JPH11297177A - Contact open and close device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce electric power for closing a movable contact and a fixed contact and make structure simple by arranging a tripping means for opening the fixed contact and an energizing means for applying force in the closing direction to a movable structural body between a base and the movable structural body. SOLUTION: A cross bar 35 is pushed against an opening stopper by the resisting force of a tripping spring 22 and rested, and magnetic attractive force is applied to between a permanent magnet 29 and an attracting member 31 through a yoke 30. In order to close a movable contact 23a and a fixed contact 16a, a driving means 17 needs the driving force exceeding the resisting force of a main contact spring and the tripping spring 22. Force almost equal to the sum of the resisting force of the main contact spring 24 and that of the tripping spring 22 is applied to the opposite direction, and balanced to force applied to the cross bar 35 to drive a driving means 17 with less input power. For balancing, a cancel mechanism 27A, a magnet unit 32, a first and second balancing springs 33, (34) are installed. A frame is strongly held against shock or the like and opening of the contact is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact switching device, and more particularly to an improvement of a mechanism for driving a movable contact.

[0002]

2. Description of the Related Art FIG. 11 is a cross-sectional view showing an initial state of an example of a conventional contact opening / closing device. FIG. 12 is a view showing a moving distance of a movable core shown in FIG. FIG. 4 is a relationship diagram showing an outline of the relationship.

In FIG. 11, reference numeral 1 denotes a base having a mounting base 1a, a housing 1b, and an upper stopper 1c; 2, 3; an excitation coil and a fixed core provided in the base 1; The movable core 5 provided in the base 1 is a crossbar made of an insulating material connected to the movable core 4, and 6 is slidably held in a window 5a at the upper part of the crossbar 5 in the vertical direction in the figure. A movable contact 6 a is attached to both ends of the movable contact 6.

[0004] Reference numeral 7 denotes a main contact spring for applying a contact pressure to the movable contact 6. The main contact spring 7 is constituted by a compression coil spring, and is attached by applying a preload in an initial state. Reference numeral 8 denotes a fixed contact that is electrically connected to and fixed to the terminal plate 9.
The fixed contact 8a to which the movable contact 6a comes and goes is attached to one end of the fixed contact 8a. The terminal plate 9 is provided with terminal screws 9a for connecting an external circuit (not shown). Reference numeral 10 denotes a trip spring provided between the fixed iron core 3 and the movable iron core 4.

[0005] Next, in FIG.
, The moving distance from the initial state, the Y axis is the suction force, the reaction force, a
Is the resultant of the reaction forces of the trip spring 10 and the main contact spring 7, b
Is an attractive force excited between the fixed iron core 3 and the movable iron core 4,
c is a position where the movable contact 6a and the fixed contact 8a are in contact with each other, d
Is the position where the closing operation of the movable contact 6a and the fixed contact 8a is completed, e is the reaction force of the trip spring 10 in the initial state, and f is the trip at the moment when the movable contact 6a and the fixed contact 8a come into contact with each other. The reaction force g of the spring 10 is the trip spring 10 and the main contact spring 7 at the moment when the main contact spring 7 is preloaded at the moment following f.
H is a suction force in a state where the closing operation of the movable contact 6a and the fixed contact 8a is completed.

Next, the operation will be described. Movable contact 6
a to close the fixed contact 8a with the trip spring 10
It is necessary to apply power to the exciting coil 2 in the initial state to generate an attractive force equal to or more than the reaction force e. When such power is applied to the exciting coil 2, an attractive force is generated between the fixed iron core 3 and the movable iron core 4 by the generated magnetic flux. Due to this suction force, the combined body of the movable iron core 4 and the crossbar 5 moves downward in FIG. 11 against the reaction force e of the trip spring 10.

[0007] The combined body of the movable iron core 4 and the crossbar 5 is c
When the movable contact 6a moves to the position, the movable contact 6a and the fixed contact 8a come into contact with each other. The reaction force of the trip spring 10 at the moment of contact is f, but the pre-load of the main contact spring 7 is applied at the next moment, so the reaction force is the resultant force g of the reaction forces of the trip spring 10 and the main contact spring 7. become.

Since the iron core gap in the open state of FIG. 11 is configured to be larger than the contact gap, the crossbar 5 moves further below the contact start position of the movable contact 6a and the fixed contact 8a. At that time, the main contact spring 7 is compressed,
The movable contact 6 is urged by the reaction force, and a main contact force is obtained. When the movable core 4 moves to d and collides with the fixed core 3, the closing operation of the movable contact 6a and the fixed contact 8a is completed, and this state is maintained. At this time, the suction force is maintained at h.

On the other hand, when the power of the exciting coil 2 is removed,
The magnetic attraction between the movable core 4 and the fixed core 3 disappears,
Due to the reaction force of the main contact spring 7 and the trip spring 10, the combined body of the movable core 4 and the crossbar 5 is moved upward in FIG. When the combination moves to the position c in FIG. 12, the contacts are opened. Thereafter, the combined body of the movable iron core 4 and the crossbar 5 is moved only by the reaction force of the trip spring 10,
It is stopped by being pressed against the upper stopper 1c. At the time when the assembly stops, the opening operation of the movable contact 6a and the fixed contact 8a is completed.

Here, in the initial state of FIG. 11, the distance between the fixed core 3 and the movable core 4 is maximum, and the distance between the movable contact 6a and the fixed contact 8a is naturally maximum. . Therefore, when closing the movable contact 6a and the fixed contact 8a, a sufficiently large electric power is applied to the exciting coil 2 and the combined body of the movable iron core 4 and the crossbar 5 is tripped to resist the reaction force e of the spring 10. It is necessary to generate a suction force that is sufficient to move the object.

In the state d in which the closing operation of the movable contact 6a and the fixed contact 8a is completed, the displacement of the main contact spring 7 and the displacement of the trip spring 10 are both maximum. To be max. However, in this state,
The fixed iron core 3 and the movable iron core 4 collide and come into close contact with each other, and since the distance between them is zero, the suction force is maximized.
For this reason, the required attraction force h can be obtained without applying a large amount of power to the exciting coil 2 as in the initial state.

As described above, in the system in which electric power is applied to the exciting coil 2 attached to the fixed core 3 to excite it, and the movable core 4 arranged with a gap therebetween is attracted, when the gap length increases, the fixed core becomes larger. Since the attractive force acting between the movable core 3 and the movable core 4 decreases nonlinearly, it is necessary to apply a large power to the exciting coil 2 in an initial state. However, when the fixed iron core 3 and the movable iron core 4 collide and come into close contact with each other, and the closing operation of the movable contact 6a and the fixed contact 8a is completed, the reaction force between the main contact spring 7 and the tripping spring 10 becomes maximum. However, the required suction force h can be obtained with an extremely small applied power as compared with the initial state.

Conversely, if the power applied to the exciting coil 2 is fixed, the power in the initial state requiring the largest attraction force must be constantly applied, and when the closing operation is completed, an excessive amount of power is required. That is, a strong suction force is generated.

[0014] For example, AC class 3 stipulated by the JIS standard C8325-1977 AC electromagnetic switch described in the technical data book of the electromagnetic switch MS-K series manufactured by Mitsubishi Electric Corporation, which is a conventional contact switch. Electromagnetic switch that satisfies
When the voltage applied to the exciting coil 2 is AC220V, 60H
In the case of z, the initial power applied to the exciting coil 2 needs to be about 270 W in order to move the combined body of the movable iron core 4 and the crossbar 5 from the initial state. On the other hand, in the state d in which the closing operation of the movable contact 6a and the fixed contact 8a is completed and held, the electric power applied to the exciting coil 2 needs only about 2 W. Thus, there is a large difference in the applied power required for the exciting coil 2 between the initial state and the state where the closing operation is completed.

For this reason, in the conventional contact opening / closing device, just before the displacement of the main contact spring 7 becomes maximum, that is, immediately before d in FIG. %, And DC is produced by full-wave rectification, so that the power applied to the exciting coil 2 = about 2 W is obtained by DC. The reason for holding at DC is that the fixed core 3 and the movable core 4 vibrate at 60 Hz,
This is to eliminate the beating sound generated by the collision.

[0016]

In the conventional contact switching device constructed as described above, the distance between the fixed iron core 3 and the movable iron core 4 is maximized in the initial state, so that the movable contact 6a and the movable contact 6a are fixed. To close the contact 8a, there is a problem that it is necessary to apply a large electric power to the exciting coil 2. In addition, a limit switch and a built-in circuit are necessary to hold the voltage at DC, and there is a problem that the number of parts increases. Furthermore, the variation in the operation start point of the limit switch is large, the operation of the limit switch is too early, the switching to DC low power is too early, and the closing operation of the movable contact 6a and the fixed contact 8a may not be completed. There was also.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and can reduce the power required for closing the movable contact and the fixed contact, and can reduce the number of parts. An object of the present invention is to provide a contact switching device that can be reduced in size and simplified in structure.

[0018]

According to a first aspect of the present invention, there is provided a contact opening / closing device including a base, a fixed contact provided on the base and having fixed contacts, and a reciprocating movement provided on the base. A movable structure, a movable contact provided on the movable structure so as to be able to reciprocate in the reciprocating direction of the movable structure, and having a movable contact that comes into contact with and separates from the fixed contact; A main contact spring that is provided in a pressurized state between the contact and applies a main contact force to the movable contact when closed, and a driving unit that is provided on the base and moves the movable structure in the closing direction; A tripping means provided between the base and the movable structure for separating the fixed contact from the movable contact, and a force provided between the base and the movable structure in a closing direction with respect to the movable structure And urging means for acting the

A contact switching device according to a second aspect of the present invention is provided with a rod reciprocated by a driving means, a movable contact and a main contact spring, and is displaceable in the reciprocating direction of the movable structure with respect to the rod. A frame, an internal force generating spring stopper that is provided on the rod, and regulates a relative displacement of the frame with respect to the rod in the closing direction; and an internal force generating spring stopper that is provided between the internal force generating spring stopper and the frame. A movable structure having an internal force generating spring for generating a spring force corresponding to the displacement is used.

The contact opening and closing device according to the third aspect of the present invention has a base provided with a closing stopper for restricting the movement of the frame in the closing direction.

A contact switching device according to a fourth aspect of the present invention is provided between the base and the movable structure, and is configured to move the movable structure in the opening direction with respect to the movable structure during the displacement of the movable structure in the closing direction. It is provided with a balancing spring for applying a spring force.

According to a fifth aspect of the present invention, there is provided a contact switching device including a plurality of balancing springs for applying a spring force to the movable structure at different timings.

According to a sixth aspect of the present invention, there is provided a contact opening / closing device provided with a permanent magnet provided on one of the movable structure and the base and a permanent magnet provided on the other of the movable structure and the base. A magnet unit having a suction member attracted by the above is used as the urging means.

According to a seventh aspect of the present invention, in the contact opening / closing device, a canceling mechanism for applying a canceling force to the movable structure to cancel the preload of the main contact spring acting on the movable structure at the moment when the movable contact comes into contact with the fixed contact. It is provided with.

The contact opening and closing device according to the invention of claim 8 is provided with a plurality of canceling mechanisms for applying a canceling force under different conditions.

A contact switching device according to a ninth aspect of the present invention uses a canceling mechanism that magnetically generates a canceling force.

[0027] According to a tenth aspect of the present invention, there is provided a contact switching device.
One using a permanent magnet provided on one of the movable structure and the base, and a suction mechanism provided on one of the other of the movable structure and the base and attracted by the magnetic force of the permanent magnet It is.

The contact switching device according to the eleventh aspect of the present invention
A base, a fixed contact provided on the base and having a fixed contact, a movable structure provided reciprocally on the base, and movable reciprocally in a reciprocating direction of the movable structure. A movable contact provided on the structure and having a movable contact which comes into contact with and separates from the fixed contact; and a movable contact provided between the movable structure and the movable contact in a pressurized state. A main contact spring for applying a main contact force, provided on a base,
Drive means for moving the movable structure in the closing direction, trip means provided between the base and the movable structure, for separating the fixed contact from the movable contact, and at the moment the movable contact comes into contact with the fixed contact A canceling mechanism for applying a canceling force to the movable structure to cancel the preload of the main contact spring acting on the movable structure.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. 1 is a sectional view of an initial state of a contact switching device according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, FIG. 3 is a sectional view taken along line III-III of FIG. FIG. 4 is a sectional view taken along line IV-IV of FIG. 3. In addition,
FIG. 1 corresponds to a cross-sectional view taken along line II of FIG.

In the drawing, reference numeral 11 denotes a mounting base provided with a closing stopper 11a, 12 denotes a housing fixed on the mounting base 11, 13 denotes an opening stopper fixed in the housing 12, and 14 denotes a mounting base. 11, housing 1
2 and a base having an opening stopper 13. Reference numeral 15 denotes a plurality of terminal boards fixed to the opening stopper 13;
Are fixed contacts which are electrically connected to and fixed to the respective terminal boards 15, and these fixed contacts 16
Are provided with fixed contacts 16a, respectively.

Reference numeral 17 denotes a drive unit fixed above the base 14, and a DC linear motor is used as the drive unit 17. Numeral 18 denotes two rods which penetrate the driving means 17 and are reciprocally slid in the vertical direction in FIG. 1 by the driving means 17.
It is inserted into the base 14. A bearing mechanism (not shown) for guiding the rod 18 is provided in the driving unit 17.

A frame 19 is provided in the base 14 so as to be able to reciprocate up and down in FIG. 2 and comes into contact with and separates from the closing stopper 11a and the opening stopper 13.
Is provided with a spring accommodating portion 19a and three windows 19b penetrating in the left-right direction of FIG. 20 is a spring receiving part 1
An internal force generating spring stopper 21 fixed to the lower end of the rod 18 within 9a is provided between the internal force generating spring stopper 20 and the frame 19, and the frame 19 is moved downward with respect to the rod 18 in FIG. A plurality of internal force generating springs for urging the frame 19 into contact with the upper surface of the internal force generating spring stopper 20, and these internal force generating springs 21 are given a preload that does not cause bending in the initial state. ing.

A frame 22 is provided between the mounting base 11 and the frame 19 and urges the frame 19 upward to move the frame 19
A plurality of tripping springs as tripping means for contacting the opening stopper 13 with the opening stopper 13, and a plurality of movable contacts 23 provided on the window 19b of the frame 19 so as to be slidable in the vertical direction in FIG. At both ends of these movable contacts 23, movable contacts 23a that come into contact with and separate from the fixed contact 16a are provided. Reference numerals 24 are main contact springs respectively provided in the windows 19b and applying a main contact force to the movable contact 23. These main contact springs 24 are provided in the window 1 in a preloaded state.
9b.

Numeral 25 denotes a small permanent magnet fixed to the base 14, and 26 denotes a small permanent magnet 2 fixed to the rod 18.
Small suction members 27A and 27B attracted by 5 are canceling mechanisms having small permanent magnets 25 and small suction members 26.

A balancing spring stopper 28 is connected to the internal force generating spring stopper 20 and reciprocates in the vertical direction in FIG. 2 integrally with the rod 18, and 29 is a balancing spring stopper 28.
, A yoke made of a magnetic material fixed to both ends of a permanent magnet 29, and 31 a mounting base 1.
32, a magnetic adsorption member fixed to the bottom of 1
Is a magnet unit as an urging means having a permanent magnet 29, a yoke 30, and an attraction member 31.

Reference numerals 33 and 34 denote first and second balancing springs which stand upright on the bottom of the mounting table 11, respectively. The first and second balancing springs 33 are casings 33a and 34, respectively.
a, a contact member 3 which is provided at the ends of the casings 33a and 34a so as to be able to protrude and retract, and against which the balancing spring stopper 28 contacts
3b, 34b and spring bodies 33c, 34c provided in the casings 33a, 34a to urge the contact members 33b, 34b in the protruding direction. Further, as shown in FIG. 4, in the initial state, the height of the contact member 33 b of the first balancing spring 33 is equal to the height of the contact member 3 of the second balancing spring 34.
It is higher than the height of 4b.

The cross bar 35, which is a movable structure according to the present embodiment, comprises a rod 18, a frame 19, an internal force generating spring stopper 20, and an internal force generating spring 21.

Next, the operation will be described. In the initial state, the crossbar 35 is pressed against the opening stopper 13 by the reaction force of the tripping spring 22 and remains stationary, as in the conventional case. However, in this embodiment, since the magnet unit 32 constituted by the magnet unit 32 is provided, the magnetic attraction force between the permanent magnet 29 and the attraction member 31 via the yoke 30 even in the initial state. Working. Therefore, the force corresponding to the reaction force e of the conventional tripping spring 10 of FIG.
The crossbar 35 is only large enough to overcome the sum of its own weight (when the vertical direction in FIG. 1 is used as the top and bottom) and press the crossbar 35 against the opening stopper 13.

In this state, the driving means 17 operates the tripping spring 2
2 generates a driving force greater than the reaction force e, the crossbar 3
5 moves downward in FIGS. 1 and 2. Driving means 17
Is a DC linear motor, so that if the input power is constant, the generated driving force is always constant without depending on the distance between the movable contact 23a and the fixed contact 16a.

However, the movable contact 23a and the fixed contact 16a
In order to complete the closing operation with
A driving force must be generated to overcome the reaction force of the main contact spring 24 and the trip spring 22. In the conventional contact opening / closing device, the main contact spring 7 and the trip spring 1 when the closing operation is completed.
The total reaction force of 0 is 7.6 kgf = 74.5N.

Here, the thrust obtained per 1 W by the linear motor is about 5 N / W even at very high efficiency, and less than half of that at normal efficiency. That is, even if this high-efficiency linear motor is used, the required input power is about 15 W. Compared with the conventional example, the input power in the initial state is reduced to about 6%, but the closing operation is completed. Conversely, the input power at the time increases about seven times and deteriorates.

On the other hand, in order to suppress the power applied to the driving means 17 to the power applied to the exciting coil 2 at the time of completion of the closing operation of the conventional example = about 2 W, the main contact spring 24 and the trip spring are required. 22 is the easiest way to reduce the reaction force. However, when the spring force of the main contact spring 24 is reduced, hunting occurs due to an electromagnetic repulsion generated between the movable contact 23a and the fixed contact 16a when the movable contact 23a and the fixed contact 16a come into contact, an arc is generated, and the heat causes wear of the contact. Abnormally accelerated. In the worst case, the movable contact 23
a and the fixed contact 16a are welded and cannot be separated, and the opening operation cannot be performed.

If the spring force of the trip spring 22 is reduced, the crossbar 35 cannot overcome its own weight and cannot be returned to the initial state, so that the opening operation cannot be performed. Therefore, it is difficult to reduce the reaction force of the main contact spring 24 and the trip spring 22.

Therefore, the main contact spring 24 and the trip spring 2
In order to achieve the same level of power when the closing operation of the conventional example is completed while securing the same reaction force as that of the prior art, a force having substantially the same magnitude as the reaction force of the main contact spring 24 and the trip spring 22 is applied. The force acting on the crossbar 35 in the opposite direction may be reduced in such a manner as to be substantially balanced. In this case, since only a small force is applied to the crossbar 35, the power applied to the driving means 17 can be made equal to the power applied when the conventional closing operation is completed.

As described above, in order to substantially balance the force applied to the cross bar 35, in this embodiment, the cancel mechanisms 27A and 27B, the magnet unit 32, the first balancing spring 33, and the second balancing spring 34 are used. Have been.

Looking at the direction in which the force is generated, the magnet unit 32 always generates a force in the closing direction, that is, downward in FIG. The first balancing spring 33 and the second balancing spring 34 generate a force in the opening direction, that is, upward in FIG. The canceling mechanisms 27A and 27B generate a downward attractive force in the closing direction, that is, the downward direction in FIG. 2 until the small attracting member 26 faces the small permanent magnet 25. This downward attractive force is maximized when the small attraction member 26 is near the upper end surface of the small permanent magnet 25, and gradually decreases thereafter, when the small attraction member 26 faces the small permanent magnet 25. It becomes 0.

Thereafter, as the small attracting member 26 moves near the lower end surface of the small permanent magnet 25, an attraction force is generated in the opening direction, that is, in the upward direction in FIG. The upward attraction force becomes maximum when the small attraction member 26 is near the lower end surface of the small permanent magnet 25, and thereafter gradually decreases.

Further, the frame 19 is provided with the closing stopper 11a.
Since the internal force generating spring 21 hardly contracts until the rod 18 and the frame 19 stop,
They generally move together. After that, after the frame 19 stops by hitting the closing stopper 11a, the rod 18
Only the rod 1 moves, so the internal force generating spring 21 has the rod 1
A large spring force is generated according to the displacement of No. 8. Since the large spring force balances the driving force of the magnet unit 32 via the internal force generating spring stopper 20, the large spring force is not applied to the rod 18 as a reaction force. For this reason, the driving force required for the driving means 17 to move the rod 18 toward the base 14 is the same as when the driving means 17 hits the closing stopper 11a and stops.

On the other hand, the large spring force generated in the internal force generating spring 21 is transmitted to the frame 19 as a reaction force. Since the frame 19 cannot move stationary, the force causes the frame 19 to be strongly pressed against the closing stopper 11a. As a result, even when a sudden disturbance such as an impact force is applied, the frame 19 does not move, so that the main contact force does not change, and the movable contact 23a is prevented from being separated from the fixed contact 16a. Also, the frame 1 in the closing direction
9 is regulated by the closing stopper 11a, the displacement of the main contact spring 24 can be made constant, and the main contact force can be stabilized.

FIGS. 5 to 10 are graphs showing the results of analysis of the change with respect to the moving distance of the rod 18 of the contact switch of FIG. 1. FIG. 5 shows the force acting on the upper end of the rod 18, and FIG. 7 shows the spring force of the main contact spring 24, FIG. 7 shows the canceling force generated by the canceling mechanisms 27A and 27B, and FIG.
9 shows the spring force of the first balancing spring 33, and FIG.
FIG. 10 shows the reaction force against the spring force of the internal force generating spring 21 applied to the closing stopper 11a.

First, the crossbar 35 in the initial state is moved downward in FIGS. 1 and 2 by the driving means 17. At this time, the required driving force is, for example, the reaction force in the initial state of the tripping spring 10 in the conventional contact switching device shown in FIG. 11 = 2 kgf = 19.6 N. Assuming that a high-efficiency linear motor is used, the required input power is about 4 W, which achieves the same input power as when the closing operation of the conventional example is completed.

Here, the solid line in FIG.
3. Second balancing spring 34 and canceling mechanisms 27A, 27
The case of no correction in which no force balancing by B is performed is shown. The vertical axis of the graph in FIG. 5 shows the result of the balance of the force at the upper end of the rod 18. At 0, the magnetic attractive force and the spring force are exactly balanced, and in the plus direction, the magnetic attractive force, that is, FIG. Indicates that the downward force is strong, and the negative direction indicates that the spring force, that is, the upward force in FIG. 2 is strong. In the case of no correction, the result of the balance between the magnetic attraction force of the magnet unit 32, its own weight, and the spring force of the main contact spring 24, the trip spring 22, and the internal force generating spring 21 is shown.

5A to 5J are the states until the movable contact 23a and the fixed contact 16a come into contact with each other. Here, the displacement of the trip spring 22 increases, and the spring force gradually increases linearly upward in FIG. Also, the magnet unit 32
With regard to (2), the permanent magnet 29 and the yoke 30 move closer to the attracting member 31 with the movement of the rod 18, so that the magnetic attractive force gradually increases nonlinearly downward in FIG.

The magnetic attraction of the magnet unit 32 in this state increases almost linearly because the increase is small. For this reason, the spring force and the magnetic attraction force are almost balanced as shown in FIGS. Therefore, the electric power supplied to the driving means 17 may be equal to that of the conventional example when the closing operation is completed. Until the frame 19 comes into contact with the closing stopper 11a and stops, the internal force generating spring 21 hardly shrinks, and the frame 19 of the crossbar 35 and the rod 1
8 moves substantially integrally.

In FIG. 5j, the contact between the movable contact 23a and the fixed contact 16a is started. For this reason, from j to k, the preload of the main contact spring 24 rises rapidly, and the line indicating the balance suddenly swings to the minus side. Then, from k to l
, The trip spring 22 and the main contact spring 24
Is substantially balanced with the increase in the magnetic attraction force of the magnet unit 32, so that the line indicating the balance is a substantially horizontal straight line. However, in the latter half of the section from k to l, the magnetic attraction force of the magnet unit 32 increases non-linearly and rapidly, so that the line indicating the balance gradually swings to the positive side. The section from l to m is the same as the latter half of the section from k to l.

When the frame 19 comes into contact with the closing stopper 11a and stops at m in FIG. 5, only the rod 18 continues to move from here. At this time, the displacement of the trip spring 22 and the main contact spring 24 also does not increase, so that the spring force of the trip spring 22 and the main contact spring 24 is constant. m until the rod 18 stops, the spring force of the internal force generating spring 21 and the magnetic attraction force of the magnet unit 32 are balanced.
Since the magnetic attraction force of the non-linear magnetic field rapidly increases in a non-linear manner, the balance line swings to the plus side.

In this section, the spring force generated by the internal force generating spring 21 is transmitted to the frame 19 as a reaction force, and the frame 19 is strongly pressed against the closing stopper 11a of the base 14 by this force. This force acts to hold the frame 19 against a sudden disturbance such as an impact force, so that the movable contact 23a and the fixed contact 16a can be prevented from being separated.

As described above, unless the forces of the first balancing spring 33, the second balancing spring 34, and the canceling mechanisms 27A, 27B are balanced at all, when the rod 18 stops, the magnetic attraction force is smaller. 16 kgf = 157 N is larger. For this reason, the input power required for the driving means 17 to open the movable contact 23a and the fixed contact 16a is about 31 W, and the opening operation is performed with the same input power as when the closing operation is completed in the conventional example. Can not do.

Therefore, in the contact opening / closing device shown in the embodiment, the first balancing spring 33, the second balancing spring 34, and the canceling mechanisms 27A and 27B are used to balance the force after j, and the conventional art is used. Opening / closing operation can be performed with the same input power as when closing operation is completed. Hereinafter, the operation when the force is balanced will be described.

As described above, j to k in FIGS. 5 and 6
In the section (1), the movable contact 23a and the fixed contact 16a start contacting, so that the preload of the main contact spring 24 rises rapidly. In order to balance forces in this portion, cancel mechanisms 27A and 27B are used. That is, a canceling force (magnetic attraction force) that rapidly rises downward in FIG. 2 is applied to the rod 18.

In this embodiment, two sets of cancel mechanisms 27A and 27B having different conditions are used. These canceling mechanisms 27A and 27B simultaneously generate canceling forces having different sizes (different ranges acting on the displacement amount of the rod 18), that is, two types of canceling forces indicated by narrow and wide. These two
The same canceling force is simultaneously applied in the sections from j to k in FIG. 7 and further ahead, so that not only the sudden rise due to the preload of the main contact spring 24 but also the balance of the force of the horizontal part thereafter are simultaneously performed. It is possible to take. The conditions such as the time for applying the canceling force and the magnitude of the canceling force depend on the thickness, length, gap size, type of magnet, etc. of the small attracting members 26 and the small permanent magnets 25 of the canceling mechanisms 27A and 27B. By changing it, optimization can be achieved.

In the canceling mechanisms 27A and 27B using the magnetic attractive force, the small attracting member 26 faces the small permanent magnet 25 in principle, and then applies the attracting force in the opposite direction, that is, the upward direction in FIG. Occur. However, the optimized na
The effect of the suction force in the opposite direction of the narrow is reduced by simultaneously applying and canceling the two canceling forces of the row and the wide. Further, after l in FIG. 7, the attractive force in the opposite direction of the wide remains as it is, but this section is a section in which the non-linear increase of the magnetic attractive force of the magnet unit 32 increases rapidly, and Since the attraction force in the opposite direction acts in the direction to cancel the magnetic attraction force of the magnet unit 32, it is preferable to balance the force at the upper end of the rod 18.

As described above, the canceling mechanisms 27A, 27
By balancing the forces using B, in the section from j to l, the spring force can be at least about 1 kgf = 9.8 N higher. At this time, the driving means 1
The input power required for 7 is about 2 W, and the closing operation can be performed with the same input power when the closing operation of the conventional example is completed.

Next, 1 to m in FIG.
2 is a section where the magnetic attraction force is rapidly increased non-linearly. In order to balance the forces in this section, the spring force of the first balancing spring 33 having the characteristics shown in FIG. 8 is applied to the rod 18 upward in FIG. Can be canceled.

As described above, by balancing the forces using the spring force of the first balancing spring 33, the spring force is larger by at least about 0.5 kgf = 4.9 N in the section from 1 to m. Can be At this time, the driving means 17
Is required to be about 1 W, and the closing operation can be performed with the same applied power as when the closing operation of the conventional example is completed.

Next, in the section from m in FIG. 5 to when the rod 18 stops, the spring force of the internal force generating spring 21 and the magnetic attraction force of the magnet unit 32 are balanced. This is a section in which the non-linear increase of the magnetic attraction force rapidly increases. In order to balance forces in this section, a second balancing spring 34 having characteristics as shown in FIG.
Is applied to the rod 18 upward in FIG. 2 to cancel the magnetic attraction of the magnet unit 32.

As described above, by balancing the forces using the spring force of the second balancing spring 34, the spring force is at least 0.1 in the section from m to the time when the rod 18 stops.
kgf = 1N. At this time, the input power required for the driving means 17 is about 0.2 W, and the closing operation can be performed with the same input power as when the closing operation of the conventional example is completed.

Also in this case, since the spring force of the second balancing spring 34 is applied to the rod 18, a part of the spring force generated in the internal force generating spring 21 is less than the spring force of the second balancing spring 34. Canceled by minutes. However, the internal force generating spring 21
The rest of the spring force generated in the frame 1 is transmitted to the frame 19 as a reaction force as shown in FIG.
9 is strongly pressed against the closing stopper 11a. This force is applied to the frame 1 against sudden disturbances such as impact forces.
9, the movable contact 23a can be prevented from being separated from the fixed contact 16a.

As described above, the magnet unit 32, the first balance spring 33, the second balance spring 34, and the cancel mechanism 27
A and 27B are used to substantially balance the forces acting on the crossbar 35, so that only the input power at the same time as when the closing operation of the conventional example is completed, that is, about 2W, is applied to the driving means 17, and the movable contact The closing operation of the fixed contact 23a and the fixed contact 16a can be performed.

In the above embodiment, the first and second
Although a spring using a compression spring as the balancing springs 33 and 34 has been described, the present invention is not limited to this. For example, a combination of leaf springs, a conical spring exhibiting nonlinear characteristics, a bamboo spring, or a combination thereof It may be.

In the above embodiment, the permanent magnet 29 magnetized with the N pole on the left side and the S pole on the right side of FIG. 2 is used for the magnet unit 32. However, if a predetermined magnetic attraction force can be obtained. The magnetized state is not limited to this. For example, the upper side in FIG. 2 may be magnetized to the N pole, and the lower side may be magnetized to the S pole. Further, the shape, dimensions, material, mounting position, and the like of the yoke 30 can be changed as long as a predetermined magnetic attraction force can be obtained.

Further, in the above embodiment, the rod 18
The movable member on the side is a magnet 29 and a yoke 30, and the base 1
Although the fixing member on the fourth side is the suction member 31, the fixing member may be arranged reversely, and the moving part can be reduced in weight and the operating characteristics can be improved.

Further, in the above-described embodiment, two sets of canceling mechanisms 27A and 27B are provided in order to balance with one force that rises sharply. However, one canceling mechanism balances a plurality of forces that suddenly rise up. The canceling mechanism may be combined in any manner as long as the forces can be balanced.

In the above embodiment, the rod 18,
First and second balancing springs 33 and 34 and internal force spring 21
The material of the magnet unit 3 is not particularly limited.
2, any material may be used as long as it does not adversely affect the magnetic circuits of the cancel mechanisms 27A and 27B, and it is not necessary to use a non-magnetic material.

Further, in the above-described embodiment, the yoke 30 of the magnet unit 32 and the attraction member 31 are directly attracted, but at least one of the attraction surfaces of the yoke 30 and the attraction member 31 is, for example, a non-magnetic sheet. Or the like may be attached, thereby reducing the influence of variations in magnetic attraction due to variations in magnetization and variations in surface roughness.

Further, in the above-described embodiment, the balancing spring stopper 28 is received by the balancing springs 33 and 34 fixed in the base 14, but at least one of the balancing springs is replaced by the balancing spring. The base 14 may be fixed to the stopper 28 and may be separated from the base 14.

In the above embodiment, the balance springs 33 and 34 are provided between the base 14 and the balance spring stopper 28, but at least one of the balance springs is connected to the frame 1
9 and the base 14 may be provided. In this case, the balancing spring may be fixed to the base 14 side or the frame 19 side. Further, at least one of the balancing springs may be provided between the internal force generating spring stopper 20 and the base 14. In this case, the balancing spring may be fixed to the base 14 side or the internal force generating spring stopper 20 side.

Further, in the above embodiment, all the internal force generating springs 24 are pressurized and arranged, but at least one internal force generating spring may be arranged without applying pressure. In this case, the internal force generating spring to which no pressurization is applied may be fixed to the rod 18 side or the frame 19 side.

Further, in the above-described embodiment, a DC linear motor is used as the driving means 17. However, if a predetermined performance is obtained and dimensional restrictions and costs are satisfied, for example, a plunger or the like may be used. Any of the above may be used. Further, a displacement enlargement mechanism, a deceleration mechanism, and the like may be used together.

In the above embodiment, the canceling mechanisms 27A and 27B using a magnetic circuit have been described.
Any other method may be used as long as a predetermined canceling force can be obtained. Further, the urging means is not limited to the magnet unit 32. Furthermore, the movable structure is not limited to the crossbar 35.

[0081]

As described above, in the contact opening and closing device according to the first aspect of the present invention, the urging means for applying a force in the closing direction to the movable structure is provided between the base and the movable structure. With this arrangement, the urging force of the urging means can be substantially balanced with the force in the opening direction acting on the movable structure, and the driving force required for the driving means can be reduced. Can be reduced.

In the contact opening / closing device according to the second aspect of the present invention, since the movable structure is constituted by the rod, the frame, the internal force generating spring stopper and the internal force generating spring, it is generated in accordance with the relative displacement between the rod and the frame. The spring force can be stored as an internal force in the internal force generating spring, whereby the frame can be firmly held against sudden disturbance such as an impact force, and the movable contact and the fixed contact can be separated. Can be prevented.

In the contact opening / closing device according to the third aspect of the present invention, since the closing stopper for restricting the movement of the frame in the closing direction is provided on the base, the displacement of the main contact spring can be made constant, and the main contact force can be made constant. Can be obtained.

According to a fourth aspect of the present invention, there is provided a contact opening / closing device comprising a balancing spring for applying a spring force in the opening direction to the movable structure during the displacement of the movable structure in the closing direction. Since it is provided between the body and the body, even when the urging force of the urging means changes nonlinearly, the resultant force acting on the movable structure can be stabilized, and the power input to the driving means can be kept small. it can.

The contact opening and closing device according to the fifth aspect of the present invention is provided with a plurality of balancing springs having different operation timings of the spring force.
It is possible to respond more reliably.

In the contact switching device according to the sixth aspect of the present invention, since the magnet unit having the permanent magnet and the attraction member is used as the urging means, the non-linear urging force acts on the movable structure without consuming power. Can be done. Further, since electric wiring and the like are unnecessary, the number of parts is small, the reliability is excellent, and the cost can be reduced.

According to a seventh aspect of the present invention, there is provided a contact opening / closing device having a canceling mechanism for applying a canceling force to the movable structure to cancel a preload of the main contact spring acting on the movable structure at the moment when the movable contact comes into contact with the fixed contact. With the provision, the driving force required for the driving means can be reduced, and the power input to the driving means can be reduced.

The contact switching device according to the eighth aspect of the present invention uses a plurality of canceling mechanisms for applying the canceling force under different conditions, so that the driving force required for the driving means can be reduced, and The input power can be reduced.

The contact switching device according to the ninth aspect of the present invention uses a canceling mechanism that magnetically generates a canceling force, so that the canceling force can be obtained without consuming power. Further, since electric wiring and the like are unnecessary, the number of parts is small, the reliability is excellent, and the cost can be reduced.

The contact switching device according to the tenth aspect of the present invention uses the canceling mechanism having the permanent magnet and the attraction member, so that the canceling force can be more reliably generated with a simple structure.

According to the eleventh aspect of the present invention, there is provided a contact opening / closing device having a canceling mechanism for applying a canceling force to the movable structure for canceling the preload of the main contact spring acting on the movable structure at the moment when the movable contact comes into contact with the fixed contact. With the provision, the driving force required for the driving means can be reduced, and the power input to the driving means can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an initial state of a contact switching device according to an example of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III of FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

5 is a relationship diagram showing a relationship between a displacement amount of the rod of FIG. 1 and a force acting on an upper end of the rod.

FIG. 6 is a relationship diagram showing a relationship between a displacement amount of a rod of FIG. 1 and a spring force of a main contact spring.

FIG. 7 is a relationship diagram showing a relationship between a displacement amount of a rod of FIG. 1 and a canceling force generated by a canceling mechanism.

8 is a relationship diagram showing a relationship between a displacement amount of a rod in FIG. 1 and a spring force of a first balancing spring.

FIG. 9 is a relationship diagram showing a relationship between a displacement amount of a rod in FIG. 1 and a spring force of a second balancing spring.

10 is a relationship diagram showing a relationship between a displacement amount of a rod of FIG. 1 and a reaction force against a spring force of an internal force generating spring applied to a closing stopper.

FIG. 11 is a cross-sectional view showing an initial state of an example of a conventional contact switching device.

12 is a relationship diagram schematically showing a relationship between a moving distance of the movable iron core of FIG. 11 and a resultant force of a suction force and a reaction force acting on the movable iron core.

[Explanation of symbols]

11a closing stopper, 14 base, 16 fixed contacts, 16a fixed contact, 17 driving means, 18 rod, 19 frame, 20 internal force generating spring stopper,
21 internal force generating spring, 22 tripping spring (tripping means), 23 movable contact, 23a movable contact, 24 main contact spring, 25 small permanent magnet, 26 small attracting member,
27A, 27B cancellation mechanism, 29 permanent magnets, 3
1 attracting member, 32 magnet unit (biasing means), 33
First balancing spring, 34 Second balancing spring, 35 Crossbar (movable structure).

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takaaki Mori 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation

Claims (11)

[Claims] 1. A base, a fixed contact provided on the base and having a fixed contact, a movable structure provided reciprocally on the base, and a reciprocating direction of the movable structure. A movable contact provided on the movable structure so as to be able to reciprocate, and having a movable contact that comes into contact with and separates from the fixed contact; and a state in which pressure is applied between the movable structure and the movable contact. A main contact spring for applying a main contact force to the movable contact at the time of closing; a driving means provided at the base for moving the movable structure in a closing direction; and the base and the movable structure. A tripping means for separating the fixed contact from the movable contact; and a tripping means provided between the base and the movable structure to apply a force to the movable structure in a closing direction. And a biasing means for acting. Contact switching apparatus. 2. A movable structure includes a rod reciprocated by a driving means, a frame provided with a movable contact and a main contact spring, and displaceable in the reciprocating direction of the movable structure with respect to the rod. An internal force generating spring stopper that is provided on the rod and regulates relative displacement of the frame in the closing direction with respect to the rod; and an internal force generating spring stopper that is provided between the internal force generating spring stopper and the frame. 2. The contact opening and closing device according to claim 1, further comprising: an internal force generating spring that generates a spring force corresponding to a relative displacement between the contact opening and closing device. 3. The contact opening / closing device according to claim 2, wherein the base is provided with a closing stopper for restricting the movement of the frame in the closing direction. 4. It is provided between the base and the movable structure,
4. A balancing spring according to claim 1, further comprising a balancing spring for applying a spring force to the movable structure in an opening direction during the displacement of the movable structure in the closing direction. The contact switching device according to any one of the above. 5. The contact opening / closing device according to claim 4, further comprising a plurality of balancing springs for applying a spring force to the movable structure at different timings. 6. A permanent magnet provided on one of the movable structure and the base, and an attracting member provided on one of the other of the movable structure and the base and attracted by a magnetic force of the permanent magnet. The contact switching device according to any one of claims 1 to 5, wherein a magnet unit having the following is used as the urging means. 7. A cancel mechanism for applying a canceling force to the movable structure to cancel a preload of a main contact spring acting on the movable structure at the moment when the movable contact comes into contact with the fixed contact. The contact switching device according to any one of claims 1 to 6. 8. The contact opening / closing device according to claim 7, further comprising a plurality of canceling mechanisms for applying a canceling force under mutually different conditions. 9. The contact opening / closing device according to claim 7, wherein a canceling mechanism that magnetically generates a canceling force is used. 10. A permanent magnet provided on one of the movable structure and the base, and a cancellation mechanism provided on one of the other of the movable structure and the base.
The contact opening / closing device according to claim 9, further comprising an attraction member that is attracted by a magnetic force of the permanent magnet. 11. A base, a fixed contact provided on the base and having a fixed contact, a movable structure provided reciprocally on the base, and a reciprocating direction of the movable structure. A movable contact provided on the movable structure so as to be able to reciprocate, and having a movable contact that comes into contact with and separates from the fixed contact; and a state in which pressure is applied between the movable structure and the movable contact. A main contact spring for applying a main contact force to the movable contact at the time of closing; a driving means provided at the base for moving the movable structure in a closing direction; and the base and the movable structure. A tripping means for separating the fixed contact from the movable contact, and canceling a preload of the main contact spring acting on the movable structure at the moment when the movable contact comes into contact with the fixed contact. Above cancellation power Contact switching apparatus characterized by comprising a cancel mechanism to be applied to the structure.