JPS62259870A - Printing head of wire dot printer - Google Patents

Abstract

PURPOSE:To facilitate leaf spring mounting work without lowering printing quality, by a method wherein a laminate structure positioning the fixed end side of a leaf spring by grasping the same along with a spacer is mounted on a base so that the leaf spring and a base mounting surface form a predetermined angle. CONSTITUTION:A press member 19 is positioned on a spacer 18 by inserting pins 20, 20 in through-holes 21, 21 in such a state that a leaf spring 8 is interposed between the press member 19 and the spacer 18. A laminate structure consisting of a base 1, the spacer 18, the leaf spring 8 and the press member 19 is integrally tightened by a fixing screw 17 to constitute the fixing part of the leaf spring 8. Because a length (l) is set to a predetermined value so that the left end of the press member 19 does not come near to the right side from the left end of the spacer 18 and the leaf spring 8 and the press member 19 are fixed to the base 1 by the fixing screw 17, uniform pressing force is applied to the contact surfaces of the leaf spring 8 and the spacer 18 and the plastic force of the leaf spring in each movable part 27 is easily made uniform over a plurality of the movable parts 27 in a printing head.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention provides a print head for a wire dot printer in which an armature is attached to the free end of a cantilever leaf spring, and the armature is magnetically driven to print dots using a print wire provided on the armature or the temporary spring. In particular, the present invention relates to a structure of a leaf spring fixing part that facilitates the work of attaching a leaf spring.

[Prior art and its problems]

The print head of a wire dot printer (hereinafter referred to simply as the print head) is of the m-air suction type, which prints dots by magnetically attracting the armature, or of the m-air suction type, which prints dots by magnetically attracting the armature. There is a spring open type that prints dots by the repulsive force of a temporary spring when demagnetized, and the configuration shown in Fig. 4, which is disclosed in Japanese Patent Laid-Open No. 131470/1982, is known as a magnetic attraction type print head. . In FIG. 4, 1 is an annular plate-shaped base made of non-magnetic material;
2 has one end 2a inserted inside the base 1. It is a fixed cylindrical body, and 3 is a cylindrical solenoid storage body with bottoms at both ends. The solenoid housing 3 is made of a magnetic material, and a cylindrical core 4 with one end fixed to one bottom of the housing 3 is provided inside the housing 3, and a circular penetrating core 4 is provided at the other bottom of the housing 3. A hole 5 is provided. Storage body 3
The iron core 4 and the through hole 5 are formed coaxially, and a coil 6 is wound around the iron core 4. The storage body 3 is fixed to the base 1 with its end on the side where the through hole 5 is provided fitted into a through hole 7 provided in the base 1. Reference numeral 8 designates a cantilever leaf spring in which one end surface of a cylindrical armature 9 is brought into contact with and fixed in the middle, and the fixed end 8a side is fixed to the base 1 via a spacer lO. Print wire fixed to free i8b. The tip 11a of the printing wire 11 is connected to an intermediate guide hole 12 provided in the middle of the cylindrical body 2 and a tip provided at the other end 2b of the cylindrical body 2!
They pass through the taX inner hole 13 one after another and protrude outside the other end 2b of the cylindrical body 2. The armature 9 is housed so that when the fixed end 8a of the temporary spring is fixed to the base 1, the end surface opposite to the contact surface with the leaf spring 8 faces the end surface of the iron core 4 through the gap 14. Since it is loosely inserted into the through hole 5 at the bottom of the body, when the coil 6 is energized and the iron core 4 is excited, the iron core 4. Storage body 39 through hole 5. Armature9. A magnetic flux is generated that circulates through the air gap 14, and the armature 9 is attracted to the iron core 4 against the reaction force of the leaf spring 8. 15 is an armature drive mechanism that drives the armature 9 in the thickness direction of the temporary spring 8 as described above. In this case, when the coil 6 is de-energized, the armature 9 returns to its old position due to the repulsive force of the leaf spring 8. Although not shown in FIG. 4, the printing wire 11
A plurality of slope springs 8 are provided, and these slope springs 8 are arranged radially such that each free end 8b side is oriented toward a radial center set on the axis of the base 1. Therefore, the armature drive mechanism 15 A plurality of drive mechanisms 15 are provided corresponding to the leaf springs 8, and these drive mechanisms 15 are connected to the mechanism 1.
5 are arranged so that their axes pass through the same circumference centered on the center of the base l. A guide pin 16 has one end fixed to the base 1 and the other end projected from the base 1, and the spacer 10 is positioned relative to the base 1 by fitting the guide pin 16 into a through hole provided in the spacer. Ru. With the leaf spring 8 stacked on the spacer 10 positioned in this way, the spacer 10 and the leaf spring 8 are integrally tightened by the fixing screw 17 and fixed to the base 1 (not shown). However, the axis of the fixing screw 17 is perpendicular to the surface of the base l. In the printhead shown, armature 9 is
When the armature 9 collides with the iron core 4 due to suction by the armature drive mechanism 15, a gap 14 is formed. If the two end surfaces are not parallel, the protruding edge on either of the two end surfaces will wear out as the printing operation is repeated many times, and as a result, the dimensions of the gap 14 will change, causing the printing wire 11 to Print power changes. Therefore, in FIG. 4, in order to make the end face of the armature 9 collide with the end face of the iron core 4 in a parallel state, when the coil 6 is not energized, the longitudinal direction of the leaf spring 8 and the surface of the base 1 are The contact surface of the spacer 10 with the leaf spring 8 is formed into a slope shape so that the angle θ forms a predetermined angle θ. The print head of FIG. 4 operates as described above, but
In this case, while the leaf spring 8 forms an angle θ with the surface of the base 1, the fixing screw 17 tightens the leaf spring 8 perpendicularly to the surface of the base 1, so that the temporary spring 8 and the spacer 10 The pressing force generated on the contact surface becomes uneven depending on the location. As a result, a problem arises in that the spring constant of the leaf spring 8, which affects the printing force of the printing wire 11, is not uniform across the plurality of leaf springs 8, and since the pressing force is uneven depending on the location, the armature 9 A problem also arises in that the lengths of the arms of the driving moment are uneven in the plurality of spinal pressure springs. If the aforementioned uneven spring constants or moment arm lengths occur, the print quality of the print head will deteriorate. Therefore, in order to prevent the print quality from deteriorating due to such causes, it is necessary to It is necessary to accurately determine the position, the position and attitude of the spacer lO with respect to the pin 16, the position of the armature 9 with respect to the spacer 10, and the distance between the armature 9 and the circumference of the head of the fixing screw 17. As a result, it is difficult to attach the leaf spring 8 to the print head shown in FIG. 4, and the manufacturing process is time-consuming.

[Purpose of the invention]

The present invention solves the above-mentioned problems with the conventional print head, and provides a print head for a wire dot printer that has a leaf spring fixing part with a structure that facilitates the work of attaching the leaf spring without deteriorating print quality. The purpose is to provide.

[Key points of the invention]

In order to achieve the above object, the present invention includes a base having a planar mounting surface, a cantilever leaf spring whose fixed end side is fixed to the mounting surface via a spacer, and an armature fixed to the leaf spring. , armature drive to drive this armature! In the printing head consisting of a horizontal side and a printing wire, a holding member that pinches the fixed end side of the temporary spring together with a spacer, and a fastening means that tightens the laminated structure consisting of the mounting surface of the base, the spacer, the temporary spring, and the holding member. In addition, each surface of the spacer and the holding member that comes into contact with the temporary spring is formed into an inclined surface such that the longitudinal direction of the leaf spring and the mounting surface of the base form a predetermined angle toward the holding member. By configuring this structure, when the laminated structure is tightened by the fastening means, the pressing force generated on the contact surface of the leaf spring with the spacer is uniform over a wide range of the contact surface, and the pressure against the armature is made uniform. The fixing position of the leaf spring can be set accurately.
It is thus possible to obtain a print head for a wire dot printer having a leaf spring fixing portion having a structure that facilitates the installation work of the slope spring without causing a deterioration in print quality.

[Embodiments of the invention]

FIG. 2 is a vertical sectional view of a main part of an embodiment of the present invention, FIG. 1 is an enlarged view of the main part in FIG. 2, and FIG. 2 is a drawing corresponding to FIG. 4. The main difference between FIGS. 1 and 2 and FIG. 4 is the structure of the fixing part of the leaf spring 8. In FIGS. 1 and 2, 18 is a spacer corresponding to the spacer 10 shown in FIG. Reference numeral 9 denotes a holding member that holds the fixed end 8a side of the leaf spring 8 together with the spacer 18. 20 and 20 are guide pins each having one end fixed to the spacer 1, and 21 and 21 are through holes provided in the holding member 19. The holding member 19 is the spacer 18
The pins 20 and 20 are inserted into the through holes 21 and 21 with the leaf spring 8 interposed between them, thereby positioning the pins 20 and 20 in the spacer 18. Of course, in this case, the leaf spring 8 is constructed such that the pins 20 and 20 pass through through holes (not shown) provided in the cedar leaf spring, and the base 1, the spacer 18, the leaf spring 8, and the pressing member 19 is integrally tightened by a fixing screw 17 to constitute a fixing part of the leaf spring 8. In this print head as well, in order to ensure that when the armature 9 and the iron core 4 collide, their collision surfaces are parallel, the longitudinal direction of the leaf spring 8 and the surface of the base 1 are aligned when the iron core 4 is not energized. The contact surface of the spacer 1 with the leaf spring 8 is formed into a slope shape so that the spacer 1 forms a predetermined angle θ. Furthermore, since the surface of the spacer 18 that comes into contact with the leaf spring 8 is formed in a sloped shape, the surface of the presser member 190 that comes into contact with the temporary spring 8 also has a slope shape.
The upper surface 19a of the member 19, on which the head of the fixing screw 17 comes into contact, is formed substantially parallel to the surface of the base 1, but is formed in an inclined shape. In this print head, the fixing part of the leaf spring 8 is configured as described above, and each part is configured so that the left end of the pressing member 19 shown in the figure is not closer to the right side than the left end of the substrate spring 8 shown in the figure. Therefore, when the fixing screw 17 is sufficiently tightened, a uniform pressing force is applied to the contact surface of the leaf spring 8 with the spacer 18, and a moment is applied to the armature 9 by the armature drive mechanism 15. The length of the arm is based on the left end of the spacer 18. The l shown in the figure is the length of the leaf spring 8 between the spacer 1 and the armature 9, which represents the length of this arm. . Also in the print head shown in FIGS. 1 and 2, the coil 6 has ia! When the power is turned on, the iron core 4, the solenoid storage body 3,
A magnetic flux φ flows through a closed magnetic path consisting of the air gap 22, the armature 9, and the air gap 14 between the inner wall of the through hole 5 provided in this storage body and the armature 9, and the armature 9 is attracted to the iron core 4 by this φ. Tip part 11 of printing wire 11
A platen 2 is disposed opposite to a via an ink ribbon 25.
The tip portion 11a collides with the edge 24 on the paper 3, and dot printing is performed. As soon as the armature 9 collides with the iron core 4, the current flowing through the coil 6 is cut off. At this point, the temporary spring 8 is bent downward, so when the current in the coil 6 is cut off, the leaf spring 8 exerts a repulsive force. bounces upwards,
Eventually it returns to its old position and stands still. Reference numeral 26 denotes a damper which absorbs the rebound energy of the leaf spring 8 by colliding with the free 0ta8b of the leaf spring 8 during the above-mentioned rebound operation, thereby quickly returning the printing wire 11 to its normal resting position. The printing force of the print head that performs the printing operation as described above is determined by Faf applied to the movable part 27 consisting of the leaf spring 8, armature 9, and printing wire 11, and this force Faf is applied to the armature 9 by the drive mechanism 15. This is the difference between the magnetic attraction force F, which is exerted and the elastic force Fee of the leaf spring 8. Therefore, in order to make each printing force of the plurality of printing wires 11 uniform without variation, it is necessary to make both F@ll and Fm1l uniform. However, in the above-described print head, the print wire 11 and the armature 9 are first attached to the leaf spring 8, and then the print wire 11 is inserted into the guide hole 12.13 and the armature 9 is
is placed in the through hole 5 of the solenoid housing 3, and then the fixed end 8a side of the leaf spring 8 is connected to the spacer 18 and the pressing member 1.
9, then fix the spacer 1, the leaf spring 8, and the holding member 19 with the fixing screw 17 so that the length l becomes a predetermined value.
It is fixed to base 1 by. Therefore, in such a print head, the fixed end 8a side of the leaf spring 8 is firmly sandwiched between the spacer 18 and the pressing member 19 with uniform pressing force and fixed to the base 1, and the length l is reliably kept at a predetermined value. Therefore, it is easy to make the elastic force F0 of the above-mentioned leaf spring in the movable part 27 uniform over the plurality of movable parts 27 in the above-described print head. In addition, the above-mentioned magnetic attraction force F1. Movable part 2 by
It is also easy to uniformly apply the moment to the plurality of Kato parts 27. That is, the above-described print head can easily attach the leaf spring 8 without deteriorating print quality. FIG. 3 is an enlarged vertical cross-sectional view of a main part in a second embodiment of the present invention, and this figure corresponds to the fixing portion of the leaf spring 8 in FIG. 1. In FIG. 3, reference numerals 28 and 29 are spacers and pressing members corresponding to 18 and 19 in FIG. The fixed end 8a is spot-welded to the slope 28b of the spacer 28 while being in contact with the stopper 28a. p, , po are these welding points. Further, the holding member 29 has a U-shaped cross section,
Furthermore, each U-shaped protruding end surface is brought into contact with the upper surface of the temporary spring 8, and the right end side surface is brought into contact with the stopper 28a, which is then tightened with the screw 17. In Fig. 3, each part is constructed as described above, so the screw 1
7 is tightened, the holding member 29 does not shift on the leaf spring 8 along the slope 28b, and the leaf spring 8 is firmly fixed with a wide contact area between the spacer 28 and the holding member 29. In a plurality of leaf springs having such a leaf spring fixing portion, irregularities in spring constant, or in other words, elastic force, are less likely to occur. It is obvious that the leaf spring fixing part having the structure shown in FIG. 3 has the same advantages as the leaf spring fixing part having the structure shown in FIG. 1 in addition to the above-mentioned advantages. be. In the above-described embodiment, the printing wire 11 was fixed to the leaf spring 8, but in the present invention, the printing wire 11 may be fixed to the armature, and the present invention is also applicable to the spring. It can also be applied to open print heads.

【Effect of the invention】

As described above, the present invention includes a holding member that clamps the fixed end side of the temporary spring together with the spacer, and a fastening means that tightens the laminated structure consisting of the mounting surface of the base, the spacer, the temporary spring, and the holding member. Furthermore, each surface of the spacer and the holding member that comes into contact with the temporary spring is sloped so that the longitudinal direction of the leaf spring and the mounting surface of the base form a predetermined angle toward the holding member, so that the laminated structure can be tightened. When the temporary spring is tightened by this method, the pressing force generated on the contact surface of the temporary spring with the spacer becomes uniform over a wide range of the contact surface, and the fixing position of the leaf spring relative to the armature is set accurately. This has the effect of providing a print head for a wire dot printer in which the work of attaching a leaf spring can be easily performed without deteriorating print quality.

[Brief explanation of drawings]

FIG. 1 is an enlarged vertical cross-sectional view of the main part that best represents the features of the present invention, FIG. 2 is a partial vertical cross-sectional view of the first embodiment of the present invention using the mechanism shown in FIG. 1, and FIG. FIG. 4 is an enlarged cross-sectional view of main parts in a second embodiment of the present invention, and FIG. 4 is a partial vertical cross-sectional view of a conventional print head. l: Base, 8: Leaf spring, 8a: Fixed end, 8b: Free end, 9: Armature, 10.18.21 Spacer, 11
:Printing wire, 15 near-machi air drive mechanism, 17: Fixing screw, 19.29=pressing member. Figure 2 No. 3 Entrance

Claims (1)

[Claims] 1) a base having a planar mounting surface, a cantilever leaf spring whose fixed end side is fixed to the mounting surface of the base via a spacer, and an armature fixed to the free end side of the leaf spring; A printer that includes an armature drive mechanism that drives the armature in the thickness direction of the leaf spring, and a printing wire fixed to a movable part consisting of the leaf spring and the armature, and prints dots at the tip of the printing wire. In the print head, a pressing member that clamps the fixed end side of the leaf spring together with the spacer, and a fastening means that tightens the laminated structure consisting of the mounting surface of the base, the spacer, the leaf spring, and the pressing member. Further, each surface of the spacer and the holding member that comes into contact with the leaf spring is formed into a slope shape such that the longitudinal direction of the leaf spring and the mounting surface of the base form a predetermined angle toward the holding member. Characteristic print head of wire dot printer.