JPH0620611Y2 - Printer head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a spring release type printer head.

(Prior art and problems to be solved) In the spring-release type printer head, the drive arm that drives the printing wire is attracted to the core piece by the permanent magnet, the leaf spring is biased backward, and the permanent magnet is excited by the degaussing coil. The magnetic field of the magnet is canceled to release the drive arm in the attracted state. This causes the leaf spring to move forward by its own elastic force to drive the print wire. Thus, the motion characteristics of the leaf spring affect the print quality.

At the outer end portion of the printer head, a ring-shaped spring support plate that faces the outer end portion of the leaf spring and supports the outer end portion of the leaf spring is provided. When the spring support plate and the plate spring are in close contact with each other by the fixing means, the spring support plate supports the outer end portion of the plate spring, determines the fulcrum of the plate spring, and measures the length from the fulcrum to the tip of the plate spring (of the plate spring. Effective length) is determined. This effective length influences the motion characteristics of the leaf spring and needs to be accurately determined. As shown in the ninth and tenth figures, the spring support plate 1 has a flat plate shape.

According to the above conventional technique, when the plate surface of the spring support plate 1 is not smooth, the spring support plate 1 does not completely adhere to the plate spring.
Therefore, the fulcrum of the leaf spring cannot be set at a predetermined position. Therefore, the effective length of the leaf spring cannot be set to a predetermined length. Therefore, the desired operation of the leaf spring may not be obtained, and the desired print quality may not be obtained. Further, in order to prevent this, if the spring support plate 1 and the plate surface of the plate spring are smoothed in order to smooth them, there is a risk that the cost will increase.

An object of the present invention is to solve the above problems,
It is to improve the printing quality by accurately setting the fulcrum of the leaf spring at a desired position without using special polishing or the like.

(Means for Solving the Problems) In order to achieve the above object, a printer head according to the present invention comprises a permanent magnet, a leaf spring provided with a drive arm,
It has a core piece behind which the demagnetizing coil is wound, which is arranged opposite to the driving arm, and the driving arm is attracted by the permanent magnet to bias the leaf spring, and the permanent magnet is excited by the degaussing coil. In the printer head that cancels the magnetic field of the device to open the drive arm in the attracted state and drives the print wire through the drive arm, a ring provided at the outer end of the printer head and facing the outer end of the leaf spring. -Shaped spring support plate, a bending portion or a protrusion formed on the inner end of the spring support plate and protruding in the direction of the leaf spring, and the bending portion or the protrusion are deformed to form a flat plate-shaped spring support plate. And a fixing member for closely contacting the outer end of the leaf spring with the spring support plate, and the outer end of the leaf spring is supported by the contact surface between the outer end of the leaf spring and the spring support plate.

(Operation) When the outer end portion of the leaf spring and the spring supporting plate are fixed by the fixing member, the spring supporting plate receives a pressing force in the direction perpendicular to the plate surface thereof, and the bending portion or the protrusion of the spring supporting plate. The portion is deformed, and the spring support plate becomes flat.

At that time, the repulsive force of the spring support plate is applied to the leaf spring plate surface from the tip of the bent portion or the protrusion of the spring support plate. Therefore, the leaf spring plate surface and the tip of the bent portion or the protrusion are surely brought into close contact with each other, and this close contact portion serves as a fulcrum when the leaf spring moves.
Therefore, the fulcrum of the leaf spring can be set to a desired position and the effective length of the leaf spring can be set to a desired length by changing the position of the spring supporting plate bending portion or the protruding portion. Therefore, desired print quality can be obtained without performing special processing on the spring support plate and the leaf spring, which is useful for improving print quality and reducing costs.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a permanent magnet 4 is provided on the front surface of the core piece 3 around which the degaussing coil 2 is wound, and yoke plates 5 and 6 are provided on the front surface of the permanent magnet 4. A ring-shaped spring support plate 7 is provided on the front surface of the yoke plate 6 as shown in FIG. 5 showing the relationship between the spring support plate and the leaf spring before being fixed, and the front surface of the spring support plate 7 is provided with a leaf spring. 8 are provided.

The spring support plate 7 has a shape as shown in FIGS. 2 and 3. A bending portion 7a is formed at the inner end of the spring support plate 7. The through hole 7b is provided so that a fixing member described later can pass through. As shown in FIG. 5, the spring support plate 7 is installed so that the bending portion 7 a contacts the back surface of the leaf spring 8. A plurality of tongue pieces 8a of the leaf spring 8 are provided toward the center of the leaf spring 8 as shown in FIG. As shown in FIG. 1, a drive arm 9 is fixed to the tip of the tongue 8a, and the print lever 10 is attached to the tip of the drive arm 9.
Is fixed, and the print wire 11 is fixed to the tip of the print lever 10. As shown in FIG. 5, a spring support plate 7 is installed on the front surface of the leaf spring 8 so that the bending portion 7 a contacts the front surface of the leaf spring 8. Further, a yoke plate 12 is provided on the front surface of the yoke plate 1.
A core piece 13 is provided on the front surface of 2, and a drive arm 9 is movably inserted back and forth in a groove 13a of the core piece 13 as shown in FIG. Yoke plate 5,
6, spring support plates 7, 7, leaf springs 8, yoke plate 1
2, the core piece 13 forms a common magnetic path. Also, the fifth
As shown in the figure, the yoke plate 6 includes the above-mentioned spring support plate 7
A through hole through which a fixing member common to the spring supporting plate 7 and the spring supporting plate 7 described above penetrate is formed through a screw hole through which a fixing member common to Has penetrated.

Next, the operation will be described. When assembling the printer head, as shown in FIG. 1, the yoke plate 6, the spring support plates 7, 7, the leaf springs 8, the yoke plate 12, and the core piece 13 are screwed by screws 14 which are an example of a fixing member. To fix.

At this time, as shown in FIG. 1, the spring support plates 7, 7, the leaf spring 8
Is the screw 1 through the core piece 13 and the yoke plate 12.
The pressing force of 4 is received downward. Therefore, the spring support plate 7,
The bent portions 7a, 7a of 7 are deformed, and the spring support plate 7 becomes flat.

At that time, the repulsive force of the spring support plates 7, 7 is
From the tip of 7a, it joins the front and back of the leaf spring, respectively.
Due to the two spring support plates 7, 7, the position of the leaf spring 8 to which a repulsive force is applied is the same in the left-right direction. Therefore, the leaf spring 8 and the tip of the bent portion 7a of the spring support plates 7, 7 are surely brought into close contact with each other, and this close contact portion 15 serves as a fulcrum when the leaf spring 8 moves.
The leaf spring 8 is swingably supported at this fulcrum 15 by the spring support plates 7, 7. FIG. 4 is a view of this state seen from the front.

At the time of non-printing, the drive arm 9 is attracted to the core piece 3 through the magnetic flux of the permanent magnet 4, and the tongue piece 8a of the leaf spring 8 is in the retracted position against its own elastic force. It is in the retracted position (not shown).

Next, as shown in the first diagram, during printing, the degaussing coil 2 is energized to cancel the magnetic flux of the permanent magnet 4, thereby releasing the magnetic attraction of the drive arm 9 to the core piece 3. Then, the tongue piece 8a of the leaf spring 8 moves forward by its own elastic force to move the printing wire 11 forward, and dots are formed on the printing medium (not shown). After that, when the power supply to the degaussing coil 2 is stopped, the drive arm 9 is again attracted to the core piece 3, and the tongue piece 8a of the leaf spring 8 also retracts.

By changing the position of the bending portion 7a of the spring support plate 7,
The fulcrum of the leaf spring 8 can be accurately set to a desired position, and the effective length of the leaf spring 8 can be set to a desired length. Therefore, a desired motion characteristic of the leaf spring 8 can be obtained, and a desired print quality can be obtained.

FIG. 6 shows another embodiment of the spring support plate, and a bending portion 16a is formed at the inner end of the spring support plate 16. The point that the through hole for the fixing member is provided is the same as in FIG.

When the spring support plate 16 is provided in the printer head,
As in FIG. 1, the bending portion 16a is provided so as to face the leaf spring.

Further, FIGS. 7 and 8 show another embodiment of the spring support plate, in which the protrusion 17a is formed at the inner end of the spring support plate 17. The point that the through hole 17b for the fixing member is provided is the same as in FIG.

When the spring support plate 17 is provided in the printer head,
Similar to FIG. 1, the protrusion 17a is provided so as to face the leaf spring.

In each of the embodiments shown in FIGS. 6, 7, and 8, the repulsive force of the spring support plate is applied to the leaf spring from the tip of the bending portion or the protrusion, and the leaf spring and the above-mentioned tip surely come into close contact with each other. The fulcrum of the spring is the same as described above.

The core piece 13 may be omitted.

Further, of the two spring supporting plates sandwiching the leaf spring, the bending portion or the protruding portion may be formed on at least one of the spring supporting plates. At this time, in order to determine the fulcrum of the spring, it is necessary to align the inner ends of the two spring support plates in the left-right direction.

(Effects) As described above, according to the present invention, the spring supporting plate is provided with the bending portion or the protruding portion projecting in the direction of the leaf spring at the inner end portion of the spring supporting plate, and the spring supporting plate is formed into a flat plate shape by the fixing member. The end portion and the spring support plate are brought into close contact with each other, and the outer end portion of the leaf spring is supported by the contact surface between the outer end portion of the leaf spring and the spring support plate,
The leaf spring plate surface and the tip of the bent portion or the protruding portion of the spring support plate are in close contact with each other, and this contact portion serves as a fulcrum of the leaf spring, and by changing the position of the bent portion or the protruding portion of the spring support plate,
Since the fulcrum of the leaf spring can be accurately set to the desired position and the effective length of the leaf spring can be set to the desired length, the desired action of the leaf spring can be achieved without special processing on the spring support plate and leaf spring. Can be achieved reliably and desired print quality can be obtained, which is useful for improving print quality and reducing costs. Further, since the leaf spring is supported by the contact surface between the outer end portion of the leaf spring and the spring support plate, the leaf spring can be stably supported, and the effective spring length does not change when the leaf spring moves forward and backward, so that the leaf spring is stable. The print quality is stable.

[Brief description of drawings]

FIG. 1 shows an embodiment of a printer head according to the present invention. FIG. 1 is a sectional view of an essential part, FIG. 2 is a front view showing an embodiment of a spring support plate according to the present invention, and FIG. 3 is FIG. FIG. 4 is an enlarged sectional view taken along line BB, FIG. 4 is a partially cutaway front view showing the relationship between a spring support plate and a leaf spring according to an embodiment of the present invention, and FIG. 5 is a spring support plate according to an embodiment of the present invention. FIG. 6 is a sectional view showing an essential part of a spring supporting plate, which shows a relation before fixing with a leaf spring, FIG. 6 is an enlarged sectional view showing an essential part of another embodiment of a spring supporting plate, and FIG. Front view, FIG. 8 is an enlarged sectional view taken along line CC of FIG. 7, FIG. 9 is a front view showing an example of a conventional spring support plate, and FIG. 10 is an enlarged sectional view taken along line AA of FIG. . 2 ... Degaussing coil, 3 ... Core piece, 4 ... Permanent magnet, 7, 16, 17 ... Spring support plate, 7a, 16a ... Bending portion, 8 ... Leaf spring, 9 ... Drive arm, 11 ... Printing wire, 14 ... Fixing member (screw), 17a ... Protrusion.

Claims (1)

[Scope of utility model registration request] 1. A permanent magnet comprising: a permanent magnet; a leaf spring provided with a drive arm; and a core piece arranged behind the drive arm and facing a demagnetizing coil and wound around the demagnetization coil. The drive arm is attracted by means of which the leaf spring is biased, the magnetic field of the permanent magnet is canceled by the excitation of the degaussing coil, the drive arm in the attracted state is released, and the print wire is passed through the drive arm. A ring-shaped spring support plate which is provided at an outer end portion of the printer head and faces an outer end portion of the leaf spring; and a plate formed at an inner end portion of the spring support plate. A bending portion or a protrusion protruding in the spring direction, and a fixing member for deforming the bending portion or the protrusion to make the spring support plate flat and bringing the outer end of the leaf spring into close contact with the spring support plate. Equipped with the above Printer head, characterized in that for supporting the outer end portion of the plate spring by the contact surface between the outer end and the spring support plate of the spring.