JPH0732702A - Dot impact print head - Google Patents

Abstract

(57) [Summary] [Purpose] To enhance the heat dissipation effect of the dot impact print head and suppress noise. [Structure] A plurality of printing units 3 are provided on the front frame 25.
0 is supported, and a thermally conductive silicone rubber 11 is filled between the printing unit 30 and the cover 26. Cover 2
A vibration-proof rubber ring 10 is provided between the front side frame 6 and the front frame 25, and a metal tape 14 which is heat-conductive and flexible is wound around the rubber ring 10. The heat generated by the piezoelectric actuator 33 in the printing unit is transferred from the cover 26 to the front frame 25 via the metal tape 14 via the silicone rubber 11. The vibration of the printing unit 30 is not transmitted from the front frame 25 to the cover 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dot impact print head capable of preventing temperature rise and suppressing noise.

[0002]

2. Description of the Related Art A conventional dot impact print head is
As shown in FIG. 1, the front frame 25 and the bottomed cylindrical cover 26 are formed into a substantially cylindrical outer shape, and a nose portion 25 a is projected from the front surface of the front frame 25. An annular ring member 28 is attached to the inner surface of the front frame 25 via an annular spacer 27 made of rubber.
8 sets 24 printing units 30.

The printing unit 30 includes a support frame 31,
It is composed of a piezoelectric actuator 33 and a movable arm 32 that drives a printing wire 36.

The support frame 31 includes a main support portion 31a,
The sub-support portion 31b and the base portion 31c that connects the sub-support portions 31b to each other at one end are formed into a substantially U-shaped plate material.
The piezoelectric actuator 33 composed of a laminated body of piezoelectric elements is
It is arranged between the main support portion 31a and the sub-support portion 31b, one end of which is adhesively supported by the base portion 31c, and the movable body 34 is adhesively fixed to the other end thereof. One spring 35a of the Eden spring 35 is fixed to the other end of the main support portion 31a, and the other spring 35b is fixed to the corresponding end of the movable body 34. This Edenbane 35
The base end portion of the movable arm 32 is fixed to the free end portion 35c of the movable arm 32, and the print wire 36 is attached to the distal end portion of the movable arm 32.
Is stuck.

In the 24 sets of printing units 30, the tip of the main supporting portion 31a of the supporting frame is abutted against the ring member 28 and fixed by screws (not shown), and the movable arm 32 has a radial shape with its tip facing inward. The eggplants are arranged in a substantially circular shape. The print wire 32 is the nose portion 2 of the front frame.
5a is inserted and it protrudes at the front end. The cover 26 covers the printing units 30 and is fixed by the silicone rubber 11 described later.

When a voltage is applied to the piezoelectric actuator 33, the piezoelectric actuator 33 is stretched and deformed by a predetermined length in the stacking direction, that is, the front-rear direction P, so that the movable body 34 moves in the same direction. As a result, the Eden spring 35 flexes outward in a curved shape. As a result, the movable arm 32 moves the printing wire 36 in the platen direction, and executes dot printing on the printing paper.

On the other hand, when the voltage application to the piezoelectric actuator 33 is stopped, the piezoelectric actuator 3
Since 3 is contracted and deformed to the original state, the movable arm 32 returns and rotates. At this time, the contact member 38 of the movable arm is brought into contact with the stopper member 37 so that the movable arm 32 does not retract from the initial position.

Since the piezoelectric actuator 33 generates heat when it is driven, it is necessary to prevent the temperature around the printing unit 30 from rising due to the heat. Therefore, the cover 26 and the front frame 25 are made of a metal having a high thermal conductivity, for example, aluminum, a silicone rubber 11 capable of conducting heat is filled between the support frame 31 and the cover 26, and the cover 26 radiates heat. Fins 13 are provided.

The front frame 25 is fixed to the carriage 20 which moves in the print line direction.

[0010]

The heat generated by the piezoelectric actuator 33 is dissipated outside the print head from the fins 13 of the cover 26 along the support frame 31 and the silicone rubber 11. Further, although the heat is transmitted from the support frame 31 to the front frame 25 and is also radiated to the carriage 20, heat transfer is blocked between the cover 26 and the front frame 25. Therefore, the heat of the cover 26 is hard to be transmitted to the carriage 20 via the front frame 25, and there is a limit in preventing the temperature rise of the print head. Also cover 2
When 6 and the front frame 25 are brought into close contact with each other so as to be able to conduct heat, the vibration accompanying the printing operation is transmitted to the cover 26 and the noise increases.

An object of the present invention is to enhance the heat dissipation effect by efficiently dissipating heat from the entire print head and to suppress the vibration accompanying the printing operation.

[0012]

To achieve the above object, the present invention provides a plurality of printing units having a printing wire, a front frame for supporting the printing units and the printing wires, and the plurality of printing units. A cover for covering the unit, a vibration isolating member interposed between the front frame and the cover, and a flexibility for connecting the front frame and the cover so that heat can be conducted and the both can be displaced relative to each other. And a heat conductive member having

[0013]

The heat generated in the printing unit is dissipated from the cover to the outside, but is also transmitted to the front frame through the heat conductive member and is also dissipated from the front frame. Therefore, it is possible to prevent overheating of the print head and improve printing performance. The vibration accompanying the printing operation is not transmitted to the cover by the vibration isolating member and the flexible heat conductive member, and the noise can be suppressed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to FIG. The description already given in the section of the prior art will be omitted.

This dot impact print head is shown in FIG.
As shown in, the cover 26 and the front frame 25
An anti-vibration rubber ring 10 is interposed between and, and a heat conductive member 14 is provided on the outer circumference thereof. The heat conductive member 14 is specifically a metal tape having high heat conductivity and flexibility. The metal tape is wrapped around a cylindrical wall surface formed by the cover 26, the rubber ring 10 and the front frame 25 overlapping each other with an adhesive such as an adhesive, so that the cover 26 and the front frame 25 can be displaced relative to each other. And connected so that heat can be conducted.

The front frame 25 is fixed by bringing the front surface and the nose portion 25a into contact with the protrusion 20b on the carriage 20 so that heat can be conducted.

As a result, the heat generated by the piezoelectric actuator 33 is applied to the support frame 31 and the silicone rubber 1.
1 is transmitted to the outside of the print head from the fins 13 of the cover 26. Also, from the support frame 31 to the front frame 2
5 is also transmitted to the carriage 20. Further, the front frame 25 is passed through the cover 26 and the heat conductive member 14.
To the carriage 20 and diffused into the air. Further, even if the vibration accompanying the printing operation is transmitted from the printing unit 30 to the front frame 25, the vibration from the front frame 25 to the cover 26 is caused by the vibration isolating member and the heat conductive member formed of the flexible metal tape. Noise is suppressed without being transmitted.

[0018]

According to the present invention, the heat generated in the printing unit can be transferred from the cover to the front frame through the heat conductive member, and can also be dissipated from the front frame. Therefore, the heat dissipation effect of the print head can be enhanced and the printing performance can be improved. Further, the vibration accompanying the printing operation is not transmitted to the cover by the vibration isolating member and the flexible heat conductive member, and the noise can be suppressed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a dot impact print head according to the present invention.

[Explanation of symbols]

 30 printing unit 36 printing wire 25 front frame 10 anti-vibration member 26 cover 14 heat conductive member

Claims (4)

[Claims] 1. A plurality of printing units having printing wires, a front frame supporting the printing units and the printing wires, a cover for covering the plurality of printing units, and a space between the front frame and the cover. A dot impact print head comprising: a vibration isolating member that is interposed; and a flexible heat conductive member that is capable of heat conduction between the front frame and the cover and that is relatively displaceable therebetween. 2. The dot impact print head according to claim 1, further comprising a silicone rubber filled between the plurality of print units and the cover so as to be able to conduct heat. 3. The dot impact print head according to claim 1, wherein the heat conductive member is a metal tape wound so as to extend over the front frame. 4. The dot impact print head according to claim 1, wherein the front frame is fixed to a carriage movable in a print row direction so as to be capable of heat conduction.