JPS61102261A - Dot printer head - Google Patents

Abstract

PURPOSE:To involve the force of an auxiliary spring in addition to the force of a leaf spring to shorten a time required for displacement by fixing the auxiliary spring to a yoke and give supplementary spring force by the auxiliary spring to the leaf spring in a direction where the leaf spring separates from the yoke. CONSTITUTION:An auxiliary spring 41 is fixed with a screw 42 near the edge of a permanent magnet 24 at an external leg 23. The auxiliary spring 41 curves toward the inside of a radial direction with the other end contacting a leaf spring 29. Accordingly the auxiliary spring 41 gives supplementary spring force to the leaf spring 29 in the second housing direction. An armature 34 is displaced in a direction where it separates from a magnetic polar surface 22a by the spring force of both leaf spring 29 and auxiliary spring 41 involved. Thus a printing wire 36 is displaced in an arrow J direction to perform printing operation. An impact caused by the collision of the polar surface 34a of the armature 34 which begins a return operation with the magnetic polar surface 22a is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a dot printer head in which a printing wire is driven by electromagnetic force.

BACKGROUND OF THE INVENTION FIG. 6 is a cross-sectional view of a portion of a prior art dot printer head 1. A yoke 2 is provided around the axis of the dot printer head 1 with a space therebetween. Yoke 2 is
A cross section taken along a plane including the axis is roughly U-shaped, and includes an inner pa-shaped portion 3 and a seven-sided leg portion 4 . A permanent magnet 5, a leaf spring 6, and an auxiliary member 7 are provided at one end of the outer leg 4 and fixed to each other in this order. Further, a coil 8 is provided on the inner leg portion 3 by winding the inner leg portion 3,
By energizing the coil 8 as described below,
The yoke 2 is made to function as an electromagnet.

An amatia 9 is fixed to the inner leg portion 3 side near the radially inner end portion of the plate spring 6. Also leaf spring 6 and amachia 9
An arm 10 is fixed to the radially inner end of the arm 10, and one end of a printing wire 11 is fixed to the radially inner end of the arm 10.

Here, the inner leg 3 side end surface 9a of the Amatia 9 and the Amatia 9 side end surface 3aH of the inner leg 3 are magnetic pole surfaces that are magnetically coupled to each other when the coil 8 is energized. It is.

FIG. 7 is a graph showing the temporal displacement of Amathia 9. Window 11 shows this displacement. Figures 6 and 7
The operating state of the dot printer head 1 will be explained with reference to the drawings. When the coil 8 is not energized, the magnetic flux caused by the permanent magnet 5 flows in the directions of arrows A and B. Therefore, magnetic pole face 3
a and 9a are magnetically coupled to each other, and the amatia 9 is attracted to the magnetic pole face 3a.

Next, when the coil 8 is energized, a magnetic flux that cancels the magnetic flux produced by the permanent magnet 5 flows in the direction of arrow C9D. Therefore, the magnetic coupling between the magnetic pole surfaces 3a and 9a is lost, and the spring force of the leaf spring 6 causes the amachia 9, etc.
It is displaced in the direction away from the magnetic pole i'1O3a. Therefore, the printing wire 11 is displaced in the direction of arrow E to perform printing. Here, period L1 in FIG. 7 is a period from when the tip of the printing wire 11 in FIG. 6 is displaced in the direction of arrow E until it comes into contact with a printing object (not shown) such as paper. The period L2 is a period during which the tip of the printing wire 11 is in contact with the printing target.

Around time to in FIG. 7, power to the coil 8 in FIG. 6 is turned off. Therefore, the magnetic flux generated by the permanent magnet 5 appears again, and the magnetic attraction force between the magnetic pole faces 3a and 9a and the impact when the printing wire 11 collides with the printing target cause the amachia 9 to move in the opposite direction to the arrow E direction. Return. As a result, the magnetic pole face 9a is magnetically attracted to the magnetic pole face 3a again and collides with the magnetic pole face 3a. At this time, the displacement of Amathia 9 is shown as a line in period L3 of line 11 in FIG.

As mentioned above, when the amatia 9 returns in the direction opposite to the direction of the arrow E, the magnetic pole face 9a collides with the magnetic pole face 3a, causing the leaf spring 6 to move as shown by the imaginary line 12 in FIG. It may curve.

Such curvature and the aforementioned magnetic pole iIT] 3a, 9
There is a problem in that the amatia 9 is displaced unnecessarily due to the collision between the wires 1 and 2, as shown by the line of period L4 in FIG. 7, and the printing speed of the printing wire 11 is slowed down.

Problems to be Solved by the Invention It is an object of the present invention to solve the above-mentioned problems and to provide an improved dot printer head with improved printing speed for printing wires and the like.

Means for Solving the Problems The present invention comprises: an amathia that supports a printing wire; a leaf spring to which the amathia is attached at one end; a yoke magnetically coupled to the amathia; This dot printer head is characterized in that it includes an auxiliary spring that suppresses the displacement of the leaf spring toward the magnetic pole when approaching the magnetic pole of the dot printer head.

The other end of the auxiliary spring is fixed so that one end abuts the partial leaf spring and biases the leaf spring in a direction opposite to the yoke. By using such an auxiliary spring, when the amatia, printing wire, etc. are displaced to perform a printing operation, the spring force that causes the displacement is increased. In addition, when the amatia and printing wire return, the auxiliary spring biases the sheet spring in the opposite direction to the return direction, so the impact of the collision between the amatia and the yoke at the time of return is suppressed, and this collision It is possible to suppress the displacement of the leaf spring caused by such factors.

Embodiment FIG. 1 shows a dot printer head 2 according to an embodiment of the present invention.
FIG. 2 is a front view showing a partial cross section of FIG. 0, and FIG. 2 is a plan view showing a partial cross section of FIG. The configuration of the dot printer head 20 will be explained using FIGS. 1 and 2. A plurality of yokes 21 are provided at intervals around the axis of the dot printer head 20. The yoke 211/'i includes an inner leg 22 and an outer leg 23. A permanent magnet 24, a magnetic pole piece 25, a spacer 26, and an auxiliary yoke 27 are provided at one end of the outer leg 23 and fixed to each other in this order. Further, a screw hole 27a is formed in the auxiliary yoke 27.

On the opposite side of the MBIJ yoke 27 from the spacer 26, a spacer 28, a leaf spring 29, an auxiliary member 30, and a second housing 31 each having a through hole are provided in this order, and the spacer 28, each having a through hole, is provided in this order. , one person inserts the screw 32 into the tapped hole 27a of the auxiliary yoke 27. This screw 32 connects the second housing 31 and the auxiliary yoke 27.
d can be determined.

A coil 33 is wound around the inner leg portion 22 of the yoke 21 . By energizing this coil 33, the yoke 21 is made to function as an electromagnet. An amatia 34 is fixed to the inner yJ leg 22 side of the leaf spring 29, facing the magnetic pole surface 22a which is the end surface of the inner leg 22 on the leaf spring 29 side. An arm 35 is fixed to the radially inner end of the amatia 34.
A -@ portion of the printing wire 36 is fixed to the end opposite to the printing wire 4 . A nose 37 is fixedly provided near the radially inner end of the second housing 31. The printing wire 36 is connected to the guide members 3B and 39 provided in the nose 37.
．． 40 guide holes 38a.

1. The outside KW of the nose 37 is routed through 39a and 40a.

An auxiliary spring 41 is fixed by a screw 42 near the end of the outer leg 23 on the permanent magnet 24 side.

The auxiliary spring 41 is curved inward in the radial direction, and its other end abuts against the leaf spring 29 . Therefore, the auxiliary spring 41 is
The leaf spring 29 is biased in the direction of the %2 housing 31. Further, a printed wiring board 43 is fixed to the opposite side of the yoke 21 from the second housing 31 with screws 44 .

This printed wiring board 43 includes a plurality of yokes 2 provided on the axis of the dot printer head 20 as described above.
Power is supplied to energize each coil 33 of 1 as described below. Further, a first housing 45 is provided surrounding the yoke 21 and the printed wiring board 43.

3 is an enlarged view of a portion of the dot printer head 20 shown in FIG. 1, and FIG. 4 is a diagram for explaining the installation state of the auxiliary spring 41. As mentioned above, the auxiliary spring 41
One end portion 41a is (2) fixed near the end of the outer leg portion 23 of the yoke 21 on the permanent magnet 24 side by the screw 42,
While being curved radially inward from one end 41a to the other end 41b, the other end 41a abuts between the spacer 28 of the leaf spring 29 and the amatia 34.

FIG. 5 is a graph for explaining the operating state of the dot printer head 20. The vertical axis in FIG. 5(1) is the intensity of the current, the horizontal axis is the time, and the solid line 12 shows the change in the current applied to the coil 33 in FIG. Also, Figure 5 (2
) is the displacement amount of the amatia 34, and the horizontal axis is time, and the solid line 13t/'i represents the state of displacement of the amacia 34. The operating state of the dot printer head 20 will be explained using Figures 3 and 5 as rare examples. When the coil 33 is not energized, the magnetic flux generated by the permanent magnet 24 flows in the directions of arrows F and G. Therefore, the magnetic pole faces 34 a, 22 a
are magnetically coupled to each other, Amathia 34L/i, magnetic pole face 22
It is magnetically attracted to a.

Next, at time t1 in FIG. 5, the coil 33 is energized. The magnetic flux generated at this time is
It flows in the directions of arrows H and I so as to cancel out the magnetic flux caused by. Therefore, the magnetic coupling between the magnetic pole surfaces 22a and 34a disappears, and the amatia 34 is connected to the leaf spring 29 and the auxiliary spring 4.
Due to the synergistic spring force of 1, the magnetic pole face 22a is displaced in a direction away from the magnetic pole face 22a. In this way, the printing wire 36 is displaced in the direction of the arrow J, and performs a printing operation.

Amathia 34 starts displacement from time t2 in FIG.
At time t3, the tip of the printing wire 36 reaches the printing target such as paper. The period W1 from time t3 to t5 is
This is the period during which the tip of the printing wire 36 is in contact with the printing target. Here, at time t4 in FIG.
3 is deenergized. Therefore, the magnetic flux caused by the above-mentioned permanent magnet 24 appears again, and a magnetic attraction force begins to act between the magnetic pole faces 22a and 34a.

This magnetic attraction force and the impact when the tip of the printing wire 36 collides with the printing target cause the printing wire 3
At 6t/i, the return operation to the magnetic pole face 22a side is started.

The Amachia 34 that has started the return operation completes the return operation when the magnetic pole surface 34a is magnetically attracted to the magnetic surface 22a. At this time, the auxiliary spring 41 moves the leaf spring 29 with the arrow J
Since the spring is biased in the direction, the impact caused by the collision of the magnetic pole face 34a with the magnetic pole face 22a at the time of return can be reduced. Therefore, the Amathia 34 can be moved without unnecessary displacement as mentioned in the explanation of FIG. 7 of the prior art.
The return operation can be completed.

As described above, in this embodiment, when the coil 33 is energized and the amatia 34 is displaced in the direction away from the magnetic pole face 22a, this displacement is added to the spring force of the leaf spring 29, and the auxiliary force is Since the displacement is caused by the combined force of the spring force of the spring 41, the length of the period from time t2 to t3 in FIG. 5(2) is made shorter than the period L1 in FIG. be able to. Even when the Amachia 34 returns, the auxiliary spring 41 has a so-called damper function to prevent the Amachia 34 from violently colliding with the magnetic pole face 22a and causing unnecessary displacement. did it.

Although the permanent magnet 24 was used in the above embodiment,
The present invention can be widely implemented even with respect to a dot printer head having a structure that does not use such a permanent magnet.

Effects As described above, according to the present invention, an auxiliary spring is fixed to the yoke, and the auxiliary spring biases the leaf spring in the direction away from the yoke. Therefore, when the amachia moves to the y position for printing, the spring force of the auxiliary spring is used synergistically in addition to the spring force of the leaf spring. Therefore, the time required for this displacement can be shortened. Furthermore, when Amathia returns, due to the spring force of the auxiliary spring that biases the leaf spring in the direction away from the yoke, Amathia can complete the previous work without unnecessary displacement. can.

[Brief explanation of drawings]

FIG. 1 shows a dot printer head 20 according to an embodiment of the present invention.
2 is a front view showing a partial cross section of FIG. 1, FIG. 3 is an enlarged sectional view of a portion of FIG. 1, and FIG. 4 shows the installation state of the auxiliary spring 41. FIG. 5 is a graph for explaining the operating state of the dot printer head 20, FIG. 6 is a sectional view of a portion of the prior art dot printer head 1, and FIG. 7 is a graph showing the operating state of the dot printer head 1. This is a graph that is difficult to explain. 20... Dot printer head, 21... Yoke,
22a, 34a... Magnetic pole surface, 29... Leaf spring, 34
... Amachia, 36... Printing wire, 41... Auxiliary spring agent Patent attorney Kei Nishi part Todo Koto ■ C Hitsugi Nen-1

Claims (1)

[Scope of Claims] An amatia supporting a printing wire, a leaf spring to which the amatia is attached to one end thereof, a yoke magnetically coupled to the amatia, and a yoke provided when the amatia approaches a magnetic pole of the yoke. A dot printer head comprising: an auxiliary spring that suppresses displacement of the leaf spring toward its magnetic pole side;