JPH0647731Y2 - Print hammer assembly - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application of the Invention The present invention relates to a printing hammer assembly used in a line printer.

[Background of the invention]

A printing hammer assembly in a conventional high-speed line printer will be described with reference to FIGS. FIG. 3 shows the printing mechanism of the line printer. An actuator 1 having an electromagnetic coil 3 for attracting the armature 2, a push rod 4 slidably held by a guide plate 5, a print hammer 6 driven by an armature 2 via the rod 4, and a paper 7 on the print hammer 6. , A print carrier 9 facing each other via the ink ribbon 8.

The printing hammer 6 is mounted in a guide groove 18 of the hammer block 11 and is rotatably supported by a hammer pin 12 mounted orthogonal to the guide groove 18 of the hammer block 11. The hammer block 11 is provided with a guide hole 13 extending in a direction perpendicular to the print line inside a guide groove 18, and a plunger 14 and a spring 15 are slidably provided in the guide hole 13. The plunger 14 pushes the lower end of the print hammer 6 to urge the print hammer 6 to a stationary position. Guide hole
A stopper plate 16 for holding the spring 15 is attached to the hammer block 11 at the rear of 13 via a screw 17.

The hammer block 11 is attached to the hammer bridge 10 supporting the guide plate 5, and the printing hammer 6, the rod 4 and the armature 2 are integrally configured and arranged by the biasing force of the spring 15 mounted in the hammer block 11. .

When the electromagnetic coil 3 is excited, the amateur 2 is attracted,
The rod 4 and the printing hammer 6 fly together. The printing hammer 6 slides the plunger 14 rearward, flies at a constant speed while compressing the spring 15, and collides with the character carrier 9 via the paper 7 and the ink ribbon 8 to perform printing. Printing hammer 6
Runs at a high speed of 2,000 times per minute. Since it operates at such a high speed, when the printing timing fluctuates by 10 μs, the character arrangement of the characters printed on the paper 7 deviates by 0.1 mm, which reduces friction and load fluctuations when the hammer drive unit, especially the plunger 14, slides. And it is essential to keep it stable. According to the prior art, the comb-shaped guide groove 18 for mounting the printing hammer 6 is formed by simultaneously processing a large number of comb-shaped cutters having a large number of cylindrical cutting blades with an outer diameter of φ40 to φ50. The bottom of the guide groove 18 is the plunger 14
Forms an angle of about 45 ° with respect to the guide hole 13 in which is mounted. Therefore, the end surface of the guide hole 13 becomes an acute angle,
Burrs are generated on the entire circumference of the end face of the guide hole 13. On the other hand, since the guide hole 13 is inside the guide groove 18, a great amount of time is spent for the deburring work and the finishing of the sharp ridge line portion, and the finishing of a large number of holes (132 per unit) is completed completely. Difficult to finish. Therefore, the sliding characteristics of the plunger 14 and the guide hole 13 which operate at high speed are obstructed. As a result,
There is a drawback in that the normal operation of the printing hammer 6 is hindered and a serious error such as erroneous printing, missing characters, or misalignment of characters occurs. On the other hand, since the guide groove 18 is processed at an angle of 45 ° as described above, paper scraps and ink ribbon scraps generated during printing adhere to the vicinity of the guide groove 18 and the guide hole 13, and the plunger 14 slides. There is a defect that it becomes a factor that promotes the load variation of the printing section and further adversely affects the operation of the printing hammer 6.
Since the plunger 14 comes into contact with the printing hammer 6, it is made of a molding material such as polyimide resin.
If there are sharp edges or burrs at the end of the guide hole 13, there is a drawback that wear on the sliding surface is increased and life is extremely shortened.

[Purpose of device]

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, to stably maintain the operating characteristics of a printing hammer which operates repeatedly at high speed, and to extend the life of the printing hammer mechanism.

[Outline of device]

In the present invention, the guide hole for mounting the plunger and the spring is inside the comb-shaped guide groove for mounting the printing hammer, and intersects with the inclined portion inside the guide groove to form a sharp edge. Paying attention to the fact that the operating characteristics of the plunger are obstructed by, cut off a part of the guide groove that supports the hammer pin so that the end surface of the guide hole on the print hammer side is located outside the guide groove, and create a space directly under the hammer pin It was devised to be provided.

[Example of device]

The present invention will be described below with reference to FIGS. A space A is formed by cutting off a portion of the comb-shaped guide groove 18 provided for mounting the printing hammer 6 in the hammer block 11 just below the hammer pin 12. A guide hole 13 for mounting a plunger 14 and a spring 15 provided at the lower end of the printing hammer 6 to urge the printing hammer 6 to a stationary position.
The end portion of is located outside the guide groove 18. The lower end of the guide groove 18 is guided so that the outer diameter portion of the guide hole 13 does not coincide with the lower end portion of the guide groove 18 directly below the hammer pin 12.
It is secured so that it is located 0.5 to 1.0 mm above the outer diameter of the. The end surface of the outer diameter portion of the guide hole 13 is set at a position that does not intersect the inclined surface a at the bottom of the guide groove 18. As a result of devising the shape of the end portion of the guide hole 13 as described above, the guide hole 13 and the bottom inclined surface a of the guide groove 18 do not intersect, so that the guide hole 13
Since a sharp edge generated at the end of the guide can be avoided and a large space can be secured in front of the guide hole 13, burrs generated by machining can be easily and surely finished. Therefore, the sliding characteristics of the plunger 14 are stable. That is, the high speed operation of the printing hammer 6 is not disturbed at all,
The printing hammer 6 operates stably. Further, since the space is provided right below the hammer pin 12, the paper and ribbon waste attached to the inclined portion of the guide groove 18 can be easily removed, and the operation of the printing hammer 6 is further stabilized.

[Effect of device]

According to the present invention, since the sharp edge generated in the guide hole of the hammer block can be removed, the operation of the printing hammer becomes stable, and printing defects such as erroneous printing, missing characters, and misalignment of characters can be prevented. Further, since the plunger can be slid smoothly, the printing hammer assembly can have a long service life.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part showing an embodiment of a printing hammer assembly of the present invention, FIG. 2 is a sectional view of FIG. 1, FIG. 3 is a side view showing a printing part of a line printer, and FIG. 5 and 6 are a perspective view and a sectional view showing an example of a conventional device. In the figure, 1 is an actuator, 6 is a printing hammer, 11 is a hammer block, 12 is a hammer pin, 13 is a guide hole, 14 is a plunger, 15 is a spring, and 18 is a guide groove.

Claims (3)

[Scope of utility model registration request] 1. A hammer block extending along a printing position and provided with comb-shaped guide grooves at a predetermined pitch, and a hammer pin rotatably mounted on a hammer pin mounted orthogonally to the guide grooves of the hammer block. A printing hammer having a striking surface on the inside and a guide hole formed so as to extend in the direction perpendicular to the printing line inside the guide groove of the hammer block are slidably provided, and the lower end of the printing hammer is pushed to stop the printing hammer. A print hammer assembly including a plunger and a spring for urging the guide hole to a position, and a stop plate attached to a hammer block so as to close the rear of the guide hole, the end surface of the guide hole of the hammer block on the print hammer side. A printing hammer assembly characterized in that a space is formed in front of the hammer pin by cutting off further forward and below the hammer pin. 2. The printing hammer according to claim 1, wherein the lower end of the guide groove is located above the outer diameter portion of the guide hole so that the guide hole and the lower end of the guide groove do not coincide with each other. Assembly. 3. The printing hammer assembly according to claim 1, wherein the outer peripheral end surface of the guide hole does not intersect with the inclined surface inside the guide groove.