JPS6199593A - Hole or slit working method onto elastic member - Google Patents

Abstract

PURPOSE:To perform a hole or slit work of fine dimension with high accuracy onto the object to be worked by irradiating with condensing a laser beam on the working position of the object to be worked with the condition of extending the object to be worked having an elasticity. CONSTITUTION:The object 1 to be worked having the elasticity like the nipple, etc. for a nursing bottle is crowned to the jig 2 for extension with the condition of extending it within its surface to be worked. The extension ratio thereof is decided by the ratio of the opening size at the extension time and stationary time of the object 1 to be worked. The laser beam 3 condensed by a condenser lens 4 is then irradiated from the direction crossing with the surface to be worked and the focus 5 position thereof is set to the work position of the object 1 to be worked. In case of the work shape being a slit the object 1 to be worked is moved in the necessary direction within the surface to be worked with the condition of maintaining said focus position as it is. After working the hole or slit with the above the object 1 to be worked is removed from the jig 2 for extension and restored with shrinking to the stationary state of the original size.

Description

Detailed Description of the Invention (1) Purpose of the Invention (Field of Industrial Application) The present invention is applicable in the technical field of valves that are provided with extremely small holes or thin slits in a telescoping member and open only when pressure is applied. In particular, the present invention relates to a method of processing the above-mentioned extremely small holes or narrow slits.

(Prior Art) Conventionally, as this type of processing method, a mechanical method using a cutter or the like and a method using laser light irradiation are known.

In the former method, for example, when processing slits,
Since this method uses a cutter to shear the workpiece, the cut surfaces of the slits may adhere to each other due to the elasticity of the material during storage after processing, causing problems during use, or the edges of the slits may become damaged due to long-term use. There were problems in use due to cracks occurring. In addition, as for the problem of the cutter itself, in the case of complicated slits, the production cost of the cutter increases, and the life of the cutter has to be taken into consideration.

In the latter method, for example, when the processed shape is a very small hole, the focal point 3 of the laser beam 30 is
1 on the surface to be processed 11, or in the case of a slit, the focal point is moved within the surface to be processed, and furthermore, a slit-shaped transmission hole 21 as shown in FIG. As shown in FIG. 5, a mask pattern 20 having a mask pattern 20 is placed on the surface to be processed, and laser light is irradiated to form predetermined holes and slits.

Since the diameter of the hole or the width of the slit (hereinafter referred to as "aperture size") is extremely small, the drive mechanism is complicated and expensive when moving the laser beam, and when using a mask pattern, it is difficult to match the aperture size of the product. It is difficult to produce a mask pattern with the same dimensions, and in the case of a metal mask pattern, the maximum thickness is less than the slit width due to manufacturing technology. Further, due to the diffraction of the laser beam and the thermal influence from the mask pattern, there is a tendency for the slit width to be processed to be wider than the width of the mask pattern.

(Problems to be Solved by the Invention) The present invention solves the problems of the conventional methods as described above all at once, and accurately processes narrow slits without requiring precision of the focus position of the laser beam or the precision of the mask pattern. provide a method to do so.

(2) Structure of the Invention (Means and Effects for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a method for applying a laser beam to a stretchable workpiece in a state where the workpiece is stretched on its workpiece surface. A hole slit with a size larger than the desired size is machined by irradiating the workpiece surface with light, and after machining, the stretching force of the workpiece is released and the workpiece contracts and returns to its original size, resulting in high precision in a steady state. It is used to obtain holes and slits with minute dimensions. The following two methods are possible for laser beam irradiation.

The first method is to focus the laser beam on the processing position of the elongated workpiece. If the workpiece is thin, the processing position will be the upper surface of the workpiece, but if the workpiece is thick, the processing will be performed in multiple steps starting from the upper surface, so the position will be a position that has entered a certain depth from the upper surface one after another. becomes. In this case, if the machined shape is a very small round hole, irradiation with laser light at one point is sufficient, but in the case of a slit, for example, the slit is formed by moving the laser light or the workpiece relatively in a predetermined direction within the workpiece surface. can do. The second method is to irradiate the workpiece surface with a laser beam regardless of its focal position, and in this case, a similar shape larger than the desired processing shape is transmitted between the workpiece surface and the laser beam oscillation device. A mask pattern with holes is arranged, and holes and slits are processed by irradiating a laser beam with a width to an area including the transmission holes. As a result, when the tension is released from the workpiece after machining, the workpiece shrinks back to its original size, and the dimensions of the machined holes and slits uniformly decrease to the specified dimensions.
You can get precision stuff.

(Example) Hereinafter, an example of the present invention will be described based on FIGS. 1 to 3 of the accompanying drawings, taking as an example the case of machining a hole in a nipple for a baby bottle.

FIG. 1 shows a first embodiment in which processing is performed by irradiating a laser beam so that the surface to be processed is focused.

In the same figure, ■ is a nipple for a baby bottle which is a workpiece, and 2
3 is a stretching jig with a flat top surface, 3 is a laser beam, 4 is a condensing lens, and 5 is a laser beam focal point. The ratio of the outer diameter of the stretching jig 2 to the inner diameter of the nipple (i.e., the stretching ratio) is determined by the ratio of the dimension of the machined hole when the workpiece is stretched and the dimension at steady state, that is, the desired opening dimension, The output of the laser beam and the size of the mask pattern are determined by the stretching ratio. Therefore, the finer and more precise the desired opening size, the larger the expansion. However, the above elongation ratio has an upper limit depending on the strength of the workpiece.

In processing, first, the nipple 1 is stretched and attached to a stretching jig. The nipple head is then stretched at the stretching ratio described above. Next, the laser beam 3 condensed by the condenser lens 4 is irradiated with the focal point 5 set on the surface to be processed. As a result, a hole is machined into the nipple head. When the processing shape is a slit, if the laser beam or the workpiece is moved in the desired direction within the processing surface (for example, in the direction of the two-dot chain line in the same figure) while maintaining the focal position as described above, the desired result can be obtained. Can form shaped slits. When the nipple 1 processed in this way is removed from the stretching jig, the nipple shrinks and returns to its original size (steady size) due to its elasticity, and the hole/slit also shrinks to form a hole of the desired size and accuracy.・Suj
You can get lit.

Next, FIG. 2 shows a second embodiment in which a mask pattern is used. According to this embodiment, there is an advantage that the effort of setting the focus of the laser beam on the surface to be processed can be saved, and there is no difference in processing dimensions due to the accuracy of the focus position.

In FIG. 2, a mask pattern 7 similar to the mask pattern already explained in the conventional example is arranged on and in contact with the head of the nipple 1, which is the workpiece. However, the dimensions of the transparent holes 8 of this mask pattern 7 are smaller than those of the conventional mask pattern.
It is expanded by the expansion ratio, and the accuracy may be lower by that amount. Further, the focal point 5 of the laser beam 3 is connected between the mask pattern 7 and the condensing lens 4, so that the laser beam 3 irradiates the entire area of the transmission hole 8 of the mask pattern 7. Therefore, the laser beam transmitted through the transmission hole 8 of the mask pattern 7 processes a slit having the same shape and size as the transmission hole.

After processing, the nipple 1 is removed from the stretching jig 2 to obtain a product similar to that of the previous example.

Similarly, even if a mask pattern is used, depending on the shape of the workpiece, the mask pattern may be moved away from the workpiece and a condenser lens may be used before the focus passes or as shown in the third embodiment in FIG. Although there is no change in principle in the method of directly irradiating the mask pattern without laser beams, it is preferable to place the mask pattern close to the workpiece when considering processing accuracy due to diffraction of the laser beam.

(3) Effects of the Invention According to the present invention, holes and slits are formed in the workpiece in a stretched state, and the workpiece is contracted and returned to its original size after processing, so that the following effects can be obtained.

■ The limit slit width, which was conventionally determined by laser beam diffraction and thermal effects, can now be made even smaller by restoring the workpiece to its original size.

(2) When a mask pattern is used, the size of the through hole can be made relatively large, which facilitates manufacturing and improves durability.

■ Since the wall thickness of the workpiece becomes thinner during machining, machining becomes easier and machining accuracy can also be improved.

(2) In slit processing, the processing width is extremely small, but since it is a groove processing, there will be no adhesion on the slit surface, and if the slit ends are rounded, no cracks will occur.

[Brief explanation of drawings]

1 to 3 show embodiments of the present invention, FIG. 1 is a schematic sectional view showing the first embodiment, FIG. 2 is a schematic sectional view showing the second embodiment, and FIG. 3 is a schematic sectional view showing the second embodiment. FIGS. 4 and 5 are schematic sectional views showing different conventional examples, and FIG. 6 is a perspective view of a mask pattern used in the example of FIG. 5. l... Workpiece (nipple) 3...
...Laser beam 5...Focus 7...Mask pattern 8...Transmission hole patent applicant Vision Co., Ltd. Shimada Rika Kogyo Co., Ltd. Company Agent Patent Attorney Toru Fujioka Figure 1 Figure 2

Claims (3)

[Claims] (1) While a stretchable workpiece is stretched within its workpiece surface, a laser beam whose focus position is set at the processing position of the workpiece is irradiated from a direction intersecting the workpiece surface. A method for forming holes or slits in a telescopic member, characterized in that: (2) A method for forming holes or slits in a telescopic member according to claim (1), characterized in that the positions of the laser beam and the workpiece are relatively moved in a desired direction within the workpiece surface. (3) With the workpiece having elasticity stretched within the workpiece surface, a mask pattern having a transmission hole similar to the desired processing shape is placed between the workpiece surface and the laser beam oscillation device. A method for machining holes or slits in an elastic member, characterized in that the laser beam is transmitted through the transmission hole and irradiated onto the surface to be machined.