JPH0560207B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an electromagnetic contactor intended for forced separation means for welding.

[Background technology]

Conventional examples are shown in FIGS. 13 to 16. That is, 50 is an electromagnet, 51 is a lever, 52 is a movable frame, 53 is a return spring, and 54 is a movable contact. When the electromagnet 50 operates and its plunger 50a protrudes, the lever 51 moves the movable frame 52 in the direction of the arrow. When pressed, the movable contact 54 opens to a fixed contact (not shown), and when the excitation of the electromagnet 50 is stopped, the movable frame 52 returns to its original position due to the return spring 53, and the lever 51 is reversed, so that the plunger 50a of the electromagnet 50
returns to normal.

However, if the contacts 54 are welded, there is a drawback that the movable contacts 54 are slow to open or cannot be opened. On the other hand, if the return spring 53 is made larger, the welding resistance improves, but on the other hand, it is necessary to increase the attractive force of the electromagnet.

In addition, a contact 54 is formed by polarizing the electromagnet 50 and welding it.
It is considered that the electromagnet 50 can be used to remove the magnet, but the removal force F ₁ is small as shown in FIG. 16, and the welding resistance is not sufficient. In Figure 16, Q ₁ is the operating spring plus attraction force characteristic, Q ₂ is the spring load characteristic,
Q ₃ is the attraction force characteristic for return (off).

[Purpose of the invention]

An object of the present invention is to provide an electromagnetic contactor that has a simple configuration and can further ensure separation when welding contacts.

[Disclosure of the invention]

The electromagnetic contactor of the present invention includes a polarized electromagnet and a movable contact that is movable in a direction parallel to the reciprocating direction of the plunger of the polarized electromagnet and that closes the fixed contact in one direction. a movable frame,
The movable frame is provided with a return spring that biases the movable frame in a direction in which the movable contact opens and separates, and a lever whose intermediate portion is pivotally supported and whose both ends are linked to the plunger and the movable frame. When the movable frame is closed by a unidirectional movement of the plunger, such that the driving force of the plunger when the movable frame is opened is greater than the driving force of the plunger during operation. The lever ratio of the distance from the rotation center of the lever to the first position where the plunger and the movable frame engage with the lever, respectively, and the lever ratio when the movable frame is opened by the movement of the plunger in the other direction. The present invention is characterized in that the lever ratios of the distances from the center of rotation of the lever to the second positions where the plunger and the movable frame engage with the lever are made different.

According to the configuration of the present invention, the leverage ratio of the lever when removing a welded contact can be made larger than when it is turned on, so the separation during welding is more reliable than in the past, and the structure is relatively simple. It's easy to do.

Embodiment A first embodiment of the present invention will be described based on FIGS. 1 to 9. In the figure, 1 is a main body case, 2 is a terminal case, and 3 is a cover.A polarized electromagnet 4 is housed in the main body case 1, and a movable frame 6 is placed thereon via a partition plate 5.

The polarized electromagnet 4 includes a coil frame 7, a coil 8, a plunger 9, a pair of inner yokes 10, a pair of permanent magnets 11, a pair of outer yokes 12, a pair of armatures 13a and 13b fixed to the plunger 9, and a pair of armatures 13a and 13b fixed to the plunger 9. By moving the plunger 9 in any one direction as shown in FIG. 2, one armature 13a approaches the outer yoke 12 and the other armature 13b approaches the outer yoke 12, for example in the case of the arrow. It approaches the inner yoke 10 and is attracted and held by the magnetic flux of the permanent magnet 11, and by exciting the magnetic flux flowing through the plunger 9 in the coil 8 in the opposite direction, the plunger 9 is moved in the opposite direction to the arrow. . At this time, the operating spring 14 assists the plunger 9 in the projecting direction.

Attach the connecting frame 15 to the tip of the plunger 9,
A hole 16 is provided in the connecting frame 15, a pushing surface 17 is formed above the hole 16, and a pulling surface 18 is formed below the hole 16. Also, a shaft 1 is placed above the connecting frame 15 of the coil frame 7.
9, the middle part of the lever 20 is supported on the shaft 19, the lower part of the lever 20 is loosely fitted into the hole 16 of the connecting frame 15, and the lower end protrusion 21 of the lever 20 is inserted into the connecting frame 15.
facing the pulling surface 18 of the connecting frame 15, and the pushing surface 17 of the connecting frame 15.
A pin 22 is provided opposite to. The upper side of the connecting frame 15 protrudes from the sides of the partition plate 5 to the upper surface side of the partition plate 5, and the upper end disk portion 24 of the lever 20 is fitted into a notch 23 formed at the end of the movable frame 6. .

A terminal case 2 is attached to the upper surface of the main body case 1, and the terminal case 2 covers the movable frame 6 and supports the polarized electromagnet 4 so that it can move parallel to the reciprocating direction of the plunger 9. A plurality of movable contact plates 25 are passed through the movable frame 6, and a spring 26
A movable contact 27 is provided on the surface of the movable contact plate 25 . On the other hand, a fixed contact 28 is provided in the terminal case 2 corresponding to the movable contact 27,
Terminal screws 30 of the fixed contact plate 29 holding the fixed contacts 28 are covered on the outer surface. Also, the movable frame 6
A return (opening) spring 31 is interposed between the end opposite to the notch 23 and the inner surface of the terminal case 2 to urge the movable frame 6 in the opening direction.

In this electromagnetic contactor, when the coil 8 of the polarized electromagnet 4 is energized in one direction, the plunger 9 protrudes, and when the pin 22 is pressed by the pressing surface 17 of the connecting frame 15, the lever 20 rotates around the shaft 19 and is movable. Frame 6
is pushed against the return spring 31, and the movable contact 27 is closed to the fixed contact 28. On the other hand, when turning off the electromagnetic contactor, when a current is passed through the coil 8 in the opposite direction, the electromagnet 4 releases the holding force of the plunger 9 and moves backward in the opposite direction.The movable frame 6 is simultaneously moved by the return spring 31 and opened. .

When turning this off, if the movable frame 6 cannot be returned by the return spring 31 when the contacts are welded, the pulling surface 18 of the connecting frame 15 will come into contact with the protrusion 21 of the lever 20 due to the backward movement of the plunger 9 of the electromagnet 4. contact, pull the lever 20 to forcefully separate the contact weld, and move the movable frame 6
to be reinstated. In this case, the lever ratio of the lever 20 is a distance a from the shaft 19 to the upper disk portion 24, a distance b from the shaft 19 to the pin 22, and a distance c from the shaft 19 to the protrusion 21. The leverage ratio at the first pair of application points acting on the lever 20 is b/a, the leverage ratio at the second pair of application points acting on the lever 20 at the time of tripping is c/a, and b< c, the latter has a larger leverage ratio.

As a result, for example, if a=2, b=1, and c=2, the stroke is half, but the tripping force is twice as much as in the on operation. This suction force curve is shown in FIG. 9 in comparison with a conventional example. Figure a shows the conventional example, Figure b shows this embodiment, and the suction force characteristics Q ₃ and Q ₃ ' that pull the movable frame 6 are such that the stroke is halved, but the tripping force is F ₁ < F _2. .

A second embodiment of the invention is shown in FIGS. 10 to 1.
Shown in Figure 2. That is, the lever 2 of the first embodiment
0, two protrusions 33 and 34 are formed on the upper side of the shaft 19 of the lever 20' at different distances from the shaft 19, and a pin 22 is provided at the lower end of the lever 20'. A pair of vertical slits 35 are formed at both ends of the connecting frame 15', and the pin 22 is slidably supported in the vertical slits 35. The rest is the same as the first embodiment.

In this embodiment, the ON operation is caused by the protruding operation of the plunger 9, which rotates the lever 20' and pushes the notch 23 of the movable frame 6 with the protrusion 34 at the most distal end. On the other hand, when the contacts are welded, the movable frame 6 is pulled by the protrusion 33 on the pin side of the lever 20' by the retreating movement of the plunger 9.
The leverage of lever 20' in each of these movements is:
Distance a ₁ from axis 19 to most protrusion 24, axis 19
Distance a ₂ from to protrusion 33, from shaft 19 to pin 22
If the distance b is ₁ , lever 2
The leverage at the first pair of points acting on 0' is
b ₁ /a ₁ , the leverage ratio at the second pair of points of action acting on the lever 20' during the tripping operation is b ₁ /a ₂ ;
Since b ₁ > a ₂ , the latter is larger, and it can be seen that the force for tripping the movable frame 6 is larger than the former. For example, if b ₁ =1, a ₁ =2, and a ₂ =2, the suction force characteristics for the movable frame 6 will be the same as those shown in FIG. 9 because twice the tripping force will be obtained with half the stroke.

〔Effect of the invention〕

According to this invention, the leverage of the lever when the welded contacts are tripped is greater than when the welded contacts are turned on, so that the welded contacts can be opened more reliably than before, and the structure is relatively simple. There is an effect that

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a first embodiment of the invention;
Figure 2 is an explanatory diagram of the operation of a polarized electromagnet, and Figure 3 is an illustration of the operation of a polarized electromagnet.
Figure 4 is a sectional view taken along the lines shown in Figure 1, Figure 5 is an exploded perspective view, Figure 6 is a front view of the polarized electromagnet, and Figure 7 is a side view showing the relationship between the plunger and lever. , Fig. 8 is an explanatory diagram showing the leverage ratio of the lever, Fig. 9 is an attraction force characteristic diagram, Fig. 10 is a partial side view showing the relationship between the plunger and lever of the second embodiment, and Fig. 11 is a diagram showing the lever. An explanatory diagram showing the lever ratio, Fig. 12 is an exploded perspective view of the lever and the connecting frame, Fig. 1
3 is a sectional view of the conventional example, FIG. 14 is a side view of the electromagnet, FIG. 15 is an enlarged view of the lever, and FIG. 16 is a characteristic diagram of the attraction force. 4...Polarized electromagnet, 6...Movable frame, 9...Plunger, 27...Movable contact, 28...Fixed contact,
31...Return spring, a, b...Distance (first pair of points of action), a, c...Distance (second pair of points of action), _a1 , _b1 ...Distance (first pair of points of action) a pair of points of action),
a ₂ , b ₁ ... distance (second pair of points of action).

Claims (1)

[Claims] 1 A movable frame having a polarized electromagnet, a movable contact that is movable in a direction parallel to the reciprocating direction of the plunger of the polarized electromagnet and that closes the fixed contact in one direction; A return spring that biases the frame in a direction in which the movable contact opens and separates the movable contact, and a lever that is pivotally supported at an intermediate portion and that connects both ends to the plunger and the movable frame, and performs the closing operation of the movable frame. The lever is configured such that the driving force of the plunger when opening the movable frame is greater than the driving force of the plunger when the plunger is operating in one direction, when the plunger is operating in one direction to close the movable frame. the plunger and the movable frame respectively engage the lever from the center of rotation of the first
and a second position at which the plunger and the movable frame engage with the lever, respectively, from the center of rotation of the lever when the movable frame is opened by the operation of the plunger in the other direction.
An electromagnetic contactor characterized by having different lever ratios for the distance to the position.