JP2579585B2 - Electromagnet device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnet apparatus having a plunger type electromagnet and capable of driving a driven body.

[0002]

2. Description of the Related Art Conventionally, as a driving source for linearly driving a driven body such as a power switching device, an electromagnet device which is relatively small and generates a strong driving force has been used.

[0003] Such an electromagnet apparatus generally comprises an excitation coil 51 and an excitation coil 5 as shown in FIGS.
1 and a plunger 53 constantly urged outward (retreating direction) of the exciting coil 51 by a load from a driven body (not shown) not shown and a cylindrical fixed core 52 surrounding the exciting coil 51.
And a plunger-shaped electromagnet 50 is provided, and the electromagnet 50 is provided in the operation box 61 via the mounting member 54. A drive shaft 57 having a connecting plate 58 and a lever 59 is pivotally attached to the operation box 61.
The linear operation of the plunger 53 is performed by the drive shaft 5 through an engagement portion 56 formed by a long hole 58 a provided at the front end of the connection plate 58 and a bolt 55 provided at the rear end of the plunger 53.
7 is rotated, and the driven body is pulled and driven by the lever 59.

Further, on an extension of the axis of the plunger 53, a position detection switch 60 composed of a limit switch is provided.
The tip of the plunger 53 presses the operating piece 60a of the position detection switch 60 to detect the advance of the plunger 53.

[0005]

However, in such an electromagnet device having the conventional configuration, the forward operating force of the plunger 53 when energized is transmitted through the engaging portion 56.
When the plunger 53 advances, the bolt 5
5 and the long hole 58a are stopped by impact and stopped (shown by a solid line in FIG. 5), at which time a large metallic noise is generated. Further, when the power is turned off, the plunger 53 is pulled out of the exciting coil 51 via the engaging portion 56 due to the disappearance of the attraction force and the load by the driven body. As described above, the retraction of the plunger 53 is impulsively stopped at the engaging portion 56 and stopped (indicated by a two-dot chain line in FIG. 5), causing a problem of generating a large metallic noise.

Further, since the plunger 53 impacts the operating piece 60a in the forward position, the position detecting switch 60 may be broken.

Further, the mounting member 54 is used for mounting the electromagnet 50.
Therefore, there is a problem that the mounting height (h) of the electromagnet 50 is increased, and the operation box 61 is enlarged.

The present invention has been made in view of the above, and an object of the present invention is to provide an electromagnet apparatus capable of reducing operating noise, preventing breakage of a position detection switch, and miniaturizing the apparatus. It is intended to provide.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object, and comprises an exciting coil, a fixed iron core, and a plunger which moves linearly. An electromagnet device comprising a drivable electromagnet and a plunger position detection switch, wherein the plunger of the electromagnet includes a rear stopper rubber provided at a rear end and a front stopper rubber provided at an intermediate portion. And a straight rod-shaped position detecting member is extended at one end of the plunger, a permanent magnet is attached to the position detecting member, and a magnetic field of the permanent magnet is generated along the moving direction of the permanent magnet. A position detection switch that can be opened and closed in accordance with the presence or absence is provided, and the operation box is formed of a magnetic member and constitutes a part of a fixed iron core of the electromagnet. It includes a stopper rubber and capable of abutting stopping plate after plunger, to become Te is an electromagnet and wherein the.

[0010]

The present invention is constructed as described above,
The operation box forms a part of the magnetic circuit by forming a part of the fixed core surrounding the excitation coil of the electromagnet, thereby reducing the height of the electromagnet.

The rear stopper rubber of the plunger elastically abuts the stop plate of the operation box in the retracted position of the plunger, and the front stopper rubber elastically contacts the front of the fixed core of the electromagnet in the advanced position of the plunger. Abut and reduce the operating shock of the plunger at each position.

The position detecting member moves together with the plunger, and responds to the presence or absence of the magnetic field of the permanent magnet following the plunger.
Turn the position detection switch on and off.

[0013]

FIG. 1 shows an embodiment of the electromagnet apparatus of the present invention.
The description will be made based on Nos.

The electromagnet device 1 includes a rear stopper rubber 2
1, an electromagnet 10 having a plunger 20 provided with a front stopper rubber 23, and a position detecting member 25 extending at one end of the plunger 20 and having a permanent magnet 27 attached thereto.
And a position detection switch 30, 31 disposed along the moving direction of the permanent magnet 27 so as to be openable and closable in accordance with the presence or absence of a magnetic field of the permanent magnet 27, and an operation box 40 provided with a stop plate 42. It is configured.

The electromagnet 10 includes an exciting coil 11, a fixed iron core 13, and a plunger 20. The exciting coil 11 is wound around a cylindrical bobbin 12, and a fixed iron core 13 is provided so as to surround the exciting coil 11. I have. The fixed core 13 includes a fixed magnetic pole 14 made of a magnetic material, a rectangular box-shaped assembly including a fixed core rear portion 15, a fixed core front portion 16, and a fixed core body 17 each made of a magnetic plate material. It is formed by a part (specifically, the magnetic circuit forming portion 41a).

The fixed magnetic pole 14 is fitted into the bobbin 12 and is formed in a round bar shape having a through hole (not shown) through which the position detecting member 25 can penetrate, and has one end side (the right end side in FIG. 1). ) Has a cone-shaped receiving portion 14 a and is fixed to the fixed core rear portion 15. The fixed core rear portion 15 is formed in a rectangular shape and has a through hole (not shown) through which the position detection member 25 can pass.
Is fixed to the rear portion (the left end side in FIG. 1).

The fixed core front portion 16 is formed in a square shape, and has a through hole (not shown) into which the plunger 20 can be loosely fitted.
It is fixed to the front part (the right end side in FIG. 1) of the fixed core body 17. The fixed core body 17 is formed in a U-shaped cross section, and mounting portions 17a, 17a are formed at open ends thereof, respectively.

The plunger 20 is formed of a magnetic material in the shape of a round bar that can move directly inside the bobbin 12. The rear end 20a of the plunger 20 is made of, for example, NBR
After being bent in a letter shape, a stopper rubber 21 is attached by a bolt 22. In the middle of the longitudinal direction of the plunger 20, an annular front stopper rubber 23 is
4 and attached. The tip 20b is formed in a conical shape, and when the plunger 20 is in the forward position, the tip 20b and the receiving portion 1 of the fixed magnetic pole 14 are formed.
4a so as to maintain a predetermined gap.

The electromagnet 10 is mounted on the fixed core body 1.
7 is integrally attached to a bolt stud-welded to the main body 41 of the operation box 40 with a nut 18. As a result, the main body 41 is fixed to the fixed core rear portion 15.
A magnetic circuit forming portion 41 a is formed between the magnetic core forming portion 41 and the fixed iron core front portion 16 in the vicinity of the exciting coil 11.

The position detecting member 25 is formed in a straight rod shape.
The plunger 20 is fixedly attached to the distal end portion while sharing an axis. A permanent magnet 27 for opening and closing the position detection switches 30 and 31 is provided at a predetermined position of the position detection member 25.
Is installed.

Each of the position detecting switches 30 and 31 is constituted by a reed switch which closes a contact under the influence of the magnetic field when the permanent magnet 27 approaches, and opens the contact when the permanent magnet 27 moves away. The main body 41 is attached to the main body 41 by the mount 33 at a predetermined distance from the permanent magnet 27 while being parallel to the moving direction of the permanent magnet 27. When the plunger 20 moves forward, the permanent magnet 27 closes its contact relative to the position detection switch 30.
One contact is open. Further, at the retracted position of the plunger 20, the permanent magnet 27 is disposed so as to close the contact thereof relative to the position detection switch 31 and open the contact of the position detection switch 30. Accordingly, the position detection switches 30 and 31 operate mechanically in a non-contact manner, have extremely high durability, and can perform stable position detection with respect to the vibration of the device.

Instead of the position detection switches 30 and 31, a single reed switch may be provided which can selectively switch a contact or b contact depending on the presence or absence of a magnetic field. Similar effects can be obtained by performing position detection using a magnetic sensor instead of the position detection switch.

The operation box 40 is formed of a main body 41 made of a thick magnetic plate and a lid 43 covering the opening thereof. A stop plate 42 for abutting a predetermined position of the main body 41 with the rear stopper rubber 21 to define a retreat end of the plunger 20.
Is provided. The main body 41 also includes the plunger 20.
A drive shaft 45 is provided, which is orthogonal to the axis and is rotatably supported by a bearing plate 43.

A connecting plate 46 protrudes in the middle of the drive shaft 45, and a long hole 46 a at the end of the connecting plate 46 is rotatably engaged with the bolt 22 attached to the plunger 20. An engaging portion 48 is formed.

A lever 47 extending substantially in the vertical direction in FIG. 2 is fixed to the outer end of the drive shaft 45. Is rotated, and the drive end 47 at the tip end of the lever 47 is rotated.
a and 47b are configured to move in opposite directions to each other. Reference numeral 49 denotes a terminal block for electrically connecting the electromagnet 10 and the position detection switches 30 and 31 to the outside.

Next, the electromagnet apparatus 1 configured as described above
Will be described.

The electromagnet device 1 is electrically connected to a control panel (not shown), and has a drive end 47a,
47b are connected to the driven body, respectively,
The load of the driven body that always rotates the drive shaft 45 counterclockwise is applied to 7a and 47b. This allows
When the excitation coil 11 of the electromagnet 10 is not energized, the plunger 20 is at the retracted position via the engaging portion 48, and the rear stopper rubber 21 is in contact with the stop plate 42 (see FIG. 4). The position detecting member 25 is located on the right side of the figure, and its permanent magnet 27 faces the position detecting switch 31, and the magnetic flux closes the position detecting switch 31 to detect the retreat position of the plunger 20. At this time, the position detection switch 30 is outside the magnetic field of the permanent magnet 27 and is in an open circuit state.

When the excitation coil 11 is energized, the fixed core 1
3. A magnetic flux is generated in the magnetic circuit formed by the magnetic circuit forming portion 41a and the plunger 20, and an attractive force toward the fixed magnetic pole 14 acts on the plunger 20. As a result, the plunger 20 is sucked, and moves forward (to the left in the drawing) through the engaging portion 48 and the drive shaft 45 against the load of the driven body.
The front stopper rubber 23 comes into contact with the fixed core front portion 16, and the forward end is defined and stopped. At this time, the plunger 20
There is a gap between the distal end portion 20b of the fixed magnetic pole 14 and the receiving portion 14a of the fixed magnetic pole 14, and the plunger 20 does not collide with the fixed magnetic pole 14. Then, the operating force of the plunger 20 is absorbed by the rubber elasticity of the front stopper rubber 23, the impact at the time of stopping at the engaging portion 48 is reduced, and the metallic noise is reduced. Therefore, both the level and the frequency of the operation noise decrease.

As a result, the drive shaft 45 rotates clockwise, and the lever 47 rotates clockwise to move the drive ends 47a, 47b to each other.
They move right and left, respectively (see FIG. 2). Due to this movement, the driven bodies connected to the driving ends 47a and 47b are respectively driven in tension. At this time, the position detecting member 25 moves to the left along with the plunger 20, the permanent magnet 27 moves laterally, faces the position detecting switch 30, and the magnetic flux closes the position detecting switch 30, so that the plunger 20 is closed. The forward position of the vehicle. At this time, the position detection switch 31 is out of the magnetic field of the permanent magnet 27 and is in an open state.

When the current supply to the exciting coil 11 is stopped, the magnetic flux, that is, the attractive force of the plunger 20 disappears. Thereby, the drive shaft 45 rotates counterclockwise due to the load by the driven body, the lever 47 returns to the position shown in FIG. 4, the rear stopper rubber 21 abuts on the stop plate 42, and the plunger 20 is moved. Move to the retracted position. At this time,
The retraction force of the plunger 20 is absorbed by the rubber elasticity of the rear stopper rubber 21, the impact at the time of stopping at the engagement portion 48 is reduced, and the metallic noise is reduced. Therefore, both the level and the frequency of the operation noise decrease.

Then, the tension drive of the driven body is turned off,
The permanent magnet 27 of the position detecting member 25 is
The plunger 20 is moved to a position opposite to the position 1 to detect a retreat position of the plunger 20.

[0032]

As described above, according to the electromagnet apparatus of the present invention, the rear stopper rubber and the front stopper rubber provided on the plunger absorb and reduce the impact during the operation of the plunger, thereby reducing the operating noise of the electromagnet. can do.

Further, the movement of the magnetic field of the permanent magnet attached to the position detecting member causes the position detecting switch to turn on and off mechanically in a non-contact manner, so that the switch has extremely high durability and is resistant to vibration of the device. On the other hand, stable position detection can be performed.

Furthermore, since a part of the fixed core of the electromagnet is constituted by the operation box, and the electromagnet and the operation box are formed integrally, the mounting member of the electromagnet can be omitted, and the configuration height of the electromagnet can be reduced. This makes it possible to reduce the size and to form the device compact.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an electromagnet device according to an embodiment of the present invention.

FIG. 2 is a front sectional view of the same.

FIG. 3 is a partial side view as viewed in the direction of arrow A in FIG. 2;

FIG. 4 is a front sectional view showing a retracted state of the plunger.

FIG. 5 is a front sectional view of a conventional electromagnet device.

6 shows a conventional plunger type electromagnet B in FIG.
Arrow view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electromagnet apparatus 10 Electromagnet 11 Excitation coil 13 Fixed iron core 20 Plunger 21 Rear stopper rubber 23 Front stopper rubber 25 Position detecting member 27 Permanent magnet 30, 31 Position detecting switch 40 Operation box 41a Magnetic circuit forming part

Claims (1)

(57) [Claims] 1. An electromagnet device comprising an exciting coil, a fixed iron core, and a plunger that moves linearly, an electromagnet provided in an operation box, capable of driving a driven body, and a position detection switch of the plunger. The plunger of the electromagnet includes a rear stopper rubber provided at a rear end and a front stopper rubber provided at an intermediate portion, and a straight rod-shaped position detecting member is extended from one end of the plunger. In addition, a permanent magnet is attached to the position detecting member, and a position detection switch that can be opened and closed in accordance with the presence or absence of a magnetic field of the permanent magnet is provided along the moving direction of the permanent magnet. And a stop plate formed of a magnetic member and constituting a part of the fixed core of the electromagnet and capable of abutting against a rear stopper rubber of the plunger. Electromagnet device to.