JPH0441744Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to a mechanism provided to reduce vibrations generated when a motor stops rotating, and in particular relates to a spring that slides into friction prevention friction drum. relating to anti-wear means.

Type wheel type serial printers have a slower printing speed than dot matrix type printers, but are widely used because of their good print quality.

However, in type wheel type serial printer devices, a disc type type wheel having a large number of type fingers is rotated by a type selection mechanism, and the type to be printed is selected depending on the amount of rotation. Therefore, if there is an unstable technical defect in the type selection operation, the print quality will be significantly impaired when the selected type is struck by a printing hammer onto the printing paper through the ink ribbon.

For this reason, stable operation is also required for the motor that rotates the type wheel.

[Conventional technology]

The conventional technique will be explained below with reference to FIG.

FIG. 2 is a perspective view illustrating a type selection mechanism and a motor rotation stop mechanism in a type wheel type serial printer device.

A motor, for example, a stepping motor 1, is used to select type, and the motor 1 moves an ink ribbon 7 and a carrier 5 that moves parallel to the axial direction of a platen 6 to which a printing paper 8 is attached. It is installed in.

On one side of the rotating shaft of the motor 1 is a disc-type wheel 2 having a number of fingers with printed characters.
is installed.

Further, a friction drum 3 made of, for example, plastic is attached to the other side of the rotating shaft in order to stabilize the selection operation of the type, and the friction drum 3 is in sliding contact with the friction drum 3 with a predetermined frictional force. A substantially U-shaped torque control spring 4 made of, for example, a stainless steel spring plate is provided so as to clamp the friction drum 3.

In such a mechanism, when printing, the carrier 5 on which the type selection motor 1 is mounted is moved parallel to the axial direction of the platen 6 to position the print, and the type is selected depending on the print signal. A disc type wheel 2 is rotated by a motor 1.

In this case, the vibration of the motor 1 is caused by the frictional force of the torque control spring 4 against the friction drum 3 provided on the other side of the rotating shaft of the motor 1.
Prevent hunting.

For this reason, it becomes possible to quickly position the desired type on the type wheel 2 at a predetermined position.
Desired characters can be printed by operating the printing hammer mechanism 9 on the printed characters.

[Problems that the invention is intended to solve]

However, as mentioned above, the torque control spring that slides into sliding contact with the friction drum with a predetermined frictional force has the problem that the sliding contact portion gradually wears out and the friction area changes, making it impossible to obtain the predetermined frictional force. The dot was hot.

[Means for solving problems]

The above-mentioned problem can be solved by applying a treatment to prevent wear on the sliding contact portion of the torque control spring that comes into sliding contact with the friction drum. Examples of methods for wear-resistant treatment include hardening treatment, polishing after hardening treatment, and hard plating.

[Effect]

By using the above means, it is possible to prevent wear of the torque control spring that clamps the friction drum, and the frictional force does not change even if the spring position is changed.
Stable positioning of the type wheel is possible and high print quality can be maintained.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a perspective view of the torque control spring of the present invention.

In the figure, 10 is a torque control spring. Identical parts are designated by the same reference numerals throughout the figures.

As shown in Fig. 1, torque control spring 1
0, the hardened layer 1 is coated with wear-resistant treatment only on the part that comes into sliding contact with the friction drum 3, or on the entire part.
0a is obtained.

Surface hardening methods for wear resistance can be roughly divided into two types: a surface modification method using heat treatment and a surface coating method using plating.

Surface transformation methods include carburizing, which involves heating low-carbon steel in a carburizing agent (oxygen diffusing agent) to permeate and diffuse carbon from the surface of the steel into the interior, making the surface layer the composition of high-carbon steel; Common methods include nitriding, which hardens the surface layer by diffusing nitrogen from steel, and surface hardening, which rapidly heats only the surface of the steel and rapidly cools it.

On the other hand, surface coating methods include methods for coating wear-resistant hard metals or non-metals, such as a thermal spraying method in which a molten or semi-molten metal is thermally sprayed, and an electroplating method in which electrodeposition is performed from a solution.

In the present invention, the hardened layer 10a is formed by nitriding or hard electroplating of hard chrome or the like as shown by the two-dot chain line.

In the figure, the hardened layer 10a is shown to be formed only on the surface that makes sliding contact with the friction drum, but it goes without saying that the effect is the same even if the hardened layer 10a is formed on the entire surface.

In addition, nitriding treatment may be performed, and further barrel polishing or the like may be performed to make the surface smooth.

By doing so, it is possible to prevent wear of the sliding contact portion with the plastic friction drum 3.

Furthermore, in order to achieve good positioning, if you change the friction force by moving the spring position, the sliding contact part will not wear out even if the spring's sliding contact point moves, so the friction force will always be constant. This enables stable positioning.

[Effect of idea]

As explained above, by using the torque control spring that has been subjected to wear-resistant treatment of the present invention in the vibration prevention mechanism of the motor, the printing operation of the type wheel type serial printer device is stabilized and high quality printing is achieved. Now I can do it.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a torque control spring of the present invention, and FIG. 2 is a perspective view illustrating a type selection mechanism and a motor rotation stop mechanism in a type wheel type serial printer device. In the figure, 1 is a type selection motor, 2 is a disc type wheel, 3 is a friction drum,
4 and 10 are torque control springs, 5 is a carrier, 6 is a platen, 7 is an ink ribbon, 8 is a printing paper, 9 is a printing hammer mechanism, and 10a is a hardening layer.

Claims (1)

[Claims for Utility Model Registration] (1) A vibration prevention mechanism for a motor including a friction drum attached to a rotating shaft of a motor and a torque control spring slidingly in contact with the friction drum, the vibration prevention mechanism comprising: A vibration prevention mechanism for a motor, characterized in that at least a sliding contact portion that comes into sliding contact with a friction drum is subjected to wear-resistant treatment. (2) The motor vibration prevention mechanism according to claim (1) of the utility model registration, which is subjected to a hardening treatment as an anti-wear treatment. (3) The motor vibration prevention mechanism according to claim (1), which is coated with hard plating as an anti-wear treatment.