JP3188341B2 - Manufacturing method of leaf spring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a leaf spring used for an objective lens actuator of an optical disk drive.

[0002]

2. Description of the Related Art FIG. 14 shows a main part of the structure of an objective lens actuator. A coil 3 for focusing is wound around a bobbin 2 on which the objective lens 1 is mounted, and a coil 4 for tracking is adhered and fixed. The bobbin 2 is supported by four leaf springs 5... Which can be deformed in both the focusing direction and the tracking direction, and the bobbin 2 is controlled by a magnetic circuit by controlling the current flowing through the focusing and tracking coils 3 and 4. Drive control is performed in a focusing direction and a tracking direction by an electromagnetic action with a constant magnetic field. The leaf spring 5 has a thickness of several tens of microns, and the deformed portion 6 has a width of about several times the thickness and is deformed in both the focusing direction and the tracking direction. The upper and lower two deforming portions 6 are connected in parallel by a fixed portion side adhesive portion 7, and the bobbin 2 is supported so as to be able to move in parallel in the focusing direction and the tracking direction. The movable-side bonding portions 8 are provided at both ends of the deformed portion 6 of the leaf spring 5.
The protrusion 9 protrudes from each of the a and the fixed-side adhesive portion 8b, and a damping member 10 wider than the deformed portion 6 is attached. The damping member 10 is made of a viscoelastic material such as butyl rubber, and serves to suppress the amplitude of resonance caused by the leaf spring 5. A hole 13 for receiving a leaf spring fixing pin 12 is provided in the leaf spring support portion 11 of the bobbin 2.
The movable portion-side adhesive portion 8a is bonded and fixed between leaf spring fixing pins 12.

However, such a structure has a problem that the work of attaching the damping member 10 is difficult, and the adhesion between the leaf spring 5 and the damping member 10 is not stable, so that the dispersion of the damping performance is large.

[0004] In order to overcome such disadvantages, there has been proposed a method of covering and forming a damping member on a leaf spring. This method is as shown in FIGS. First, a leaf spring 2 is formed by etching a sheet-like spring material.
0 is formed. The portion serving as the leaf spring 20 is connected to the frame 21 by a bridge 22 (FIG. 7). At the same time, the dummy portion 2 prevents the rubber 23 covering both sides of the leaf spring 20 from spreading in the in-plane direction of the sheet-like spring material.
4 is formed. Dummy part 24 is also bridge 2 on frame 21
5 (FIG. 7). Then, a sheet-like spring material etched by the molding dies 27 and 28 in which a cavity 26 is formed by digging a shape corresponding to the rubber 23 is sandwiched from above and below, and the rubber is injected from the injection port 29 while holding the spring material. After the rubber is cured, the upper and lower dies 27, 28 are removed (FIGS. 8, 9, 10). Then, the plate spring 20 is covered with rubber 23 and formed as shown in FIG. 10, so that the bridges 22 and 25 of the plate spring 20 and the dummy portion 24 are cut apart.

According to this method, in addition to overcoming the above-mentioned drawbacks, a plurality of leaf springs 20 are further formed on one spring material, and cavities 26 are provided at several places in the molding die as well. Therefore, there is an advantage that rubber molding can be performed at once. In the step of separating the leaf spring 20 and the dummy portion 24, the bridges 22, 25 are mechanically cut by a blade 29 like a press (FIG. 11), or the bridges 22, 25 are cut by applying a high-frequency vibration f to the sheet. There are two ways to do this.

However, in the mechanical cutting, the end face of the dummy portion 24 and the rubber 23 come into close contact with each other. And this leads to an increase in cost). In the cutting by high frequency, the end face of the dummy portion 24 and the rubber 23 are peeled off by high frequency vibration.
There is a possibility that the leaf spring 20 alone with the cut pieces 2 and 25 may be scattered by vibration and deformed by an impact at the time of falling, and the separated leaf spring 20 and the dummy portion 24 may drop and be mixed. A troublesome sorting operation is required, which causes a problem that the yield is lowered and the cost is increased (FIG. 13).

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and provides a method of manufacturing a leaf spring capable of efficiently separating leaf springs and dummy portions with good yield and reducing costs. The purpose is to do.

[0008]

In order to achieve the above object, a leaf spring manufacturing method according to the present invention comprises the steps of: etching a sheet-like spring material; connecting a leaf spring to a frame via a bridge; Forming rubber on both sides of the leaf spring through the bridge or the dummy connected to the frame or the leaf spring, forming rubber between the dummy parts on both sides of the leaf spring so as to enclose the leaf spring, and separating the bridge to form a frame. In the method of manufacturing a leaf spring that separates the leaf spring and the dummy part, a bridge connecting the leaf spring is formed thicker than a bridge connecting the dummy part, and after the rubber molding, the dummy part is first subjected to high frequency vibration. The connecting bridge is cut to remove the dummy portion, and then the bridge connecting the leaf springs is mechanically cut.

In the method of manufacturing a leaf spring according to the present invention, the dummy portion may be provided with a slit along a longitudinal direction of the leaf spring.

In the method for manufacturing a leaf spring according to the present invention, the sheet-shaped spring material may be plated before the rubber molding.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. First, as shown in FIG. 1, a leaf spring 30 and a dummy portion 31 are formed by etching a sheet-like spring material. Frame 32
The bridge 33 connecting the leaf springs 30 is thick, and the bridge 34 connecting the dummy portions 31 is thin. For example, in the case of a leaf spring having a thickness of 50 μm, the bridge width of the leaf spring is 0.2 m.
m or more, the bridge width of the dummy portion is preferably about 0.07 mm. A slit 35 is provided in the dummy portion 31 in parallel with the leaf spring 30. The slit width may be about 0.2 mm.

As shown in FIG. 2, after the shape is completed by etching, plating is applied to the entire spring material. In the state where plating is not performed, as shown in (A), the cross section of the spring material is jagged at the etched end face X,
It becomes difficult for the dummy portion 31 to be separated from rubber after rubber molding described later. When plating is applied, the jagged edges X are rounded and the rubber is easily separated as shown in FIG. The type of plating may be nickel plating, solder plating, or the like, but gold plating, which has a small thickness and does not easily affect the spring constant and has good solderability when soldering in a later step, is preferable.

After plating, the rubber 36 is formed in the same manner as in the conventional example shown in FIGS. When high-frequency vibration f is applied to the sheet-like spring material formed with the rubber 36, the thin bridge 34 of the dummy portion 31 is cut, and only the dummy portion 31 is removed from the sheet and falls (see FIG. 3). At this time, the portion of the dummy portion 31 in contact with the rubber 36 is easily vibrated by the slit 35 provided in the dummy portion 31, and the rubber 36 and the dummy portion 31
Are easily separated (see FIG. 4).

Finally, in a state where only the leaf spring 30 is attached to the sheet (see FIG. 3), the bridge 33 is mechanically cut by a cutter or the like as shown in FIG. By doing so, the leaf spring 30 does not scatter due to vibration, and the dummy portion 31 is removed in advance.
There is no need to separate and remove the dummy portion 31 after cutting.

FIG. 6 is a sheet-like spring material for producing an object lens actuator using the leaf spring shown in FIG. 14 in which the ends of the leaf spring are connected to form a pair. (After etching). In such a case, the leaf springs 30a, 3
As shown in the figure, the bridge 34a of the dummy portion 31a sandwiched between 0a is not the frame 32 but the connecting portion 3 of the leaf spring 30a.
7 In FIG. 6, the bridge 34 on the upper side of the dummy portion 31a is connected to the frame 32. However, when the leaf springs are connected to both ends to form a pair in the shape of a letter, all the bridges on the inner side of the dummy portion are connected to the connecting portions of the leaf springs. Will lead to

[0016]

As described above, the method of manufacturing the leaf spring according to the first aspect is as follows. The bridge of the leaf spring is made thicker, the bridge of the dummy portion is made thinner, and after removing the dummy portion by high-frequency vibration, the leaf spring is removed. The bridge is mechanically cut, so that the leaf spring does not scatter and bend due to vibration and does not deform due to a drop impact, thereby improving the yield and separating the dummy part and the leaf spring one by one. Since there is no need, there is no need for labor, and there is an effect that it does not cause a factor of cost increase.

In the method for manufacturing a leaf spring according to the second aspect, the slit is provided in the dummy portion along the longitudinal direction of the leaf spring.
In addition to the above common effects, when the dummy portion is removed by high-frequency vibration, the vibration is transmitted well to the portion of the dummy portion that comes into contact with the rubber, so that the rubber and the dummy portion are easily separated.

According to a third aspect of the present invention, in addition to the above-mentioned common effect, the edge of the spring material end face which is jagged by the etching is rounded to produce a high frequency vibration. When removing the dummy portion, there is an effect that the rubber is easily separated from the dummy portion.

[Brief description of the drawings]

FIG. 1 is a partial plan view showing a sheet-like spring material used in a method of manufacturing a leaf spring according to the present invention.

FIG. 2 is a cross-sectional view showing (a) before plating on the spring material of FIG. 1 and (B) after plating.

FIG. 3 is a perspective view showing a state where a dummy portion is removed from a spring material after plating by applying a high frequency.

FIG. 4 is a partial plan view showing a slit provided in a dummy unit.

FIG. 5 is a plan view of a leaf spring (single unit) manufactured by the method for manufacturing a leaf spring according to the present invention.

FIG. 6 is a plan view showing a sheet-shaped spring material having another shape used in the method for manufacturing a leaf spring according to the present invention.

FIG. 7 is a partial plan view showing a sheet-shaped spring material used in a conventional leaf spring manufacturing method.

FIG. 8 is an exploded perspective view showing rubber molding in a conventional leaf spring manufacturing method.

FIG. 9 is a cross-sectional view illustrating rubber molding in a conventional leaf spring manufacturing method.

FIG. 10 is a partial plan view showing a sheet-like spring material formed of rubber as shown in FIGS.

FIG. 11 is a cross-sectional view showing a state in which a leaf spring is cut off from a rubber-shaped sheet-like spring material by cutting.

FIG. 12 is a partial plan view showing a relationship between a dummy portion and rubber in a sheet-like spring material formed of rubber as shown in FIGS.

FIG. 13 is a perspective view showing a state where a dummy portion is removed from a conventional spring material by applying a high frequency.

FIG. 14 is an exploded perspective view showing an objective lens actuator using a leaf spring.

[Explanation of symbols]

 30, 30a Leaf spring 31, 31a Dummy part 32 Frame 33, 34, 34a Bridge 35 Slit 36 Rubber

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G11B ⁷ /09-7/22 B21D 53/00 C23C 2/34 C23F 1/00-4/04 F16F 1/00-6 / 00

Claims (3)

(57) [Claims] 1. A sheet-like spring material is etched to form a leaf spring connected to a frame via a bridge, and a dummy portion connected to the frame or the leaf spring via a bridge on both sides of the leaf spring. Then, rubber is molded so as to wrap the leaf spring between the dummy parts on both sides of the leaf spring, and in a method of manufacturing a leaf spring in which the bridge is separated to separate the frame, the leaf spring and the dummy part, the leaf spring is formed. The bridge connecting the dummy portions is formed thicker than the bridge connecting the dummy portions.After the rubber molding, first, the bridge connecting the dummy portions is cut by high frequency vibration to remove the dummy portion, and then the bridge connecting the leaf springs is mechanically formed. A method for manufacturing a leaf spring, comprising cutting. 2. The method for manufacturing a leaf spring according to claim 1,
A method for manufacturing a leaf spring, wherein a slit is provided in the dummy portion along a longitudinal direction of the leaf spring. 3. The method for manufacturing a leaf spring according to claim 1, wherein the sheet-like spring material is plated before the rubber molding is performed.