JPH0430350B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a spring charge type dot printing head that is ultra-compact by reducing high-order vibrations of the spring and wear of the spring fulcrum.

[Prior art]

A conventional spring charge type dot printing head, for example, as shown in Utility Model Application No. 56-39251, has an armature and a yoke located closer to the core than a leaf spring, and the yoke shape is such that the armature is attached to the core without the yoke. The high-order vibration of the leaf spring is reduced by creating a shape that is almost the same as the deflection curve of the leaf spring when it is attracted, but in these types of dot printing heads, the fixing point of the leaf spring is located closer to the outer circumference than the armature. Therefore, to make the print head smaller, the armature must be smaller in shape or the effective spring portion of the leaf spring must be shorter. If this is done, there is a risk that the necessary printing force will not be obtained, and if the printing force is increased, the spring stress will become too large, resulting in disadvantages such as the leaf spring breaking.

[Purpose of the invention]

The present invention solves these conventional drawbacks and provides a high-performance dot printing head that is small, lightweight, and capable of high-speed printing that provides high printing power with almost no wear or bending of the leaf springs. The purpose is to realize the following.

[Structure of the invention]

In order to achieve this object, the present invention utilizes a magnetic flux of a permanent magnet to attract a plurality of armatures to the corresponding core when no current is applied to the electromagnetic coil wound around the core, and to attach a tongue of a leaf spring supporting each armature to the corresponding core. A spring charge type that prints dots by leaving the piece bent and energizing the electromagnetic coil to cancel the magnetic flux of the permanent magnet, and then using the restoring force of the tongue piece of the leaf spring to protrude the dot wire attached to the end of the armature. In this dot printing head, the tongues of the leaf spring are integrally formed so as to be connected to each other at one end, and each tongue has a portion wider than the width of the groove in the yoke into which the armature is inserted, and is approximately H-shaped. This leaf spring is stacked on the yoke on the side opposite to the core, and the armature is arranged in the groove of the yoke so that the end to which the dot wire is attached is on the connecting part side of the tongue piece, and It is characterized in that the part between the armatures on the connecting part side of each tongue piece is fixed to the yoke, and the armature is fixed to the inner part of the slit of each tongue piece.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. Fig. 1 is a partially cutaway plan view, Fig. 2 is a partially cutaway side view, Fig. 3 is an exploded perspective view, Fig. 4 is an enlarged plan view showing one embodiment of the leaf spring, and Fig. 5 is an armature. FIG. 6 is a partial enlarged view showing the armature when it is released, and FIG. 6 is a partial enlarged view showing the armature when it is suctioned. In the figure, 1 is a guide frame, which has a plurality of guide holes 1a for dot wires, which will be described later. 2 is a core, 3 is an electromagnetic coil wound around this core 2, 4
a first base yoke that engages with the core 2;
is a second ring-shaped yoke, 6 is a permanent magnet inserted between the first base yoke 4 and the second ring-shaped yoke 5, and 7 is a disk-shaped yoke, with grooves 7a extending radially from approximately the center. The armature 8 is movably arranged in the groove 7a. Note that if the thickness of this armature 8 is made the same as the thickness of the disk-shaped yoke 7, it is easy to make the surface of each armature 8 the same as the surface of the disk-shaped yoke 7 after it is fixed to the leaf spring described later. becomes.

Reference numeral 9 denotes a leaf spring, which is integrally formed by punching or the like so that a plurality of tongue pieces 9b are arranged radially and connected to each other at one end (inside), and a hole 9a is provided approximately in the center of the leaf spring. The whole flower is petal-shaped. Here, each tongue piece 9b has a portion wider than the width of the groove 7a of the yoke 7, and has a substantially H-shaped slit 9c.

This leaf spring 9 is stacked on the yoke 7 on the side opposite to the core 2, and at this time, the armature 8 is arranged so that the end to which the dot wire is attached is lined up with the hole 9a on the connection side of the tongue piece 9b, as shown in FIG. is located in the groove 7a of the yoke 7, and the portion between the armatures 8 on the connecting portion side of each tongue piece 9b is the fixed point 11.
The armature 8 is fixed to the upper surface of the yoke 7 at a fixing point 10 including the inner part of the slit 9c of each tongue piece 9b. In this way, each tongue piece 9b is fixed to the disc-shaped yoke 7, and also fixed to the armature 8, respectively.

12 has one end attached to the end of armature 8,
A dot wire whose other end is guided by a guide hole 1a of a guide frame 1 and becomes a dot printed end, 1
3 is the disk-shaped yoke 7 and the ring-shaped yoke 5
14 is a substrate to which the ring shape of the electromagnetic coil 3 is soldered, and 15 is a clamp spring for stacking and fixing each member. A plurality of legs 15b are formed by bending from the flat ring 15a, and each leg 15
A claw 15c is provided inwardly protruding from b, and as shown in FIG. 2, the above-mentioned members are stacked and fixed by the flat ring 15a and the claw 15c.

Next, the operation of the above configuration will be explained.

First, when the electromagnetic coil 3 is not energized, as shown in FIG. At this time, each tongue piece 9b of the petal-shaped leaf spring 9 is attracted to the tip of the core 2.
As shown in Fig. 6, armature 8 and tongue piece 9 are attached.
The force couple M, p, r acts on the fixed point with b, and the tongue piece 9
The outer circumferential tip of the armature 8 is bent effortlessly in the direction opposite to the direction in which the armature 8 is attracted to the core 2, and is held in a state in which it stores strain energy to obtain sufficient printing force.

Next, when the electromagnetic coil 3 is energized, the permanent magnet 6
A magnetic flux is generated that cancels the magnetic flux of , and the armature 8, which had been attracted to the core 2, is released from the attraction force and performs a printing operation due to the strain energy of the tongue piece 9b of the leaf spring 9. That is, initially, the surface of the tongue piece 9b on the side that is fixed to the disc-shaped yoke 7 and the disc-shaped yoke 7
The surface on the side to which the leaf spring 9 is fixed is the leaf spring 9.
The contact area is gradually increased as the armature 8 is released, that is, the tongue piece 9b of the leaf spring 9 is in contact with the upper surface of the disc-shaped yoke 7, but there is no deflection. Go back to your condition. This restrains high-order vibrations of the tongue piece 9a, allowing high-speed and efficient printing.

Further, since the fixing points of the leaf springs 9 are on one plane, there is almost no wear on the fixing points, and a dot printing head with stable printing characteristics can be obtained.

In the above embodiment, a circular serial dot printing head was described, but when applied to a printing head of a line printer in which a plurality of each element is linearly arranged in a row or in a plurality of rows, the plurality of tongue pieces are used as comb teeth. A similar effect can be achieved by using leaf springs arranged in parallel.

〔Effect of the invention〕

As explained above, in the present invention, the tongues of the leaf spring are integrally formed so as to be connected to each other at one end, and each tongue has a portion wider than the width of the groove of the yoke into which the armature is inserted. It has a structure with a roughly H-shaped slit, and this leaf spring is stacked on the yoke on the side opposite to the core, and the armature is placed in the groove of the yoke so that the end where the dot wire is attached is on the connecting part side of the tongue piece. In addition, the part between the armatures on the connection side of each tongue piece is fixed to the yoke, and the armature is fixed to the inside part of the slit of each tongue piece, so the outer diameter of the dot printing head is smaller than the conventional one. The leaf spring can be made smaller and lighter than the previous model, and the fixed point of the leaf spring is in one plane.
There is almost no wear or breakage of the leaf spring,
Moreover, since a large printing force can be obtained, it is possible to realize a high-performance dot printing head that can handle high-speed printing.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway plan view showing an embodiment of the present invention, Fig. 2 is a partially cutaway side view, Fig. 3 is an exploded perspective view, and Fig. 4 is an enlarged plan view showing an embodiment of the leaf spring. 5 is a partially enlarged view showing the armature when it is released, and FIG. 6 is a partially enlarged view showing the armature when it is sucked. DESCRIPTION OF SYMBOLS 1... Guide frame, 2... Core, 3... Electromagnetic coil, 4... Base yoke, 5... Ring-shaped yoke, 6... Permanent magnet, 7... Disc-shaped yoke,
8... Armature, 9... Leaf spring, 9b... Tongue piece, 12... Dot wire.

Claims (1)

[Claims] 1. When no current is applied to the electromagnetic coil wound around the core, a plurality of armatures are attracted to the corresponding core by the magnetic flux of the permanent magnet, and the tongues of the leaf springs supporting each armature are bent. This is a spring charge type dot printing head that prints dots by canceling the magnetic flux of the permanent magnet by energizing the electromagnetic coil and causing the dot wire attached to the end of the armature to protrude using the restoring force of the tongue of the leaf spring. In the above, each tongue of the leaf spring is integrally formed so as to be connected to each other at one end, and each tongue has a portion wider than the width of the groove of the yoke into which the armature is inserted, and has a substantially H-shaped slit. Then, stack this leaf spring on the yoke on the opposite side of the core,
Arrange the armature in the groove of this yoke so that the end on which the dot wire is attached is on the connecting part side of the tongue piece, and fix the part between the armatures on the connecting part side of each tongue piece to the yoke. A dot printing head characterized by an armature fixed to the inner part of the slit of the tongue. 2. The dot printing head according to claim 1, characterized in that it uses a leaf spring formed into a petal shape with a plurality of tongues arranged radially. 3. The dot printing head according to claim 1, characterized in that it uses a plate spring formed by arranging a plurality of tongue pieces in parallel in a comb-teeth shape.