JP4874703B2 - Electromagnetic actuator - Google Patents

Description

  The present invention relates to an electromagnetic actuator that opens and closes a switch, and more particularly to an electromagnetic actuator that can improve the efficiency when the switch is closed.

  Conventional electromagnetic actuators used in this type of switch operating mechanism include a yoke for forming a magnetic path, an armature that moves movably in the yoke, a permanent magnet that moves or holds the armature closed, and a magnetic flux in the yoke It is known that it is composed of a non-magnetic operating rod that is fixed to an open circuit, a closed coil, and an armature that increase / decrease, and that is connected to a contact of a switch.

And when closing a switch, the closing coil is excited and the armature is moved in the closing direction. In the closed state, the closed coil is de-excited and the closed state is maintained by the magnetic force of the permanent magnet. When opening the circuit, the opening coil is excited to move the armature in the opening direction. In the open circuit state, the open coil is de-energized, and the open circuit state is maintained by the spring force of the open spring (see, for example, Patent Document 1).
JP 2002-270423 A (4th page, FIG. 1)

The above conventional electromagnetic actuator has the following problems.
When the armature is held by the magnetic force of the permanent magnet (closed circuit holding), the cross-sectional area of the armature or yoke may be larger than the residual magnetic flux density of the permanent magnet, and the magnetic flux density may not be sufficiently increased. Also, the leakage flux may increase due to the armature being square or the magnetic circuit having an open portion. For this reason, it has been desired that the cross-sectional area of the armature or yoke is set to a predetermined size, the magnetic flux density is increased, the magnetic force of the permanent magnet is sufficiently drawn, and the efficiency at the time of holding the closed circuit is improved.

  The present invention has been made to solve the above problems, and an object thereof is to provide an electromagnetic actuator capable of increasing the magnetic flux density of an armature or a yoke and improving the efficiency at the time of holding a closed circuit.

In order to achieve the above object, an electromagnetic actuator of the present invention includes a yoke for forming a magnetic path, an armature that moves movably in the yoke, a permanent magnet that moves or holds the armature closed, An operation rod fixed to the armature and movably penetrating one side surface of the yoke and connected to a switch; the yoke includes a first yoke provided on an outer periphery of the operation rod; A second yoke connected to the first yoke and provided on the switch side, a third outer yoke connected to the second yoke, and an intermediate portion of the third yoke a fourth yoke securing the and the permanent magnet projects radially inward while being connected, the fifth provided to face the fourth yoke so as to hold said permanent magnets Is composed of a chromatography click, the armature, first has a first armature having a suction surface of said first yoke, the suction surfaces of the fifth yoke while being connected to the first armature And the second armature is provided with a groove on an adsorption surface on which the second armature is adsorbed by the fifth yoke.

  According to the present invention, the cross-sectional area of the attracting surface of the yoke and the armature is a cross-sectional area that does not cause magnetic saturation with respect to the residual magnetic flux density of the permanent magnet, and the magnetic flux density at each attracting surface is increased. The suction force between the yoke and the armature can be increased, and the efficiency when the closed circuit is maintained when the switch is closed can be improved.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, an electromagnetic actuator according to Embodiment 1 of the present invention will be described with reference to FIG. 1 is a cross-sectional view illustrating a configuration of an electromagnetic actuator according to a first embodiment of the present invention. FIG. 1 shows a closed state.

  As shown in FIG. 1, the electromagnetic actuator moves a cylindrical yoke 1 for forming a magnetic path, a cylindrical magnetic armature 2 that moves movably in the yoke 1, and moves or holds the armature 2 closed. An annular permanent magnet 3, an annular closed coil 4 and an open coil 5 for increasing or decreasing the magnetic flux in the yoke 1, and an operation of a non-magnetic material fixed to the central axis of the armature 2 and movably penetrating one side of the yoke 1 The rod 6 and the armature 2 are constituted by a stopper 7 for preventing the armature 2 from coming off from the inside of the yoke 1. The operating rod 6 is connected to a switch 9 having a pair of contact points 8 that can be contacted and separated.

  Here, the yoke 1 is connected to the columnar first yoke 1a provided on the switch 9 side on the outer periphery of the operation rod 6 and the first yoke 1a, and the disk 1 is inserted into the operation rod 6. The second yoke 1b and the second yoke 1b are connected to the cylindrical third yoke 1c provided on the outer peripheral side of the closed coil 4 and the like, and are connected to the intermediate portion of the third yoke 1c and the armature. An annular fourth yoke 1d protruding in the inner diameter direction on the second side and fixed to the permanent magnet 3, and an annular provided on the side opposite to the switch 9 so as to face the fourth yoke 1d so as to sandwich the permanent magnet 3 The fifth yoke 1e.

  The armature 2 is connected to the columnar first armature 2a provided on the outer periphery of the operating rod 6 and in the axial direction of the first yoke 1a, and to the anti-switch 9 side of the first armature 2a and has a radius. It is comprised from the cyclic | annular 2nd armature 2b extended in a direction. That is, the armature 2 has a convex shape.

  Thereby, when the switch 9 is closed, the end surface portion of the first yoke 1a and the end surface portion of the first armature 2a come into contact with each other. Further, the fifth yoke 1e and the second armature 2b come into contact with each other. That is, these end surface portions become suction surfaces. Then, the magnetic flux φ by the permanent magnet 3 is, as indicated by a two-dot chain line in the figure, the permanent magnet 3 → the fifth yoke 1e → the second armature 2b → the first armature 2a → the first yoke 1a → the second. The yoke 1b → the third yoke 1c → the fourth yoke 1d → the permanent magnet 3 is formed. The magnetic circuit holds the switch 9 closed.

  Here, the sectional area of the permanent magnet 3 perpendicular to the magnetic flux φ is Smg, the first yoke 1a is perpendicular to the magnetic flux φ Sy1, and the first armature 2a is perpendicular to the magnetic flux φ Sa1. The sectional area of the second armature 2b perpendicular to the magnetic flux φ is Sy2. These cross-sectional areas Smg, Sy1, Sa1, and Sa2 are all formed in an annular shape so as to surround the operation rod 6.

  The cross-sectional areas Sy1, Sa1, and Sa2 are smaller than the cross-sectional area Smg. That is, Sy1 / Smg = 0.6 to 1, Sa1 / Smg = 0.6 to 1, and Sa2 / Smg = 0.6 to 1.

  For example, when a neodymium magnet is used for the permanent magnet 3, the residual magnetic flux density is about 1.3 terraces, and when the general structural rolled steel (SS400) is used for the yoke 1 and the armature 2, magnetic saturation occurs at about 2.2 terraces. For this reason, if the cross-sectional areas Sy1, Sa1, and Sa2 are made the same as the cross-sectional area Smg, the magnetic flux φ is formed in the yoke 1 and the armature 2 by 1.3 / 2.2≈0.6 times. In order to increase the magnetic flux density in the yoke 1 and the armature 2 with respect to the magnitude of the magnetic flux φ, the cross-sectional areas Sy1, Sa1, and Sa2 may be reduced. When the cross-sectional areas Sy1, Sa1, and Sa2 are 0.6 times the cross-sectional area Smg, magnetic saturation does not occur and the magnetic flux density can be maximized.

  The attractive force between the yoke 1 and the armature 2 is proportional to the product of the square of the magnetic flux density and the cross-sectional areas Sy1, Sa1, Sa2, so if the magnetic flux density is increased even if the cross-sectional areas Sy1, Sa1, Sa2 are reduced, As a result, the suction force of the suction surface between the first yoke 1a and the first armature 2a can be increased. Similarly, the suction force of the suction surface between the fifth yoke 1e and the second armature 2b can be increased. For this reason, the holding force at the time of closing can be enlarged, and efficiency can be improved.

  When the magnetic flux density is increased without causing magnetic saturation between the first yoke 1a and the first armature 2a and between the fifth yoke 1e and the second armature 2b, the leakage magnetic flux and the like are suppressed, so that The suction force can be increased. Here, between the first yoke 1a and the first armature 2a, the magnetic flux φ is easily formed in parallel with the axial direction of the operation rod 6, and a large attractive force can be obtained.

  In this way, increasing the magnetic flux density without increasing magnetic saturation and increasing the attractive force, the effective cross-sectional area where the attracting surface of the yoke 1 and the armature 2 does not cause magnetic saturation with respect to the residual magnetic flux density of the permanent magnet 3. It is defined that As described above, the effective cross-sectional area means that when the general structure rolled steel is used for the yoke 1 and the armature 2 and the neodymium magnet is used for the permanent magnet 3, the cross-sectional areas Sy1, Sa1, and Sa2 are 0.6 with respect to the cross-sectional area Smg. It is in the range of ~ 1. In the case of 0.6, the largest suction force can be obtained.

  If the ratio of the cross-sectional areas Sy1, Sa1, Sa2 to the cross-sectional area Smg is more than 1, the cross-sectional area attracted by the yoke 1 and the armature 2 can be increased, but the magnetic flux density is decreased, resulting in the adsorption surface. It is not possible to increase the suction power at Further, the yoke 1 and the armature 2 are enlarged and become heavy. In particular, the armature 2 is accompanied by movement, and an increase in weight is not preferable.

  According to the electromagnetic actuator of the first embodiment, the adsorption area where the yoke 1 and the armature 2 are adsorbed has a cross-sectional area that does not cause magnetic saturation with respect to the residual magnetic flux density of the permanent magnet 3. The magnetic flux density of the armature 2 can be increased, the attraction force between the yoke 1 and the armature 2 can be increased, and the efficiency at the time of holding the closed circuit when the switch 9 is closed can be improved.

  In the first embodiment, the general structure rolled steel is used for the yoke 1 and the armature 2 and the neodymium magnet is used for the permanent magnet 3. However, for example, the silicon steel plate and the permanent magnet 3 having different magnetic saturation are used for the yoke 1 and the armature 2. Even if, for example, an alnico magnet having a different residual magnetic flux density is used, if the attracting surfaces of the yoke 1 and the armature 2 have an effective cross-sectional area that does not cause magnetic saturation, the mutual attractive force is increased. can do.

  Next, an electromagnetic actuator according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 2 is a cross-sectional view illustrating the configuration of the electromagnetic actuator according to the second embodiment of the present invention. The second embodiment differs from the first embodiment in the shape of the armature. In FIG. 2, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 2, the first armature 2a has a trapezoidal cross section with a small diameter on the first yoke 1a side and a large diameter on the fifth yoke 1e side. An annular second armature 2b extending in the radial direction is connected to the large-diameter side of the first armature 2a.

  Thereby, since the adsorption | suction surface of the 1st armature 2a adsorb | sucked with the 1st yoke 1a can be made small, magnetic flux density can be raised. In the trapezoidal cross section, the sectional area adsorbed to the first yoke 1a can be easily controlled by the taper angle, so that it is easy to increase the suction force.

  According to the electromagnetic actuator of the second embodiment, the same effect as that of the first embodiment can be obtained.

  Next, an electromagnetic actuator according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view illustrating the configuration of the electromagnetic actuator according to the third embodiment of the present invention. The third embodiment is different from the first embodiment in the shape of the armature. In FIG. 3, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 3, an annular groove 2c is provided on the adsorption surface where the first armature 2a adsorbs to the first yoke 1a.

  Thereby, since the adsorption | suction surface of the 1st armature 2a adsorb | sucked with the 1st yoke 1a can be made small, magnetic flux density can be raised. By controlling the width of the groove 2c, the suction surface with the first yoke 1a can be controlled, so that the suction force can be easily increased. The groove 2c may be provided in the first armature 1a having a trapezoidal cross section according to the second embodiment.

  According to the electromagnetic actuator of the third embodiment, the same effect as that of the first embodiment can be obtained.

  Next, an electromagnetic actuator according to Embodiment 4 of the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view illustrating the configuration of the electromagnetic actuator according to the fourth embodiment of the present invention. The fourth embodiment differs from the first embodiment in the shape of the armature. In FIG. 4, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, an annular groove 2d is provided on the adsorption surface where the second armature 2b adsorbs the fifth yoke 1e.

  Thereby, since the adsorption | suction surface of the 2nd armature 2b adsorb | sucked with the 5th yoke 1e can be made small, magnetic flux density can be raised. By controlling the width of the groove 2d, the suction surface with the fifth yoke 1e can be controlled, so that it is easy to increase the suction force. The first armature 2a may have a trapezoidal cross section as in the second embodiment, or a groove 2c as in the third embodiment.

  According to the electromagnetic actuator of the fourth embodiment, the same effect as that of the first embodiment can be obtained.

  In addition, this invention is not limited to the said Example, In the range which does not deviate from the summary of invention, it can implement in various deformation | transformation. In the above-described embodiment, the fifth yoke 1e is disposed so as to face the fourth yoke 1d so as to sandwich the permanent magnet 3, but the fifth yoke 1e is removed and the permanent magnet 3 is attached to the second magnet 1e. The armature 2b may be adsorbed.

Sectional drawing which shows the structure of the electromagnetic actuator which concerns on Example 1 of this invention. Sectional drawing which shows the structure of the electromagnetic actuator which concerns on Example 2 of this invention. Sectional drawing which shows the structure of the electromagnetic actuator which concerns on Example 3 of this invention. Sectional drawing which shows the structure of the electromagnetic actuator which concerns on Example 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Yoke 1a 1st yoke 1b 2nd yoke 1c 3rd yoke 1d 4th yoke 1e 5th yoke 2 Armature 2a 1st armature 2b 2nd armature 2c, 2d Groove 3 Permanent magnet 4 Closed coil 5 Opening coil 6 Operating rod 7 Stopper 8 Contact 9 Switch

Claims (1)

A yoke for forming a magnetic path;
An armature movably moving in the yoke;
A permanent magnet for moving or holding the armature closed;
An operation rod fixed to the armature and movably penetrating one side of the yoke and connected to a switch;
The yoke includes a first yoke provided on an outer periphery of the operation rod;
A second yoke connected to the first yoke and provided on the switch side;
An outer peripheral third yoke connected to the second yoke;
A fourth yoke connected to an intermediate portion of the third yoke and protruding in an inner diameter direction and fixing the permanent magnet ;
A fifth yoke provided to face the fourth yoke so as to sandwich the permanent magnet ;
The armature includes a first armature having a suction surface with the first yoke;
A second armature connected to the first armature and having a suction surface with the fifth yoke ;
An electromagnetic actuator characterized in that a groove is provided in an adsorption surface where the second armature is adsorbed by the fifth yoke.

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