JPH0241787Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] This invention relates to a contact opening/closing device applied to relays, switches, contactors, etc.

[Background technology]

In general, contact switching devices are required to take measures against contact welding due to arcs generated between contacts during opening/closing operations.
Particularly when the load includes a motor, capacitor, etc., contact welding is more likely to occur due to inrush current flowing.

By the way, conventional hinge-type relays have a contact opening/closing device that uses the deflection of a leaf spring serving as a movable contact to relatively slide (wipe) a movable contact and a fixed contact when the contacts make contact. In addition to providing a cleaning effect, the wiping action can be expected to destroy contact welds. However, because there are limits to the amount of wiping and the wiping force, it has been difficult to shear the weld bridges on the contact surface.

On the other hand, as shown in FIG. 7, a movable contact 71 facing a fixed contact 70 is fixed to a movable contact 72, and a shaft 74
The contact holder 73 and the movable contact 7 are connected by
2, the spring 75 is compressed between the contactor holder 73
It has been proposed that the proximal end of the shaft is supported by a shaft 76.
According to this contact opening/closing device, when the contact holder 73 rotates in the direction of the arrow around the shaft 76 as shown in FIG.
1 is inserted into the fixed contact 70, and when the contact holder 73 is further rotated in the same direction, the shaft 74 side of the movable contact 73 rotates around the fixed contact 70 as a fulcrum, as shown in FIG. 71 performs a wiping operation in the direction of the arrow while rolling relative to the fixed contact 70. Therefore, even if a welding bridge is generated between the contacts due to the arc of the contact bounce at the initial stage of contact closing (state b in the same figure), this welding bridge cannot be destroyed by the rotational moment caused by the rolling of the movable contact 71. This makes it possible to reliably prevent contact welding.

However, this contact opening/closing device has a complicated structure on the movable contact side, increases the number of parts, and has many problems in manufacturing, such as part accuracy and adjustment method.

[Purpose of invention]

The purpose of this invention is to provide a contact opening/closing device that has a simple structure and can reliably prevent contact welding.

[Disclosure of invention]

The contact opening/closing device of this invention includes a fixed contact, a movable contact having a movable contact at the tip opposite to the fixed contact, and a base end of the movable contact connected to the base end of the movable contact. The movable contact has a curved motion section extending in the opposite direction to the longitudinal direction from the movable contact to the tip end, and a telescoping motion section that extends and contracts in a direction perpendicular to the longitudinal direction of the movable contact, which is continuous with the curved motion section. an elastic body that holds the movable contact; a stopper that is engaged with a side of the elastic body that is continuous with the bending motion section of the telescoping motion section to restrict the maximum extension position of the telescoping motion section; By pressing the movable contact, the movable contact is brought into contact with the fixed contact from an open state, and the movable contact is rotated about the fixed contact as a fulcrum while the movable contact is in contact with the fixed contact. and a driving means, the elastic body performs the bending operation with the telescoping portion in contact with the stopper from the initial stage of rotation of the movable contact around the fixed contact to the middle of the rotation range. This feature is characterized in that the spring constant is set so that the part moves in a curved manner.

According to the configuration of this invention, the movable contact contacts the fixed contact due to the operation of the driving means, and in this contact state, the movable contact rotates about the fixed contact as a fulcrum, so that the movable contact returns to the contact position at the time of closing. Since it rolls to a different contact position, this rolling can break the contact weld. Moreover, the spring load applied by the elastic body to the drive means until the movable contact and the fixed contact come into contact is small because it is a cantilever-supported bending motion part, and therefore the difference between the spring load and the driving force of the drive means is large. Therefore, when the movable contact rotates around the fixed contact, a large driving force can be applied to the movable contact, which increases the destructive force of contact welding and further ensures welding resistance. become. Furthermore, since such an operation is achieved using a movable contactor and an elastic body, the structure is simple and easy to manufacture.

Embodiment An embodiment of this invention will be described based on FIGS. 1 to 6. That is, this contact opening/closing device includes a fixed contact 1, a movable contact 3 having a movable contact 2 facing the fixed contact 1 at its tip, and a movable contact 3 connected to a base end 4 of the movable contact 3. It has a curved movement part 5 that extends in the opposite direction to the longitudinal direction from the base end 4 of the contactor 3 to the distal end part, and also has a curved movement part 5 that extends in the longitudinal direction of the movable contact 3 and continues from this bending movement part 5. An elastic body 7 that has a telescoping portion 6 that expands and contracts in a right angle direction and holds the movable contact 3, and a portion of the elastic body 7 that is engaged with the contiguous side of the telescoping portion 6 and the bending portion 5. a stopper 9 for regulating the maximum extension position of the telescopic operation section 6;
By pressing the movable contact 3, the movable contact 2 is brought into contact with the fixed contact 1 from the open state, and while the movable contact 2 is in contact with the fixed contact 1, the movable contact 3 is brought into contact with the fixed contact 1. 1
The elastic body 7 is provided with a driving means 8 for rotating the movable contact 3 about the fixed contact 1 as a fulcrum, and the elastic body 7 is rotated from the initial stage of rotation when the movable contact 3 rotates about the fixed contact 1 to the middle of the rotation range. It is characterized in that the spring constant is set so that the bending motion part 5 makes a bending motion while in contact with the stopper 9.

The fixed contact 1 has a substantially flat surface,
The movable contact 2 is formed into a substantially hemispherical surface so that the movable contact 2 can smoothly roll relative to the fixed contact 1. The fixed contact 1 is fixed to a fixed contact 10 having an integrally formed terminal. The movable contactor 3 is rigid and formed into a long plate shape, and the movable contact 2 is fixed to the tip portion by a pin portion 2a.

The elastic body 7 has a conductive elongated plate shape, and has one end bent into a substantially W shape and the other end extending at a right angle. and the extended part is the bending motion part 5
This configuration allows the movable contactor 3 to rotate and roll. This elastic body 7
The tip of the bending motion part 5 is connected to the base end 4 of the movable contact 3 by welding or the like, and the telescoping motion part 6 is fixed and held by the pin part 11a to the terminal 11.
Holds the movable contact 3. Further, the end of the telescopic movement section 6 on the side of the bending movement section 5 is regulated by a stopper 9.

The driving means 8 is an embodiment of a relay to be described later, and includes a movable frame 13 having a notched engagement portion 12 for driving the movable contact 3, and a movable frame 13.
It has a return spring 14 that urges it back. The width of the engaging portion 12 through which the movable contact 3 is inserted is about 1.5 to 3 times the thickness of the movable contact 3.

The operation of this contact switching device will be explained. That is, FIG. 1 shows the open state, in which the movable contact 2 is separated from the fixed contact 1. FIG. 2 shows the initial state of contact closing, in which the movable frame 13 moves in the direction of the arrow against the return spring 14, which presses the movable contact 3 and rotates about the stopper 9 as a fulcrum, making it movable. Contact 2
contacts the fixed contact 1. In this case, the movable frame 13
The spring load applied to the return spring 14 and the elastic body 7
However, since the bending movement part 5 is in a cantilevered state, the spring force is weak and is substantially equal to the load by the return spring 14.

FIG. 3 shows a state in which the movable frame 13 further moves in the same direction and enters overtravel, and the movable contact 3 rotates about the fixed contact 1 as a fulcrum, and is in the middle of its rotation range from the initial stage of rotation. This is the state immediately before the telescoping portion 6 leaves the stopper 9. That is, when the movable contact 3 rotates about the fixed contact 1 as a fulcrum and elastically bends the bending movement part 5, the spring constant of the bending movement part 5 is _K1 , and the spring constant of the extension and contraction movement part 6 is K1.
K ₂ , and the displacement δ ₁ of the movable frame 13 from the initial position of the movable contact 3 (Fig. 2) to the position shown in Fig. 3.
Assuming that the displacement of the telescoping portion 6 from its fully extended state to the position where it is compressed and regulated by the stopper 9 is δ ₀ , and the load applied to the stopper 9 at that time is P ₀ , the state shown in FIG. 3 is K ₁ δ ₁ =P ₀ =K ₂ δ ₀ . That is, from the initial stage of rotation when the movable contact 3 rotates around the fixed contact 1 after the movable contact 2 contacts the fixed contact 1, until this state is reached, the elastic member 7's telescoping portion 6 is held against the stopper 9. While in contact, the bending movement section 5 performs a bending movement. At the same time, this curved movement causes the movable contact 2 to
increases the contact pressure with respect to the fixed contact 1.

FIG. 4 shows a state in which the movable contact 3 has further rotated and the movable frame 13 has stopped at the final position. In this case, since K ₁ δ ₁ > P ₀ =K ₂ δ ₀ , the expansion/contraction unit 6
moves away from the stopper 9 and elastically contracts.
Since the springs with spring constants K ₁ and K ₂ are connected in series, the contact pressure at this time increases as the springs have spring constants K ₁ K ₂ /K ₁ +K ₂ .

FIG. 5 shows the characteristics of the driving force (attraction force by an electromagnet) and spring load of the movable frame 13 with respect to the stroke of the movable frame 13, where Q ₁ is a driving force curve and Q ₂ is a spring load line. Further, a ₁ is the contact opening position in FIG. 1, and a ₂ is the contact opening position in FIG. 2. The spring load line Q ₂ at this time is due to the return spring 14 of the movable frame 13. _a3 is a position corresponding to FIG. 3, and the spring load line _Q2 from position _a2 to position _a3 is based on the spring constant _K1 . _A4 is a position corresponding to FIG. 4, and the spring load line _Q2 from position _{a3 to} position _a4 is based on the spring constant _K1K2 / _K1 + _K2 . As is clear from this figure, at position _a2 of the movable frame 13, that is, when the contact is closed, the spring load line _Q2 from the open state position _a1 to the position _a2 is almost driven only by the return spring 14. The difference f from the force curve can be increased, and therefore the rotational force when rotating the movable contact 3 about the fixed contact 1 can be increased. As a result, the force that destroys the welding bridge when the contacts are welded, which is generated by the bounce arc accompanying the contact bounce when the contacts are closed, is increased, and the welding resistance is further ensured.

FIG. 6 shows an example in which this contact switching device is applied to a relay. That is, 18 is a case and the cover is omitted. 19 is a contact block; 20 is a clapper-type electromagnetic device constituting the driving means 8;
1 is a yoke, 22 is a coil frame, 23 is an iron core, 24
25 is the coil, and 25 is the tip of the yoke 21 attached to the pivot part 21.
The armature is denoted by a, and 26 is a coil terminal.

This electromagnetic device 20 is installed inside the case 18,
A contact stand 19 is arranged on the upper surface of the electromagnet device 20. The movable frame 13 is movably supported by a guide portion 27 of the contact base 19 and supported by a return spring 17, and a bent portion 28 at the tip of the movable frame 13 is movably supported by a guide portion 27 of the contact base 19.
The notch 29 faces the electromagnet device 20 , and the engaging portion 30 of the bent portion 28 engages with the rotating end of the armature 25 . Further, the terminal of the fixed contact 10 and the terminal 11 are fixed to the contact base 19, and the movable contact 3 is fitted into the engaging portion 12 of the movable frame 13. moreover,
The engagement notch 5a formed in the movable contact 3 is the engagement portion 1
The movable frame 1 engages with a protrusion 32 formed on the bottom of the
Positioning is performed in a direction perpendicular to the drive direction of No. 3. A stopper 9 is also provided on the contact base 19. Note that the coil terminal 26, the terminal portion of the fixed contact 10, and the terminal 11 are connected to the slit 31 of the case 18.
stand out more. When the coil 20 is energized, the armature 25 is attracted to the end face of the fixed iron core 23.
At this time, the armature 25 moves the movable contact 3 through the movable frame 13 from FIG. 1 to FIG. 4, and current is passed between the terminals 11 and the fixed contact 10.

Because of this structure, the contact switching device of this embodiment has the following advantages. That is, (1) by rolling the movable contact 2 after making contact with the fixed contact 1, it is possible to reliably prevent contact welding due to the arc of contact bounce. In particular, when the movable contact 3 rotates about the fixed contact 1, the driving force by the driving means 8 and the return spring 1 are
Since the difference f from the resistance due to 4 is large, the destructive force of the welded bridge is large.

(2) Since the rolling motion of the movable contact 2 is realized by the movable contact 5, the elastic body 7, and the driving means 8, the structure is simple.

(3) Since the elastic body 7 has conductivity, a connecting wire between the movable contactor 3 and the terminal 11 is unnecessary, the number of parts can be further reduced, and assembly can be facilitated.

The surface shape of the movable contact 2 is not limited to a hemispherical surface, but may be semi-cylindrical or may have one or more corners on the surface. Further, it may be formed on the fixed contact 1 instead of the movable contact 2. Further, the movable contactor 5 may be formed of a leaf spring.
Furthermore, the contact pressure spring 8 is not limited to the shape described above, but may be bent or curved so as to be expandable and contractible, for example, so as to perform the above-described operation.

[Effect of idea]

According to the contact opening/closing device of this invention, the movable contact contacts the fixed contact due to the operation of the driving means, and in this contact state, the movable contact rotates about the fixed contact as a fulcrum, so that the movable contact contacts the fixed contact at the time of closing. Since it rolls to a different contact position, this rolling can break the contact weld. Moreover, the spring load applied by the elastic body to the drive means until the movable contact and the fixed contact come into contact is small because it is a cantilever-supported bending motion part, and therefore the difference between the spring load and the driving force of the drive means is large. Therefore, when the movable contact rotates around the fixed contact, a large driving force can be applied to the movable contact, which increases the destructive force of contact welding and further ensures welding resistance. become. Furthermore, since such an operation is achieved using a movable contactor and an elastic body, the structure is simple and easy to manufacture.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the open state of one embodiment of this invention, Fig. 2 is an explanatory diagram of the initial state of contact closing, and Fig. 3 is an explanatory diagram of the open state of one embodiment of this invention.
The figure is an explanatory diagram of the state in the middle of overtravel.
The figure is an explanatory diagram of the on state of the driving means in its final position.
FIG. 5 is a characteristic diagram of the driving force and spring load of the movable frame with respect to the stroke of the movable frame, FIG. 6 is an exploded perspective view of the relay, and FIG. 7 is an explanatory diagram of a conventional example. DESCRIPTION OF SYMBOLS 1... Fixed contact, 2... Movable contact, 3... Movable contact, 4... Base end part, 5... Curved operation part, 6
. . . Telescopic operation section, 7 . . . Elastic body, 8 . . . Driving means, 9 . . . Stopper.

Claims (1)

[Scope of utility model registration request] a fixed contact, a movable contact having a movable contact at its distal end opposite to the fixed contact, and a longitudinal direction connected to the proximal end of the movable contact from the proximal end of the movable contact to the distal end; The movable contact has a curved motion part that extends in the opposite direction, and a telescoping motion part that extends and contracts in a direction perpendicular to the longitudinal direction of the movable contact, which is continuous with the curved motion part, and holds the movable contact. an elastic body, a stopper that locks on a side of the elastic body continuous with the bending motion section of the telescoping motion section and regulating the maximum extension position of the telescoping motion section; and a stopper that presses the movable contact. driving means for bringing the movable contact into contact with the fixed contact from an open state and rotating the movable contact about the fixed contact while the movable contact is in contact with the fixed contact; The body is configured such that the bending movement part performs a bending movement with the telescoping movement part in contact with the stopper from the beginning of rotation when the movable contact rotates around the fixed contact point to the middle of the rotation range. A contact opening/closing device characterized by having a set spring constant.