JPH0411325Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to improvements in circuits and disconnectors that cut off electrical circuits.

FIG. 1 shows an example of a circuit or breaker to which this invention is applied. In the figure, 1 is a cover, 2
is a base, and the cover 1 and the base 2 constitute a housing A. A sheath cutting mechanism 100 is built into the housing A. The shearing mechanism 100 includes a repulsive contact 3, a movable contact 4 that comes into contact with and separates from the repulsive contact 3,
A toggle link mechanism T that separates the movable contact 4 from the repulsive contact 3 when an overcurrent flows, a response device R consisting of an overcurrent tripping device such as an electromagnetic tripping mechanism or a thermal tripping mechanism, and a extinguisher. It has an arc plate 5. Repulsion contact 3 has repulsion contact 3
a. The movable contact 4 is provided with movable contacts 4a facing each other, and these contacts 3a, 4a
The arc-extinguishing plate 5 is arranged nearby. Reference numeral 6 denotes an arm made of an insulating material (this arm 6 has a structure unique to the present invention), and the movable contact 4 is held by this arm 6 and rotates together with the arm 6 about an axis 7. ing.

8 is a pin pivotally attached to the arm 6, and this pin 8
is connected to the lower end of a lower link 9 that constitutes a part of the toggle link mechanism T. As shown in the fourth figure, a pair of pins 8 are formed facing each other inside the arm 6, and thin plate-like lower links 9, 9 are connected to these pins 8, 8, respectively. Therefore, there is a gap between the lower links 9, 9 in which the movable contact 4 can move up and down. The upper end of the lower link 9 is connected to a thin plate-like upper link 11 by a pin 10.
The upper end of the upper link 11 is connected to the cradle 13 by a pin 12. The cradle 13 is rotatably supported on a shaft 14 and has a locking portion 13a at its free end. A spring 15 is stretched between the operating lever 16 and the pin 10.

The response device R is a solenoid 17, a bimetal 1
8, a trip bar 19, a latch 20, a locking lever 21, etc. 22 is the power supply side terminal, 23
2 is a shunt that electrically connects the power supply side terminal 22 and the repulsive contact 3, and 24 is a load side terminal.

Next, the operation will be explained.

In a normal state, by tilting the operating lever 16 to the right, the upper link 11 and the lower link 9 are extended as shown in FIG.
Since the movable contact 4a is applied with a clockwise rotational force about the shaft 7, the movable contact 4a comes into contact with the repulsive contact 3a. At this time, the locking portion 13a of the cradle 13 is locked to the locking lever 21, so the upper link 1
1 and the lower link 9 are held in the extended state, and the contact point 3
a and 4a remain in contact. That is, the electric circuit is in a closed circuit state.

Now, in the closed circuit state, if an overcurrent flows in the circuit, solenoid 17 or bimetal 1
8 is activated, the trip bar 19 is rotated clockwise around the shaft 19a, and the latch 20 is moved around the shaft 20.
Rotate counterclockwise around a. As a result, the engagement between the latch 20 and the locking lever 21 is released, and the locking lever 21 is rotated counterclockwise about the shaft 21a by the biasing force of a spring (not shown), and the locking portion of the cradle 13 is rotated counterclockwise. 13a is removed from the locking lever 21. For this reason, the upper link 1
1 and the lower link 9 buckle, and the arm 6 is rotated counterclockwise about the shaft 7, so that the movable contact 4a is separated from the repulsive contact 3a. At this time,
The repulsive contact 3 also rotates clockwise about the shaft 3b under the electromagnetic repulsive force and separates from the movable contact 4. As a result, the electrical circuit is automatically cut off.

By the way, in the above-mentioned circuit and disconnector, the movable part has conventionally been constructed as shown in FIGS. 2a and 2b. In the figure, 25 is a support frame having arm portions 25a, and this support frame 25 has a cross bar 26
is inserted into the crossbar 26 by the presser plate 27.
is fixed. The crossbar 26 connects a plurality of parallel contacts, and by connecting this crossbar 26 to a single operating lever 16, a single lever operation opens and closes the plurality of contacts at the same time. be. Reference numeral 28 denotes a movable contact, which is rotatably supported by a shaft 29 on the arm portion 25a. 30 is a contact pressure spring, and this contact pressure spring 3
0 is a double torsion spring having a helical portion 30a, and the helical portion 30a is inserted into the shaft 29. One end of the contact pressure spring 30 is press-fitted to a recess 28a on the upper surface of the movable contactor 28, and the other end is pressed to a corner of the cross bar 26. Note that 28b is a movable contact, 31 is a fixed contact, and 31a is a fixed contact.

According to the above configuration, when an overcurrent flows between the contacts 28b and 31a, first the movable contact 28
is rotated counterclockwise around the shaft 29 against the spring force of the contact pressure spring 30 due to the electromagnetic repulsion force generated between the contacts 28b and 31a, and as a result, as shown in FIG. 2b, The movable contact 28b opens by a distance H from the fixed contact 31a. Then, as the support frame (arm) 25 is driven by the links 9 and 10 and rotates counterclockwise about the crossbar 26, the movable contact 28b is further separated from the fixed contact 31a, causing the circuit to break and break. It is maintained in a closed or disconnected state.

However, in the conventional circuit breakers described above, when the movable contact 28 opens and separates due to electromagnetic repulsion, the center of rotation is the shaft 29, and the center of rotation of the support frame 25 is the cross bar 26. does not match. Therefore, the length L of the arm of the movable contactor 28 at the time of opening is
1 (FIG. 2a) becomes shorter, the rotation angle θ1 when separated to a predetermined distance H shown in FIG. 2B becomes larger. As a result, the electromagnetic repulsion force decreases, causing a disadvantage that the opening operation of the movable contactor 28 is delayed. Furthermore, as the angle θ1 increases, fatigue of the contact pressure spring 30 also increases. Even if you try to make the center of rotation of the movable contact 28 coincide with the cross bar 26, the cross bar 26 is made of a molded resin rod or a metal core with an insulating cloth wrapped around it, and the shape is different. Since they were prismatic, it was structurally impossible to make the movable contact 28 and the crossbar 26 coaxial.

This idea was made in view of the above-mentioned conventional problems, and it is possible to speed up the electromagnetic repulsion of the movable contact when the contact is opened, and to create a circuit or disconnection with less fatigue of the contact pressure spring. The purpose is to provide.

Embodiments of this invention will be described below with reference to the drawings. In Figure 3 a, b, 32a, 32b
are a pair of arm parts formed on the frame of the solenoid 17, a shaft 7 is inserted between the arm parts 32a and 32b, and a movable contact 4 and an arm holding the movable contact 4 are attached to the shaft 7. 6 is rotatably supported.

This arm 6 is rotated together with the movable contact 4 by a response device R shown in FIG.

33 is a contact pressure spring, and this contact pressure spring 33 has a pair of side parts 33a, 33b, and these side parts 33a, 3.
A substantially U-shaped double torsion spring consisting of a connecting portion 33c that connects 3b at one end,
Each side portion 33a, 33b has a helical portion 3.
4a and 34b are formed. The helical portions 34a, 34b are inserted into the shaft 7, and the connecting portion 33c side of the side portions 33a, 33b is connected to the arm by elastic force in a counterclockwise direction centered on the helical portions 34a, 34b. 6 is press-fitted to an end 101 of the upper wall 6d.

On the other hand, a pin 35 is inserted between the free ends of the side parts 33a, 33b and the lower surface 4b of the movable contact 4. The free ends of the side portions 33a, 33b are pressed against the pin 35 by elastic force in a clockwise direction around the helical portions 34a, 34b.

In other words, the contact pressure spring 33 has side portions 33a, 3
3b is connected to the lower surface 4b of the movable contactor 4 via the pin 35.
The connecting portion 33c side is press-fitted to the end 101 of the upper wall 6d of the arm 6. As a result, an elastic force in a clockwise direction about the shaft 7 is constantly applied to the movable contactor 4 by the spring force of the contact pressure spring 33.

Moreover, the connecting portion 33c side of the contact pressure spring 33 is
It is separated from the upper surface 4c of the movable contactor 4 by a distance d. Thereby, the movable contact 4 can rotate within the range of angle θ2 until it comes into contact with the contact pressure spring 33 due to the electromagnetic repulsion between the contacts.

A stopper 102 is provided on the arm 6 and comes into contact with the lower surface 4b of the movable contact 4 to restrict clockwise rotation of the movable contact 4.

Next, the assembly order of the movable parts as described above is changed to the fourth step.
This will be explained with reference to FIGS. First, the contact pressure springs 33 are mounted across both sides of the movable contactor 4. At this time, the spiral portion 34 of the contact pressure spring 33
a, 34b are aligned with the shaft hole 36 formed in the movable contact 4. Next, the movable contact 4 and the contact pressure spring 3
3 is inserted between the arm parts 32a and 32b, and the shaft holes 37a and 3 of the arm parts 32a and 32b are inserted.
37b and the shaft hole 36 of the movable contact 4 are aligned. In this state, the shaft 7 is inserted across the shaft holes 36, 37a, and 37b.

Thereafter, the arm 6 is inserted into the movable contact 4 through its opening 6c from the direction A shown in FIG. 5, and the recess 38 shown in FIG. 4 provided in the arm 6 is engaged with the shaft 7. At this time, the movable contact 4 is located between the both side pieces 6a and 6b of the arm 6, and the contact pressure spring 3
As shown in FIG. 6a, the connecting portion 33c side of No. 3 is
The end 101 of the upper wall 6d of the arm 6 and the movable contact 4
It is located between the top surface 4c and the top surface 4c.

Next, one of the side parts 33a and 33b of the contact pressure spring 33, for example, the free end side of the side part 33a, is elastically deformed from the position of the dashed line to the position of the solid line as shown in FIG. The pin 35 is inserted between the lower surface of the rear end of the spring 4 and the side portion 33a of the contact pressure spring 33. When the elastic deformation is released with the pin 35 inserted to some extent, the side portion 33a of the contact pressure spring 33 is pressed against and locked to the pin 35.

In this state, the connecting portion 33c side of the contact pressure spring 33 is pressed against the end portion 101 of the upper wall 6d, so that a clockwise elastic force is applied to the movable contactor 4.
As a result, the lower surface 4b of the movable contact 4 comes into contact with the stopper 102, and a distance d is created between the upper surface 4c of the movable contact 4 and the contact pressure spring 33.

Finally, the free end side of the other side part 33a is similarly slightly elastically deformed downward, and the pin 35 is further pushed in, so that the lower rear end of the movable contact 4 and the side part 33b
When the elastic deformation is released with the pin 35 inserted between the
5 is pressed and locked.

In this way, both sides 33 of the contact pressure spring 33
The free end sides of a and 33b are both press-locked to the pin 35, and the pin 35 is sandwiched between the lower surface of the movable contact 4 and both sides 33a and 33b of the contact pressure spring 33, so that the movable contact 4 is held in a state where a clockwise rotational force is applied, that is, in a state where it is in elastic contact with the contact point 3a of the repulsive contact 3.

In addition, in FIG. 4, 35a and 35b are locking grooves formed in the pin 35;
5b on both sides 33a, 33b of the contact pressure spring 33.
is positioned.

In addition, in the present invention, by adopting the arm 6 having the above-described structure, the function of a conventional cross bar can be performed by this arm 6, and the rotation centers of the movable contactor 4 and the arm 6 can be made to coincide with each other. be able to.

According to the above configuration, since the center of rotation of the movable contact 4 coincides with the center of rotation of the arm 6, that is, since it is rotatably supported on the same shaft 7,
When the movable contact 4 is separated by electromagnetic repulsion, the arm length L2 of the movable contact 4 shown in FIG. 6a is equal to the arm length L1 shown in FIG. 2 (conventional example).
It will be longer than Therefore, the rotation angle θ2 when the movable contact 4 is opened to a predetermined distance H shown in FIG. .

Moreover, as the angle θ1 becomes smaller, the fatigue of the contact pressure spring 33 is shortened, and as a result, the life of the contact pressure spring 33 is extended.

Furthermore, assuming that the fatigue of the contact pressure spring 33 is the same as in the past, the separation distance H becomes larger when the contact spring 33 is rotated by the same angle, so that the shearing performance is improved.

In the present invention, the contact facing the movable contact 4 is not limited to the approximately C-shaped repulsive contact 3 as shown in FIG. 1, but may be a normal straight-shaped contact as shown in FIG. The fixed contact 3 may also be used, and even in this case, the effect of the present invention is exerted because a large electromagnetic repulsive force is generated between the contact points of both the contacts.

As explained above, according to this invention, there are a pair of contacts that can be brought into and out of contact, a movable contact that has one contact at one end and is swingably supported on a shaft, and a movable contact that is attached to the shaft. an arm that is rotatably supported coaxially with the movable contact, is connected to a toggle link mechanism, and holds an approximately intermediate portion of the movable contact, one end of which is connected to the arm, and the other end of which is connected to the other end of the movable contact; and a contact pressure spring that is press-fitted to each side and applies contact pressure between both contacts,
When the movable contact opens to a predetermined separation distance, the angle it makes with the repulsive (fixed) contact becomes smaller, so that the electromagnetic repulsion force against the movable contact does not decrease as in the past. The opening action of the movable contact becomes faster, improving the breaking performance of circuits and disconnectors, and the rotation angle of the movable contact also becomes smaller, reducing fatigue of the contact pressure spring and allowing long-term use. It has a durable effect. Further, according to this invention, by rotatably supporting the movable contact and the arm that holds it on the same axis, the movable contact and the arm that are necessary as a pair of circuit breakers and breakers are included. Because it is possible to lengthen only the movable contact without changing the absolute length, it is useful as a movable contact for circuits and breakers that have limited storage space and require smaller size. .

[Brief explanation of the drawing]

Figure 1 is a front sectional view showing an example of a circuit breaker to which this invention is applied, Figure 2a is a front view showing the structure of a conventional movable part, and Figure 2b is a front view in its open state. Fig. 3a is a front view showing the structure of the movable part in the embodiment of this invention, Fig. 3b is a rear view of the same, and Fig. 4 is an exploded perspective view for explaining the assembly of the movable part in this invention. , Figure 5 is a front view of the same,
FIG. 6a is a front view of the movable part in the closed state of the movable contact, and FIG. 6b is a front view of the movable part in the opened state. 4...Movable contact, 4a...Movable contact, 3a...
... Repulsion (fixed) contact, 6... Arm, 7... Axis,
33...Contact pressure spring, T...Toggle link mechanism.

Claims (1)

[Scope of utility model registration request] A pair of contacts that can be brought into and out of contact, a movable contact that has one contact on one end side and is swingably supported on a shaft, and a movable contact that is rotatably supported on the shaft coaxially with the movable contact. and an arm that is connected to the toggle link mechanism and holds a substantially middle portion of the movable contact, one end of which is press-fitted to the arm, and the other end of which is press-fitted to the other end of the movable contact, and between both contacts. A circuit disconnector comprising a contact pressure spring that applies contact pressure to the circuit.