JPH0432115A - Switch base board - Google Patents

Abstract

PURPOSE:To improve reliability of switching by providing a groove on a switch base board to heighten an oil holding effect and to suppress wear-out at the sliding time of the switch base board with a contact brush. CONSTITUTION:A synthetic resin 1 able to be plated, after a projection part matching a conductive pattern is formed thereon, sandwichedly embedded by a synthetic resin unable to be plated by a double color molding, and the surface of the exposed projection part is plated with a conductive metal to form a conductive pattern. In the face of a synthetic resin 2 unable to be plated, a groove 3 is peripherally of fragmentarily provided near the conductive pattern on the non-sliding part of a contact brush. Oil is applied to such switch substrate and oil is accumulated in a groove. Good conductive metal plating 7 is formed on the platable synthetic resin 1, and lublicating oil 6 is applied to the groove 3 provided on the unplatable synthetic resin 2, and the contact brush 5 is in contact with the good conductive metal plating 7 in a state where the lublicating oil 6 flows out from the groove to the surface of the switch base board.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a contact-type switch board that performs switching by sliding on a contact brush in electronic equipment components. More specifically, the present invention relates to a rotary switch board used for detecting the position of a type wheel in a printer, detecting the number of rotations in a counter, and the like.

[Conventional technology]

The conventional switch board of this type is
has been disclosed. Generally, rotary switches used for detecting the position of a type wheel in a printer are required to have extremely good wear resistance.

FIGS. 5 and 6 show this type of switch, that is, a switch pattern on the substrate 10, which is attached to a rotating shaft 8 that drives a type wheel 9 and rotates at high speed together with the rotating shaft 8. An example of a high-speed rotary switch is shown in which a contact brush 5 made of a highly conductive metal piece is brought into elastic contact with the rotary type wheel 1 to detect the rotational position of the type wheel 9.

[Problem to be solved by the invention]

However, the rotary switch boards used for detecting the position of the type wheel in printers and the number of rotations in counting machines are subject to significant wear of the contact brushes and switch boards during high-speed rotation (several thousand revolutions), resulting in chattering and other problems. Poor continuity becomes a problem. In addition, even if oil is applied to the switch board, the high-speed rotation causes the oil to scatter, making it impossible to obtain a sufficient lubrication effect.
The present invention has been made to solve these drawbacks, and its purpose is to improve the switching reliability of the switch board.

[Means to solve the problem]

The present invention provides a switch board in which a switch pattern is formed by a conductive part and a non-conductor part by a combination of a synthetic resin with plating and a synthetic resin without plating, and a contact on which a contact brush slides on the switch board. The structure is characterized in that a groove is provided on the non-plated synthetic resin surface of the switch board, which is the non-sliding surface of the contact brush.

[Effect]

According to the above configuration of the present invention, it is possible to provide an oil retaining effect by using the groove provided in the unplated synthetic resin surface of the contact brush non-sliding surface of the switch board as an oil reservoir. , wear of the contact brush and the switch board is reduced.

[Embodiment] As an embodiment of the present invention, a rotary switch board used for detecting the position of a type wheel in a printer, detecting the number of revolutions in a counter, etc. will be explained. FIG. 1 is a plan view showing one embodiment of the present invention. FIG. 0 shows a disk-shaped switch board made of a synthetic resin 1 with plating and a synthetic resin 2 without plating. 4 is the center hole of the switch board. The synthetic resin to be plated is formed to match the conductive pattern 1.

The synthetic resin 1 to be plated is formed with a protrusion corresponding to the conductive pattern, and then buried in a sandwich-like manner with a non-plated synthetic resin by two-color molding, and the exposed protrusion surface is plated with a highly conductive metal. Form a conductive pattern.

On the unplated surface of the synthetic resin 2, grooves 3 are provided in the non-sliding portion of the contact brush in the vicinity of the conductive pattern in the form of a circumference or a fragment. The switch board is coated with oil, and the oil is collected in the groove. Even when the switch board rotates at high speed, the oil on the surface of the switch board can be prevented from scattering outside the switch board due to centrifugal force, and the oil flowing out from the grooves can be continuously supplied to the contact brush sliding surface.

As a result, lubricating oil is present at the contact portions of the contact brush and the switch pattern of the switch board, thereby preventing each part from being worn out.

FIG. 2 is a cross-sectional view of FIG. 1, in which grooves 3 are formed in a synthetic resin 2 that is not plated.

FIG. 3 is a partially enlarged view of FIG. 2. A highly conductive metal plating 7 is formed on the synthetic resin 1 to which the plating is applied, and lubricating oil 6 is applied to the groove 3 provided in the unplated synthetic resin 2, and the lubricating oil 6 is applied from the groove onto the switch board surface. In the flowing state, the contact brush 5 is in contact with the highly conductive metal plating 7.

FIG. 4 is a partially enlarged sectional view showing a schematic manufacturing process of the switch board. Figure 4 (a) shows synthetic resin 1 to which plating is applied.
Form a protrusion corresponding to the conductive pattern in the first color with
In FIG. 4(b), a second color consisting of an insulating synthetic resin 2 without plating is formed. At the time of forming this second color, the grooves 3 are formed at the same time. FIG. 4(C) is a diagram showing conductive metal plating applied to the synthetic resin 1 after molding. Although the switch board is formed in this way, there is a degree of freedom regarding the groove shape, and it is possible to form it on the surface of the second color synthetic resin. As described above, in view of the gist of the present invention, the present invention contemplates any shape of the groove as long as it is aimed at oil retention.

〔Effect of the invention〕

As described above, according to the present invention, the oil retention effect is enhanced by the groove provided on the switch board, and the wear during sliding between the switch board and the contact brush is suppressed, thereby greatly improving the reliability of switching. can be done. As described above, the present invention has great effects, and can be utilized for contact-type switch boards that perform switching by sliding on contact brushes in electronic equipment parts.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the switch board of the present invention. FIG. 2 is a sectional view of FIG. 1. FIG. 3 is a partial enlarged view of the contact portion between the contact brush and the switch board. FIG. 4 is a partially enlarged sectional view showing a schematic manufacturing process of the switch board. FIG. 5 and FIG. 6 are diagrams showing an example of a high-speed rotation switch. 1...Synthetic resin 2...Synthetic resin 3...Groove 4...Center hole 5...Contact brush 6...Lubricating oil 7...Metal plating 8...Rotating shaft 9...・Type wheel 10...switch board

Claims (1)

[Claims] In a switch board in which a switch pattern of a conductive part and a non-conductor part is formed by a combination of a plated synthetic resin and an unplated synthetic resin, and a contact structure in which a contact brush slides on the switch board, A switch board characterized in that a groove is provided in the unplated synthetic resin surface of the switch board, which is the non-sliding surface of the contact brush.