JPS61215064A - Printing hammer - Google Patents

Abstract

PURPOSE:To attain to enhance a printing speed by effectively and rapidly suppressing rebound, by attracting the flight hammer driven by a piezoelectric element by a permanent magnet. CONSTITUTION:In a printing hammer for a dot impact type printer, when a flight hammer 13 is contacted with the force transmitting member 15 connected to the leading end of a piezoelectric element 11, the magnetic flux generated from a permanent magnet 18 passes through a first yoke 16, the flight hammer 13 and a second yoke 17 to be returned to the permanent magnet 18 as shown by an arrow B. Therefore, attraction force acts on the flight hammer 13. Because the flight hammer 13 flies out forwardly during printing operation, the magnetic flux generated from the permanent magnet 18 reaches the second yoke 17 through the first yoke 16 and does not pass through the flight hammer 13 and, therefore, almost no attraction force 13 acts on the flight hammer 13. Because large attraction force acts only when the flight hammer 13 is contacted with the force transmitting member 15 as mentioned above, rebound can be rapidly suppressed without almost exerting adverse effect on printing operation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a printing hammer for a dot impact printer using a piezoelectric element.

(Prior Art and its Problems) Conventionally, electromagnetic printing hammers using coils have been widely used as printing hammers for dot impact printers. However, electromagnetic printing hammers generate a magnetic field by energizing a coil and are driven using the magnetic force, so they require a large amount of input energy and have problems such as heat generation and magnetic interference. Therefore, in recent years, a printing hammer as shown in Figure 5 has been reported, which uses an EIE electronic element that has good electrical and mechanical energy conversion efficiency, low power consumption, low heat generation, and no magnetic interference. BMC84-49).

This has a structure in which a flight hammer 53 supported by a leaf spring 52 is disposed in front of the piezoelectric element 51 in the direction of displacement (in the direction of the arrow). Note that the flight hammer 53 is provided with a printing wire for printing dots.

When a voltage is applied to the piezoelectric element 51 in this printing hammer, the flight hammer 53 receives a force from the EEt element 51, is accelerated, leaves the piezoelectric element 51, and flies. Then, the printing wire 54 collides with the platen 57 via the ink ribbon 5 paper group in front to form dots on the printing material. Thereafter, the flight hammer 53 returns to the piezoelectric element 51 due to the repulsive force from the platen 57 and the return force of the leaf spring 52. However, at this time, the flight hammer 53 collides with the piezoelectric element 51 and is repelled, causing rebound. The flight hammer 5
The displacement waveform of No. 3 is shown in FIG. It took about 2 ms for the bounce to stabilize after the printing operation started, which was a bottleneck in increasing the speed.

(Object of the Invention) An object of the present invention is to eliminate such conventional drawbacks and provide a high-speed printing hammer with low power consumption, low heat generation, and no magnetic interference.

(Structure of the Invention) According to the present invention, there is obtained a printing hammer characterized in that it is composed of a flight hammer, a suction mechanism that attracts the flight hammer, and a piezoelectric element that applies force to the flight hammer.

(Detailed Description of Configuration) The present invention solves the problems of the prior art by adopting the above-described configuration.

First, electricity is used as the driving source for the flight hammer.

By using a piezoelectric element known for its high mechanical energy conversion efficiency, it uses less power, generates less heat, and eliminates magnetic interference. In addition, by using a suction mechanism using a permanent magnet that applies a large suction force to the flight hammer when it is in contact with the piezoelectric element, the rebound can be effectively and quickly stabilized, increasing speed. can.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention. In FIG. 1, forward in the displacement direction (arrow direction) of the piezoelectric element 11,
The structure includes a magnetic flight hammer 13 supported by a leaf spring 12. The flight hammer 13 is provided with a printing wire 14 for printing dots, and a force transmitting member 15 is connected to the tip of the piezoelectric element 11. Further, on both sides of the flight hammer 13, one ends of first and second yokes 16 and 17 made of magnetic material face each other with a gap in between, and the other ends are connected to the permanent magnet 18 in a G polygonal manner. serves as a suction mechanism for suctioning the flight hammer 13.

In the printing hammer having such a configuration, the flight hammer 13 has a force transmitting member 15 connected to the tip of the piezoelectric element 11.
When in contact with , the magnet emitted by the permanent magnet 18 is
It passes through the first yoke 16, the flight hammer 13, and the second yoke 17 and returns to the permanent magnet 18 as shown in FIG. Therefore, a suction force acts on the flight hammer 13. Also, during the printing operation, the flight hammer 13 jumps forward, so the magnetic flux generated by the permanent magnet 18 passes through the first yoke 16 and reaches the second yoke 17, and does not pass through the flight hammer 13, so it is directed to the flight hammer 13. has almost no suction power.

Therefore, when the flight hammer 13 is in contact with the force transmission member 15, a large suction force acts on the flight hammer 13,
During the printing operation, that is, the flight hammer 13 is
5, the flight hammer 13 has a structure in which almost no suction force acts on it. Therefore, the rebound can be quickly stabilized without having almost any adverse effect on the printing operation.

FIG. 2 shows a displacement waveform of the flight hammer 13 when the piezoelectric element 11 is driven by applying a voltage. It only takes about 1 m8 from the start of printing operation until the rebound stabilizes.
It was possible to obtain a printing hammer that is approximately twice as fast as the conventional case (FIG. 6).

FIG. 3 shows another embodiment of the invention. In Figure 3,
The structure is such that a flight hammer 33 made of a magnetic material and supported by a plate spring 32 is arranged in front of the piezoelectric element 31 in the displacement direction (direction of arrow A). In addition, at the tip of the leaf spring 32,
A printing bin 34 for printing dots is provided, and a force transmitting member 35 is connected to the tip of the piezoelectric element 31.

Further, a permanent magnet 38 is arranged in the air gap between the flight hammer 33 and the permanent magnet 38, which serves as a suction mechanism for attracting the flight hammer 33.

In the printing hammer having such a configuration, the permanent magnet 38
The magnetic flux emitted by the flight hammer 3 flows as shown by arrow C.
3 is very close to the permanent magnet 38, a large attractive force acts on the flight hammer 33, but the flight hammer 33
When the distance between the permanent magnet 38 and the permanent magnet 38 becomes a little larger, the permanent magnet 38
The suction power decreases rapidly and becomes almost useless. Therefore, the rebound can be quickly stabilized without having almost any adverse effect on the printing operation, and the same buds as in the above-mentioned embodiments are exhibited.

FIG. 4 shows another embodiment of the present invention. In FIG. 4, a flight hammer 43 provided with a printing wire 44 is disposed in front of the EEm element 41 in the direction of displacement (arrow direction), and the printing wire 44 is supported by a guide 49. The flight hammer 43 is connected to the piezoelectric element 4 by the coil spring 42.
It is pressed by a force transmitting member 45 connected to the tip of 1. Further, one ends of the first and second yokes 46 and 47 of the crushable body are opposed to each other (ill!) of the flight hammer 43 with a gap in between, and the other end is connected to the permanent magnet 48. It serves as a suction mechanism for suctioning the flight hammer 43.

In the printing hammer having such a configuration, the flight hammer 43 has a force transmitting member 45 connected to the tip of the piezoelectric element 41.
When the magnetic flux generated by the permanent magnet 48 passes through the first yoke 46, the flight hammer 43, and the second yoke 47 and returns to the permanent magnet 48, the flight hammer 43 has an attractive force. work.

Further, during the printing operation, the flight hammer 43 flies out in the TTI direction, so the flight hammer 43 has almost no -1 suction force. Therefore, the rebound can be stabilized without causing any negative effects on the printing (M), and the same effect as in the above-mentioned embodiment is achieved.

Further, in the present invention, similar effects can be obtained by using a multi-plate piezoelectric element having a vertical effect or a horizontal effect, a laminated piezoelectric element, or an electrostrictive element.

In the above-mentioned embodiment, an example was shown in which a leaf spring or coil flap was used to return the flight hammer to the force transmitting member after printing, but as in the embodiment shown in FIG. It is not necessary to use a coil spring to prevent the flight hammer from being supported by a guide or the like. It is possible to return to the force transmitting member by the repulsive force of the platen in the printing direction and a small amount of suction force of the suction mechanism.

(Effects of the Invention) According to the present invention, a high-speed printing hammer can be applied with low power consumption, low heat generation, and no signal/air interference.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing a displacement waveform of a flight hammer in the case of an embodiment of the present invention,
Fig. 3 is a diagram showing another embodiment of the present invention, Fig. 4 is a diagram showing another embodiment of the present invention, Fig. 5 is a diagram showing a conventional embodiment, and Fig. 6 is a diagram showing a conventional embodiment. It is a figure which shows the displacement waveform of the flight hammer in the case of an Example. In the figure, 1131, 41.51...piezoelectric element, 12.32.5
2... Leaf spring, 42... Coil spring, 13.33.
43.53...Flight hammer, 14.44.54
...Print wire, 34...Print bottle, 15, 35.
45... Force transmission member, 16.46... First yoke, 17.47... Second yoke, 18.38.48.
...Permanent magnet, 55... Ink ribbon, 56... Paper, 57... Platen, 49... Guide, respectively. Fig. 1 Δ 18 permanent magnet Fig. 2 Time (ms) Fig. 3 Fig. 4 Fig. 5 b

Claims (1)

[Claims] A printing hammer comprising a flight hammer, a suction mechanism that attracts the flight hammer, and a piezoelectric element that applies force to the flight hammer.