JPH0339248Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a dot type printer head, such as a dot matrix printer, that prints characters, symbols, etc. with a plurality of dots.

(Prior Art) As is well known, a printer head is mounted on a carriage and transported, and this printer head is equipped with a plurality of printing elements, such as a dot plate, for forming a plurality of dots. In order to drive each dot plate separately,
It has multiple drive coils built-in. These multiple drive coils are attached to a coil bobbin and housed in the printer head. There is a space around the coils, and a heat dissipation fin is attached to the outer periphery of the yoke, which has an iron core that passes through the coils. be.

However, when printing is performed continuously, the coil generates heat, which is transmitted through the yoke and dissipated from the heat dissipation fins, but the layer of air surrounding the coil does not have sufficient thermal conductivity. The temperature inside the head frame rose, causing the coil to burn out and other malfunctions.

Therefore, conventionally, heat has been dissipated by filling a part of the outer circumference of the drive coil (magnet coil) with synthetic resin (Japanese Utility Model Publication No. 54-147409), or by using heat sink members made of such synthetic resin and metal members. (Japanese Unexamined Patent Publication No. 57-34979) is known.

(Problem that the invention aims to solve) However, in the former case, the heat dissipation effect is insufficient;
Also, since the heat dissipation effect is not sufficient in the latter case, a heat sink member made of a metal member is provided, but inserting the metal member into the printer head increases the weight of the printer head itself. As mentioned above, since the printer head is mounted on a carriage and moved, the problem of inertia of the heavy printer head occurs, and this method is intended to solve this problem.

Therefore, the purpose of this invention is to effectively guide the heat of the magnetic coil to the heat dissipation fins, dissipate the heat efficiently, and prevent the temperature from rising inside the head frame. An object of the present invention is to provide a printer head that can facilitate printing.

(Means for solving the problem) The features of the present invention include a magnetic coil through which multiple iron cores pass, a yoke to which the iron cores are fixed, and a coil terminal to which the magnetic coils are attached. The yoke has a recess for housing multiple iron cores and terminal plates, and a synthetic resin that is electrically insulating, heat resistant, and has good thermal conductivity is molded into the recess. This synthetic resin molds the outer periphery of the magnetic coil within the recess of the yoke, and at the same time fixes the yoke and the terminal plate.

(Function) According to the present invention, the heat generated in the magnet coil is transmitted to the yoke via the iron core and the synthetic resin with good thermal conductivity, and is efficiently dissipated from the heat dissipation fins attached to the outer periphery of the yoke. Therefore, it is possible to prevent heat from accumulating in the head frame and increasing the temperature.The yoke and the terminal plate are fixed to each other using synthetic resin, and the electromagnet portion is made into a block.

(Example) Embodiments of the present invention will be described based on the drawings.

In Fig. 1, a head frame 1 is integrally molded from synthetic resin such as carbon graphite, and a guide protrusion 1 is provided in the center of the front half of the head frame 1.
A is provided in a protruding manner, and a guide hole 1b through which the dot plate advances and retreats is bored in the front end surface of this protrusion.
The paper guide 1c is formed so as to stand upward from the lower front end of the head frame 1 so as to face a platen (not shown). An opening window 1d is provided in the center of the paper guide 1c, both sides of this guide are bent backwards according to the flow of printing paper, and the upper end is slightly bent forward. There is. The front end surface of the outer periphery of the opening window 1d is arranged at the same level so that the printing paper sliding on the front end surface of the guide protrusion 1a can come into contact with it. Then apply an ink ribbon (not shown) to the back side of the paper guide 1c.
can be inserted through it.

The guide protrusion 1a is formed in a hollow shape with an opening at the lower end, and three hammer guides 2 serving as guide means are inserted in parallel from the lower end opening. A plurality of dot plates 3, for example, nine dot plates 3, are slidably inserted into each hammer guide in a direction orthogonal thereto. At the rear end of each dot plate 3..., there is a vertically bent portion 3b having an external protrusion 3a.
are integrated into one.

Next, the printing drive mechanism of the dot plate will be explained.

A return spring 4 comes into elastic contact with the front end of the vertically bent portion 3b of the dot plate 3, a drive hammer 5 comes into contact with the rear end, and a stopper plate 6 can come into contact with the protrusion 3a. There is. The drive hammer 5 is supported by a support plate 7, and a yoke plate 8 and a permanent magnet 9 are disposed on the rear surface of the support plate with a spacer interposed therebetween. The yoke plate 8 has the same number of through holes as the dot plate 3, and each movable yoke 10 is placed in each through hole.
...is located. The front end surface of the movable yoke 10 is
The iron core 12 is press-fitted into the drive hammer 5 and its rear end surface is magnetically coupled to the front end surface of an iron core 12 which is press-fitted into the yoke 11. A magnetic coil 13 is wound around each iron core 12, and the rear end of this coil is inserted into a terminal plate 14 of the coil fixed to the yoke 11.

The yoke 11 has a U-shaped cross section, so the front side of this yoke is a recess, and the iron core 1
2 is positioned protruding within this recess. York 11
A coil terminal plate 14 is housed in the recess on the front surface of the coil, and a magnet coil 13 around which an iron core 12 is wound is fixed to this terminal plate.

As shown in FIG. 2, the terminal plate 14 of the coil has a center hole 14a and through holes 14b for the same number of iron cores 12 as the dot plates 3. On the front surface of the terminal plate 14 of the coil, a plurality of guide protrusions 14d, 14e, .
is installed protrudingly. That is, along the front outer periphery of the terminal plate 14 of the coil, there is a guide protrusion 14d with an inner surface shape in which nine circular arcs are continuous, and nine guide protrusions 14e forming a rhombus at positions along a circle including these arcs. is installed protrudingly. Then, it is surrounded by one circular arc of the guide protrusion 14d and two guide protrusions 14e, 14e along the circumference including this circular arc.
A recess 14 into which two magnetic coils 13 are inserted.
c... is formed, and the center of this recess is the through hole 14b.... Also on the back is the center hole 14.
A ring-shaped protrusion 14f is provided around a,
Nine protrusions 14g are provided near the outer periphery of the intermediate portion of adjacent through holes 14b. Projections 14f and 14
Terminal pins 14h and 14i are provided with one end buried and protruding from the terminal pins g. Grooves 14j for drawing out the ends of the magnet coil 13 are formed on the outer peripheral surface of the terminal plate 14 of the coil.

When the magnet coils 13... are inserted into the respective recesses 14c..., the outer periphery of the magnet coils 13... is inserted into the guide projections 14d and 2.
It is positioned surrounded by two guide protrusions 14e, 14e. Both ends of the magnet coil 13 are
One passes through the groove 14j and is connected to the terminal pin 14i, and the other passes through the center hole 14a and is connected to the terminal pin 1.
Connected to 4h.

As shown in FIGS. 1 to 3, the concave portion of the yoke 11 is filled with a synthetic resin material such as silicone resin, which is electrically insulating, heat resistant, and has good thermal conductivity.
5 is molded. The outer peripheries of the magnet coils 13 are molded with synthetic resin 15, and the yoke 11 and the terminal plate 14 of the coils are fixed to each other to form a block.

Each terminal pin 14h, 14i is connected to a predetermined position of the flexible cable 16. A radiation fin 17 is fitted around the yoke 11.
A head cover 18 is connected to the back of the printer head and covers the connection portion of the flexible cable 16.

Therefore, when assembling the printer head of the present invention, the magnetic coils 13 are first inserted into the recesses 14c of the terminal plate 14 of the coils, and both ends of the coils are connected to the terminal pins 14h, 14i. The terminal plate 14 of the coil thus assembled is inserted into the yoke 11 to which the iron core 12 is fixed so that the iron core 12 passes through the hollow part of the magnet coil 13. Protrusion 14f, 1 on the back side of the terminal board of the coil
4g... penetrate through holes made in the yoke 11 and protrude toward the back. Therefore, the inside of the recess of the yoke 11 is molded with silicone resin 15, for example, and the outer periphery of the magnetic coils 13 is molded.At the same time, the yoke 11 and the terminal plate 14 of the coil are fixed to form a block together with the iron core 12 and the coil 13. become

Therefore, the heat dissipation fin 17 is fitted to the yoke 11,
The protruding terminal pins 14h, 14i, . . . are connected to the flexible cable 16, and a driving electromagnetic block is assembled.

Next, the electromagnetic block described above is attracted behind the block of the dot plate 3 incorporated in the head frame 1 and the drive hammer 5 that drives this dot plate via the permanent magnet 9, and then the head cover 18 is attached to complete the assembly. .

(Effects of the invention) In the printer head according to the invention, the outer periphery of the magnet coil is molded in the recess of the yoke with synthetic resin having high thermal conductivity, so the heat of the magnet coil is transmitted to the yoke and transferred to the outside. It has good dissipation efficiency and can effectively prevent a rise in temperature within the head frame. In addition, since heat is dissipated by using synthetic resin, there is no increase in weight compared to conventional products, so there is no inertia problem.Furthermore, this synthetic resin allows the yoke and terminal board to be made into blocks, making it easier to assemble. It is something that can make your work easier.

[Brief explanation of the drawing]

FIG. 1 is a sectional view, FIG. 2 is a sectional view taken along the line of FIG. 1, and FIG. 3 is a sectional view taken along the line of FIG. 3...Printing element, 11...Yoke, 12...Iron core, 13...Magnetic coil, 14...Terminal plate of coil, 15...Synthetic resin.

Claims (1)

[Claims for Utility Model Registration] A plurality of iron cores for driving a plurality of printing elements, a magnet coil through which the iron cores pass, a yoke to which the iron cores are fixed, and a magnet a coil terminal plate to which a coil is attached; the yoke has a recess formed therein for accommodating the plurality of iron cores and the terminal plate; the recess has an electrically insulating and heat resistant material; The synthetic resin molds the outer periphery of the coil within the recess of the yoke, and at the same time fixes the yoke and the terminal plate. Features a printer head.