JPH11320007A - Suspension wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To impart the insulation performance, to make the diameter fine and to improve the straightening spring property of a suspension wire by coating/baking an insulation paint on the outer periphery of a metal core wire having a spring property performed to straightening to form an insulation coated film. SOLUTION: This suspension wire 1 is a wire in which an insulation paint is coated/baked on the outer periphery of a metal core wire having a straightening spring property and a baked insulation coated film 3 having a film thickness capable of retaining insulation e.g. about 5 μm is formed. Accordingly, the baked insulation coated film 3 does not affect the straightening property of the wire 1. Further, even when the wire 1 is brought into contact with a conductive member, there is no fear that the wire 1 is short-circuited and a problem in which current control becomes impossible to a focussing coil and a tracking coil, is dissolved. Further, the reduction of the wire diameter is made possible because the insulation of the wire is a coated film. The baked insulation coated film 3 is preferably formed by an insulation resin e.g. a urethane resin and by this methed, the efficiency of connection work is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension wire used for a straight spring lead wire or a straight spring suspension wire of an electronic component.

[0002]

2. Description of the Related Art A suspension wire is used as a suspension member and a lead member of an objective lens of an optical pickup device as shown in FIG. FIG. 2 is a schematic perspective view of the objective lens unit 20 of the optical pickup device. The objective lens 21 is mounted on an insulating bobbin type objective lens support frame 22. The objective lens support frame 22 includes a focusing coil 23 wound around the objective lens support frame 22 and an objective lens support frame 22.
The flat tracking coils 24A and 24B adhered to two opposite sides of the objective lens support frame 22 and the terminal plates 26A and 26B are fixed to the other two opposite sides of the objective lens support frame 22.
The terminals of the focusing coil 23 and the tracking coils 24A and 24B are connected to 6A and 26B, respectively. Further, magnets 25A and 25B are provided separately from the objective lens support frame 22 so as to face the tracking coils 24A and 24B, respectively. Further, a suspension wire supporting side plate 28 provided with terminal plates 29A and 29B on both right and left sides is provided for the objective lens supporting frame 2.
It is arranged separately from 2. The objective lens support frame 22 has two suspension wires 2 on both sides thereof.
Suspended in parallel by 7A and 27B and 27C and 27D. That is, the suspension wires 27A and 27B are provided between the terminal plate 26A of the objective lens support frame 22 and the terminal plate 29A of the suspension wire support side plate 28, and the suspension wires 27C and 27D are provided between the terminal plate 26B of the objective lens support frame 22 and the suspension wire. Each of the suspension wires 27A to 27D is connected to a corresponding one of the terminal plates 26A and 26D.
B and the terminal plates 29A, 29B are respectively soldered and fixed. Thus, the objective lens support frame 22 is suspended by the straight spring force of the suspension wires 21A to 21D stretched with the suspension wire support side plate 28 as a support point. In such a configuration,
Terminal plate 29A, 2 of suspension wire supporting side plate 28
9B as a power supply end and suspension wires 21A-21
When an electric current is applied to the focusing coil 23 and the tracking coils 24A and 24B through D, an electromagnetic force F1 in the focusing direction and an electromagnetic force F2 in the tracking direction are generated. It is displaced in the focusing direction or the tracking direction according to the strength of F2. The displacement inertia of the objective lens support frame 22 is controlled by the straight spring force of the suspension wires 21A to 21D.

[0003]

In the objective lens unit 20 having such a configuration, it is important that the objective lens support frame 22 is quickly displaced by following the magnitude of the electromagnetic force F1 or F2. This includes the objective lens support frame 22
It is necessary to reduce the inertial force of the objective lens as much as possible, and therefore, it has been required to reduce the overall mass of the objective lens support frame 22. As a countermeasure, the objective lens support frame 22 itself has been studied for weight reduction, and as a result, a carbon fiber reinforced resin support frame that can be made even lighter than the conventional insulating plastic support frame and has good moldability can be obtained. It has been adopted. However, since carbon fiber reinforced resin has conductivity, if a conventional suspension wire made of a bare wire is used, when the suspension wire is energized, the suspension wire and the carbon fiber reinforced resin support frame become conductive, and the focusing coil In addition, there is a problem that the current control to the tracking coil becomes impossible.
In order to solve this inconvenience, the use of a conventional suspension wire made of bare wire covered with an insulating tube made of silicon or the like has also been considered. In addition, the outer diameter of the suspension wire becomes large, which is not preferable from the viewpoint of reducing the weight and size of the objective lens unit 20.

Accordingly, an object of the present invention is to provide a suspension wire which is required to have a straight spring function and a power supply function, has insulation performance, can be reduced in diameter, and has excellent straight spring characteristics. To contribute to downsizing.

[0005]

In order to achieve the above-mentioned object, a suspension wire according to the present invention has an insulation coating formed by applying and baking an insulation paint on the outer periphery of a metal core wire having straightness and having spring properties. Is a structural feature.

[0006]

With the suspension wire of the present invention, an insulating paint is applied and baked on the outer periphery of a metal core wire having straightness and having spring properties, and the coating thickness is within a range capable of maintaining the insulating property, for example, 5 mm.
Since the insulation film has a thickness of about μm, the insulation film does not affect the straightness characteristics of the suspension wire, and the obtained suspension wire has the same straightness as the initial straightness of the metal spring core wire. Can be kept. In addition, the baked insulating film formed on the outer periphery of the suspension wire eliminates the possibility of short-circuiting even if the suspension wire comes into contact with the conductive member, and also solves the problem that current control to the focusing coil and tracking coil becomes impossible. Is done. Therefore, the function can be expanded as a suspension wire having a straight spring function and a power supply function. Further, unlike the insulation tube, the insulation of the suspension wire is a baked insulation film, so that there is no obstacle to reducing the diameter of the suspension wire.

In the above suspension wire, if the baking insulation film of the suspension wire is formed of a solderable insulating resin, for example, a polyurethane resin, the suspension wire terminal is insulated when a solder terminal is connected to a coil terminal or a power supply terminal. This eliminates the need for a coating stripping process, thereby increasing the efficiency of the connection work.

[0008] In the above suspension wire, the straightness of the suspension wire is a radius of curvature of 300.
mm or more is desirable. This has a radius of curvature of 300
This is because the straight spring performance becomes insufficient with a suspension wire of less than mm, and the function of suspending the member is inferior.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in more detail with reference to FIG. Note that the present invention is not limited by this.

FIG. 1 is a sectional view of a suspension wire according to the present invention. The suspension wire 1 is formed by applying and baking an insulating paint to the outer periphery of a metal core wire 2 having a spring property and having been subjected to a straightening process to form a baked insulating film 3.
The metal core wire 2 is preferably a beryllium copper alloy or a phosphor bronze alloy having excellent spring properties and relatively high conductivity.

An embodiment of manufacturing the suspension wire 1 will be described below. (1) Drawing process: A phosphor bronze alloy spring wire (standard JIS C 5212 W) having an outer diameter of 0.290 mm is drawn at a wire speed of 2 by a wire drawing machine.
Wire drawing at 00m / min, outer diameter 0.150mm
To be processed W was obtained. The straightness of the wire W to be processed was 50 mm in radius of curvature. (2) Straightening process: Straightening process of the wire W to be processed was performed by a normal mechanical straightening machine 10 shown in FIG. The straightening machine 10 includes cylindrical cage-shaped straightening heads 11a and 11b that are arranged so as to rotate in opposite directions in series with the passing direction of the wire W to be processed, and the passage of the wire W to be processed in the straightening heads 11a and 11b. A plurality of carbide dies 12 are arranged with their centers shifted from each other, and a die support rod 14 that rotatably supports each of the dies 12 with a bearing 13. The wire W to be processed was straightened at a linear velocity of 6 m / min through a plurality of carbide dies 12 in the straightening heads 11a and 11b rotating at 15,000 rpm in opposite directions. The straightness of the obtained metal core wire 2 was improved to a radius of curvature of 3,000 mm. (3) Insulating film baking process: A low-temperature brazing polyurethane paint is applied to the metal core wire 2 which has been subjected to the straightening process, and the furnace temperature 2
Pass through the baking furnace at 50 ° C three times at a linear speed of 30 m / min,
A suspension wire 1 having an insulating film thickness of 5 μm and a finished outer diameter of 0.16 mm was obtained. The radius of curvature of the obtained suspension wire 1 did not change from the radius of curvature of the metal core wire 2 subjected to the straightening process, and no decrease in straightness due to the insulating film baking step was observed.

The suspension wire 1 of the above embodiment was subjected to a withstand voltage test by mandrel winding.
Breakdown voltage was 1 KV (DC). The withstand voltage test was performed using 10 sample samples, each sample was wound around a metal mandrel having an outer diameter of 30 mm for 5 turns, and 20 gr was wound on the lower end of the sample.
Was applied, a voltage was applied between the metal mandrel and the end of the sample, and the breakdown voltage was measured. As is clear from the performance results of the above embodiment, the suspension wire 1 of the present invention has a small diameter and is excellent in straight spring performance and insulation.

[0013]

The suspension wire of the present invention has a small diameter and is excellent in insulation performance and straight spring characteristics. Therefore, a lead wire material having a straight spring function and a high conductivity function,
The use as a suspension material can be expanded. Further, when the suspension wire of the present invention is used as a power supply suspension material for an optical pickup or the like, it greatly contributes to its high-speed operation and reduction in size and weight.

[Brief description of the drawings]

FIG. 1 is a sectional view of a suspension wire according to the present invention.

FIG. 2 is a schematic perspective view of an objective lens unit of the optical pickup device.

FIG. 3 is a schematic explanatory view of a straightening machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Suspension wire 2 Straight spring metal core wire 3 Baking insulation film W Wire to be processed

Claims (3)

[Claims] 1. A suspension wire, wherein an insulating coating is formed by applying and baking an insulating paint on the outer periphery of a metal core wire having a straightness and having a spring property and having a spring property. 2. The suspension wire according to claim 1, wherein the insulating film is a solderable insulating film. 3. The suspension wire according to claim 1, wherein the straightness has a radius of curvature of 300 mm or more.