JPH0755837B2 - Optical lens press molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a press molding apparatus for an optical lens,
In particular, the present invention relates to the improvement of precision of a molded lens in which misalignment between the upper and lower molds during mold clamping is reduced to maintain parallelism.

(Prior Art) In recent years, as a method of forming an optical lens, a method of heating a pre-measured glass lump to plasticize it and processing it by a precision press has attracted attention as a method of processing by polishing finish which requires complicated steps. It's starting to happen.

Conventionally, in this type of optical lens press molding apparatus, as shown in FIG. 3, both upper and lower fixing plates 1,
2 are connected and fixed by a tie bar nut 4 via a tie bar 3, and a slide plate 5 is movably provided in the vertical direction between the upper and lower fixed plates 1 and 2, and the slide plate 5 is a drive device such as a hydraulic cylinder. 6, the upper and lower molds 7 and 8 respectively installed on the upper fixed plate 1 and the slide plate 5 are clamped to thereby mold a lens molding material such as raw glass (not shown) by precision press molding. Some have the following configurations.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional apparatus, the mold is clamped while sliding the slide plate 5 on which the lower mold 8 is supported and fixed on the tie bar 3 during press molding. From that,
As shown in FIG. 4, a small amount of clearance a is required between the bush 9 provided on the slide plate 5 and the tie bar 3, so that when the slide plate 5 is pushed up and the upper and lower molds 7, 8 are There is always a lateral displacement during mold matching.

In the case of an optical lens, such a shift amount is normally required with a final accuracy of about 10 μm as an allowable limit, but as described above, in order to smoothly slide the slide plate 5 in the vertical direction. Requires a clearance a of 10 to 20 μm, which cannot meet the required accuracy.

Therefore, conventionally, the upper and lower molds 7 and 8 have a fifth
A positioning hole 71 and a positioning pin 81 as shown in the figure, or a positioning projection 72 and a positioning recess 82 as shown in FIG.
By adopting a positioning mechanism composed of, for example, when the lower die 8 is raised by the slide plate 5, even if there is some misalignment, positional accuracy can be obtained when the upper and lower dies 7 and 8 are aligned. However, even in this case, a clearance of 5 to 10 μm is required for the engaging portions of each other.
If a misalignment error of about 5 μm is combined, it is difficult to secure the required accuracy described above.

Further, as described above, the drive device 6 such as a hydraulic cylinder is mounted on the lower fixed plate 2, and the slide plate 5
With a structure that raises, it is difficult to push up the slide plate 5 in a parallel state, and the tie bar 3 extends due to the reaction force of the mold clamping force.
There is a problem in that the mold matching accuracy and the parallelism accuracy of the molds 7 and 8 are reduced.

The present invention has been made under the above circumstances, and its purpose is to prevent parallel movement when the lower mold is lifted or misalignment when the mold is clamped, and to improve the mold matching accuracy and parallelism of the mold. An object of the present invention is to provide a press molding device for an optical lens, which has a high degree of precision and is capable of obtaining a highly accurate optical lens.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention corresponds to the upper mold by fixing the upper mold to the upper part of the molding chamber including the housing. The lower die is movably arranged in the lower part, and the lower die is configured to interlock with a driving means installed on the lower surface of the casing. The driving means is a press connected to the lower die. A shaft is provided, and the press shaft is attached to a slider that is moved by a plurality of high precision guide devices.

(Operation) That is, according to the present invention, with the above configuration,
The driving means of the upper die and the lower die can be attached to the same housing with high precision and high strength, and the driving means of the lower die moves the press shaft connected to the lower die by a plurality of high precision guide devices. Since it is mounted on the slider, it can be lifted while maintaining high positional accuracy when the lower mold is lifted. Therefore, if the mold is positioned during mounting, the positioning mechanism of the mold itself during molding can be used. The mold clamping accuracy can be improved without the need for a mold, and there is almost no clearance for smoothly sliding the lower mold in the vertical direction as in the past, so there is little deformation of the device itself due to the reaction force during mold clamping. As a result, it becomes possible to mold a highly accurate optical lens.

(Example) Hereinafter, the present invention will be described in detail with reference to an example shown in FIG. 1 and FIG.

FIG. 1 schematically shows the overall structure of an optical lens pressing device according to the present invention. A column 12 is erected on a base 11, and a housing 13 is fixed on the column 12. At the same time, the internal space of the housing 13 serves as the molding chamber 14. An upper die 15 is fixed to an upper ceiling surface 14a of the molding chamber 14 via a mounting plate 16, while a lower bottom surface 14b side of the upper die 15 is installed on a lower surface portion of the housing 13 and will be described later. A lower die 17 which is interlocked with a driving means 18 is disposed so as to face the upper die 15 so as to be vertically movable.

That is, the drive means 18 includes a high-rigidity bracket 19 fixed to the lower surface of the housing 13 and having a strength that does not deform at least with respect to the mold clamping force, and a hydraulic cylinder 20 assembled to the lower portion of the bracket 19. , Swivel joint attached to the tip of cylinder rod 21 of this hydraulic cylinder 20
22 and a plurality of high precision guide devices 24 for vertically guiding the slider 23 assembled in the bracket 19 via the swivel joint 22. The high precision guide device 24 is shown in FIG. As shown in FIG. 5, a linear motion guide bearing (product name) that is assembled to the bracket 19 and a slider 23 is engaged with the guide shaft 25a with low sliding resistance and with high rigidity and positional accuracy. ) 25b, the slider 23 can be vertically guided through the high precision guide device 24, and the slider 23 has an upper end 26a on the bottom surface side in the housing 13. The press shaft 26 that is exposed is assembled, and the lower die 17 is assembled and fixed to the upper end portion 26a of the press shaft 26.

Therefore, according to the configuration of the present invention described above, the press shaft 26 to which the lower mold 17 is attached is assembled to the slider 23 that is slidably guided by the high precision guide device 24 including the guide shaft 25a and the linear motion guide bearing 25b. From the fact that
The sliding resistance is low, the rigidity is high, and the lower die 17 can be guided by sliding with a high positional accuracy of 1 to 2 μm. Further, since the hydraulic cylinder 20 as a drive source for vertical movement is attached to the lower part of the bracket 19 of the drive means 18 firmly attached to the housing 13, it is not affected by the reaction force of the mold clamping, and Since the slider 23 is connected to the tip of the cylinder rod 21 of the hydraulic cylinder 20 by the swivel joint 22, the lateral displacement of the cylinder rod 21 does not affect the slider 23. Furthermore, since the driving means 18 is adapted to be directly attached to the housing 13, the parallelism, the centering, etc. at the time of assembling the housing 13 on the base 11 are different from those of the conventional tie bar type. It will be much easier to do by comparison.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[Effects of the Invention] As is apparent from the above description, according to the present invention, the upper mold is fixed to the upper part of the molding chamber formed of the housing, and the lower mold is movably arranged at the lower part corresponding to the upper mold. In addition, since the lower die is attached to the slider which is moved by a plurality of high-accuracy guide devices of the driving means installed on the lower surface of the casing, the lower die is lifted while maintaining high positional accuracy. Since it is possible to improve the mold clamping accuracy without requiring the positioning mechanism of the mold itself at the time of molding, and since the upper mold and the lower mold can be attached to the same housing with high strength, Since there is almost no clearance for smoothly sliding the lower mold in the vertical direction, the deformation of the device itself due to the reaction force at the time of mold clamping is small, and thus a highly accurate optical lens can be molded. Say It is possible to provide a press molding apparatus for an optical lens that has a staggered effect.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a press molding device for an optical lens according to the present invention, FIG. 2 is a transverse sectional view of a high precision guide device portion taken along line II-II in FIG. 1, and FIG. Is a schematic explanatory view of a conventional optical lens press molding apparatus, FIG. 4 is an enlarged sectional view of an essential part of a sliding portion between a tie bar and a slide plate, and FIGS. 5 and 6 are conventional molds. FIG. 3 is an enlarged sectional view of an essential part showing the alignment mechanism of FIG. 11 …… base, 13 …… case, 14 …… molding room, 15 …… upper mold,
17 …… Lower mold, 18 …… Driving means, 20 …… Hydraulic cylinder, 23
...... Slider, 24 …… High precision guide device, 26 …… Press axis.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshizo Komiyama 2068-3, Ooka, Numazu-shi, Shizuoka Toshiba Machine Co., Ltd. Numazu office (72) Inventor Masami Endo 2068-3, Ooka, Numazu, Shizuoka Toshiba Machine Co., Ltd. Numazu On-site (56) References JP-A-61-21926 (JP, A)

Claims (1)

[Claims] 1. An upper mold is fixed to an upper part of a molding chamber composed of a housing, a lower mold is movably arranged at a lower part corresponding to the upper mold, and the lower mold is installed on a lower surface part of the housing. The drive means is interlocked with the drive means.
A press molding apparatus for an optical lens, comprising a press shaft connected to the lower die, and the press shaft is attached to a slider which is moved by a plurality of high precision guide devices.