JPH0528642U - Wire dot print head - Google Patents

Abstract

(57) [Abstract] [Purpose] In a wire dot print head, the variation in the amount of deformation of the bias leaf spring is adjusted to suppress the variation in the printing force. [Structure] An adjusting screw 19 is provided at a position facing the convex portion 5a pressing the leaf spring 3. When the adjusting screw 19 is tightened, the amount of deformation of the leaf spring 3 that deforms via the convex portion 5a increases, and the printing force increases. Further, when the adjusting screw 19 is loosened, the amount of deformation of the leaf spring 3 is reduced and the printing force is weakened.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to the structure of a wire dot print head used in a serial printer.

[0002]

[Prior Art]

 Conventionally, various types of wire dot print heads, such as a plunger type, a spring charge type, and a clapper type, have been provided for printing by driving a print wire.

Among them, the spring charge type supports an armature, to which a printing wire is fixed, swingably by a bias leaf spring, and the armature is preliminarily resisted against the elastic force of the bias leaf spring. The magnet is attracted to the core, and when printing, the coil wound around the core is excited to generate a magnetic flux in the direction opposite to that of the permanent magnet, thereby releasing the armature.

FIG. 5 is a sectional view showing the above-mentioned conventional wire dot print head.

In the figure, 1 is a print wire for printing on a print medium via an ink ribbon, 2 is an armature having the print wire 1 fixed to the tip, and 3 is the armature 2 fixed to an inner end that is a free end. Bias leaf springs for supporting and swinging, 4 are armature yokes arranged in the vicinity of the armature 2, 5 are spacer yokes, and 6 are second yokes. The leaf spring 3 is sandwiched.

Further, 7 is a permanent magnet provided between the second yoke 6 and the first yoke 8, and is formed in an annular shape together with the second yoke 6 and the first yoke 8, and is fixed. It is laminated and fixed on the outer edge of the base 10 by screws 9. Reference numeral 11 denotes a core fixed to the base 10 so as to be located inside the first yoke 8, the second yoke 6 and the permanent magnet 7, and by winding the coil 12 around the outer periphery of the core 11. An electromagnet is formed. A head substrate 14 is provided on the back surface of the base 10 via an insulating rubber packing 13, and the terminals of the coil 12 are soldered to predetermined positions on the head substrate 14.

Reference numeral 15 is a sub-core, and one end of the sub-core 3 is always in contact with the plate panel 3 through a wear-resistant metal sheet 16.

In the above structure, the magnetic flux generated by the permanent magnet 7 during non-printing is the first yoke 8, the base 10, the core 11, the armature 2, the armature yoke 4, the spacer yoke 5, the bias leaf springs 3, the second. The magnetic circuit composed of the yoke 6 is circulated, and the armature 2 is attracted to the core 11 by this, and the free end of the leaf spring 3 for biasing adheres substantially parallel to the surface of the tip of the core 11 via the metal sheet 16. Is displaced.

On the other hand, during printing, the coil 12 is excited for a short time, and a magnetic flux in the direction opposite to the magnetic flux of the permanent magnet 7 is generated in the core 11 to cancel the magnetic flux of the permanent magnet 7. As a result, the armature 2 is released from the suction force of the core 11 and the free end of the bias leaf spring 3 is restored, and accordingly, the printing wire 1 moves in the direction of arrow A and passes through an ink ribbon (not shown). Dots are printed on print media such as paper. That is, the armature 2 and the printing wire 1 are integrally rotated about the contact point between the bias leaf spring 3 and the sub core 15 to perform printing.

By the way, in order to deform against the elastic force of the bias leaf spring 3 at the time of attraction, conventionally, the fixed end of the bias leaf spring 3 of the second yoke 6 and the surface of the core 11 which is the attraction surface. There was a certain amount of steps on the surface of the.

FIG. 6 is a partially enlarged view showing a conventional example.

In the same figure, in order to form the above-mentioned step, conventionally, after the surfaces of the core 11, the sub-core 15 and the second yoke 6 are finished on the same surface, only the surface of the second yoke 6 is formed. A step d is provided between the other surface by performing processing such as grinding so that the bias plate panel 3 is deformed during suction.

Further, as an improvement, as shown in FIG. 7, at least one metal sheet 17 made of a magnetic material is first interposed between the second yoke 6 supporting the bias leaf spring 3 and the base 10. Next, the surface of the second yoke 6 and the surface of the core 11 are flattened, and finally the metal sheet 17 is removed to form a step between the surface of the second yoke 6 and the surface of the core 11. There is something like this. FIG. 7 is a sectional view showing another conventional wire dot print head.

Further, as shown in FIG. 8, a convex portion 5 a that deforms the bias leaf spring 3 is provided on the spacer yoke 5 that supports the bias leaf spring 3, and the bias leaf spring 3 is also supported. There is a second yoke 6 provided with a relief facing the convex portion 5a. 8 is a partially enlarged view showing another conventional example. As described above, there is also one in which assembling accuracy is improved by deforming the bias leaf spring and not forming the step.

[0015]

[Problems to be solved by the device]

 However, in the conventional head that forms the above-mentioned step, the number of processing steps and the number of parts are large, and the assembly accuracy is lowered due to reassembling the one that is once fixed with screws. It has drawbacks.

Further, in the case where the spacer yoke is provided with a convex portion that deforms the bias leaf spring without forming a step, the bias leaf spring may be deformed due to variations in processing accuracy and assembly accuracy of the spacer yoke and the like. The amount of deformation of the printing paper varies, and the variation of the deformation of the printing paper causes the printing power of the plurality of printing wires to vary, resulting in poor printing quality.

The present invention solves the above-mentioned problems of the conventional wire dot print head, in which a spacer yoke is provided with a convex portion that deforms a bias leaf spring without forming a step. The wire dot printing head with excellent manufacturability and performance is provided with adjusting means for adjusting the variation of the amount of deformation, which is its drawback, without increasing the man-hours for forming the step and suppressing the variation of the printing force. The purpose is to

[0018]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention supports a biasing leaf spring in a cantilevered manner, attracts an armature fixed to the leaf spring to the core by the magnetic flux of a permanent magnet, biases the leaf spring, and winds it around the core. The coil is excited to cancel the magnetic flux of the permanent magnet and release the armature to perform printing, make the suction surface of the core flush with the support surface of the leaf spring, and deform the leaf spring to deform the leaf spring. In a wire dot print head having a convex portion that applies a bias force to the, a adjusting unit that adjusts the elastic deformation of the bias leaf spring by pressing the convex portion is provided.

[0019]

[Action]

 When the adjusting means is tightened, the convex portion is pushed and the convex portion presses the leaf spring with a larger force, and the amount of deformation of the leaf spring increases, so that the energy stored in the leaf spring during suction increases. .. Therefore, when the armature is released and the dot printing is performed, the printing power is increased. On the other hand, when the adjusting means is loosened, the force with which the convex portion presses the leaf spring becomes weaker and the amount of deformation of the leaf spring becomes smaller, so that the energy stored in the leaf spring during suction becomes smaller. Therefore, when the armature is released and the dot printing is performed, the printing power is weakened.

[0020]

【Example】

 An embodiment of the present invention will be described with reference to the drawings. The elements common to the drawings are given the same reference numerals.

FIG. 1 is a sectional view showing an embodiment according to the present invention.

In the figure, a first yoke 8, a permanent magnet 7, a second yoke 6, a bias leaf spring 3 (hereinafter referred to as a leaf spring 3), a spacer yoke 5, and an armature yoke 4 are laminated on a base 10. The base 10, the first yoke 8, the permanent magnet 7, and the second yoke 6 are fixed by screws 9. The base 10, the first yoke 8, the permanent magnet 7, the second yoke 6, and the spacer yoke 5 are annular. The leaf spring 3 is circular and has a plurality of tongues 3a (free ends) radially extending toward the center. An armature 2 having a printing wire 1 at the tip is fixed to each tongue piece 3a of the leaf spring 3. The armature yoke 4 has a circular shape and has a groove radiating toward the center for allowing the armature 2 to escape, and as shown in FIG. 2, a screw hole 18 is provided at a position corresponding to the upper portion of the convex portion 5a of the spacer yoke 5. It is provided. An adjusting screw 19 is screwed into the screw hole 18, as shown in FIG. The adjusting screws 19 are provided on each of the convex portions 5a as shown in FIG. 2 is a partially enlarged view showing the present embodiment, and FIG. 3 is a partial plan view showing the present embodiment.

In FIG. 1, a core 11 around which a coil 12 is wound and a sub core 15 are radially arranged so as to face each armature 2, and are erected on a base 10. Armature suction surfaces (hereinafter referred to as suction surfaces) of the core 11 and the sub core 15 are covered with a wear-resistant metal sheet 16. During grinding, the attraction surfaces of the core 11 and the sub core 15 and the support surface of the leaf spring 3 of the second yoke 6 are fixed to the base 10 to which the core 11 and the sub core 15 are fixed, the first yoke 8, the permanent magnets 7, The second yoke 6 is laminated in this order, fixed by screws 9, and ground to the same height. As shown in FIG. 2, the inner edge of the spacer yoke 5 is provided with a convex portion 5a formed by pressing along the inside as shown in FIG. 2, and the base of each tongue piece 3a of the leaf spring 3 is moved in the direction of arrow B. It is pressing. Therefore, each tongue piece 3a is in contact with the peripheral portion of the suction surface of the opposing sub-core 15 via the metal sheet 16. Further, the second yoke 6 has a portion where the spacer yoke 5 faces the convex portion 5a is escaped so that the deformation of the leaf spring 3 due to the pressing of the convex portion 5a is not hindered. As shown in FIG. 1, a head substrate 14 is provided on the back surface of the base 10 via an insulating rubber packing 13, and the terminals of the coil 12 are soldered to the coil terminal attachment portions of the head substrate 14.

Next, the operation of this embodiment having the above configuration will be described separately for non-printing and printing. At the time of non-printing, the magnetic flux of the permanent magnet is returning as shown by the annular arrow 20 in FIG. 1, and the armature 2 is in close contact with the attraction surfaces of the core 11 and the sub core 15 through the metal sheet 16 almost in parallel. There is. Therefore, since the unconstrained portion between the suction surface of the sub-core 15 and the leaf spring supporting surface of the second yoke is curved in the direction of arrow B on each tongue piece 3a of the leaf spring 3, printing is performed. The energy required for is stored.

On the other hand, at the time of printing, the circuit of the head substrate 14 is activated, so that the coil 12 is excited for a short time, and a magnetic flux is generated in the core 11 so as to cancel the magnetic flux of the permanent magnet 7. As a result, the armature 2 is released from the attraction force of the core 11, the energy stored in the leaf spring 3 causes the printing wire 1 to move in the direction of arrow A, and dot printing is performed on paper or the like via an ink ribbon (not shown). To do.

Next, the operation of adjusting the printing force when the adjusting screw 19 provided on the armature yoke 4 is tightened and loosened will be described with reference to FIG. FIG. 4 is a sectional view showing the operation of this embodiment.

In the figure, when the adjusting screw 19 is tightened, the convex portion 5a of the spacer yoke 5 is pushed and the convex portion 5a presses the leaf spring 3 with a large force, and the amount of deformation of the leaf spring 3 is shown by the solid line. Becomes larger, the energy stored in the leaf spring 3 during non-printing becomes larger. Therefore, the printing force is increased when the wire 1 prints dots on paper or the like via an ink ribbon (not shown). On the other hand, when the adjusting screw 19 is loosened, the convex portion 5a of the spacer yoke 5 weakens the force for pressing the leaf spring 3, and the amount of deformation of the leaf spring 3 becomes small as indicated by the broken line. The energy stored in 3 becomes smaller. Therefore, the printing force when the dots are printed on the paper or the like by the wire 1 via the ink ribbon (not shown) is weakened.

As described above, by pressing and adjusting the convex portion 5a of the spacer yoke 5 with the adjusting screw 19, the deformation amount of the leaf spring 3 corresponding to the convex portion 5a is changed, and the printing force is adjusted to a predetermined value. be able to.

[0029]

[Effect of the device]

 As described in detail above, according to the present invention, the adjusting screw is screwed onto the armature yoke, and the protruding portion of the spacer yoke is pressed by the adjusting screw, thereby elastically deforming the leaf spring corresponding to the protruding portion of the spacer yoke. Since the printing power can be adjusted, variations in the printing power can be suppressed and the printing power can be adjusted to a predetermined value.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment according to the present invention.

FIG. 2 is a partially enlarged view showing the present embodiment.

FIG. 3 is a partial plan view showing the present embodiment.

FIG. 4 is a sectional view showing the operation of this embodiment.

FIG. 5 is a sectional view showing a conventional wire dot print head.

FIG. 6 is a partially enlarged view showing a conventional example.

FIG. 7 is a cross-sectional view showing another conventional wire dot print head.

FIG. 8 is a partially enlarged view showing another conventional example.

[Explanation of symbols]

 2 Armature 3 Leaf spring for bias 5a Convex part 7 Permanent magnet 11 Core 12 Coil

Claims (1)

[Scope of utility model registration request] 1. A cantilevered support for a bias leaf spring,
The armature fixed to the leaf spring is attracted to the core by the magnetic flux of the permanent magnet to bias the leaf spring, and the coil wound around the core is excited to cancel the magnetic flux of the permanent magnet and release the armature to perform printing. In a wire dot print head having a convex portion that deforms the leaf spring and applies a biasing force to the leaf spring, while making the suction surface and the supporting surface of the leaf spring flush with each other, by pressing the convex portion, A wire dot print head, characterized in that adjustment means is provided for adjusting the elastic deformation of the bias leaf spring.