JPH0241422B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a print head of an impact type printer, and in particular, the strain energy of a spring member stored by the attraction force of a permanent magnet is absorbed by the attraction of a permanent magnet by the magnetic flux of an electromagnet. It relates to a print head of a printer of the cancel type, in which force cancellation is applied to a suction member.

[Background of the invention]

The print head of an impact-type printer generally biases a spring member using the attraction force of an electromagnet, stores strain energy in this spring member, and releases the attraction force of the electromagnet to convert the strain energy of the spring member into printing operation force. There are so-called electromagnet-driven types that bias a spring member by the attractive force of a permanent magnet, store strain energy in this spring member, and cancel the attractive force of the permanent magnet with an electromagnet. There is a so-called cancel type type in which the strain energy of a member acts as a printing operation force.

The aforementioned cancelled-type printheads have been widely used in recent years because they have various advantages over electromagnetic-driven printheads. In this type of print head, as described above, the strain energy stored by the biasing of the spring member causes the print wire and the suction member provided therewith to fly toward the printing paper.
That is, since the spring force of the spring member becomes the printing energy of the instant printing wire, the magnitude of the spring force of this spring member has a great influence on printing quality.

However, in conventional print heads of this type, the end of the spring member on the side opposite to the suction member is fixedly supported, as seen in, for example, Japanese Patent Laid-Open No. 127462/1983. Therefore, the spring force of this spring member must be adjusted by the amount of magnetic flux of the permanent magnet or the excitation force of the electromagnet, and there is a problem in that it is very difficult to manage the adjustment.

[Purpose of the invention]

The present invention has been made in order to solve the above-mentioned problems, and provides a printing head that can easily manage the spring force adjustment of a leaf spring member, improve printing quality, and improve productivity. With the goal.

[Summary of the invention]

The present invention provides a yoke that includes a permanent magnet and a coil that generates a magnetic field during excitation in a direction that cancels the attraction force of the permanent magnet, an attraction member that has an application wire at one end, and the other end of the attraction member. A movable body consisting of a leaf spring member provided in In a printing head that has a receiving member that biases the leaf spring member, the ends of the leaf spring member are unrestrained so that they can move toward the yoke and toward the opposite side of the yoke, and the receiving member is provided on the side opposite to the yoke of the leaf spring member, and is located at a position where it comes into contact with the end of the leaf spring member and causes deflection during suction.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show an embodiment of the printing head of the present invention, in which 1 is a printing wire, 2 is a suction member provided with the printing wire 1, and 3 is a reaction member of the suction member 2. A leaf spring member provided on the printing wire attachment side (hereinafter simply referred to as a spring member), 4
A and 4b are yokes, 5 is a permanent magnet provided between the yokes 4a and 4b, and 6 is a coil installed in a part of the yoke 4a. Yokes 4a, 4b, suction member 2
and permanent magnet 5 form a magnetic circuit of permanent magnet 5 and coil 6. The permanent magnet generates magnetic flux that attracts the attraction member 2 toward the yoke. The coil 6 is set to cancel the magnetic flux of the permanent magnet 5 by its excitation. 7 is a print head frame;
This frame 7 includes a yoke 4a and a receiving member 9.
is installed. Reference numeral 8 denotes an attraction member holding portion provided on the magnetic pole surface of the yoke 4b, and has a shape that slightly protrudes from the magnetic pole surface of the yoke toward the side opposite to the yoke. A notch 2a of the suction member 2 is engaged with this holder 8. As a result, this engaging portion serves as a pivot point for the suction member, and also serves as a position regulating member that prevents the movable body composed of the suction member 2 and the spring member 3 from falling. Regarding the structure of the position regulating member that has a rotational fulcrum on the magnetic pole surface of the yoke and prevents the movable body from falling, for example, Japanese Utility Model Application No. 56-1697 and Japanese Utility Model Application No. 56-16908 are disclosed. Since this is a well-known matter as disclosed in et al., no further detailed explanation will be given. On the opposite side of the yoke at a position corresponding to the end of the spring member 3,
A receiver for causing bias in the spring member 3 when the attraction member 2 is attracted and held by the yoke by the attraction force of the permanent magnet (that is, for receiving the reaction force accompanying the bias of the spring member 3). A stop member 9 is provided. In this example, the receiving member 9 is composed of a screw body. As described above, this receiving member 9 plays the main role of catching the reaction force generated due to the deflection of the spring member, and can also play the role of adjusting the spring force due to aging of the spring member.

Next, the operation of one embodiment of the above-described print head of the present invention will be explained.

Before printing starts, the attraction member 2 is attracted to the magnetic pole surface of the yoke 4a using the holder 8 as a pivot point by the attraction force of the permanent magnet, as shown in FIG. At this time, the spring member 3 is biased by the receiving member 9, gives a reaction force to the receiving member 9 due to the bias, and stores strain energy.
Next, when a current is applied to the coil 6 to cancel the magnetic flux of the permanent magnet 5, the attraction member 2 is moved counterclockwise by the strain energy of the spring member 3, using the holder 8 in the drawing as a fulcrum, as shown in FIG. The rotational displacement occurs, and the deflection of the spring member disappears. Thereafter, since the end of the spring member 3 is not restrained, it separates from the receiving member 9 as shown in FIG. In this separated state, the suction member 2 rotates around the engagement portion between the notch 2a of the suction member 2 and the holding portion 8 as a fulcrum. The application wire 1 is supported by a guide (not shown) and moves straight toward the printing surface. When the tip of the printing wire 1 comes into contact with the printing surface, the printing wire 1 prints on the printing surface. When this state is reached, the rotation of the suction member 2 is blocked by a blocking member (not shown), so that the printing wire 1 no longer advances.
When the excitation to the coil 6 is stopped after the rotation of the attraction member 2 is blocked, the attraction member 2 is attracted to the magnetic pole surface of the yoke by the attraction force of the permanent magnet 5.
Return to original state. During the period from the state shown in FIG. 3 to the moment when the rotation of the suction member 2 is blocked in the state shown in FIG. Therefore, it remains almost constant. That is, the printing wire 1 is
Printing is performed on the print surface at a speed close to the speed when the spring member 3 is at the neutral position as shown in FIG.

With this configuration, in the above-described embodiment, only the rotation fulcrum is provided near the boundary between the suction member 2 and the spring member 3, and the receiving member 9 is in contact with the end of the spring member 3. Therefore, even if the spring member 3 flies toward the platen, the kinetic energy, that is, the printing energy and the speed of the printing wire 1 remain unchanged and are not related to the stroke.

The characteristics of one embodiment of the print head of the present invention described above are shown in FIG. In this figure, A indicates the neutral position of the spring member 3, and the printing energy by the printing head of the present invention is transferred from the suction member 2 to the spring member 3.
It can be seen that the printing energy hardly decreases even after passing the neutral position A of . Here, it is clear that the required printing energy margin is H, and the stroke of the printing pin that can secure this margin H is S', which can be wide.

As described above, according to the above-described embodiment of the present invention, the pivot point of the suction member 2 is configured at the magnetic pole surface portion of the yoke 4b, so that the moment of inertia of the suction member 2 is reduced, making it possible to increase the speed. Become. Furthermore, since the spring forces of the plurality of spring members 3 are set equally by the receiving member 9, high processing accuracy is not required and productivity can be improved. Also, ease of assembly is improved. Moreover, even if the magnetic pole surfaces of the yokes 4a and 4b are located on the same plane, they do not come into uneven contact with the attraction member 2, resulting in wear resistance, easy production, and the ability to reduce variations in the attraction force of the magnets. can. Moreover, a printing energy margin can be secured over a wide range.

In addition, in the embodiment of the present invention described above, the spring member 3
Although the receiving member 9 at the end of the spring body is constructed of a spring body, it is also possible to provide a separate member and make the member adjustable by means such as a screw. Further, the pressing force of the end of the spring member 3 may be adjusted not only by rotating the screw, but also by means such as a cam. Further, in the present invention, the receiving member 9 does not necessarily have to be movably provided on the head frame 7. Further, in this embodiment, the suction member 2 and the leaf spring member 3 are supported by the holder 8, but the present invention is not limited to this and may be used as a known position regulating means for preventing the suction member and the leaf spring member from falling. good. Furthermore, the spring member 3 and the suction member 2 may have an integral structure.

〔Effect of the invention〕

As described above, according to the present invention, the receiving member is provided on the side opposite to the yoke so that the end portion of the leaf spring member is not restrained and the leaf spring member is deflected only during suction. Variations in printing energy are eliminated, printing quality can be improved, and productivity can also be increased.

[Brief explanation of drawings]

FIG. 1 is a side view showing the configuration of an embodiment of the print head of the present invention, FIG. 2 is a perspective view showing the assembled state of the embodiment of the print head of the invention shown in FIG. 1, and FIGS. FIG. 4 is an explanatory diagram of the operation of one embodiment of the print head of the present invention, and FIG. 5 is a characteristic diagram showing the print energy characteristics of the print head of the present invention. DESCRIPTION OF SYMBOLS 1... Printing wire, 2... Attraction member, 3... Spring member, 4a, 4b... Yoke, 5... Permanent magnet, 6... Coil, 7... Head frame, 9...
...Receiving member.

Claims (1)

[Claims] 1. A yoke including a permanent magnet and a coil that generates a magnetic field in a direction that cancels the attraction force of the permanent magnet when excited; an attraction member having a printing wire at one end; A leaf spring member is provided on the opposite side of the wire attachment end, and the magnetic pole face of the yoke is attracted by the attractive force of the permanent magnet, the leaf spring member is biased by the displacement during the attraction, and the coil is energized. a movable body that rotates about the magnetic pole surface of the yoke as a fulcrum in response to the repulsive force of the leaf spring member when attraction is released; a position regulating member that allows the movable body to rotate and prevents the movable body from falling; and a receiving member that causes the bias at a position corresponding to an end of the leaf spring member, the end of the leaf spring member being able to move toward the yoke and toward the opposite side of the yoke. The receiving member is provided at a position corresponding to the end of the leaf spring member and on the side opposite to the yoke, and when the suction member is suctioning, the receiving member is not restrained. A printing head characterized in that it is arranged at a position where it abuts and causes a deviation. 2. The receiving member is attached to the print head frame, and is movable toward and away from the yoke in order to adjust the amount of deflection of the leaf spring member. Print head as described in section. 3. The print head according to claim 1, wherein the two magnetic pole surfaces of the yoke that attract the attraction member are formed on substantially the same plane.