JPH0231486B2 - DENJISORENOIDO - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electromagnetic solenoid suitable for driving a type cup or the like of a printing device such as an electronic typewriter.

Conventional Structure and Problems When moving a rotating object in the direction of its rotation axis, a mechanism that combines an electromagnetic solenoid and a link has conventionally been used. FIG. 1 shows the printing section of the printing device, which has a mechanism for moving a rotating type cup up and down using an electromagnetic solenoid. In the figure, 10 is a platen that holds printing paper 11, and 12 is a type cup, on the outside of the spoke tips of which type letters 14a and 14b are arranged in two rows, one above the other. A printing hammer 16 is arranged on the back side of the printing type 14a, 14b, and when a signal is input, the printing hammer 16 moves the printing type 14a.
Or hit 14b on the printing paper 11. An ink ribbon 17 is located between the print 14a or 14b and the print paper 11, and printing is performed. The type cup 12 is fixed to a type holding member 18,
The convex portion 18b of the type holding member 18 is connected to the type cup 12.
Since it fits into a notch 15 formed in the bottom of the shaft, rotational motion can be transmitted. The type holding member 18 and the type cup 12 are supported on a rotating shaft 19a of a motor 19 so as to be rotatable and movable up and down. A rotation transmission member 20 is fixed to the rotation shaft 19a of the motor 19, and the pin 21 fixed to the rotation transmission member 20 and the protrusion 22 of the type holding member 18 are aligned in the longitudinal direction of the rotation shaft 19a of the motor 19. Since the rotation of the motor 19 is movably engaged with the type holding member 18,
is transmitted to the type cup 12 via. Reference numeral 23 designates an electromagnetic solenoid, and its movable core 24 is connected to one end of a shift lever 26 rotatably attached to a fixed portion by a pin 25. The other end of the shift lever 26 is connected to the groove 1 of the type holding member 18.
A roller 27 that fits into 8a is rotatably attached. The vertical movement of the movable iron core 24 causes the type cup 12 to move up and down via the type holding member 18.

The electromagnetic solenoid 23 includes a yoke 28 that forms a magnetic path together with the movable core 24, a coil 29 that generates magnetic flux in the magnetic path to attract the movable core 24 to the yoke 28, and a guide pipe 30 that guides the movement of the movable core 24. A coil spring 31 is attached to the movable core 24 to urge the movable core 24 upwardly.

The conventional configuration described above requires a complicated mechanism to move the rotating printing cup up and down, so it is not suitable for downsizing the device, and the frictional force is large, causing backlash due to wear and other problems, resulting in poor reliability. There were problems such as inferiority.

OBJECT OF THE INVENTION The object of the present invention is to provide an electromagnetic solenoid that can directly move a rotating object, which is a driven body, in the axial direction, and that can operate with low friction and inertia loads, and with low drive energy. It is about providing.

Structure of the Invention The electromagnetic solenoid of the present invention includes an excitation coil wound in a hollow shape, a yoke formed to cover the outer periphery of the excitation coil, and a shift shaft fixed in the axial direction in the hollow part of the excitation coil. a rotor having a right cylindrical magnetic body with a through hole in the center thereof, the rotor being rotatably supported on the shaft by the through hole; a movable iron core provided so as to be movable between a first position spaced a required distance from the rotor and a second position abutting the rotor; the movable iron core has a right cylindrical portion provided with a through hole in the center thereof, and in the second position, the end face portion of the right cylindrical column is aligned with the end face of the rotor. The yoke has a cylindrical hollow part that faces the cylindrical side surfaces of the rotor and the movable core with a required gap formed therein, and the part forming the cylindrical hollow part facing the rotor is Said first
This structure extends to the vicinity of the end face of the movable iron core located at the position of .With this structure, a driven object (such as a type wheel in a printing device) can be rotated by the movable iron core. and can be supported movably in the longitudinal direction of its rotation axis.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a side view of essential parts showing an embodiment in which the electromagnetic solenoid according to the present invention is used in a printing device. In the figure, 40 is a platen that holds printing paper 41. 42 is a type wheel;
This is because a plurality of spokes 44 extend from the vicinity of the outer periphery of the disk portion 43 at predetermined intervals, and at the outer tip of each spoke 44 there are two upper and lower rows of typefaces 45a,
45b is formed. A gear 46 is formed on the outer periphery of the disk portion 43 of the type wheel 42.
It meshes with a gear 48 fixed to the rotating shaft of a motor 47. The type wheel 42 has a movable iron core 49
It is attached to a holding member 50 fixed to
When the electromagnetic solenoid 51 operates to move the movable iron core 49 up and down, the type wheel 42 also moves up and down together.

The motor 47 is controlled by a control circuit (not shown) based on a signal from a detector 52 that detects the rotational position of the gear 48 to control the rotational position of the type wheel 42. The gear 48 keeps the type wheel 4 even if the type wheel 42 is shifted in the vertical direction.
It has a thickness that maintains meshing with gear 46 of No. 2.

Type 45a (or 45b) to be printed by the action of motor 47 and electromagnetic solenoid 51
is selectively stopped at a position in front of the printing hammer 53. The printing hammer 53 is moved to the right in the figure by a hammer drive mechanism (not shown), and the print hammer 53
Push a (or 45b) in the direction of the printing paper 41.
Then, since the spokes 44 have appropriate elasticity, the printed characters 45a (or 45b) are attached to the printing paper 4.
It is pressed against 1. Type 45a (or 45b)
Since an ink ribbon 54 is provided between the print paper 41 and the print paper 41, printing is performed.

FIG. 3 is a sectional view of an embodiment of the present invention which is effective when used as the electromagnetic solenoid 51, and shows a fixing base 5.
A shaft 55 is fixed at the center of 4, and a rotor 56 made of a magnetic material in the shape of a right cylinder and a movable iron core 49 to which a type wheel 42 is attached are supported in a vertical positional relationship. ing. The surface of the shaft 55 is coated with a thermosetting resin containing molybdenum disulfide. Therefore, the rotor 56 can freely rotate on the shaft 55. Although the rotor 56 can also move in the axial direction, it normally rests on a flange portion 55a provided on the shaft 55 due to its own weight. The movable iron core 49 is also made of a magnetic material, and can freely rotate and move vertically on the shaft 55. A coiled spring 57 is disposed between the movable core 49 and the shaft collar portion 55a, and urges the movable core 49 downward to move the type wheel to the first position. The movable iron core 49 is stopped at a position where its lower end touches an E-shaped ring 58 attached to the shaft 55 due to the biasing force of the spring 57 and its own weight. Since the slider washer 59 is sandwiched between the movable iron core 49 and the E-shaped ring 58,
The rotational resistance of the movable core 49 is becoming smaller.

The upper part of the movable iron core 49 has a right circular column shape, and when in the second position, the upper end surface is aligned with the rotor 56.
comes into contact with the lower end surface of. A holding member 50 is fixed to the lower part of the movable core 49, and a V-shaped groove is provided near the lower end. Slope 49 of the V-shaped groove
The type wheel 42 is moved to the holding member 50 by the force of pushing the spring 60 attached to the type wheel 42.
held on top.

A hollow magnetic field coil 61 is provided on the outer periphery of the rotor 56 and the movable iron core 49, and yokes 62 and 63 made of a magnetic material are arranged around it. The yoke 62 is fixed to the fixed base 54 with screws 64. The yoke 62 is provided with a convex portion 62a so as to have a desired positional relationship with the shaft 55, and is positioned in combination with the concave portion of the fixing base 55. The inner periphery of the yoke 62 is cylindrical, and forms a gap 65 with equal gaps around the outer periphery of the rotor 56. yoke 62
A tapered surface 62b is formed on the inner periphery of the rotor 56 below the portion facing the rotor 56. The yoke 63 has a cup shape and is connected to the yoke 62 at its upper end. A cylindrical through hole 63a is provided in the central portion, and a gap 66 with equal gaps is formed over the entire circumference of the outer peripheral surface of the movable iron core 49.

Since the through hole 63a is larger than the outer diameter of the rotor 56, the shaft 55 can be attached to the fixed base 54 after the yokes 62, 63 are attached to the fixed base 54, making assembly and maintenance convenient.

When the excitation coil 61 is energized, the movable iron core 49 moves upward and is attracted to the rotor 56 . Due to the biasing force of the spring 57, the rotor 56 to which the movable core 49 is attracted receives a downward force, so that the rotor 56
The lower end surface of the shaft flange portion 55a is stably held on the shaft flange portion 55a. In order to align and print the upper type characters 45a and the lower type characters 45b on the same printing line of the type wheel 42, a slider washer 5 with different thickness is used to adjust the amount of vertical movement of the movable iron core 49.
9 has been adjusted.

FIG. 4 schematically shows the magnetic flux generated inside the electromagnetic solenoid 51 when the excitation coil 61 is energized.
FIG. 4b shows a state in which the movable iron core 49 is in the second position and is attracted to the rotor 56. When the movable core 49 is in the first position, when the exciting coil 61 is energized, a magnetic flux is generated in the magnetic path formed by the yoke 63, the movable core 49, and the yoke 62 (see FIG. 4a). At this time, since the magnetic flux passing through the gap 66 is oriented in the radial direction, it generates a radial force on the movable core 49, but since this force is uniform over the entire circumference of the gap 66, they cancel each other out. The movable core 49 is not subjected to any radial force. Movable iron core 49 to yoke 6
The magnetic flux passing between the two generates a radial force and an axial force on the movable iron core 49, but the radial forces cancel each other out as described above. After all, when the excitation coil 61 is energized, the movable iron core 49 receives a force in the axial direction (upward in the figure) and moves upward while compressing the spring 57.

When the movable core 49 moves upward and approaches the rotor 56, part of the magnetic flux is transferred from the movable core 49 to the rotor 5.
When the movable core 49 comes into contact with the rotor 56 as shown in FIG. 4B, most of the magnetic flux flows through the rotor 56. From the movable iron core 49 to the tapered surface 6 of the yoke 62
The magnetic flux also tries to flow to the rotor 2b, but since the permeance of the air gap in this part is smaller than the permeance of the gap 65, most of the magnetic flux passes through the rotor 56. When the movable iron core 49 is attracted to the rotor 56, the air gap in the magnetic path becomes smaller and the permeance increases, so that the magnetic flux increases. Therefore, in order to keep the movable iron core 49 attracted, the current flowing through the excitation coil 61 can be reduced.

When the excitation coil 61 is de-energized, the magnetic flux disappears, so the attraction force that brought the movable core 49 and rotor 56 into contact disappears, and the movable core 49 moves downward due to its own weight and the biasing force of the spring 57.
Stop at the first position.

Generally, the movable core of an electromagnetic solenoid with a large stroke has a tapered tip as shown in FIG. However, if the tip of the movable core is tapered, the side to be attracted must also have the same taper, and if the taper angles of both sides do not match, the contact area will be small, resulting in a decrease in suction force and insufficient strength, resulting in a long life. A decrease etc. will occur. Further, in a configuration that requires a rotor like the present invention, problems arise such as the inability to reduce the taper angle.

However, as shown in the embodiment of the present invention, the shape of the yoke is changed from the part facing the rotor 56 to the movable iron core 4.
By creating a structure extending in a substantially cylindrical shape toward 9, it is possible to move a large stroke even if the tip of the movable core 49 is made into a cylindrical shape without being tapered. When the abutting portion between the movable core 49 and the rotor 56 is cylindrical, processing becomes easier, the abutting portion has a higher degree of adhesion, and the strength against impact during suction is improved.

By providing the tapered surface 62b on the yoke 62, the suction force changes.

If the yoke 62 does not have a tapered surface and extends into a cylindrical shape from the part facing the rotor 56 as shown by the broken line A in FIG. 5, the suction force is strong at the beginning, but the suction force decreases in the middle. . This characteristic is not optimal when considering the biasing force of the spring 57, frictional load, etc. By providing the tapered surface 62b, as shown by the solid line B in FIG. 5, the suction characteristics are almost constant from the beginning to near the end of suction, and the operation is reliable even when the load condition changes.
Further, since the magnetic flux flowing directly from the movable iron core 49 to the yoke 62 without passing through the rotor 56 during attraction is also reduced, the current required to maintain attraction can be reduced. Moreover, since the tapered surface 62b does not require high precision, it is easy to process.

FIG. 6 shows another embodiment of the present invention, in which the flange portion 55a of the shaft 55 shown in FIG. A shaped ring 67 is fitted together. A slider washer 68 is inserted between the E-shaped ring 67 and the rotor 56. By making the groove into which the E-shaped ring 67 is fitted into a U-shape, it is possible to accurately determine the position of the E-shaped ring, and the stroke of the movable iron core 49 is always constant. Machining is easier than providing a collar on the shaft 55.

As described above, according to this embodiment, the movable iron core to which the holding member for attaching the type wheel is fixed can be moved up and down directly by magnetic force without contact. In addition, the number of moving parts is reduced, reliability is improved, and the device can be made smaller. Moreover, since it is easy to process, it can be manufactured at low cost. Furthermore, since the rotational resistance when rotating the type wheel is small and the load inertia is also small, effects such as a reduction in the load on the motor are produced.

Effects of the Invention As is clear from the above description, the electromagnetic solenoid of the present invention has a configuration in which a driven body is rotatably supported on a shaft and the driven body is directly moved and displaced in the axial direction of the shaft. Therefore, the driven body can be reliably driven with a simple and compact structure.

In addition, since the opposing parts of the rotor, movable core, and yoke are coaxial cylindrical surfaces, the gap is uniform over the entire circumference, and the force acting in the radial direction is canceled, reducing the frictional load during rotation. The effect is that a small drive device can be used to rotate the driven body.

Furthermore, since the rotor and movable iron core are cylindrical, they are easy to process and have a long lifespan, and the shaft also has the advantage of being easier to process without degrading the accuracy of the amount of type shift. , which is also highly effective in reducing costs.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway side view showing a conventional electromagnetic solenoid and its application example, Fig. 2 is a partially cutaway side view showing an application example of the present invention, and Fig. 3 is an embodiment of the electromagnetic solenoid of the present invention. Side sectional view showing, Figure 4a, b
5 is a partially enlarged side view for explaining the operation of the same embodiment, and FIG. 5 is a characteristic diagram showing the operating characteristics of the same embodiment.
FIG. 6 is a partially enlarged side view showing another embodiment of the present invention. 51...Electromagnetic solenoid, 49...Movable iron core,
50... Holding member, 55... Shaft, 56...
Rotor, 57...spring, 61...excitation coil, 62, 63...yoke, 62b...tapered surface.

Claims (1)

[Scope of Claims] 1. An excitation coil wound in a hollow shape, a yoke formed to cover the outer periphery of the excitation coil, a shaft fixed in the axial direction in the hollow part of the excitation coil, and a central a rotor having a magnetic body in the shape of a right circular column with a through hole provided therein, and rotatably supported on the shaft by the through hole; and a rotor rotatably supported on the shaft and at a required distance from the rotor. a first position apart from the rotor; and a second position that can abut the rotor.
a movable iron core provided so as to be movable between the two positions, and a spring that urges the movable iron core from the second position to the first position, the movable iron core being movable between the central and The yoke has a right cylindrical portion with a through hole provided therein, an end surface portion of the right cylindrical column is in contact with an end surface of the rotor at the second position, and the yoke has a right cylindrical portion provided with a through hole in the second position. It has a cylindrical hollow part facing the side surface with a required gap formed therein, and the part forming the cylindrical hollow part facing the rotor extends to the vicinity of the end face of the movable iron core at the first position. An electromagnetic solenoid with a structure. 2. The electromagnetic solenoid according to claim 1, wherein the inner periphery of the portion extending from the rotor facing portion of the yoke to the vicinity of the end face of the movable iron core is a conical surface. 3. The electromagnetic solenoid according to claim 1, wherein the spring is disposed between the movable core and a convex portion provided on the shaft between the rotor and the movable core. 4 The convex part of the shaft is the U formed on the shaft.
The electromagnetic solenoid according to claim 3, characterized in that the electromagnetic solenoid has a structure in which an E-shaped ring is fitted into a shaped groove. 5. The electromagnetic solenoid according to claim 1, wherein the movable core has a structure for holding an object to be rotated on the opposite side of the portion that contacts the rotor.