JPS6154603A - Electromagnet device - Google Patents

Abstract

PURPOSE:To obtain an electromagnet device suitable for a plunger type printing head by a method wherein a movable core, consisting of magnetic metal material, and a type driving part formed with high molecular material are coupled each other and displaced in one body, thereby enabling to reduce the acceleation of displacement and to eliminate an unnecessary displacement operation. CONSTITUTION:A coil 36 is wound around a cylindrical coil frame body 22 having a through hole in the center, and the side face and the outside surface, excluding the through hole, are surrounded by the first and the second yokes 42 and 47. Then a movable core 21, having an axis part 29 in the center part, an E-ring 51 on one end through a cushioning material 52 and a tapered pole face 25 on the other end, is inserted into the center hole of the frame body 22. Besides, a fixed core 34 having a center opposing face 35a is provided on the part where said pole face and the axis part 29 are penetrated, and a magnetic circuit is constituted with yokes 42 and 47 and cores 21 and 24. Also, a flange part 30 and a type driving part 28 of high molecular material protruded from the flange part 30 are provided on the contacting surface of the axis part 29 penetrated into the core 34, a driving part 28 is protruded every time when a printing is performed, and the driving part 28 is pulled in by the coil spring 63 provided between the flange part 30 and a frame body 58 after printing work is finished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electromagnetic device suitably used in a print head of a serial printer, a plunger type print head for striking the type of a special daisy type type wheel, and the like.

BACKGROUND ART A typical prior art is shown in FIG. This electromagnet device 1 is a so-called non-polar electromagnet device that does not have a permanent magnet in its magnetic circuit. A movable iron core 2 that is freely displaceable in the longitudinal direction and has an intermediate step portion 2a as a basic component;
It includes bearings 3 and 4 that support the movable core 2, a fill frame 5 disposed around the outer periphery of the movable core 2, and a coil 6 wound around the fill frame 5.

Further, a first yotaph, which has a stepped cylindrical shape and whose stepped inner surface 7a magnetically attracts the intermediate step 2a when the coil 6 is excited as will be described later, and a first g-
The first yoke 7 has seven rungs 8a that are magnetically coupled to the first yoke 7, and includes a second yoke 8 that constitutes a housing of the electromagnet device 1 and a magnetic circuit to be described later. Further, in order to return the movable core 2 to its original state after it has been displaced in the direction of arrow W, there is a return spring 9 whose one end is in contact with the intermediate step portion 2a.
including.

A stop member 10 made of, for example, a metal material is provided between the bottom plate 8b of the second yoke 8 and the movable iron core 2. The stop member IO is used to collide with and stop the movable core 2 when the movable core 27 returns to the left in FIG. 8 as will be described later. A buffer member 11 made of an elastic material such as rubber is provided on the bottom plate 8b side of the stop member 10.

FIG. 9 shows the magnetic attraction force characteristics and spring load characteristics accompanying the displacement of the movable iron core 2 provided in such an electromagnet device 1. Line /1 shows the spring load characteristics of the coil spring 9, and line 12 shows the spring load characteristics. The attractive force characteristics of the movable iron core 2 during emotional excitation are shown. When a pulse voltage is applied to the filter 6', the movable iron core 2 is displaced in the direction of the arrow W, and the tip of the movable iron core 2 (the right end in FIG. 8) having the type drive unit moves, for example, to the type of the excitation wheel. (not shown). Thereafter, the movable iron core 2 is returned to its original state by the spring force of the spring 9. A printing operation is performed by such a series of operations.

The operating state of such electromagnet device 1 will be explained in more detail based on FIG. 9. When the coil 6 is excited, the step inner peripheral surface 7a of the first yoke 7 becomes the intermediate step 2at of the movable iron core 2.
- Magnetic g & pulling g & attractive force act in the direction of arrow W, and the movable iron core 2 begins to move in the direction of arrow W. As the movable iron core 2 moves in the direction of the arrow W, the gap between the step inner circumferential surface 7a and the intermediate step 2a becomes smaller, and the magnetic attraction force increases to
It reaches the maximum value shown as peak value P1 in the figure.

After that, the movable iron core 2 is further displaced in the direction of the arrow W, and the first
The magnetic flux exchanged between the yoke 7 and the movable iron core 2 is indicated by the arrow W.
When K becomes perpendicular to the displacement direction of the movable iron core 2 as shown by , the magnetic attraction force rapidly decreases as shown in FIG. That is, at point P2 in FIG. 9, the magnetic attractive force intersects the line 11 indicating the spring load characteristic, and further decreases.

However, the kinetic energy of the movable core 2 until it reaches this point P2 (shaded area AI in FIG. 9)
This allows the movable core 2 to move against the spring force of the spring 9 to the movement end position. Once the moving end position is reached, the movable iron core 2 returns to its original position by the spring force of the coil spring 9.

In such an electromagnetic device 1, the movable core 2 is integrally formed including the type drive section, and double printing due to bounding when the movable core 2 returns as described above can be reduced. However, as mentioned above, since the movable core 2 is integrally formed including the type drive section, there is a problem in that the manufacturing cost is high.

As other prior art to solve such problems,
It has been considered to separate the movable core 2 and the type drive section and mold the type drive section from plastic or the like. However, in such prior art, the movable core 2 and the type drive unit are arranged and driven separately, so it is impossible to eliminate the double printing caused by the bounce of the movable core 2 when it returns to its original position. Problems Remained Problems to be Solved by the Invention The present invention solves the above-mentioned problems, and when the movable iron core and the type drive means are returned by the return means when the electromagnetic device is driven, there is no problem in the printing operation. It is an object of the present invention to provide an improved electromagnetic device that is free from necessary operations.

Means for Solving the Problems The present invention provides a movable iron core made of a magnetic material that is displaceable in the longitudinal direction and has a magnetic flux receiving portion and a magnetic pole surface extending from one end to the other end. 1. A type driving section extending in the longitudinal direction of the movable iron core and coaxial with the movable iron core, and an opposing section facing the magnetic pole surface of the movable iron core, through which the type driving means is pushed. a fixed core having an insertion opening; a fill wound around the outer periphery of the movable core; a first yoke that surrounds three sides of the fill and has an opening portion sandwiching the magnetic pole surface of the movable core; a second yoke that is magnetically coupled to the open end of the first yoke and has an insertion hole through which the movable iron core is inserted; and a return means that urges the movable iron core in a direction away from the fixing means. , The electromagnetic device is characterized in that the movable iron core and the type drive unit are screwed together by a screwing means.

In the working electromagnet device, the movable core and the type drive unit are screwed together via a screwing means. When the coil of the electromagnet device is excited, the fixed iron core - the first yoke - the second yoke -
A magnetic path is formed between the magnetic flux receiving portion of the movable core and the opposing portion of the fixed core on the magnetic pole surface of the movable core. At this time, a magnetic attraction force acts between the magnetic pole surface of the movable core and the opposing portion of the fixed core. Therefore, the movable core and the type drive unit are driven in a direction in which the movable core approaches the fixed core.

When the coil is demagnetized and the movable core is displaced to the maximum, the movable core is returned to its original position by a return means that urges the movable core in a direction to move away from the fixed core.

The electromagnet device is continuously driven by such a series of operations.

Embodiment FIG. 1 is a sectional view of an electromagnet device 20 according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view thereof.

With reference to FIGS. 1 and 2, an electromagnetic device 20 of the present invention
The configuration of is explained. The movable iron core 21 made of a magnetic material has a substantially truncated conical shape, and is inserted into an insertion hole 23 formed in the coil frame 22 in the longitudinal direction, which is the axial direction. The movable iron core 21 includes a base portion 24 that is a right cylindrical magnetic flux receiving portion, and
It includes a conical portion 25 that is a magnetic pole surface that tapers in a direction away from the base portion 24 .

Also, near the end of the base 24 opposite to the truncated cone 25 ([
, four grooves 26 are formed along the circumferential direction.

An E-ring 51, which will be described later, is stopped in this four-striped groove 26. An insertion hole 21a is formed by penetrating the movable core 21 from the distal end surface 27 of the truncated cone portion 25 of the movable core 21 along the N line.

A type drive unit 28 is provided coaxially with the movable core 21 and is made of, for example, a polymeric material.

The type drive unit has a right cylindrical shaft portion 29 extending from one end to the other end, and a right cylindrical leg portion 29 having a larger diameter than the shaft portion 29.
a, the 7 rungs 30, a right cylindrical large-diameter body 31 having a larger diameter than the body 29a, and a plate-shaped striking portion 32 extending in the axial direction of the body 31 are coaxial in this order. It is formed and configured as follows.

A threaded portion 29b, which is a component of a screwing means for fixing the type driving means 28 and the movable iron core 21, is provided on the outer peripheral surface of the shaft portion 29 near the end opposite to the body portion 29a.

The shaft portion 29 of the type drive portion 28 is movably inserted through an insertion hole 35 of a fixed iron core 34 having an intermediate step portion 33 on the outer periphery.

The inner circumferential surface 35a of the insertion hole 35 is a facing portion that faces the conical portion 25 of the movable iron core 21 via the magnetic gap A, and its shape corresponds to the shape of the conical portion 25. Also fixed core 3
4 includes a large diameter cylindrical portion 34a and a small diameter cylindrical portion 34b.

The coil frame 22 has a right cylindrical portion 37 around which the coil 36 is wound.
and flange portions 38 and 39. The insertion hole 23 of the coil frame 22 is formed to have a slightly larger diameter than the base 24 of the movable iron core 21, and forms a magnetic gap B. Movable iron core 21
is inserted through the insertion hole 23 so as to be freely displaceable. Protrusion 40.4
1 has seven rungs 38.1 for positioning the fill frame 22.
39 is installed protrudingly.

A first yoke 42 made of a magnetic material is provided to surround the coil frame 22 on three sides. The first yoke 42 includes a pair of side plates 43.44 facing each other in parallel, and side plates 43.4.
4 includes a connecting plate 45 that is perpendicular to these and connects them. The small-diameter cylindrical portion 34b of the fixed iron core 34 is inserted into the hole 45a passing through the center of the connecting plate 45, and is magnetically coupled to the connecting plate 45. Further, a number of through holes 45b, 45c, 45d, and 45e are formed in the circumferential direction in the connecting plate 45,
The protrusions 40, 41 of the coil frame 22 are selectively fitted to position the coil frame 22.

The movable iron core 2
A second yoke 47 having an insertion hole 46 into which the second yoke 1 is inserted is made of a magnetic material. The second yoke 47 is connected to the coil frame 2
2 is magnetically coupled to the side plates 43 and 44 of the first yoke 42.

That is, the connecting plate 45 of the side plates 43 and 44 of the first yoke 42
A recess 43a formed at the end opposite to the recess 43a.

44a and the 2nd 'E! - The convex portions 48 and 49 of the rib 47 are respectively fitted. Through holes 47a, 47 of second yoke 47
Similar to the protrusions 40 and 41 of the coil frame 22, the protrusions b fit into a plurality of protrusions (not shown) protruding from the flange portion 38 toward the second yoke 47.

The aforementioned shaft portion 29 of the type drive portion 28 is inserted through the insertion hole 21a of the movable iron core 21 and protrudes toward the @2 yoke 47 direction.

A nut 50, which is a component of the screwing means, is screwed into the threaded portion 29b provided on this protrusion, and the type drive unit 2
8 and movable iron core 21 are fixed to each other. In addition, the second yoke 47 is inserted through the insertion hole 46 to the outside of the second yoke (the second
As mentioned above, a groove 26 is provided in a part of the base 24 of the protruding movable core 21 (right side of the figure), and the E ring 51, which is a locking member, is fitted into this groove 26. be done. An annular buffer member 52 surrounding the base 24 is arranged on the first yoke 42 side of the E-ring 51.

A frame body 58 that accommodates the protruding portion 32 of the type drive unit 28 described above.
is provided. The frame body 58 has a bottomed cap shape, and has a bottom portion 59.
An insertion hole 59a is formed in which the protruding portion 32 of the type drive portion 28 is displaceably inserted. The through hole 60 is a screw hole 45b of the first yoke 42.

The screws 61 and 62 are inserted through the mounting holes corresponding to 45clK and screwed onto the first yoke 42. A coil spring 63 serving as a return means is provided between the inner circumferential surface of the bottom 59 of the frame 58 and the flange portion 30 of the type drive unit 28, and biases the type drive unit 28 in the direction of the frame 50. Further, an annular buffer member 64 is provided between the flange portion 30 of the type drive portion 28 and the first yoke 42.

In the electromagnet device 20 having such a configuration, the movable core 21 - the magnetic gap A - the fixed core 34 - the first yoke 4
A magnetic path is configured by the path 2-second yoke 47-magnetic gap B-movable iron core 21.

FIG. 3 shows the magnetic attraction force characteristics and spring load characteristics associated with the displacement of the movable iron core 21 in the electromagnet device 20.
Line 13 is the spring load characteristic of the return spring 61, line 14
is the attraction force characteristic of the movable iron core 21 during emotional excitation,
When a pulse voltage is applied to the coil 36, the movable iron core 21 is displaced in the direction of the arrow W, and the type driving unit 28 hits, for example, the type of a daisy wheel (not shown), and then, as the pulse voltage disappears, the return spring is activated. The spring force of 61 returns it to its original state. A printing operation is performed by this series of operations.

Further, the operation of this electromagnet device 20 will be explained in detail.
In the state shown in FIG. 1, the coil 36 is not excited, and the movable core 21 is stabilized at a position separated from the fixed core 34 under the influence of only the spring force of the return spring 61.

When the coil 36 is excited in this state, ``magnetic flux φ
is the movable core 21 - magnetic gap A - fixed core 34 - first yoke 42 - second yoke 47 - magnetic gap B - movable core 2
It flows through a magnetic circuit with a path of 1. Magnetic flux φ is magnetic gap A
Since the flow in the magnetic gap B is in the axial direction of the movable core 21, that is, in the displacement direction, the fixed core 34 acts as a magnetic attraction force that attracts the movable core 21, while the flow in the magnetic gap B (between the movable core 210 base 24 and the second Since the overlapping portion of the yoke 47 with the insertion hole 46131 surface is perpendicular to the axial direction of the movable iron core 21, the second yoke 47 does not act as a magnetic attraction force to attract the movable iron core 21. This attraction characteristic is Line I! 4, which overcomes the spring force of the return spring 61, so the movable core 21 begins to be displaced in the direction of the arrow W.

In this electromagnet device 20, since the truncated conical portion 25 of the movable core 21 and the inner circumferential surface 35a of the fixed core 34 face each other on the same axis, the opposing area of both members that exchanges magnetic flux is large. As a result, magnetic efficiency is increased, and therefore a large magnetic attraction force can be obtained with low power consumption, and high-speed operation can be achieved.

Furthermore, the truncated cone portion 25 is formed into a truncated cone shape, and the inner circumferential surface 3
By forming 5a in a shape corresponding to this, the above effect can be further enhanced. Moreover, by changing the degree of inclination of the truncated conical portion 25, the magnetic attraction force characteristics can be adjusted.

In this way, the type drive unit 28 is supported by the frame 58, and is driven integrally by passing the movable core 21 through it and screwing it into the nut 50 as described above. Therefore, when the movable core 21 and the type drive unit 28 are returned by the return spring 63 as described above, the mass of the system that undergoes unnecessary displacement caused by the impact force that stops the return operation increases. As a result, the amount of unnecessary displacement can be kept low.

FIG. 5 is a sectional view of an electromagnetic device 70 according to another embodiment of the present invention, and FIG. 6 is a sectional view of 1! FIG. 7 is an exploded perspective view of a magnet device 700. This embodiment is similar to the embodiment described above, and corresponding parts are provided with the same reference numerals. The noteworthy point of this embodiment is that a threaded hole 21c is provided in the @ line direction from the tip end surface 27 of the movable core 21, so that it can be threaded into the threaded part 29b of the shaft part 29 of the type drive part 280. . By doing so, the type drive unit 28 and the movable iron core 21 can be driven integrally, so that the same effects as those described in the previous embodiments can be obtained.

Effects According to the present invention as described above, the movable iron core made of a magnetic material such as metal and the type drive part made of a polymeric material are mutually aligned so that they can be integrally displaced. Therefore, the acceleration received by the parts that are integrally displaced is reduced, and unnecessary displacement operations can be significantly reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an electromagnetic device 20 according to an embodiment of the present invention;
FIG. 2 is an exploded perspective view of the electromagnet device 20, FIG. 3 is a magnetic attraction force and spring load characteristic diagram regarding the electromagnet device 20, FIG. 4 is a sectional view of the electromagnet device 20 during printing, and FIG. 5 is a diagram of the electromagnet device 20 according to the present invention. 6 is an exploded perspective view of the electromagnet device 700, FIG. 7 is a sectional view of the electromagnet device 20 during printing, and FIG. 8 is a sectional view of the electromagnet device 1 of the prior art. , FIG. 9 is a diagram showing magnetic attraction force and spring load characteristics regarding the electromagnet device 1. 20.70...Electromagnet device, 21...Movable iron core, 2
4...Base, 25...Truncated cone part, 28...Type drive part, 29b...Threaded part, 34...Fixed iron core, 35
...Insertion port, 36...Coil, 42...First yoke, 43.44...Side plate, 46...Insertion hole, 47...
...Second yoke, 50...Nut, 63...Return spring

Claims (1)

[Scope of Claims] A movable iron core made of a magnetic material that is displaceably displaceable in the longitudinal direction and has a magnetic flux receiving portion and a magnetic pole surface formed from one end to the other end, and a longitudinal direction of the movable iron core. a type drive part that extends in the direction and is coaxial with the movable core, and a fixed core that has an opposing part facing the magnetic pole surface of the movable core and has an insertion opening through which the type drive means is inserted. , a coil wound around the outer periphery of the movable iron core, a first yoke that surrounds three sides of the coil and whose opening portion is provided to sandwich a magnetic pole surface of the movable iron core, and an opening of the first yoke. a second yoke that is magnetically coupled to a side end and has an insertion hole through which the movable core is inserted; and a return means that urges the movable core in a direction away from the fixing means, the movable core and the type drive An electromagnetic device characterized in that the parts are screwed together by screwing means.