JPH0244491Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" This invention magnetically attracts and holds a movable body that is mechanically approached, and maintains the holding state by passing a current through the coil to weaken the attraction force. The present invention relates to a trigger magnet that is released by a force applied to the movable body.

"Prior Art" Conventionally, an electromagnetic plunger or the like has been used to apply a magnetic attraction force to a movable body to attract and hold the movable body. However, when the movable body itself is mechanically driven, the driven state is held magnetically, and an electrical pulse is given to the coil to release the held state, a trigger magnet is used. There is.

In this trigger magnet, in order to strengthen the holding state in which the movable body is held by magnetic attraction force, the magnetomotive force of the permanent magnet is strengthened, but when the magnetomotive force is strengthened, when the holding is released, a large back electromotive force is generated by the coil. It is necessary to generate magnetic force. On the other hand, in order to release the hold, that is, improve the return force characteristics,
There is a device in which a small path is provided to magnetically short-circuit the permanent magnets when the magnet is released, so that more of the magnetic flux that attracts the movable body during the release passes through the short-circuit path.
In this case, even in the holding state, a part of the magnetic flux flows into the short-circuit path, resulting in a weak holding force. In some cases, a magnetic gap for the magnetic flux of the permanent magnet is provided on the opposite side of the coil, and the holding magnetic flux is passed through the magnetic gap at the time of release to improve the return force characteristics. However, in this case, if a magnetic gap with a large area is obtained, the overall shape becomes large, and it is not possible to make the return force characteristics sufficiently good to make the device compact.

``Means for solving the problem'' According to this invention, two coils are arranged side by side, a magnetic core is inserted into one end of each coil, and one end surface of these magnetic cores is slightly protruded from the coil, so that the magnetic material can be moved. It is considered as an adsorption surface to which the body is adsorbed. The other halves of these magnetic cores protrude from the coils, and permanent magnets are placed between them at the protruding portions. If necessary, the two magnetic cores are extended on the opposite side of the permanent magnet coil and brought closer to each other to provide a magnetic gap.

A mounting plate made of a magnetic material is attached to one surface of the other half of these magnetic cores via an intervening piece made of a non-magnetic material, and a magnetic gap is formed between the two magnetic cores and the mounting plate. The magnetic gap formed by this mounting plate has a large area. Therefore, when releasing the movable body from adsorption, if a current is applied to the coil to cancel the magnetic flux passing through the movable body, the movable body can be released. The magnetic flux of the permanent magnet that was passing through it now passes through the magnetic gap, and the attraction force to the movable body is weakened accordingly.
Good return force can be obtained.

``Example'' Hereinafter, an example of the trigger magnet according to this invention will be described with reference to the drawings. Coils 11, 12
are arranged side by side with their axes parallel to each other,
The coils 11 and 12 are wound on bobbins 13 and 14, respectively. Collars 13a, 14a are provided at one end of the bobbins 13, 14, and collars 13b, 1 are provided at the other end.
4b are formed respectively. Brim 13b, 1
This is a case where the terminal attachment parts 15 and 16 are integrally formed on the outer surface of 4b. Also, in this example, the collar 1
3a and 13b are connected to each other, and both bobbins 13,
14 is a case where it is configured as one molded product. The coils 11 and 12 are wound around the bobbins 13 and 14, respectively, with the outer surfaces of the flanges 13a and 14a facing each other, and then the coils 11 and 12 are arranged in parallel by being bent at the connecting portion of the flanges 13a and 14a. Terminal 1 is attached to terminal mounting parts 15 and 16.
7 and 18 are respectively erected, and these terminals 17,
Lead wires 11a and 12 of coils 11 and 12 are connected to 18.
a are wound and connected, respectively. Guide grooves 21 and 22 are formed on the side surfaces of the terminal mounting portions 15 and 16 to guide and protect the lead wires 11a and 12a of the coils.

For example, a magnetic core 23 of an iron core,
24 is inserted, and one end surface of the collar 13 is inserted.
a, 14a, and the protruding surfaces thereof serve as suction surfaces 23a, 24a. The portions of the magnetic cores 23 and 24 that protrude from the bobbins 13 and 14, that is, the magnetic core 2
A permanent magnet 25 is provided between the other halves of the magnets 3 and 24. This is a case where the magnetic cores 23 and 24 on the opposite side of the permanent magnet 25 from the coils 11 and 12 are brought close to each other to form a magnetic gap 26.

In this invention, in the other halves of the magnetic cores 23 and 24, an intervening piece 2 made of a non-magnetic metal material is placed on one surface of these.
7 are in contact with each other over almost the entire surface, and are also in contact with the permanent magnet 25. The intervening piece is a square plate. A mounting plate 28 made of magnetic material is attached to the intervening piece 27 so as to face it. A magnetic gap 29 is formed between the magnetic cores 23 and 24 and the mounting plate 28.
The mounting plate 28 has mounting holes 31 across the gap 26.
32 are opened, holes are also opened in the intervening piece 27 facing the mounting holes 31 and 32, and these holes 31 and 32 are also opened.
In the portion facing 32, the magnetic cores 23 and 24 are separated from each other without approaching each other, and therefore the magnetic gap 26 is divided into two parts 26a and 26b. The magnetic cores 23, 24, the intervening piece 27, and the mounting plate 28 are connected to each other by, for example, welding, and the permanent magnet 25 is fixed with adhesive.

According to this configuration, the movable body 33 made of magnetic material is moved by other means, and the attracting end surfaces 2 of the magnetic cores 23 and 24
3a, 24a, a magnetic path passing through the magnetic cores 23, 24 and the movable body 33 is formed for the magnetic flux of the permanent magnet 25, and the magnetic flux _φ1 shown by the arrow in the figure passes through, and the movable body 33 is magnetically It is retained by adsorption. This movable body 33 is biased in a direction away from the magnetic cores 23 and 24 by, for example, a coil spring or something, but this magnetic attraction force is stronger than the biasing force, and the movable body 33 is magnetically attracted and held. has been done.

To release this magnetic holding state, coil 1
A pulse current is applied to 1 and 12. This current generates a magnetic flux φ ₂ in the coils 11 and 12, and the magnetic flux φ ₂
is in the opposite direction to the magnetic flux φ ₁ , and therefore the magnetic flux φ ₁ due to the permanent magnet 25 passing through the movable body 33 passes through the magnetic gaps 26 and 29 as φ ₃ and φ ₄ in FIG. The movable body 33 is moved away from the suction surfaces 23a and 24a due to the biasing force applied to the movable body 33 in advance.

"Effects of the Invention" As described above, according to the trigger magnet of this invention, the mounting plate 28 made of magnetic material is attached via the intervening piece 27, and the magnetic core 2 of this mounting plate 28
3 and 24 can be made sufficiently large, a sufficiently large amount of the magnetic flux of the permanent magnet 25 can be passed through the magnetic gap 29 upon release, and therefore the magnetic attraction characteristics of the movable body 33 can be prevented from deteriorating. Good return force characteristics can be obtained. Conventionally, only the magnetic gap 26 was provided, so the area of the magnetic gap 26 was small, and sufficient restoring force characteristics could not be obtained. In order to increase the area of the magnetic gap 26, it is necessary to increase the length in the direction along the axis of the coil 11, which results in a larger shape. However, in this invention, the thickness of the intervening piece 27, for example, 0.3
It becomes only about mm larger.

Furthermore, by changing the thickness of the intervening piece 27, the magnetic resistance to the magnetic flux φ ₄ can be adjusted.
It becomes possible to select the return force characteristics according to the specifications.

[Brief explanation of drawings]

Fig. 1 is a front view showing an example of the trigger magnet according to this invention, Fig. 2 is a right side view thereof, Fig. 3 is a sectional view taken along line AA in Fig. 2, and Fig. 4 is a sectional view of Fig. 1.
It is a BB line sectional view. 11, 12... Coil, 13, 14... Bobbin, 23, 24... Magnetic core, 25... Permanent magnet, 2
6, 29...Magnetic gap portion, 27...Intervening piece, 28
...Mounting plate.

Claims (1)

[Claims for Utility Model Registration] First and second coils arranged substantially parallel to each other, first and second magnetic cores each having one half inserted into the first and second coils, and the first magnetic core. , a permanent magnet interposed between and connecting the other halves of the second magnetic core extending from the coil, and a non-magnetic material interposed across the other halves of the first and second magnetic cores. and a mounting plate that is in contact with the intervening piece and faces the other halves of the first and second magnetic cores, is made of a magnetic material, and forms a magnetic gap with the permanent magnet. trigger magnet.