JPS6229111A - Plunger type electromagnet - Google Patents

Abstract

PURPOSE:To obtain a large stroke length when low power is applied as well as to enable to adjust the sucking and retaining strength when no current flows by a method wherein the pole faces of a fixed iron core or a movable iron core are formed on the inner sidewall of a cylindrical body, and the pole faces of the other iron core opposing to said pole faces are formed on the parallel side and the right-angled end of a columnar body which is inserted and arranged in a freely slidable and displaceable manner. CONSTITUTION:Either of a fixed iron core 2 or a movable iron core 8, namely, the pole face of the fixed iron core 2, for example, is formed on the inner side face 4a of a cylindrical body 4, the pole face of the other iron core 8 opposing to the inner side face 4a, having the same axis as the inner side face of a cylindrical body, is inserted and arranged in the axial direction of the pole face of the core 8 in a freely sliding and displaceable manner, and the paralleled side face 8 in axial direction of a columnar body and a right-angled end face 8b are formed. As a result, when a current is applied on an electric winding, the magnetic flux generated by the above-mentioned application of current and the magnetic flux of a permanent magnet are supported, and the movable iron core 8 is attracted to the fixed iron core 2 by composite magnetic force. In this case, one of the core pole-face is formed on the internal side face 4a of the cylindrical body, the pole face of the other iron core is formed on the side face 8 in parallel with the axial direction of the cylindrical body of the pole-like body and the right-angled end face 8b. The distance linking both pole faces 8a and 8b is shortened, and as a void magnetic path is small, the titled electromagnet can be driven with a small type of winding and minor power is spite of having a large stroke.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to improvements in plunger type electromagnets including permanent magnets.

(b) Conventional technology As a plunger type electromagnet using a conventional permanent magnet,
For example, there are those shown in FIGS. 5 and 6.

The plunger type electromagnet shown in Fig. 5 has two excitation coils bsc wound around a bobbin a, a permanent magnet d interposed between these two excitation coils b and c, and a bobbin a.
A fixed iron core f fixed to a yoke e and a movable iron core g are provided inside. In this plunger-type electromagnet, when the excitation coil b is energized, the magnetic flux from the permanent magnet d and the magnetic flux from the excitation coil b are superimposed, and a force that attracts the movable core g toward the fixed core f acts, and the movable core g is connected to the fixed core. It is attracted to f. After attraction, even if the excitation coil b is de-energized, the movable core g is held in the attracted state by the magnetic force of the permanent magnet d. The movable iron core g is released by energizing the excitation coil C.

The plunger type electromagnet shown in FIG. 6 has one excitation coil b and a release spring h between the fixed iron core f and the movable iron core g. In this plunger type electromagnet, when the excitation coil b is energized, the movable iron core g is attracted to the fixed iron core f in the same manner as in the one shown in FIG. Even when the current is turned off, the movable iron core g is still self-held by the magnetism of the permanent magnet d, and when a reverse current is passed through the excitation coil b, the movable iron core g is released.

(c) Problems to be solved by the invention As shown in the above example, the conventional plunger type electromagnet:
Since the magnetic pole faces of the fixed core and the movable core face each other in a plane perpendicular to the axial direction, if you want to obtain a long stroke length, the distance between the magnetic pole faces of the fixed core and the movable core when released should be Therefore, when attracting the movable core, a large excitation ampere turn is required, resulting in an increase in driving power and an increase in size.

Furthermore, in the conventional device, it is difficult to adjust the adsorption and holding force of the latching operation using the permanent magnet when no current is applied.

In view of the above, it is an object of the present invention to provide a plunger-type electromagnet that is small in size and has a large stroke length with low electric power, and that can adjust the attracting and holding force when no current is applied as necessary.

(d) Means for Solving the Problems The plunger type electromagnet of the present invention includes a fixed iron core, a movable iron core, an electric winding, and a permanent magnet, and the magnetic flux generated by the electric winding is superimposed on the magnetic flux generated by the permanent magnet. in which an attractive force is generated between the magnetic pole surfaces of the two iron cores, and the movable iron core is mechanically displaced by this attractive force, wherein the magnetic pole surface of either the fixed iron core or the movable iron core is formed on the inner side surface of the cylinder. At the same time, the magnetic pole surface of the other iron core facing this,
It is formed on a parallel side surface and a right-angled end surface in the axial direction of a columnar body which has the same axis as the inner side surface of the cylinder and is inserted and arranged so as to be slidable in the direction of this axis.

(E) Effect In this plunger type electromagnet, when the electric winding is energized,
The magnetic flux generated by this energization and the magnetic flux of the permanent magnet are superimposed, and the combined magnetic force attracts the movable iron core to the fixed iron core. In this case, one core magnetic pole surface is formed on the side surface of the cylinder, and the other core magnetic pole surface is formed on the side surface parallel to the axial direction and the right-angled end surface of the columnar cylinder, and the distance connecting both magnetic pole surfaces is short. (Because the air gap magnetic path is small, it can be driven with a small electric winding and low power even though it takes a large stroke.

(f) Examples The present invention will now be explained in more detail with reference to Examples.

1 and 2 are explanatory diagrams of a plunger type electromagnet according to an embodiment of the present invention.

This plunger type electromagnet 1 has a large diameter cylindrical part 3 in the center,
A fixed iron core 2 consisting of a small-diameter cylindrical portion 4.5 connected to both ends thereof, an excitation coil (electric winding) 6 and a permanent magnet 7 provided in the large-diameter cylindrical portion 3, and a small-diameter cylindrical portion 4.5. and a cylindrical movable iron core 8 disposed within a cylinder formed by an excitation coil 6 and a permanent magnet 7.

In this plunger type electromagnet 1, when the excitation coil 6 is not energized, that is, in the open state, the movable core 8 is in the state shown in FIG. The corresponding magnetic pole surfaces of the movable core 8 are formed on a side surface 8a parallel to the axial direction of the cylinder and an end surface 8b perpendicular to the axial direction.Here, the magnetic poles of the fixed core 2 and the movable core 8 are They face each other at an angle of 45° to the axial direction.

Next, the operation of this plunger type electromagnet 1 will be explained.

Assume that when the excitation coil 6 is not energized, the state shown in FIG. 1 is stable.

In this state, if leakage is ignored, the magnetic flux due to the magnetomotive force of the permanent magnet 7 will be φa1. φb, and the magnetic flux φa
, 4, enters the magnetic pole surface 3a of the small diameter cylindrical portion 3 of the fixed iron core 2 through the magnetic pole surfaces 8a and 8b of the movable iron core 8, and the magnetic flux φb passes through the movable iron core 8 in the opposite direction to the magnetic flux φa, and is transferred to the fixed iron core. It enters the magnetic pole face 4a of the small diameter cylindrical portion 4 of No.2.

Each amount of magnetic flux is set to a predetermined value in inverse proportion to the magnetic resistance value of the respective magnetic path. Further, the combined mechanical action force due to the magnetic fluxes φa and φb1 becomes zero.

In this state, the excitation coil 6 is then energized, and the magnetic flux generated by the energization is defined as φi, and its direction is as shown in FIG. As a result, the mechanical attraction force acting on the movable iron core 8 is F+ = K ((-φa1-φ1)2-(φb,-
φi)”)+where fb: Indicates the force in the φb direction due to a spring, etc.

When this mechanical force F1 has a negative value, the movable iron core 8 is attracted and moves to the position shown in FIG.

And F'z = -K ((-φat -φi)"-(+1'
bz-φi)") +f The state shown in FIG. 2 is maintained by the negative value of b.

Next, when the excitation coil 6 is de-energized in this state, the movable core 8 has Fs −−K (φ”az −φzbz) + f b
The adsorption force of In this case, if F is a negative value, the state shown in FIG. 2 is maintained. However, F.

If is a positive value, the state shown in FIG. 1 is restored. Note that a magnetic material vi10 is provided at the end of the small diameter cylindrical portion 4 in order to strengthen the rafting force.

Here, the values of the magnetic fluxes φa2 and φb2 are easily determined by the rtli node and the values of the air gaps 9a and 9b, the presence or absence of the magnetic plate 1o, etc.
Can be configured.

By the way, under the condition that F3 is a negative value, as mentioned above, when the excitation coil 6 is not energized, the movable core 8 is held in the state shown in FIG. 2; When a current with a polarity that generates magnetic flux φi in the direction shown is passed through the exciting coil 6, F, = −K ((−φa2+φi)”−
(φb2+φi)2) The attraction force of +fb is the movable iron core 8
The movable iron core 8 can be returned to the state shown in FIG. 1 under the condition that F4 becomes a positive value.

In this plunger type electromagnet 1, when energized when released,
As described above, the magnetic flux is concentrated on the magnetic pole surface 4a and the magnetic pole surfaces 8a and 8b, and the air gap 9a is small, so the initial driving force is large.

FIGS. 3 and 4 are explanatory views of plunger type electromagnets showing other embodiments of the present invention.

The plunger type electromagnet 11 of this embodiment has two
Excitation coils (electrical windings) 13, 14 are wound, and a permanent magnet 15 is interposed between these two excitation coils 13, 14. Note that 16 is an auxiliary magnetic piece.

Further, a yoke 17 for forming a magnetic path is provided surrounding the excitation coils 13 and 14 and the permanent magnet 15, and this yoke 1
A fixed iron core 18 fixed to the bobbin 7 and a movable iron core 19 are inserted into the bobbin 12.

The fixed core 18 includes a concave magnetic pole part 20, and a concave bottom part of the magnetic pole part 20 is further provided with a concave part 21. Furthermore, the movable iron core 19 has a concave magnetic pole portion 2 of the fixed iron core 18.
0, a convex magnetic pole part 22 is provided, and this magnetic pole part 2
A concave portion 23 is further provided on the convex top portion of No. 2. Recess 2
A spring 24 is interposed between 1 and the recess 23, and the convex magnetic pole part 22 of the movable core 19 can be freely inserted into and removed from the concave magnetic pole part 20 of the fixed core 18 by resisting this spring 24 or by the force of the spring 24. It is configured.

In this plunger type electromagnet 11, the exciting coil 13.1
4 is not energized, that is, in an open state, the movable iron core 19
is in the position shown in FIG. In this state, fixed core 1
The distance between the bottom of the concave magnetic pole part 20 of No. 8 and the top of the convex magnetic pole part 22 of the movable iron core 19 is relatively large; 22a
and the distance between the tip 17a of the yoke 17 and the movable iron core 19 are minute. Therefore, here, the excitation coil 13
When electricity is applied, the magnetic flux and the magnetic flux from the permanent magnet 15 are superimposed, and the ironable core 19 is attracted to the fixed iron core 18, and in this state where it is attracted and held in the state shown in FIG. 4, the tip 17a of the yoke 17 and movable iron core 19
Since the distance from the permanent magnet 15 is large, the magnetic flux from the permanent magnet 15 is
Most of it is concentrated on the contact surface between the top 22a of the convex magnetic pole part 22 of the movable core 19 and the peripheral wall of the concave magnetic pole part 20 of the fixed core 18. In other words, a strong holding force can be obtained. Here, even if the excitation coil 13 is de-energized, if the holding force is high, the movable core 19 remains held in the state shown in FIG. 4.

When the excitation coil 14 is energized, the force of the spring 24 and the magnetic force of the excitation coil 14 exceed the holding force, and the movable iron core 19
is released from the suction hold and returns to the state shown in FIG.

(g) Effect of the invention According to this invention, the stroke distance of the movable iron core is
Since the distance between the magnetic pole faces of the fixed core and the movable core when released is small, a small size and low power are required to obtain a specified stroke, and conversely, it is possible to obtain a plunger type electromagnet with a large stroke using a specified electric saw. can.

Furthermore, by appropriately selecting the length of the movable core and setting or changing the distance between the fixed core and the movable core of the non-capturing portion during suction, the holding force during non-energization can be adjusted.

[Brief explanation of drawings]

1 and 2 are explanatory diagrams of a plunger type electromagnet according to an embodiment of the present invention. FIG. 1 is an explanatory diagram showing when the movable core is released, and FIG. 2 is an explanatory diagram showing when the movable core is attracted. Figure, 3rd
4 are explanatory diagrams of a plunger type electromagnet according to another embodiment of the present invention, FIG. 3 is an explanatory diagram showing when the movable core is released, and FIG. 4 is an explanatory diagram showing when the movable core is attracted. , FIG. 5, and FIG. 6 are diagrams showing conventional plunger type electromagnets. 1.11: Plunger type electromagnet, 2.18: Fixed iron core, 6.13.14: Exciting coil, 7.15: Permanent magnet, 8.19: Movable iron core. Patent applicant: Iwasaki Giken Kogyo Co., Ltd. (and 1 other person) Agent: Patent attorney Shigeru Nakamura

Claims (4)

[Claims] (1) A fixed core, a movable core, an electric winding, and a permanent magnet are included, and the magnetic flux generated by the permanent magnet is superimposed on the magnetic flux generated by energizing the electric winding to generate an attractive force between the magnetic pole surfaces of the two iron cores; In a plunger type electromagnet that mechanically shifts a movable core using this attractive force, the magnetic pole surface of either the fixed core or the movable core is formed on the inner side surface of the cylinder, and the magnetic pole surface of the other core facing this is formed on the inner side surface of the cylinder. , a plunger type electromagnet having the same axis as the inner side surface of the cylinder, and being inserted and arranged so as to be slidable in the axial direction, and formed on the parallel side surface and the right-angled end surface of the columnar body in the axial direction. (2) The plunger type electromagnet according to claim 1, wherein a magnetic plate is provided at one end of the inner side surface of the cylinder. (3) The fixed iron core and the movable iron core are formed such that one of the opposing magnetic pole parts has a concave axial cross section and the other magnetic pole part has a convex axial cross section, and the concave part and the convex part are formed. A plunger-type electromagnet according to claim 1, which is arranged so as to be freely inserted and removed. (4) The fixed core and the movable core are arranged such that the distance between the two cores is relatively small when they are released, and the distance between the two cores when they are attracted is larger than the distance when they are released. A plunger type electromagnet according to claim 1, wherein the axial length of the iron core is selected.