JPS6325696Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a bistable self-holding DC solenoid in which the yoke is divided into two parts along a diagonal line.

A solenoid in which the plunger is held in two symmetrical positions by the magnetic force of a permanent magnet, and the plunger is moved forward and backward by the magnetomotive force generated by energizing the coil is called a bistable self-holding DC solenoid. .

Since it is not necessary to constantly flow a coil current to hold the plunger, the amount of electric power can be saved, which is extremely useful from the viewpoint of energy saving.

However, in the past, this type of DC solenoid had two coils wound on separate bobbins, so the lead wire connecting the two coils was
There was an accident in which the wire broke due to repeated impact force.

An example of a conventional bistable self-holding DC solenoid will be explained with reference to FIGS. 7 and 8.

The bracket 21 forming the outer shell is made of a magnetic material and consists of a bracket casing 22 having a U-shaped cross section and a bracket cover plate 23. There are two bobbins 24, 24' in this, each with A coil 2.
5. B coil 26 is wound. A plurality (for example, four) of permanent magnets 27 are provided between the coils 25 and 26 so that the same polarity faces each other.

At the center of the bracket is a magnetic plunger 2.
A push rod 29 made of a non-magnetic material is fixed to one end of the push rod 8.

The forward and backward movement of the plunger 28 is regulated by stoppers 30, 30' fixed to the bracket 1. A guide pipe 32 made of steel or plastic is provided to surround the plunger 28 and guide the sliding displacement of the plunger.

A magnetic yoke 31 is interposed between the permanent magnet 27 and the guide pipe 32 in order to reduce magnetic resistance. The magnet has a rectangular parallelepiped shape, and the guide pipe 32
Since it is cylindrical, the yoke 31 that fills this gap has the shape of a square plate with a circular hole 0 in the center. Yoke 31 is one member.

As can be seen from the above example, the A coil 25 and the B coil 26 are wound around separate bobbins 24 and 24'. Since the bobbin is separate, the yoke 31 can be fitted into the middle of the bobbin even if it is a single member.

However, the windings of the A coil and the B coil are continuous, and the two coils are connected through a gap between the magnets and the bracket. The connecting parts are usually filled with epoxy resin and hardened.

Even if the connecting portions of the windings were hardened with epoxy resin in this way, there was still a possibility of wire breakage. Each time the plunger moves forward or backward, an impact force is applied to the bracket, but the bobbins 24 and 2
This is because 4' is a separate body, so the degree to which it receives the impact force is different. The distance between the A coil and the B coil is not always exactly the same, but becomes wider, albeit slightly, at the moment an impact force is applied. Then, tension is applied to the winding connection section. There was a possibility that the wire would break due to repeated shocks.

The present invention aims to solve these drawbacks. After all, since the A coil and B coil are wound on separate bobbins, the cause of wire breakage is that the plunger undergoes different displacements each time it operates. All you have to do is wind the A and B coils around the integrated bobbin. When the bobbin is integrated, the yoke that should be placed in the middle of the bobbin must not be a single member. The yoke must be divided into two parts. In the present invention, the yoke is divided into two parts along the diagonal line.

EMBODIMENT OF THE INVENTION Hereinafter, the structure, operation, and effect of the present invention will be explained in detail with reference to drawings showing embodiments.

FIG. 1 is an overall external perspective view of a self-holding DC solenoid according to an embodiment of the present invention. 2 is a cross-sectional view taken in FIG. 1, and FIG. 3 is a cross-sectional view taken in FIG. 2.

The bracket 1 forming the outer shell is made of a magnetic material and is composed of a bracket casing 2 and a bracket cover plate 3 in order to cover six sides. The bracket casing 2 is made by bending a cross-shaped iron plate with a through hole in the center, and constitutes one end surface and four adjacent side surfaces. The bracket cover plate 3 is a square iron plate with a through hole bored in the center.

Inside the bracket 1, an integrally molded synthetic resin bobbin 4 is housed. The bobbin 4 has approximately the same axial length as the inner space of the bracket, and includes two winding portions, front and rear. FIG. 4 is a perspective view of only the bobbin. An A coil 5 is wound on the front of the bobbin, and a B coil 6 is wound on the rear.

Four rectangular parallelepiped permanent magnets 7, 7, . . . are provided between the A coil 5 and the B coil 6 so that the same poles face each other.

A plunger 8 made of a magnetic material is provided within the cylindrical inner wall surface of the bobbin 4 so as to be freely movable in the axial direction. In this example, since the bobbin is made of a synthetic resin with excellent sliding properties, the bobbin also functions as a guide pipe. However, it is of course possible to use a guide pipe in addition to the bobbin.

A plunger is a thick cylindrical member with small diameter sections at both ends to reduce magnetic resistance during suction.
A non-magnetic push rod 9 is fixed to one of the small diameter portions. The push rod 9 serves as an output end for moving a target mechanical component (not shown) forward or backward.

Through holes are bored in the axial centers of the bracket casing 2 and the cover plate 3, respectively, and magnetic stoppers 10, 10' are fixed thereto by caulking. The plunger 8 is stably held at a position where it contacts the front stopper 10 or the rear stopper 10'.

A permanent magnet 7 is located between the A and B coils 5 and 6.
7... and the bobbin 4, a magnetic yoke 11 is interposed.

The bracket lid plate 3 has cutouts 12,...
are provided, and the claws 13, ... protruding from the front end of the bracket casing 2 are fitted into these, and the claws 13,...
By caulking..., the lid plate 3 and the casing 2 are integrated.

The yoke 11 has a square shape and has a through hole in the center. It is provided between the plunger 8 and the permanent magnet 7 to reduce magnetic resistance. These points are no different from the previous yoke.

However, in the solenoid of the present invention, the yoke 1
1 is divided into two parts along a diagonal dividing surface 14.

FIG. 5 is a perspective view of the yoke 11 divided into two parts. The yoke 11 is a right-angled isosceles triangle ABD,
Free-cutting pure iron members with semicircular notches provided on the oblique sides of CD'B' are assembled at diagonal dividing surfaces 14, 14. When combined, the outer shell is square
ABCD, with a bobbin hole 0 in the center. The four sides AB, BC, CD, and DA become the magnet contact surface 15, and the through hole 0 becomes the bobbin contact surface.

The yoke 11 may be formed into a strictly right-angled isosceles triangle with sharp corners. However, it is preferable to take the four corners. In this example, there are chamfered portions 16 at the four corners.
is provided.

If the chamfer 16 is at the 45° corner, it is possible to cancel out misalignment due to machining errors in the yoke, such as runout in the center of the through hole, errors in the angle between the faces, and misalignment of the permanent magnets.

FIG. 6 is an enlarged sectional view of the corner of the yoke and the abutting portion of the permanent magnet. This figure shows the case where the permanent magnet is in a slightly shifted position. Furthermore, assume that the positions of the centers of the through holes in the yokes are different for both yoke members. Even in such exceptional cases,
Since the chamfered portion 16 is provided, the magnet and yoke 1
1 can be contacted without any gaps.

Of course, if the processing precision of the yoke 11 is high,
There is no need to chamfer.

Next, we will discuss the effect.

This solenoid operates in a similar manner to a conventional bistable self-retaining solenoid. The plunger 8 is moved by the magnetic force of the permanent magnet to the front stopper 1.
0, or the state where it is attracted to the rear stopper 10' can be maintained.

By passing a direct current through the A coil 5 and the B coil 6 for a short period of time, the plunger 8 can be displaced forward or backward. In order to switch the direction of motion, it is necessary to switch the direction of the current, and there are two ways to do this.

One is to wind one coil each around the A coil and B coil, and draw out two lead wires. The windings of the A coil and B coil are connected in series, and both coils generate an equal amount of magnetomotive force in the same direction. To change the direction of movement, the lead wire connection is switched between forward and reverse with respect to the power supply.

The other type is to wind two coils each around the A and B coils, and draw out four lead wires. Current is passed through the two sets of coils so as to generate magnetomotive forces in opposite directions. That is, the two sets of coils are each assigned as a dedicated coil for either forward motion or backward motion. In this case, the effective number of coil turns is reduced by half compared to the previous example in the same volume of the bracket interior space, but since no external current switching circuit is required, the external circuit becomes simpler.

The present invention can be applied to either a single winding system or a two winding system.

Describe the effects.

The plunger is instantaneously driven by a pulse current applied to the coil, and the front and rear stoppers 10,
collides with 10'. Since the bobbin 4 is integral, the impact force generated at this time acts completely equally on the A coil and the B coil. A lead wire communication section 20 (which may be part of a continuous winding) that connects the A coil and the B coil passes through a space surrounded by the permanent magnets 7 and the bracket 1. No repetitive tension is generated by the plunger movement. This is because the distance between the A coil and the B coil does not change due to impact force. In the past, repeated tensile and compressive forces caused lead wire (winding) connection parts to break.
With the present invention, the most important cause of disconnection accidents at the connecting section can be eliminated. The contact part 20 is made of epoxy E
It's even better if you pour it in and fix it.

Since the A and B coils are wound on an integrated bobbin, the yoke naturally has to be split into two.

Although it is called a two-part yoke, if it is divided at a plane perpendicular to the magnet contact surface 15, undesirable things may occur due to machining errors of the yoke.

FIG. 9 is a cross-sectional view of the yoke, magnet, and plunger when the yoke 17 is divided into two along the right-angled dividing surface 18 and there is a machining error in the yoke. In this example, it is assumed that the centers of the bobbin through holes 0 are shifted for the two yoke members. The permanent magnets 7, 7 located on the extension line of the dividing surface 18 are supposed to contact both of the two yoke members, but due to machining errors, an air gap 19 is formed between one of the yoke members and the permanent magnet 7. remain. air gap 19
If there is, the magnetic resistance increases, so
The holding force caused by the permanent magnet, the longitudinal thrust caused by the coil current, etc. are reduced.

However, in the present invention, since the yoke is divided into two parts along the diagonal dividing surface 14, the permanent magnet 7 can contact the magnet contact surface 15 of the yoke without any gap. One permanent magnet does not contact two parts of the yoke at the same time, so even if there is a machining error in the yoke, the air gap will not touch the yoke.
There is no room between the permanent magnets. Therefore, even if there is a machining error in the yoke, the magnetic resistance will not increase. The holding force due to the permanent magnet, the thrust force due to the coil current, etc. can always take the highest values.

In the illustrated example, the bobbin also serves as a guide pipe, but the guide pipe may be provided as a separate member inside the bobbin, as in the example shown in FIG. 7.

The permanent magnets 7, . . . can be selected from suitable magnets such as ferrite magnets and rare earth metal alloy magnets. In this example, the shape is a rectangular parallelepiped, but as shown in Figure 10,
A permanent magnet with a 45° chamfer Q may also be used.
Compared to the case of the permanent magnet shown in FIG. 3, the volume of the permanent magnet can be increased by 2e corresponding to the length of the chamfer Q.
This increases the total amount of magnetic flux, thereby increasing the holding force.

Furthermore, since the yoke is divided into two parts along the diagonal dividing plane 14, there is a possibility that an air gap may occur between the dividing planes due to processing errors. However, since the permanent magnets are arranged so that the same poles face each other, the directions of the magnetic lines of force are close to radial within the yoke. The lines of magnetic force are approximately parallel to the dividing plane 14 and do not cross it. Therefore, the presence of the dividing surface 14 does not increase the magnetic resistance of the yoke.

This is a useful idea.

[Brief explanation of drawings]

FIG. 1 is an overall perspective view of a self-holding DC solenoid according to an embodiment of the present invention. FIG. 2 is a sectional view taken in FIG. 1. FIG. 3 is a sectional view taken in FIG.
FIG. 4 is a perspective view of only the bobbin. FIG. 5 is an exploded perspective view of the two-part yoke. FIG. 6 is an enlarged cross-sectional view of the dividing corner of the yoke and the abutting part of the permanent magnet when there is a machining error in the yoke. FIG. 7 is a sectional view of a conventional self-holding DC solenoid. Figure 8 is the 7th
A perspective view of only the yoke of the solenoid shown in the figure. FIG. 9 is a cross-sectional view of the yoke and magnet portion when there is a machining error in the yoke that has been divided into two along the right-angled dividing plane.
FIG. 10 is a perspective view of a chamfered permanent magnet. 1... Bracket, 2... Bracket casing, 3... Bracket lid plate, 4... Bobbin, 5...
...A coil, 6...B coil, 7...permanent magnet,
8... Plunge Ya, 9... Push Rod, 1
0,10'...Stopper, 11...Yoke, 1
4... Diagonal dividing surface, 15... Magnet contact surface, 16
... Chamfered part.

Claims (1)

[Claims for Utility Model Registration] (1) A bracket 1 having an outer shell made of a magnetic material, an A coil 5 and a B coil 6 wound in the front and rear direction around a bobbin 4 integrally formed inside the bracket 1,
Permanent magnets 7 are provided between the A coil 5 and the B coil 6 so that the same poles face each other, and a magnetic plunger 8 is provided in the bracket 1 so as to be movable in the axial direction. A self-holding device characterized by being composed of a magnetic yoke 11 which is provided between the magnets 7, ... and the bobbin, has a bobbin through hole 0, has a substantially square shape, and has a dividing surface 14 along a diagonal line. Type DC solenoid. (2) The self-holding DC solenoid according to claim 1, in which the corners of the yoke 11 are provided with chamfered portions 16. (3) The self-holding DC solenoid according to claim 2, wherein the bobbin 4 also serves as a sliding guide pipe for the plunger 8.