JP2000268694A - Switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cost and to prevent impact force of an iron core and wear and damage of an attraction surface by driving a switch by small electromagnetic force by assisting driving force of a movable part by reversal of a reverse spring when the movable part is moved in a direction that a contact is closed and rotating the reverse spring when the movable part is moved in a direction that the contact is opened. SOLUTION: When voltage is applied on a coil 12, a movable iron core 9 and a cross bar 1 are moved by electromagnetic attraction. Because a tip part 15a of a reverse spring is engaged with a rotation suppressing groove, the tip part 15a is not rotated and is moved in an attraction direction, and the reverse spring 15 is reversed and the tip part 15a is abutted on a recessed part bottom surface 19b of the cross bar 1 and driving force in the attraction direction is assisted. When voltage of the coil 12 is switched off, electromagnetic attraction is extinguished and the cross bar 1 is moved in a separating direction by restoring force of a separating spring 14. The tip part 15a is moved from the recess bottom surface 19b of the cross bar 1 to a recess side surface, the reverse spring 15 is rotated around a shaft 17, force of the attraction direction is reduced by restoring force, and electromagnetic attraction closing the iron core 9, that is, power is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch for opening and closing an electric circuit, and more particularly to an improvement of a switch capable of performing a stable switching operation with a small electromagnetic attraction force.

[0002]

2. Description of the Related Art FIG. 7 is a sectional view showing a conventional switch, in which 1 is a crossbar, 1a is a crossbar window, 2 is a movable contact arranged on the crossbar window 1a,
3 is a movable contact attached to both ends of the bottom surface of the movable contact 2, 4 is a contact presser, 5 is a cross bar 1 in a compressed state.
A contact spring, which is incorporated in the inside and presses the movable contact 2 through the contact presser 4 by the restoring force, 6 is a base, 7
Is a fixed contact fixed to the base 6, 8 is a fixed contact mounted on the upper surface of the fixed contact disposed opposite to the movable contact 3, 9 is a movable core connected to the crossbar 1, 10 is A mounting base, 11 is a fixed iron core arranged with a predetermined gap from the movable iron core 9, 12 is a coil, 13 is a coil spool serving as a winding frame of the coil 12, and 14 is a crossbar 1
And a separation spring disposed between the coil spring 13 and the coil spool 13.

In FIG. 7, when a voltage is applied to a coil 12, a magnetic flux is generated around the coil, an electromagnetic attraction is generated between the fixed core 11 and the movable core 9, and the movable core 9 is attracted to the fixed core 11. (This direction is the suction direction). At this time, the crossbar 1 connected to the movable iron core 9 also moves while receiving the resistance due to the restoring force of the separation spring 14,
The movable contact 2 arranged in the window 1a of the crossbar is drawn to the fixed contact 7, and the movable contact 3 attached to the movable contact 2 and the fixed contact 8 attached to the fixed contact 7 abut. . The gap between the movable core 9 and the fixed core 11 (A in the figure) is formed larger than the gap between the movable contact 3 and the fixed contact 8 (B in the figure), and the crossbar 1 exceeds the contact position. The movable iron core 9 and the fixed iron core 11 are further closed in the suction direction. Therefore, the contact spring 5 is further compressed, and the restoring force due to the compression is applied to the movable contact 2 via the contact presser 4 to generate a predetermined contact pressure between the movable contact 3 and the fixed contact 8. Then, the electric circuit connected to the outside of the switch is closed.

In FIG. 7, when the voltage applied to the coil 12 is cut off, the electromagnetic attraction force closing the movable iron core 9 and the fixed iron core 11 disappears, and the electric power between the crossbar 1 and the coil spool 13 is reduced. The crossbar 1 is pushed up by the restoring force of the separation spring 14 arranged at the position (this direction is referred to as a separation direction), the movable contact 3 and the fixed contact 8 are separated, and the electric circuit connected to the outside of the switch is cut off. .

In the conventional switch having such a configuration, the electromagnetic attraction force generated by energizing the coil is inversely proportional to the gap between the movable core and the fixed core, and therefore increases as the movable core is drawn and closes. Sometimes maximum. On the other hand, at the moment when the contacts come into contact, the restoring force of the contact spring is applied to the crossbar connected to the movable iron core in a direction to cancel the electromagnetic attraction force, so that the propulsive force of the crossbar decreases.
In order to exceed the restoring force of the contact spring and stably close the iron core, a large electromagnetic attraction force is required.

Next, a conventional example using a reversing spring disclosed in, for example, Japanese Patent Application Laid-Open No. 60-74225 will be described with reference to FIG. In the figure, the same parts as those in FIG. 7 are denoted by the same reference numerals. 15 is a reversing spring, 15a
Is a tip of the reversing spring 15, 15b is a fixing portion of the reversing spring 15, and 16 is a recess formed in the crossbar 1. The reversing spring 15 is formed, for example, by connecting the tips of U-shaped leaf spring materials as shown in FIG.
As shown in (b) and (c), when the shape exceeds the XY plane, the shape is reversed and the tip 15a is inserted into the recess 16 and the fixing portion 15b is fixed to the base 6.

In a conventional switch as shown in FIG. 8, when a voltage is applied to the coil 12, the movable core 9 and the crossbar 1 move in the suction direction by electromagnetic attraction, and are inserted into the recess 16 of the crossbar 1. Tip 1 of inverted spring 15
5a is also a fixing portion 15 of the reversing spring 15 fixed to the base 6.
It moves in the suction direction with b as a fulcrum. With the movement of the tip 15a of the reversing spring, the reversing spring 15 is moved to the position shown in FIG.
From the shape shown in FIG. 9C to the shape shown in FIG. The operation of the reversing spring is used to assist the thrust of the crossbar 1 in the suction direction.

In the conventional switch having such a structure, the electric circuit can be reliably closed by the restoring force of the reversing spring 15 acting in the suction direction. Until the contact is reversed in the opening direction, the reversing spring 15 exerts a restoring force against the force pushing up the crossbar 1 in the opening direction. Had to be increased. Therefore, a large electromagnetic attraction force that overcomes the restoring force of the separation spring 14 is required.

[0009]

In the conventional switch having the above configuration, a large electromagnetic attraction force is required, so that the power input to the coil and the weight of the movable iron core need to be increased. Accordingly, a large impact force is generated at the time of closing, and there is a problem that the contact surface between the movable iron core and the fixed iron core is worn, and there is a problem that the iron core is broken due to local stress when the iron core is closed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and can be driven by a smaller electromagnetic attraction force, so that the cost can be reduced and the impact force of the iron core can be reduced. It is an object of the present invention to obtain a switch capable of realizing a reduction in the number of pieces and a reduction in wear and breakage of the attraction surface of the iron core.

[0011]

A switch according to a first aspect of the present invention is a reversing spring having a concave portion formed in a movable portion and a rotatable shaft supported by a fixed portion and having a free end inserted into the concave portion. When,
A groove formed in the concave portion for engaging a free end of the reversing spring when the movable portion moves in a direction in which the contact closes, and for preventing rotation of the reversing spring; When the part moves, the reversing spring reverses the propulsive force of the movable part, and when the movable part moves in a direction in which the contact opens, the reversing spring rotates without reversing.

A switch according to a second aspect of the present invention is the switch according to the first aspect, wherein a surface of the concave portion facing a groove for suppressing rotation of the reversing spring has a convex shape.

A switch according to a third aspect of the present invention is the switch according to the first or second aspect, wherein the free end of the reversing spring has a spherical shape.

A switch according to a fourth invention is a switch according to the first invention.
In any one of the switches according to the third invention, a bearing is provided at a free end of the reversing spring.

[0015]

1 is a cross-sectional view of a switch according to the present invention. In the figure, reference numeral 1 denotes a crossbar, 1a denotes a crossbar window, and 2 denotes a movable contact disposed in the crossbar window 1a. The contacts 3, 3 are movable contacts attached to both ends of the bottom surface of the movable contact 2, 4 is a contact presser, 5 is incorporated in the crossbar 1 in a compressed state, and the restoring force of the contact presser 4
, A contact spring for pressing the movable contact 2 through the base, 6 a base, 7 a fixed contact fixed to the base 6, 8 arranged to face the movable contact 3, and attached to the upper surface of the fixed contact Fixed contact 9, reference numeral 9 denotes a movable iron core connected to the crossbar 1, reference numeral 10 denotes a mounting base, reference numeral 11 denotes a fixed iron core arranged with a predetermined gap from the movable iron core 9, and reference numeral 12 denotes a magnetic flux assembled on a side surface of the fixed iron core 11. And 13 is a coil 1
2, a coil spool serving as a bobbin 2, a separation spring 14 disposed between the crossbar 1 and the coil spool 13,
15 is a reversing spring, 15a is a tip of the reversing spring 15, 17
Is a shaft, 18 is a bearing, and 19 is a recess formed in the crossbar 1. The reversing spring 15 is rotatably supported by a bearing 18 via a shaft 17, and its tip 15 a is inserted into a recess 19.

Next, the operation of the reversing spring 15 will be described with reference to FIGS. FIG. 2 shows each part of the reversing spring, and FIG. 3 shows each part of the concave portion 19 formed in the crossbar 1. FIG.
19b is the bottom surface of the concave portion, and 19c is the side surface of the concave portion.

In FIG. 1, when a voltage is applied to the coil 12, the movable iron core 9 and the crossbar 1 move in the above-mentioned attracting direction by an electromagnetic attraction force. At this time, the reversing spring 15 is rotatably supported by the shaft.
Is engaged in the rotation inhibiting groove 19a of the reversing spring in FIG. 3, and therefore moves in the suction direction (the direction C in FIG. 3) without rotating. With the movement of the tip 15a of the reversing spring, the reversing spring 15 is displaced from the shape of FIG. 9 (b) to the shape of FIG. 9 (c). 19b, it can assist the thrust of the crossbar 1 in the suction direction.

When the voltage applied to the coil 12 is cut off,
The electromagnetic attraction force closing the movable core 9 and the fixed core 11 disappears, and the crossbar 1 moves in the opening direction (the direction D in FIG. 3) by the restoring force of the separation spring 14. At this time, since the reversing spring 15 is rotatably supported, the tip portion 15a moves from the concave bottom surface 19b of the crossbar 1 toward the concave side surface 19c, and the reversing spring 15 rotates around the axis 17. Therefore, since the reversing spring 15 rotates without reversing, the force of the reversing spring 15 exerted on the crossbar 1 by the restoring force on the crossbar 1 can be greatly reduced.

By the action of the reversing spring as described above, it is possible to reduce the electromagnetic attractive force for stably closing the iron core. Therefore, it is possible to reduce the electric power input to the coil and the weight of the movable core, thereby reducing the cost and reducing the impact force of the core and abrasion and breakage of the suction surface of the core. Can be reduced.

FIG. 4 is a partial cross-sectional view showing an example of a concave portion formed in the crossbar 1, which is different from the examples of FIGS.
A convex portion is provided on the crossbar, and a concave portion 19 is formed therein. Even when the concave portion 19 is formed in such a shape, the same operation and effect as those in the examples of FIGS.

FIG. 5 shows a recess 1 formed in the crossbar 1.
9 shows an example of the shape of FIG. 9, and in addition to the shape shown in FIG. 3 in which the shape of the rotation suppressing groove 19 a of the reversing spring is a keyway shape, FIG. 5 (a) or (b) And the like, and it is sufficient that the reversing spring 15 does not rotate when the crossbar 1 moves in the suction direction. Also, the concave bottom surface 19b
Is not limited to the circular inner peripheral surface as shown in FIGS. 3, 5A and 5B, but may be a convex shape as shown in FIG. 5C. As shown in FIG.
When b has a convex shape, the tip 15a of the reversing spring 15 abuts against the concave bottom surface 19b due to the reversal of the reversing spring 15 and assists the propulsive force of the crossbar 1 in the suction direction. Reversing spring 1 when moving in the separating direction
5 from the concave bottom surface 19b to the concave side surface 19c.
Since the movement in the direction can be easily performed, the rotation of the reversing spring 15 can be reliably performed.

FIG. 6 shows an example of the shape of the reversing spring 15, in which 20 is a spherical body, 21 is a ball joint,
Reference numeral 22 denotes a rotation support bearing having one degree of freedom. The free end of the reversing spring 15 is connected to such a spherical body 20, a ball joint 2
1. By using the rotary bearing 22 having one degree of freedom, the movement of the reversing spring 15 from the concave bottom surface 19b to the concave side surface 19c becomes smoother, and therefore, the reversing spring 15 moves when the crossbar 1 moves in the separating direction. Can be performed more smoothly. Especially the reversing spring 15
By providing bearings such as a ball joint 21 and a one-degree-of-freedom rotary bearing 22 at the free end of the above, the rotation operation of the reversing spring 15 can be performed more smoothly. Also, if a lubricating film is formed by applying a lubricant to the contact portion between the reversing spring 15 and the concave portion 19, the reversing spring 15
Can be performed more smoothly, and the reliability over a long period of time is improved.

[0023]

Since the present invention is configured as described above, it has the following effects. The switch according to the first invention assists the propulsion force of the movable portion by reversing the reversing spring when the movable portion moves in the direction in which the contacts close, and when the movable portion moves in the direction in which the contacts open, Since the reversing spring rotates without reversing, it is possible to reduce the electromagnetic attraction force for stably closing the iron core, reduce the electric power input to the coil, and reduce the weight of the movable iron core. This makes it possible to reduce the cost, reduce the impact force of the iron core, and reduce the wear and breakage of the suction surface of the iron core.

The switch according to the second aspect of the invention has the same effect as the first aspect of the invention, and has the effect that the rotation of the reversing spring can be performed more reliably.

The switch according to the third aspect of the present invention has the same effects as the first and second aspects of the present invention, and also has the effect that the rotation of the reversing spring can be performed more smoothly.

A switch according to a fourth aspect of the present invention is the switch of the first aspect.
In addition to the effects similar to those of the third invention, the rotation of the reversing spring can be performed more smoothly.

[Brief description of the drawings]

FIG. 1 is a sectional view of a switch according to the present invention.

FIG. 2 is an explanatory view of a reversing spring according to the present invention.

FIG. 3 is an explanatory view of a concave portion formed in the crossbar according to the present invention.

FIG. 4 is a partial sectional view showing a recess formed in the crossbar according to the present invention.

FIG. 5 is a diagram showing an example of a shape of a concave portion formed in the crossbar according to the present invention.

FIG. 6 is a view showing a shape of a reversing spring according to the present invention.

FIG. 7 is a sectional view showing a conventional switch.

FIG. 8 is a sectional view showing a conventional switch.

FIG. 9 is an explanatory view of a conventional reversing spring.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Crossbar, 1a Crossbar window, 2 movable contacts, 3 movable contacts, 4 contact holders, 5 contact springs, 6
Base, 7 fixed contacts, 8 fixed contacts, 9 movable cores, 10 mounting bases, 11 fixed cores, 12 coils, 13
Coil spool, 14 pull-off spring, 15 reversing spring, 15a tip of reversing spring, 15b fixing part of reversing spring, 16 recess, 17 shaft, 18 bearing, 19 recess, 19a rotation-reducing groove of reversing spring, 19b bottom of recess, 19c Side surface of concave part, 20 spherical body, 21 ball joint, 22 One-degree-of-freedom rotary bearing.

Claims (4)

[Claims] An electric circuit, comprising: a fixed contact connected to a fixed portion; and a movable contact opposed to the fixed contact connected to a movable portion, and driving the movable portion to open and close the contact. In the switch, a concave portion formed in the movable portion, a reversing spring rotatably supported by the fixed portion and having a free end inserted into the concave portion, and closing of the contact formed in the concave portion A groove for engaging the free end of the reversing spring during movement of the movable portion in the direction to inhibit rotation of the reversing spring; and reversing the reversing spring when moving the movable portion in the closing direction of the contact. The propulsion force of the movable part is assisted by the above, and when the movable part moves in the direction in which the contact point opens, the reversing spring rotates without reversing. 2. The switch according to claim 1, wherein a surface of the concave portion facing the groove for suppressing rotation of the reversing spring has a convex shape. 3. The switch according to claim 1, wherein the free end of the reversing spring has a spherical shape. 4. The switch according to claim 1, wherein a bearing is provided at a free end of the reversing spring.