JPH0245161A - Impact dot head and driving method - Google Patents

Abstract

PURPOSE:To prevent collisions with other members of a plunger at the time of return to the state of stand-by printing, and to obtain an impact dot head, noises from which are lowered and which has a long lifetime, by balancing attracting force and resilient force before the plunger is attracted to a core and brought into contact with the core and stopping the plunger in a hollow section without being brought into contact with the core at the time of non-printing stand-by. CONSTITUTION:On non-printing stand-by, a pluger 1 is attracted to a core 2 while deflecting a spring 4 by attracting force F between the core and the plunger by magnetic flux generated from a permanent magnet 3, and resilient force S and attracting force F are balanced and rested in the same absolute-value opposite direction at the position (a point A) of a gap deltabetween the plunger and the core. A magnetic coil 5 is electrified and magnetic flux is denied on printing, thus denying attracting force between the core and the plunger. When the distance delta between the position of the plunger and the core in which attracting force between the core and the plunger and resilient force are balanced is made smaller than the quantity of overshoot OS, the coil is electrified again at the time of return to the state of stand-by after printing, and speed at the time of return is decreased, thus preventing the overshoot. Accordingly, the plunger 1 does not collide with the core 2, thus acquiring an impact dot head, noises from which are lowered and which has a long lifetime.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a print head for an impact dot printer.

[Prior art] In the conventional technology, during non-printing standby, the suction force between the core and the plunger exceeds the force of the leaf spring, so the plunger is attracted while in contact with the core, or the core, When a spacer is interposed between the plungers, the plunger is attracted to the core while in contact with the spacer.

[Problems to be Solved by the Invention] However, in such a conventional impact dot head, when returning to the standby state after printing, the core and the plunger directly or if a spacer is interposed between the core and the plunger, the spacer is interposed between the core and the core. I had a wholesaler who said that the plunger would collide, making a lot of noise, and that the core and plunger would wear out, resulting in a short lifespan.

SUMMARY OF THE INVENTION In order to solve these conventional problems, it is an object of the present invention to provide an impact dot head with low noise and long life, in which the plunger does not collide with other members when returning to the standby state after printing. [Means for Solving the Problems] In order to solve the above-mentioned problem, the impact dot head of the present invention balances the attractive force and the spring force before the plunger is attracted to the core by the magnetic flux generated by the permanent magnet and comes into contact with the core. By doing so, the plunger does not come into contact with the core and stops in a hollow state during non-printing standby.

Further, the present invention is characterized in that the coil is energized again when returning to the standby state after printing.

[Operation] In the impact dot head configured as described above, the attraction force between the core and the plunger and the spring force are balanced before the plunger contacts the core when returning to the standby state after printing, and when this equilibrium point is reached, the plunger Even if the plunger has a speed in the direction of colliding with the core, the regeneration coil is energized to stop the plunger before it collides with the core, avoiding collision, reducing noise and preventing wear, resulting in long life. It is possible to measure the

[Embodiments] Examples of the present invention will be described below based on the drawings. FIG. 1 is a sectional view of the impact dot head of the present invention. The lower half of Figure 1 shows the state during non-printing standby, and the upper half shows the state during printing. During non-printing standby, the permanent magnet 30
The plunger 1 is attracted to the core 2 while deflecting the spring 4 due to the attraction force F between the core and the plunger due to the generated magnetic flux, and the spring force S and the attraction force F at the position of the gap δ between the plunger and the core, that is, at point A in FIG. are balanced and stationary with the same absolute value and opposite direction. During printing, by energizing the electromagnetic coil 5 and canceling the magnetic flux generated by the permanent magnet 3,
Cancels the suction force between the plungers. Therefore, at this time spring 4
is released in the direction to eliminate the deflection, that is, to the left in FIG. 1, and the wire 7 connected to the tip of the lever 6 is projected through the lever 6 fixed to the spring 4 to print. After printing, the magnetic flux generated by the permanent magnet 30 causes the attraction force between the core and the plunger to return to a position where the attraction force between the core and the plunger and the spring force are balanced. However, as shown in Figure 5, after overshooting from the position where the attraction force between the core and the plunger and the spring force are in equilibrium, that is, the distance between the core and the plunger is δ, the attraction force between the core and the plunger and the spring force are in equilibrium. converges to the desired position.

Therefore, if the distance δ between the core and the plunger position where the attraction force between the core and the plunger and the spring force are balanced is smaller than the overshoot amount O8, the plunger 1 collides with the core 2,
The effects of low noise and long life cannot be obtained. Therefore, the driving method as set forth in claim 2 reduces the speed at the time of return and prevents overshoot by energizing the coil again when returning to the standby state after printing as shown in FIG. Even if the plunger position where the attraction force between the plungers and the spring force are balanced and the distance δ between the cores is small, the plunger 1
It is possible to obtain an impact dot head with low noise and long life without colliding with the core 2.

[Effects of the Invention] As explained above, in the impact dot head of the present invention, the plunger is attracted to the core by the attraction force between the core and the plunger, and the attraction force and the spring force are balanced before the plunger contacts the core. does not collide with the core, and even if the distance between the core and the plunger position where the attraction force and spring force between the core and plunger are balanced is smaller than the overshoot at the time of return (even if this occurs, the return can be made by re-energizing the coil at the time of return). Since the plunger and the core collide with each other by reducing the speed and preventing overshoot, collision noise between the plunger and the core is not generated, and abrasion can be avoided, which has the effect of extending life.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the impact dot head of the present invention. Figure 2 shows the change in the distance between the core and plunger.
- A diagram showing changes in the attraction force between the core and the plunger and the spring force. FIG. 6 is a time chart of the distance between the core and the plunger and the coil current when the impact dot head according to the present invention is driven by a driving method in which the fill is energized only during printing. FIG. 4 is a diagram showing a method of driving an impact dot head according to the present invention. 1...Plunger 2...Core...Permanent magnet 4...Spring 5... ...Electromagnetic coil No.

Claims (2)

[Claims] (1) During non-printing standby, strain energy is stored in the plate spring by bending the plate spring to which the plunger is fixed by the core of the magnetic flux generated from the permanent magnet and the attraction force between the plunger, and during printing, the plate spring stores strain energy in the plate spring. In a print head that performs impact printing using a printing wire that cancels the attraction force between the core and the plunger and opens the plate spring by energizing a coil wound around the core and a lever fixed to the plate spring, the plunger is attracted to the core, and before it comes into contact with the core, the attraction force and spring force are balanced, and during non-printing standby,
An impact dot head characterized by the plunger stopping in the air without contacting the core. (2) An impact dot head driving method comprising the step of energizing the coil again when the impact dot head according to claim 1 returns to a standby state after printing.