JP2900566B2 - Print head for wire impact dot printer - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a print head for a wire impact type dot printer, and more particularly, to a wire impact type printer characterized by a heat radiating means and a means for positioning and fixing with other members. The present invention relates to a print head for a dot printer.

(Prior Art) A print head for a wire impact type dot printer usually adopts a structure in which heat generated by a coil is radiated to the atmosphere by a finned radiating member fitted around a core block.

However, in such a structure, when printing high-density characters and the like at high speed and continuously, the amount of heat generated from the coil exceeds the amount of heat released from the heat radiating member, and the printing operation must be continued. Therefore, Japanese Unexamined Utility Model Publication No. 63-68436 proposes a print head in which heat generated by a coil is released to a carriage and a guide shaft.

In other words, the print head proposed here aims to transfer heat to the carriage by directly attaching the nose base as a heat radiating member to the carriage, and to bring the nose frame and the core block into contact with the reference surface on the nose base. It is designed to be positioned and fixed to enhance the heat dissipation effect by assembly and heat conduction.
In such a structure, an unavoidable gap is formed between the carriage and the core block, so that not only heat conduction cannot be sufficiently expected, but also a shock acting on the nose frame during printing, the nose base and other components are not affected. As a result, there is a problem that a displacement may occur between the members.

(Problems to be Solved by the Invention) The present invention has been made in view of such a problem, and an object of the present invention is to effectively release the heat of the core block and the impact force acting on the nose frame to the carriage. It is another object of the present invention to provide a new print head for a wire impact type dot printer.

(Means for Solving the Problems) That is, the present invention provides a print head for a wire impact type dot printer to achieve the above objects.
A part of the heat dissipating member fitted around the outer periphery of the core block via the heat conductive resin material forms a mounting portion which is positioned and fixed in close contact with the mounting reference surface on the carriage,
The nose frame is formed with a positioning fixing portion for positioning with reference to the mounting portion on the heat radiation member and the positioning portion on the carriage as a reference.

(Operation) With this configuration, the heat radiating member is fixed in close contact with the mounting reference surface on the carriage, and the nose frame is mounted on the basis of the mounting portion of the heat radiating member and the positioning portion on the carriage as a reference. At the same time as accurately positioning and fixing, the impact force acting on the nose frame at the time of printing is released to the carriage, and the heat generated from the coil is transmitted to the heat dissipation member via the heat conductive resin material,
A part or all of the heat is efficiently dissipated to the carriage and the guide shaft via the mounting portion closely contacting the mounting reference surface of the carriage.

(Embodiment) Therefore, an embodiment illustrated below will be described.

 1 and 2 show one embodiment of the present invention.

In the figure, reference numeral 1 denotes a core block serving as a heat source, and the core block 1 is formed in a cup shape.
A large number of cores 2 on which the coil bobbins 3 are mounted are arranged in a circular shape on the inner bottom surface. Reference numeral 4 denotes a heat dissipating member which forms a heat sink. Inside the heat dissipating member 4 having a bottomed cylindrical shape having a heat dissipating fin 5 on its surface, the above-described core block 1 together with a yoke 8, a printing lever 9 and a pressing plate 10 are provided. It is tightly fitted via a heat conductive resin material 12 such as silicone resin applied to the peripheral surface. At the lower end side of the heat radiating member 4, mounting portions 6, 6 which are closely mounted on the mounting reference surface 21 of the carriage 20 as a reference are formed so as to protrude. A nose frame mounting portion 7 is integrally formed so as to protrude toward the opening end side of the nose frame.
It is configured so that 13 can be attached.

On the other hand, the nose frame indicated by reference numeral 13 has recesses on both sides of the lower end of the back plate 14 attached to the opening end of the heat radiating member 4 for fitting the nose frame mounting portion 7 of the heat radiating member 4.
15 and 15 are formed, and a projection 16 is formed on the lower surface of the concave portion 15.
Are projected downward, and the projections 16 make the lower surface 7a of the nose frame attaching portion 7 closely contact with the upper surface 15a of the concave portion 15, so that the nose frame 13 can be accurately and firmly attached to the heat radiation member 4 based on the lower surface 7a. Is configured.

Reference numeral 17 in the drawing denotes a positioning dowel protruding from the lower surface of the back plate 14, and the dowel 17 is engaged with a positioning hole 23 provided on the upper surface of the carriage 20 to position the nose frame 13 in the surface direction. Is configured to do
In the figure, reference numeral 11 denotes a printing wire, 24 denotes a screw for fixing the heat radiating member 4 to the mounting reference surface 21 of the carriage 20, and 25 denotes a traveling guide shaft of the carriage 20.

In the device configured as described above, the core block 1 integrated by assembling the yoke 8, the printing lever 9, and the holding plate 10 is connected via the heat conductive resin material 12 applied to the peripheral surface of the core block 1. While fitting inside the bottomed cylindrical heat dissipating member 4, the recesses 15, 15 provided on both sides of the lower end of the back plate 14 of the nose frame 13 are fitted into the nose frame attaching part 7 protruding forward from the lower end of the heat dissipating member 4. Nose frame 13
Is coupled to the opening end of the heat dissipating member 4, the nose frame 13 assembled on the basis of the lower surface 7 a of the nose frame attaching portion 7 and the core block assembled body assembled on the basis of the inner surface of the heat dissipating member 4, The heat dissipating member 4 is screwed onto the mounting reference surface 21 of the carriage 20 so that the positioning dowel 17 at the lower end of the nose frame 13 is fitted into the positioning hole 23 of the carriage 20. By fixing with the 24, the nose frame 13 and the core block assembly are correctly positioned in the plane direction. When a printing operation is performed in this state, the heat generated from the coil is transferred to the core block 1,
The heat is efficiently transmitted to the heat radiating member 4 through the heat conductive resin material 12, a part of the heat is radiated to the atmosphere through the heat radiating fins 5, and the remaining heat is transferred to the mounting reference surface 21 of the carriage 20.
It is effectively transmitted from the mounting portion 6 which is in close contact with the carriage 20 and further to the guide shaft 25, thereby suppressing overheating of the print head.

3 and 4, the radiating member 34 is mounted on the mounting reference surface 51 on the carriage 50, while the nose frame 43 is placed on the nose frame mounting step 37 of the radiating member 34 and By fitting it into the dowel 54, accurate positioning and efficient heat radiation can be achieved.

That is, the heat radiating member 34 in which the core block 31 is closely fitted through the heat conductive resin material 42 is provided with a mounting portion 36 for the carriage 50 on the lower end surface side, and the mounting portion 36 is provided on both sides. Nose frame mounting step based on lower surface
On the other hand, the nose frame 43 is provided with attachment portions 46, 46 to the carriage 50 on both wings thereof, and these are provided with positioning holes 47, 47, respectively.
On both sides of 44, a downward step 45 to be mounted on the above-mentioned nose frame mounting step 37 is formed.

In the radiating member 34 configured as described above, the nose frame 43 is first placed on the nose frame mounting step 37 via the downward step 45 of the back plate 44 and integrated with the screw 48. The dowel 54 on the carriage 50 is fitted into the positioning hole 47 provided in the mounting portion 46 of the frame 43 so that the lower surface of the mounting portion 36 of the heat radiating member 34 is
It is brought into close contact with the upper mounting reference surface 51, and is coupled to the carriage 50 with screws 55, 55.

In this embodiment, the impact force generated at the time of printing can be released to the carriage 50 in the horizontal direction.
No loosening of the screw 55 occurs even if the screw 55 is used for a long time without generating a moment. Further, in this embodiment, in particular, a ring-shaped resin reservoir 35 is provided at the opening edge of the heat radiation member 34.
When fitting the core block 31 from the opening end side,
Since the protruding portion of the heat conductive resin material 42 is accommodated in this portion, the parallelism between the heat radiating member 34 and the core block 31 can be easily obtained in assembling.

(Effect) As described above, according to the present invention, the lower end of the heat radiating member is provided with the mounting portion which is positioned and fixed in close contact with the mounting reference surface with the carriage, while the nose frame is provided with the heat radiating member. Since the positioning and fixing part for positioning with reference to the mounting part of the carriage and the positioning part on the carriage is formed, the heat radiating member is fixed in close contact with the mounting reference surface on the carriage, and the nose frame is fixed to the mounting part of the heat radiating member and the carriage. By using the positioning portion as a reference, the whole can be accurately positioned and fixed, and the core block and the nose frame closely fitted to the heat radiation member can be accurately aligned with the mounting reference surface on the carriage as a reference. Can be. In addition, the impact force acting on the nose frame at the time of printing can be effectively released to the carriage, and the heat generated by the coil is efficiently transmitted to the heat radiating member through the heat conductive resin material. Efficiently escape to the carriage and guide shaft through the mounting part where part or all is in close contact with the mounting reference surface of the carriage, to suppress overheating of the print head even under high load and perform required printing without any trouble. Can be.

[Brief description of the drawings]

FIG. 1 is a side view of an apparatus showing one embodiment of the present invention, a part of which is shown in cross section, FIG. 2 is a front view thereof, and FIGS. 3 and 4 are apparatuses showing other embodiments of the present invention. It is the side view and front view of. 1, 31 core block 4, 34 heat dissipating member 6, 36 mounting portion 7, 37 nose frame mounting portion 13, 43 nose frame 15 concave portion 20, 50 carriage 21, 51 …… Reference mounting surface

Claims (1)

(57) [Claims] 1. A mounting part for positioning and fixing closely to a mounting reference surface on a carriage is formed on a part of a heat radiating member which is wrapped around the core block via a heat conductive resin material. A print head for a wire impact dot printer, wherein a positioning fixing portion for positioning and fixing the mounting portion on the heat radiation member and the positioning portion on the carriage as a reference is formed in a part of the nose frame.