JPH0286470A - Printing hammer device - Google Patents

Abstract

PURPOSE:To suppress a rebound of a printing hammer and reduce noise by providing a driving means for moving a friction member in the direction for making contact with the printing hammer when the hammer is returned by a driving means. CONSTITUTION:During the return of a printing hammer 7 to a rest position after striking a type, a secondary coil 3b is timedly energized to attract an attraction member 4. By this, a friction main body part 2b of a weight 2 is turned on an arm part, and a friction surface 2a thereof is brought into contact with the inside surface of a cavity 7c in the hammer 7, thereby generating a frictional force. The frictional force is utilized as a brake to reduce the returning velocity of the hammer 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printing hammer device that performs printing by striking type in a printing device.

[Prior art] In conventional printing hammer devices, the printing hammer, which moves back and forth within the printing/printer case and hits the type, comes into contact with a stopper that defines the rest position when returning after hitting the type, producing noise. Also, there was a problem in that the subsequent rebound was also large.

In order to solve the above problem, Japanese Patent Application Laid-Open No. 199475 adopts a configuration in which a secondary coil is provided at the rear of the printing hammer device, and the suction force of this coil applies a braking force when the printing hammer returns. are doing.

Further, Japanese Patent Application Laid-Open No. 173269/1983 similarly uses suction means using a secondary coil to suppress rebound.

[Problems to be Solved by the Invention] However, in the case where a secondary coil is provided at the rear of the printing hammer device as described above and rebound is suppressed by the attraction force of the coil, the overall length of the printing hammer device is unavoidable. The drawback was that it was long.

In the case of JP-A-62-199475, since the secondary coil is configured to attract in a direction substantially perpendicular to the direction of movement of the printing hammer, a considerable amount of current must be applied to increase the attraction force.

In addition, in the case of JP-A No. 62-173269, a secondary coil is similarly used to suppress rebound, but because the attraction force by the magnetic circuit acts in the direction of bringing the printing hammer into contact with the stopper. However, when the printing hammer comes into contact with the stopper, the impact force increases and a considerable amount of noise is inevitably generated.

The present invention has been made to solve the above-mentioned problems, and it is possible to suppress the rebound of the printing hammer by the attraction force generated by a normal electric current without increasing the overall length of the printing hammer device itself, and to suppress the rebound of the printing hammer. The purpose is to reduce the noise generated when the hammer hits the stopper.

[Means for Solving the Problems] In order to achieve this object, the printing hammer device of the present invention has the following features:
In a printing hammer device including a printing hammer and a coil for magnetically driving the printing hammer, a friction member having a friction surface that contacts the printing hammer, and a friction member configured to reduce the return speed of the printing hammer when the printing hammer returns. The apparatus further includes a driving means for moving the friction member to a position where it comes into contact with the printing hammer.

[Function] According to the above-described configuration of the present invention, after the printing hammer hits the type, the driving means is driven at a timing when the printing hammer is returning to the rest position to bring the friction member into contact with the printing hammer, and the frictional force causes the friction member to come into contact with the printing hammer. This reduces the return speed of the printing hammer.

[Example 1] Hereinafter, an example embodying the present invention will be described based on the drawings.

First, the overall configuration of the printing hammer device will be explained with reference to FIGS. 1 and 2. The annular coil bobbin 8b, which has a U-shaped cross section and has the coil 9 wound thereon, has a front bearing 8 integrally formed on its front surface. Further, a rear yoke 11 to which a rear bearing 12 is fixed is arranged on the rear surface. The case 1 constituting the outer frame of the printing hammer device is U-shaped along the outer periphery from the front surface of the coil bobbin 8b, and forms a magnetic path for the magnetic flux generated by the coil 9 together with the rear yoke 11.

The printing hammer 7 has a striking part 7a at the front end and a shaft part 7b at the rear, and has an open hollow hole 7c cut in the axial direction at the rear end. And the printing hammer 7
is slidably supported by the aforementioned front bearing 8 and rear bearing 12, and is non-impacted by a compression spring 10 disposed between the inner surface of the front bearing 8 on the impacting part support side and the end of the shaft part 7b on the impacting end side. biased in the direction.

Also, the rear surface of the rear yoke 11, that is, the coil bobbin 8
A weight 2 that functions as a stopper for the printing hammer is arranged on the surface opposite to b.

As shown in FIG. 3(a), the weight 2 is a thick elastic member made of resin or the like, is formed in a C shape, and is supported slidably in the front-rear direction on the outer periphery of the rearward protruding portion of the rear bearing 12. has been done. The weight 2 is urged to come into contact with the rear yoke 11 by an intermediate bent portion 13a of a leaf spring 13 whose both ends are fixed to the case 1. As a result, the printing hammer 7, which is biased by the compression spring 10, contacts the weight 2 with its rear end surface and determines the rest position.

Further, the weight 2 has two elastic arms 2c and 2e extending from its inner circumferential side, and has a spring action. The friction body 2b has a substantially rectangular parallelepiped shape in which the friction surface 2a where the printing hammer 7 contacts the inner surface of the hollow hole 7c is a curved surface, and the opposite side is flat, and projects in the direction of the hollow hole 7c. . Furthermore, the center portion is provided with an engagement hole 2f. The arm portion 2c is connected to the tips of the two arm portions 2c and 2e described above, and is positioned at the center of the weight 2 and moves in an arc intersecting the movement path of the printing hammer 7.
, 2e as a fulcrum. Further, an adsorption member 4 made of a magnetic material such as metal is screwed into the engagement hole 2f. The suction member 4 extends from the C-shaped center portion of the weight 2 toward the outer circumference through the cutout portion thereof.

Inside the notch part of the C-shaped weight 2, the rear yoke 1
1 has a protruding core 3a, and a secondary coil 3b is wound around the core 3a. Further, the core 3a is located opposite the adsorption member 4.

Next, the operation of the printing hammer device of the present invention will be explained with reference to FIGS. 4 and 5.

FIG. 4 shows the flight curve of the printing hammer 7. First, when the coil 9 is excited in order for the printing hammer 7 to fly, it flies while drawing a curve like a-b. After printing at point b, it returns along a curve b-c due to the repulsive force with the platen and the force of the spring 10. When the secondary coil 3b is energized at the right time when returning, the attraction member 4 is attracted by the magnetic circuit as shown in FIG. do. Then, the friction surface 2a comes into contact with the inner surface of the hollow hole 7c of the printing hammer 7, and a frictional force is generated.

This frictional force acts as a brake, and the printing hammer 7 collides with the weight 2 while drawing a flight curve with a reduced speed, as shown by the curve c-d. Therefore, the rebound at this time will be as small as possible, and the aircraft will stop drawing the curve d-e and prepare for the next flight. Then, when the excitation of the secondary coil 3 is cut off, the weight 2
The friction body part 2b is caused by the elastic force of the two arm parts 2c and 2e.
is separated from the inner surface of the hollow hole 7c of the hammer 7 and returns to the initial position shown in FIG.

[Effects of the Invention] As is clear from the above description, according to the present invention, in a printing hammer device that moves a printing hammer by a magnetic drive means to perform printing, when the printing hammer is returned to its original state by the driving means, the friction member moves the friction member to the printing hammer. Since the printing hammer is moved in the direction of contact with the printing hammer, rebound is suppressed, noise is reduced, and there is no need to increase the overall length of the printing hammer device.

[Brief explanation of the drawing]

1 to 5 show embodiments embodying the present invention, FIG. 1 is a sectional view of the printing hammer device of the invention, and FIG. 2 is an exploded view of the printing hammer device of the invention. 3(a) is a plan view of the weight, FIG. 3(b) is a sectional view of the weight along line B-B, FIG. 4 is a diagram showing the flight curve of the printing hammer, and FIG. 5 is a diagram showing the flight curve of the printing hammer. , is a partial operation explanatory diagram of FIG. 1. In the figure, 1 is a printing hammer case, 2 is a weight, 2a is a friction surface, 2b is a friction body, 3 is a secondary coil, 7 is a printing hammer, and 9 is a coil.

Claims (1)

[Scope of Claims] 1. A printing hammer device including a printing hammer that is movably supported in a printing hammer case and has a striking part that strikes type, and a coil that magnetically drives the printing hammer, comprising: move in a direction that intersects the moving direction of
a friction member having a friction surface that contacts the printing hammer; when the printing hammer moves in a striking direction, the friction member is held separated from the printing hammer, and when the printing hammer returns, the printing hammer returns; A printing hammer device comprising: a driving means for moving the friction member to a position where it comes into contact with the printing hammer so as to reduce the speed of the printing hammer.