structure of a main part of an electromagnetic relay according to a third embodiment.

<Embodiment 1>
The electromagnetic relay of the first embodiment will be described with reference to Figures 1 and 2. Figure 1 shows a perspective view of the exterior of the relay when a rectangular parallelepiped cup-shaped cover is removed, and a cutaway perspective view of an enlarged essential portion. Figure 2 shows a horizontal cross-sectional perspective view of the essential portion.

Embodiment 1 is based on the electromagnetic relay disclosed in Patent Document 3, to which the improvements of the present invention have been added. In the explanation of embodiments 1 and 2, the base 10 is located on the lower side, the electromagnet block 40 is located on the rear side, and the contact opening and closing point is located on the front side (forward side). However, this is unrelated to the arrangement when actually used.

The electromagnetic relay 101 of the first embodiment includes a rectangular, generally flat resin base 10, an electromagnet block 40 attached to the rear region of the base, a rectangular, flat movable iron piece 60 arranged in front of the electromagnet block 40, a generally flat movable card member 70 made of resin and assembled by superimposing on the movable iron piece 60, a movable resin plate 5D assembled by superimposing on the movable card member 70, a metal leaf spring-like movable contact piece 5 with its base side (upper side) end embedded in the movable resin plate 5D, a movable terminal portion 3 formed at the tip portion on the lower side of the movable contact piece 5, and fixed terminal members 21 to 24 that penetrate the resin base 10 vertically along the front edge of the resin base 10. The upper ends of the fixed terminal members 21 to 24 are the fixed terminal portion 2.

A contact opening/closing point is formed along the front edge of the resin base 10 where the fixed terminal 2 and the corresponding movable terminal 3 come into contact with and separate from each other. When the electromagnet block 40 is not driven and is in a non-excited state (static state), the movable iron piece 60 is in a slightly bounced up state (inclined state) due to the action of the return spring 6, and the movable terminal 3 is pulled away from the fixed terminal 2. In the illustrated example, the horizontal part of the yoke 55 forms the ceiling of the electromagnet block 40, and the upper end of the movable iron piece 60 is combined with its front end so that it can be bounced up (raised and lowered). A coil spring-shaped return spring 6 is arranged along the upper surface of the horizontal part of the yoke 55.

When the electromagnet block 40 is driven in an excited state (stationary state), the movable iron piece 60, which was in an inclined state, is attracted to the magnetic pole formed in front of the electromagnet block 40 and becomes almost vertically erected (non-inclined state). As a result, the movable contact piece 5 is swung backward, and the movable terminal part 3 at its tip is pressed against the fixed terminal part 2. At this time, a spring force is applied due to the deformation of the leaf spring part 5A of the movable contact piece 5.

The movable terminal portion 3 is a flat plate with an elongated oval shape (racetrack shape) that is long in the left-right direction and is provided with a pair of left and right movable contacts 3A and 3B, which are electrically connected to each other. A pair of left and right fixed contacts 2A and 2B that come into contact with and separate from the pair of left and right movable contacts 3A and 3B are provided on a pair of left and right fixed terminal members 21 and 22, respectively. The parts at the lower ends of the fixed terminal members 21 and 22 that protrude downward from the resin base 10 are input/output terminals in the output side circuit of the electromagnetic relay 101. Note that, behind these, input/output to and from the opening/closing control side circuit that drives the electromagnet block 40 is performed through a pair of coil terminals 25 that vertically penetrate the resin base 10.

The resin base 10 is provided with a handrail wall 11 integrally along the periphery of the upper surface. This handrail wall 11 is useful for attaching a rectangular cup-shaped cover (not shown), but also serves as a stopper that restricts the forward movement of the movable terminal part 3. The stopper can also be formed by a separate resin member attached to the inside surface of the handrail wall 11.

As shown in Figures 1 and 2, a pair of left and right stoppers 1A and 1B are formed to protrude inward from the inner surface of the handrail wall 11 in correspondence with a pair of left and right movable contacts 3A and 3B. Here, these left and right stoppers 1A and 1B each have a flat stopper surface that extends vertically, and this stopper surface is inclined from the left and right direction. In particular, these left and right stoppers 1A and 1B are formed so that they protrude inward to different heights, that is, so that the positions of the stopper surfaces in the front-to-rear direction are staggered.

Before describing the details of the electromagnetic relay 101 shown in Figures 1 and 2, the effects obtained by each embodiment of the present application will be described using the schematic diagrams in Figures 3 and 4.

As shown in FIG. 3A, in the initial non-operated state, i.e., when stationary and not energized, the movable terminal portion 3 is close to the stopper surface at one of the left and right ends, and is sufficiently separated from the stopper surface at the other left and right end. Then, immediately after the power supply to the electromagnetic relay 10 is switched off (de-energized), the spring action of the main body portion 5A of the movable contact piece 5 and the action of the return spring 6 quickly return it to the initial, stationary position and posture.

However, at this time, as shown in FIG. 3B, overshooting can occur. In other words, when viewed from the fixed terminal portion 2, it swings to a position slightly farther than the initial, stationary state. In each embodiment of the present application, the pair of left and right stoppers 1A and 1B that regulate this overshoot have stopper surface positions that are staggered relative to the position of the fixed terminal 2. Therefore, when maximum overshooting occurs, the movable terminal portion 3 tilts so that it shifts forward and backward toward the left and right.

Figure 4 shows the schematic effects of the present embodiment in comparison with those of the prior art. When power is supplied to the electromagnet block 40, the movable and fixed contacts are in contact with each other (contact on state), and then power supply to the electromagnet block 40 is stopped, the swinging movement of the movable terminal portion 3 temporarily goes into an overshoot state, as described above. Then, when the metallic movable terminal portion 3 hits the stoppers 1A and 1B made of non-elastomeric resin, it bounces back as shown in the broken line box. The bounce at this time occurs almost simultaneously on the left and right. Note that there may be cases where the stopper 1B is not hit on one of the left and right sides (the right side of the figure) and no bounce actually occurs. However, even in this case, the left and right parts of the movable terminal portion 3 can be switched almost simultaneously to a movement away from the fixed contact, or to a movement toward the fixed contact from a temporary almost stationary state.

Because the positions of the left and right stoppers 1A and 1B are staggered, the stroke when the stopper surface is struck is larger on one side than on the other side, and the impact of the collision is also larger. As a result, as shown in the dashed box in FIG. 4, the bounce is also larger on one side. Therefore, when the movable contact approaches the fixed terminal part 2 again after bouncing, the left and right sides are also staggered. As a result, the distance between one movable contact and the corresponding fixed contact (contact separation distance) is larger on either the left or right side when they approach each other again due to the bounce. In this way, when the contact separation distance becomes sufficiently large at either the left or right contact opening and closing point, the generation of current through the movable terminal part 3 is suppressed. Therefore, the generation of an arc can be suppressed. In other words, the occurrence of re-arcing that may occur when the opening and closing control circuit is turned off can be suppressed.

In contrast, in the conventional technology shown in the right half of FIG. 4, the stopper surface of the stopper 1 does not have a slope or step in the left-right direction, but is a single plane extending in the left-right direction. Therefore, the rear parts of the left and right movable contacts 3A and 3B hit the stopper surface simultaneously and with the same stroke during overshoot. As a result, the left and right bounce simultaneously and to the same extent. Therefore, as shown in the dashed box in the right half of FIG. 4, the contact separation distance when approaching the fixed terminal part 2 again after bouncing is smaller than the larger contact separation distance on the left or right side in the present embodiment. As a result, re-ignition is more likely to occur than in the present embodiment shown in the left half of FIG. 4. The same applies when the stopper 1 is not provided. Specifically, if the handrail wall 11 is positioned farther away and is arranged so that it is not hit even during overshoot, no bounce due to collision occurs. However, the movement is almost the same. In other words, after the overshoot, the left and right parts of the movable terminal portion 3 almost simultaneously move away from the fixed contact, or switch from a temporary, almost stationary state to a movement toward the fixed contact.

Next, we will explain the structure and features in more detail, as shown in Figures 1 and 2 of this application.

The movable contact piece 5 is inverted T-shaped and mainly consists of a T-shaped main body member formed by punching out a single metal plate. As shown in FIG. 2, this main body member consists of a rectangular leaf spring portion 5A extending downward from the root portion in the movable resin plate 5D, and a terminal base portion 5B at the tip. Also, as shown in FIG. 2, a backing plate 5C that is thicker than the terminal base portion 5B and has the same contour is superimposed on the terminal base portion 5B. This backing plate 5C is made of metal or other conductive material and reduces the conductive resistance in the movable terminal portion 3. In order to configure the movable terminal portion 3, in addition to the terminal base portion 5B and the backing plate 5C, a contact rivet 4 is assembled at the left and right movable contacts 3A and 3B. The rivet head 4A forms the contact, and the rivet foot 4C is formed by expanding the tip portion of the rivet body portion 4B (shown only in "Modified embodiment 4" in FIG. 5) by crimping. In the illustrated example, the contact surface of the rivet head 4A is flat and circular.

On the other hand, the fixed terminal portion 2 is formed by assembling a contact rivet 4 similar to that described above to the upper end portion of the fixed terminal members 21, 22 for each fixed contact 2A and 2B.

As shown in Figs. 1 and 2, the electromagnetic relay 101 of this embodiment is configured almost symmetrically, and the same movable contact piece 5 and fixed terminal members 21-22 and 23-24 are provided on the left and right. Therefore, stoppers 1C and 1D exactly the same as the stoppers 1A and 1B described above are also provided on the opposite left and right sides. In this embodiment, as shown in Fig. 2, a thick plate-shaped first permanent magnet 30 for extending the arc is arranged behind the fixed terminal part 2 (the upper end of the fixed terminal members 21 and 24) located on the left and right outer side, and an auxiliary yoke 31 is arranged on the left and right outer side. A second permanent magnet 32 is arranged in the front center between the left and right contact opening and closing points. In addition, an arc elimination space 19 is formed between the first permanent magnet 30 and a cover (not shown) by a partition wall 12 extending upward from the resin base 10 in an L-shaped material shape behind the first permanent magnet 30.

The resin base 10 can be formed integrally, including the handrail wall 11 and the partition wall 12, from polyolefin or PPS resin by injection molding or the like. For this reason, it can be advantageous in terms of manufacturing to design the stoppers 1A and 1B so that they protrude inward from the handrail wall 11 and extend vertically. In the specific example shown in Figures 1 and 2, the storage sections 17, 18 that store the permanent magnets 30, 31 can be formed in a cup-like shape recessed from the underside.

<Modified embodiments 1 to 11>
Next, modified embodiments 1 to 11 shown typically in FIGS. 5 and 6 will be described.

Variations 1 to 4 shown in the left half of Figure 5 are as follows:

<Modified embodiment 1>
Of the pair of left and right stoppers 1A and 1B in the first embodiment, stopper 1B is omitted and only stopper 1A is provided. Note that the left and right position of stopper 1A only needs to be offset to the left or right from the left and right center of gravity of movable terminal portion 3.

<Modified embodiment 2>
As a further modification of the modified embodiment 1, the stopper 1A can be formed by (i) a protrusion from the handrail wall 11 having a semicircular or semi-elliptical cross section, or (ii) a rod-shaped protrusion extending upward from the bottom surface of the resin base 10 having a circular or elliptical cross section, or (iii) a member having such a shape that is separately assembled to the resin base 10. By forming the stopper surface round in this way, it is possible to prevent or suppress the corners of the stopper 1A from being scraped when the plate-shaped movable terminal part 3 is abutted against it. In addition, when the stopper 1A is formed by a member separate from the resin base 10, for example, a metal wire or a fishing line (thick filament thread) can also be used. On the other hand, as described here, the parts and members forming each stopper can be formed separately from the handrail wall 11, and in that case, the parts and members forming the stopper may or may not be in contact with the handrail wall 11.

<Modified embodiment 3>
The pair of left and right stoppers 1A and 1B in the first embodiment can be formed as one continuous protrusion. In order to make the shape as simple as possible, one protrusion can be configured to form a stopper surface as a single plane.

<Modified embodiment 4>
The stoppers 1A and 1B can be made to abut on the movable terminal portion 3 on the left-right outer side of the rivet foot 4C of each contact. In this way, damage to the contact rivet 4 when colliding with the stoppers 1A and 1B can be prevented or suppressed. Furthermore, even if the dimension of the rivet foot 4C protruding from the backing plate 5C varies due to variation in the crimping process for attaching the contact rivet 4, this variation can be ignored.

<Modified embodiment 5>
The stopper 1 is the handrail wall 11 itself extending in the left-right direction as in the conventional technology, and the backside protrusion 3C is provided on the movable terminal portion 3 side, thereby obtaining the same effect as in the modified embodiments 1 and 2. The "backside" here is based on the contact side. The backside protrusion 3C can be formed, for example, by applying elastic epoxy resin near the rivet foot 4C on the back side of the movable contact 1A and hardening it. The protrusion can also be formed by stamping out the metal material constituting the movable terminal portion 3. Furthermore, the metal material can be bent and folded once to form the protrusion, and then further stamping can be performed to form the protrusion.

<Modified embodiment 6>
Instead of the rear projection 3C in the fifth modified embodiment, a similar effect can be obtained by using a bent portion 3D formed by bending one of the left and right ends of the oval metal laminate plate constituting the movable terminal portion 3. In this case, since the tip of the oval metal laminate plate that is long in the left and right directions is bent, the bent portion 3D has an arc-shaped outer edge.

<Modified embodiment 7>
Instead of the back surface protrusion 3C in modified embodiment 5, the protruding dimension of the rivet foot 4C on the back surface of one of the left and right movable contacts 3A and 3B can be made larger than that of the other left or right to obtain the same effect.

<Deformation due to materials and elasticity of stoppers and backside protrusions>
In each embodiment and each modified embodiment of the present application, various modifications are possible with respect to the material, rigidity, and springiness of the stoppers 1A and 1B and the backside protrusions 3C. They are not limited to those made of inelastic and insulating resin materials as in the case of being formed during molding of the resin base 10, but may be made of conductive materials such as metal materials, or may be made of elastomer resins such as polyether ester elastomers. They may also be formed by attaching spring members such as leaf springs and coil springs.

Next, modified embodiments 8 to 11 will be explained using FIG. 6.

<Modified embodiment 8>
As in modified embodiment 1, a stopper 1A is arranged on only one side, the left or right, and the connection position between the leaf spring-shaped main body portion 5A and the movable terminal portion 3 in the movable contact piece 5 is biased toward the side where the stopper 1A is arranged, rather than being in the center in the left-right direction.

<Modified embodiment 9>
As in the first modified embodiment, the stopper 1A is disposed only on one side, the left or right, and a weight (mass imparting part) 3E is attached to the movable terminal part 3 on the other side. This allows the inclination or the positional difference between the left and right sides to be increased when the movable terminal part 3 overshoots and when it approaches the fixed terminal part 2 again. The weight 3E can be, for example, a metal plate or a metal block attached by a contact rivet 4.

<Modified embodiment 10>
As in the first modified embodiment, the stopper 1A is disposed only on the left or right side, and a connecting spring 5E is disposed between the leaf spring portion 5A of the movable contact piece 5 and the terminal portion 3. This connecting spring 5E has spring properties in the torsional direction. In other words, it exerts a spring effect against the movement in the rotational direction about the axis of the extension direction of the leaf spring portion 5A. By providing such a connecting spring 5E, the load acting on the tip of the leaf spring portion 5A can be reduced.

<Modified embodiment 11>
As in the first embodiment shown in Figures 1 and 2, when a pair of left and right movable contact pieces 5 are provided, and a pair of left and right movable contacts 3A-3B or 3C-3D are provided on the movable terminal portion 3 at the tip of each movable contact piece 5, the positions of the stopper surfaces in the front-rear direction can be shifted from one another for all stoppers 1A-1D. In this way, the timing and degree of bounce can be shifted from one another. As a result, restriking can be suppressed or prevented. Even if restriking does occur, restriking and its adverse effects can be suppressed by shifting the timing of the peak of restriking, which can occur at the closest point.

For example, the front-to-rear positions of the stopper surfaces of the first stopper 1A from the left end in FIG. 2 (the right end in FIG. 1) and the third stopper 1C can be offset from each other, and the front-to-rear positions of the stopper surfaces of the second stopper 1B from the left and the fourth stopper 1D can be the same.

<Embodiment 2>
Next, an electromagnetic relay according to a second embodiment will be described with reference to Figures 7 to 10. Figure 7 is a schematic side view, Figure 8 is a perspective view of the movable contact piece 7, and Figure 9 is a perspective view of the contact opening and closing portion.

In the electromagnetic relay 102 of the second embodiment, when the electromagnet block 40 is disposed in the rearward position, a pair of left and right fixed terminal members 21, 22 are located at the front end of the electromagnetic relay 102. These fixed terminal members 21, 22 extend independently and upward from the resin base 10, allowing a certain degree of deformation in the front-rear direction. In addition, by increasing the left-right dimension at the point where the resin base 10 is penetrated vertically, sufficient holding force is obtained.

In the second embodiment, a bifurcated movable contact piece 7 is provided, which is held by a resin base 10. That is, it is a U-shaped integral metal member consisting of two leaf spring parts 7A and 7B extending vertically and a root part 7C connecting them to each other, and most of the root part 7C is pressed into a slit in the resin base 10. Contact rivets 4 for forming movable contacts 3A and 3B are attached to the upper ends of the two leaf spring parts 7A and 7B. In addition, contact rivets 4 for forming corresponding fixed contacts 2A and 2B are attached to the upper ends of the fixed terminal members 21 and 22.

The protrusions of the movable card member 70 abut from behind against the movable contacts 3A and 3B at the tips of the leaf springs 7A and 7B. The movable card member 70 is attached to a movable iron piece (not shown), and when the electromagnet block 40 is driven, the protrusions are pushed forward, and the left and right movable contacts 3A and 3B are pressed against the left and right fixed contacts 2A and 2B. When the electromagnet block 40 is switched to a non-excited state, it returns to the initial, stationary state shown in Figures 7 and 9.

Figure 10 shows the main points of the second embodiment in a schematic diagram similar to that of Figure 2. As shown in Figure 10, the arrangement of the left and right stoppers 1A and 1B in a plan view is almost the same as that of the first embodiment. In other words, the stopper surfaces of the left and right stoppers 1A and 1B are in different positions in the front-to-rear direction.

The mechanism of operation of the second embodiment is the same as that of the first embodiment, except that the movable contacts 3A and 3B are formed in two parts spaced apart horizontally. However, the left and right movable contacts 3A and 3B are located at the tips of the left and right leaf spring parts 7A and 7B, respectively. In contrast, in the case of the first embodiment, the points at which the left and right movable contacts 2A and 2B are formed are supported at the tip of one leaf spring part 5A. Therefore, in the first embodiment, the action of the step generating mechanism can cause a problem of twisting around this support point. However, in the second embodiment, such a twisting problem does not occur.

Figure 11 shows a schematic diagram of modified embodiment 12, which is a modification of embodiment 2. The electromagnetic relay of modified embodiment 12, like modified embodiment 11, has two movable contact pieces 7, and thus four movable contacts 3A-3D. The four stoppers 1A-1D corresponding to these movable contacts 3A-3D are set so that the positions of the stopper surfaces in the front-rear direction are all different from one another.

<Embodiment 3>
Next, a plunger-type electromagnetic relay according to a third embodiment will be described with reference to the schematic diagram of Fig. 12 and the cutaway side view of the main part of Fig. 13. For ease of explanation, the axial direction of the plunger 8 is defined as the up-down direction, and the direction in which the two contact opening/closing parts are arranged is defined as the left-right direction.

The movable terminal part 3, which is a horizontal plate long in the left-right direction, is fitted to the tip of the plunger 8, and the left and right movable contacts 3A and 3B on the upper surface of the movable terminal part 3 face the left and right fixed contacts 2A and 2B formed by the lower ends of the left and right fixed terminal members 21 and 22, respectively. The movable terminal part 3 is subjected to a spring action of the contact spring 9 that tries to return to the tip of the plunger 8. When the plunger 8 is pushed up by the solenoid actuator 82 (Figure 13) and its tip rises above the fixed contacts 2A and 2B, the contact spring 9 is compressed. In this way, the movable contacts 3A and 3B are pressed against the fixed contacts 2A and 2B by the spring force.

The stopper 1A is provided only on the back side (lower side) as viewed from the movable contact 3A on either the left or right side. As in the above embodiment, when the solenoid actuator 82 is turned off, the plunger 8 quickly returns to its original height position due to the action of the return spring inside the solenoid actuator 82. At this time, as in the above embodiment, an overshoot may occur. That is, the movable terminal portion 3 temporarily descends below the initial position, and then the action of the contact spring 9 may cause it to bounce back. As a result of the stopper 1A being present only on either the left or right side, as explained with reference to the area enclosed by the dashed line in FIG. 4, the movable terminal portion 3 is tilted so as to hang down to either the left or right side when it approaches the fixed terminal portion again due to the bounce back. Therefore, in the contact opening and closing portion on either the left or right side, the distance between the contacts is relatively large, and re-arc is suppressed.

In the specific example shown in FIG. 10, the movable terminal portion 3 is an oval metal plate, and the left and right movable contacts 3A and 3B are formed as integral disk-shaped raised portions. The corresponding pair of left and right fixed contacts 2A and 2B are formed as disk-shaped portions integral with the lower ends of cylindrical fixed terminal members 21 and 22. The contact opening and closing portion is disposed in a gas-sealed opening and closing operating chamber 81, and thick plate-shaped permanent magnets 30 and 32 are disposed at least on the left and right of this opening and closing operating chamber 81.

1, 1A, 1B Stopper 2 Fixed terminal part 2A, 2B Fixed contact 3 Movable terminal part 3A, 3B Movable contact 3C Back projection 3D Bent part 3E Weight part (mass imparting part)
4. Contact rivet (crimp)
4A: Rivet head for contact 4B: Rivet body 4C: Rivet foot (flange formed by crimping)
5 T-shaped movable contact piece (embodiment 1)
5A: Leaf spring part of the movable contact piece (strip-shaped main body part)
5B Movable terminal base part integral with leaf spring part 5C Backing plate for movable terminal 5D Movable resin plate 5E Connecting spring 6 Return spring 7 U-shaped movable contact piece (Embodiment 2)
7A, 7B Left and right leaf spring parts (strip-shaped main body parts)
7C: Root portion connecting the left and right leaf spring portions 8: Plunger shaft (Embodiment 3)
9 Contact spring 10 Resin base (base member)
REFERENCE SIGNS LIST 11 handrail wall 12 partition wall 17 first permanent magnet storage section 18 second permanent magnet storage section 19 arc elimination space 21 to 24 fixed terminal member 25 coil terminal member 30 first permanent magnet 31 auxiliary yoke 32 second permanent magnet 40 electromagnet block 55 Yoke 60 Movable iron piece 70 Resin movable card member (drive end connection part)
81: Gas-sealed opening/closing chamber 82: Solenoid actuator 101-103: Electromagnetic relays (power relays) according to embodiments 1-3

Claims (5)

At least one movable terminal portion whose position and posture can be switched by an actuator;
a pair of fixed contacts that come into contact with and separate from the pair of movable contacts in response to switching of position and posture by the actuator;
At least one spring member that is formed by at least a part of the movable terminal portion or is provided separately from the movable terminal portion and applies a spring force to the pair of movable contacts so as to move the pair of movable contacts away from or toward the pair of fixed contacts;
a step generating mechanism that causes one of the pair of movable contacts and the other of the pair of movable contacts to be stepped in terms of distance from the corresponding fixed contact when the actuator is switched to an off state and the pair of movable contacts move away from the pair of fixed contacts and approach the pair of fixed contacts again by bouncing or swinging back;
The step generating mechanism includes:
a back surface protrusion protruding toward a back surface side of the movable terminal portion as viewed from the movable contact in the vicinity of one of the pair of movable contacts;
and a stopper against which the rear surface protrusions can be abutted when the pair of movable contacts move away from the pair of fixed contacts. The rear surface protrusion is
The movable contact is formed by piling or applying a resin material to the rear surface of the movable contact, or by attaching a separate member or material to the rear surface of the movable contact.
The movable terminal is formed by bending an end of a metal plate that constitutes the movable terminal portion toward the rear surface side, or
2. The contact opening and closing mechanism according to claim 1, wherein when a contact rivet is used to form the movable contacts, the contact rivet is formed by making the protruding dimension of the rivet foot of the contact rivet in one of the pair of movable contacts larger than the protruding dimension of the rivet foot of the contact rivet in the other of the pair. 3. The contact opening and closing mechanism according to claim 1 , wherein the stopper is formed by the base member or a member fixedly attached to the base member. At least two pairs of the movable contacts and at least two pairs of the fixed contacts corresponding thereto are provided;
The contact opening and closing mechanism according to any one of claims 1 to 3, wherein the step generating mechanism causes at least four of the movable contacts, or at least three of the movable contacts, to be step-staggered relative to one another in terms of distance from the corresponding fixed contact. The actuator may be an electromagnet block and armature, a solenoid actuator, or another electromagnetic actuator;
An electromagnetic relay comprising the contact opening and closing mechanism according to any one of claims 1 to 3 .

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