JPH02165606A - Plunger type electromagnet - Google Patents

Abstract

PURPOSE:To reduce the size and improve the sensitivity by a method wherein an annular permanent magnet is so provided as to surround a plunger coaxially with the plunger and magnetized along the thickness direction of the annulus. CONSTITUTION:An annular permanent magnet 10a is provided between the pole piece 11 of the yoke end of the other side of a fixed core 2 and an annular pole piece 8 provided on the yoke end side of a coil 5. As the annular pole piece 8 is inserted into the space of a magnetic path between the annular permanent magnet 10a and a plunger 3, the magneto-resistance of the magnetic path can be reduced. Further, by combining two electromagnets, a high sensitivity electromagnet which has bistable latching characteristics and does not need spring can be obtained. With this constitution, an electromagnet which is small in size and light in weight and has high sensitivity and a large attracting and holding force can be mass-produced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a plunger-type electromagnet, and more specifically, the present invention relates to a plunger-type electromagnet, and more specifically, the plunger is fixed against the biasing force of a spring even when the coil is de-energized. This invention relates to an improved technology for a plunger type 868 stone equipped with a permanent magnet that attracts and holds an iron core.

[Prior Art] A plunger type electromagnet conventionally used for locking etc. will be explained with reference to FIGS. 5 and 6.

In addition, in FIG. 5, a permanent magnet 6 having the same cross-sectional shape as the fixed iron core 2 is inserted between the fixed iron core 2 and the yoke l.
The figure shows an annular permanent magnet IO disposed between the yoke l and the coil 5, coaxially with the plunger 3, and surrounding the plunger 3.

In addition, the figure shows a state in which the fixed iron core 2 and the plunger 3 are separated from each other on the upper side of the central axis, and a state in which the plunger 3 is held by the fixed iron core 2 on the lower side of the central axis. . In addition, the solid line and dotted line indicate the magnetic path created by the permanent magnet and the coil, respectively (explanation of these can be found in Figures 1 to 1).
(This applies to all of Figure 6).

The electromagnet includes a yoke l, a fixed iron core 2 fixed to the yoke l, a plunger 3 that abuts the fixed iron core 2, a spring 4 that separates the fixed iron core 2 and the plunger 3 by a predetermined distance, and a fixed iron core 2. The circuit consisting of the plunger 3 and the yoke l is magnetized by energization and attracts the plunger 3 to the fixed iron core 2 against the biasing force of the spring 4. Even when the coil 5 is de-energized, the plunger It is composed of a permanent magnet 6 (or an annular permanent magnet 10), etc., which attracts and holds the jar 3 on the fixed iron core 2. To release the plunger 3 from being held by the fixed iron core 2,
A current in the opposite direction may be applied to the coil 5.

[Problem to be solved by the invention l The above-mentioned plunger type electromagnet is used in various fields of locking and locking due to its ease of handling and low cost.
In the electromagnet shown in the figure, when the coil 5 is energized, a permanent magnet 6 with a small magnetic permeability (μ41 in practice) is inserted in series in the magnetic flux path, so in order to generate a predetermined attractive force, a large Since it requires excitation ampere turns, that is, a large amount of electric power, it has the drawbacks of poor sensitivity and large size.

Furthermore, in the electromagnet shown in FIG. 6, the radial magnetization of the one-ring permanent magnet 10 has a large difference between the inner circumferential surface and the outer circumferential surface, making magnetization difficult. Therefore, the ring must be divided into multiple arcs. Therefore, there is a problem that the space factor of the annular permanent magnet 10 deteriorates, which not only increases the size of the electromagnet but also increases the number of parts per unit, which impedes productivity.

SUMMARY OF THE INVENTION An object of the present invention is to provide a plunger-type electromagnet that is compact and highly sensitive by solving the above-mentioned problems.

[Means for Solving 1 Problem] The present invention solves the above-mentioned problems, and includes a yoke, a fixed core fixed to the yoke, a plunger whose end face is attached to and detached from the fixed core, and a fixed core. A circuit consisting of a spring that urges the end faces apart, a fixed iron core, a plunger, and a yoke, and a coil that attracts the plunger to the fixed iron core against the urging force of the spring when magnetized by energization. It is applied to a plunger-type electromagnet consisting of a permanent magnet that attracts and holds the plunger to a fixed iron core against the biasing force of a spring even when the power is turned off, and the following technical measures were adopted. Namely.

(2) The permanent magnet was formed into an annular shape and was disposed coaxially with the plunger to surround the plunger, and its magnetization direction was formed in the thickness direction of the annular ring.

■ The permanent magnet is inserted between the magnetic pole piece on the opposite yoke end of the fixed iron core and the annular magnetic pole placed on the side of the magnetic pole piece of the coil, coaxially with the plunger and surrounding the plunger. can do.

■ Two plunger type electromagnets are brought into contact with one side of the magnetic poles on the end faces of the yoke, and are combined symmetrically to form one common plunger, with both ends of the plunger shaft being closer to the center. By reducing the diameter and providing holes in which the diameter portions are movable by loosely fitting them into the fixed core at both ends, the need for a spring can be eliminated.

■Furthermore, the magnetic pole piece on the end face of the yoke on the side opposite to the fixed iron core is inserted into the yoke, and the magnetic pole piece on the opposite side to the fixed iron core of the plunger, which is provided through the magnetic pole piece, is inserted perpendicularly to the plunger axis and inside the yoke. A suction vane inscribed in the plunger is provided, and the length of the plunger is such that when the plunger is not attracted to the fixed core, the suction vane surface coincides with the yoke end face device, and the permanent magnet is placed between the suction vane and the magnetic pole piece. It is even more effective if it is placed in

■ ■ In the plunger type electromagnet, the permanent magnet is
An annular magnetic pole piece that surrounds the plunger may be disposed between the permanent magnet and the coil and coaxially with the plunger between the permanent magnet and the coil.

[Effect 1 The present invention is configured as described above.

(2) When the coil 5 is energized, no permanent magnet is inserted in series in the magnetic flux path, so the magnetic resistance to the magnetomotive force generated by energizing the coil can be reduced.

■Since the magnetization direction of the circular permanent silver stone is formed in the thickness direction of the circular ring, one magnetization is easy and the number of parts per piece is reduced, making it suitable for mass production.

- Magnetic resistance can be reduced because one piece of annular EBtf is inserted in the space of the magnetic path between the permanent magnet and the plunger.

■Equipped with a suction vane at one end of the plunger and forming a magnetic path between the pair of yokes, allowing the plunger to be strongly attracted and held on the fixed iron core.

■'': By combining 4:4 magnets, it is possible to obtain a highly sensitive f4 magnet that has bistable latching characteristics and does not require a spring.

[Example] FIG. 1 is a detailed explanatory diagram of the present invention, in which one annular magnetic pole piece 10a is attached to the magnetic pole piece 11 on the opposite yoke end face of the fixed iron core 2.
In the figure 0, which is provided between the coil 5 and the annular magnetic pole piece 8 provided on the yoke end surface side, the solid line and the dotted line indicate the magnetic path by the permanent magnet and the coil, respectively (the same is true in each figure). be).

In this embodiment, a permanent magnet is not inserted in series in the magnetic flux path unlike the conventional example shown in FIG. Since the annular magnetic pole piece 8 is inserted, the magnetic resistance of the magnetic path can be reduced.

FIG. 2 is an explanatory diagram of another embodiment of the present invention.

The two electromagnets shown in FIG.
The two plungers are combined into a single common plunger, with the diameter of both ends of the three plunger shafts being smaller than that of the center, and The fixed iron core 2 is provided with a hole 12 into which the diameter portion is loosely fitted and movable. When the two coils 5 are energized, the plunger 3 is attracted to one of the fixed iron cores 2, and the two coils 5 are energized in the opposite direction, and the plunger 3 remains magnetic until it is attracted to the other fixed iron core 2. A stable state is obtained.

That is, a bistable state can be obtained in terms of F11. Therefore, a spring is not required and a plunger operating force greater than that of the ':4 magnet shown in FIG. 1 can be obtained.

FIG. 3 is an explanatory diagram of still another embodiment of the present invention, in which a magnetic pole piece 11 on the end face of the yoke opposite to the fixed iron core 2 is inserted into the yoke 1 and placed on the coil 5, and the magnetic pole piece 11 is inserted into the yoke 1 and placed on the coil 5. Fixed iron core 2 of plunger 3 provided through and opposite II
A suction i[t7 is provided at the I end, which is perpendicular to the plunger axis and inscribed in the inner surface of the yoke, and the length of the plunger is the same as the suction gR plate surface, yoke end surface, when the plunger 3 is not attracted to the fixed iron core 2. One annular permanent silver stone 10a is arranged on the magnetic pole piece li between the suction vane plate 7 and the piece 1ifIti to match the position.

FIG. 4 shows another embodiment of FIG. 3 using the suction vane root 7, in which one annular permanent silver stone 10a has a magnetic pole piece 11 and a coil 5.
An annular magnetic pole piece 8 is provided between the one annular permanent silver stone 10a and the coil 5.

The electromagnets shown in FIGS. 3 and 4 can attract and hold the plunger to the fixed core more strongly than the electromagnet shown in FIG. 1 due to the action of the suction blade roots 7.

[Advantageous Effects of the Invention 1] According to the present invention, extremely excellent effects can be achieved in the mass production of electromagnets that are small, lightweight, highly sensitive, and have a large attraction and retention force.

[Brief explanation of the drawing]

1 to 4 are cross-sectional explanatory diagrams of embodiments of the present invention, and FIG.
FIG. 6 is an explanatory diagram of a cross section of a conventional example. In each of the figures, the upper side of the central axis shows a state in which the fixed iron core and the plunger are separated, and the lower side of the central axis shows a state in which the plunger is held by suction on the fixed iron core. Moreover, the solid line and the dotted line indicate the magnetic paths formed by the permanent magnet and the coil, respectively. 1...Yoke, 2-...Fixed core, 3...Plunger, 4...Spring, 5...Coil, 6...
Permanent 1i11 stone, 7... Suction vane plate, 8... Annular M
One pole piece. 10, lOa = circular permanent magnet, 11-... magnetic pole piece, l 2-... hole applicant Mic Kogyo Co., Ltd.

Claims (1)

[Scope of Claims] 1. A yoke, a fixed iron core fixed to the yoke, a plunger whose end face is attached to and detached from the fixed iron core, and a spring which urges the end face away from the fixed iron core. a coil that attracts the plunger to the fixed core against the urging force of the spring when the circuit consisting of the fixed core, the plunger, and the yoke is magnetized by energization; and a coil that attracts the plunger to the fixed core against the biasing force of the spring, and when the coil is de-energized. and a permanent magnet that attracts and holds the plunger on the fixed iron core against the biasing force of the spring, the permanent magnet being formed in an annular shape and coaxial with the plunger. 1. A plunger-type electromagnet, characterized in that the plunger is disposed in a core surrounding the plunger, and the magnetization direction is formed in the thickness direction of the annular ring. 2. The permanent magnet has a magnetic pole piece on the opposite yoke end surface of the fixed iron core, and an annular magnet disposed on the side surface of the magnetic pole piece of the coil so as to be coaxial with the plunger and surrounding the plunger. 2. The plunger type electromagnet according to claim 1, wherein the plunger type electromagnet is inserted between a magnetic pole piece. 3. Two plunger-type electromagnets according to claim 2 are brought into contact with one side of the magnetic poles of the end faces of the yoke and combined symmetrically, and the two plungers are configured into a common one, and the plunger shaft is A plunger-type electromagnet characterized in that both ends have a diameter smaller than that of the center and are provided with holes in which the diameter parts are movable by loosely fitting them into fixed iron cores at both ends, thereby eliminating the need for the spring. 4. The magnetic pole piece on the end face of the yoke on the opposite side to the fixed iron core is inserted into the yoke, and the magnetic pole piece on the opposite side to the fixed iron core of the plunger, which is provided through the magnetic pole piece, is perpendicular to the plunger axis. and a suction vane inscribed on the inner surface of the yoke, the length of the plunger being such that the suction vane surface coincides with the yoke end surface position when the plunger is not attracted to the fixed iron core, and the permanent magnet 2. The plunger type electromagnet according to claim 1, wherein is disposed between the attraction vane and the magnetic pole piece. 5. The permanent magnet is disposed between the magnetic pole piece and the coil, and an annular magnetic pole piece that surrounds the plunger and is coaxial with the plunger is disposed between the permanent magnet and the coil. The plunger type electromagnet according to claim 4, characterized in that: