JP2003053746A - Method for assembling molding tool and assembly device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an assembling method by which an interference between molding tools due to an erroneous use of the molding tool is detected beforehand during their assembly and at the same time, the molding tool whose direction is set so that a stable injection is ensured, can be supplied to an injection device, and to provide an assembly device. SOLUTION: During assembling of the molding tool, an interval between the molding faces of outer peripheral parts of two molding tools is measured, and the interference between the two molding tools is previously detected by comparing the measurements with the transfer of the molding tools and judging the comparison results. Consequently, the precision deviation of the device is eliminated and the generation of an ensuing failure can be avoided. In addition, the molding tool whose direction is set so that an injection is performed from the maximum part of an interval between the molding faces of the outer peripheral parts of the molding tools, can be supplied to the injection device. Thus, it is possible to curtail the working manhour by stabilizing the injection and compounding a large quantity of a raw material for plastic lens.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for assembling a molding mold for molding a plastic lens.

[0002]

2. Description of the Related Art A conventional method of assembling a molding mold is as disclosed in Japanese Patent Laid-Open No. 148906/1992, which is shown in FIG.
Fig. 5 shows a process flow chart, and Fig. 5 shows a schematic diagram up to cavity formation. First, in the conventional assembling method, after centripetalizing the molding die 16 that defines the surface on the side of the visual field and the molding die 17 that defines the surface on the side of the eye, the non-molding surface side of the two molding dies is held. Then, the central height of the molding surface with respect to the reference heights 18a and 18b is measured by the first measuring means 10a and 10b. Then, the mold holding means 19a, 19b are moved to the first transfer means 11a so that the centers of the two molds are on the same axis.
Transfer at 11b. After that, arithmetic processing is performed based on the height data of the center parts of the two molding dies with respect to a predetermined reference position, and the molding surfaces of the two molding dies are separated by a predetermined distance 1.
The mold holding means 19a, 19b are transferred by the second transfer means 12a, 12b so as to become 3. Finally, the adhesive tape 15 is wound around the outer peripheral surfaces of the two molds once or more to form a cavity.

In the injection device in the subsequent step, a plastic lens raw material is filled in a cavity formed by two molding dies and an adhesive tape. In the case of a spectacle lens, since there is an astigmatism prescription, as shown in FIG. 6, molds having different curvature radii (R1 and R2) in the orthogonal axial directions are used. Therefore, the molding surface spacing at the outer peripheral portion of the molding die becomes nonuniform in the circumferential direction. However, conventionally, since the molding die is not axially extended, an injection needle is inserted at an arbitrary position in the molding mold circumferential direction to perform injection.

[0004]

In the conventional method of assembling the molding mold, the combination of two molding dies requires five combinations.
There are more than 00 kinds, so make a mistake in the combination,
When different types of molds are mixed in the lot or the two molds are mixed upside down, the mold surfaces are separated by a predetermined distance 13.
When the mold holding means 19a and 19b are moved so as to become, the molds may interfere with each other. FIG. 7 shows an example of a case where interference occurs due to a wrong mold. In this example, the molding die 14 is not a regular molding die. Second
If the molding die holding means 19a is moved so that the transfer means 12a of FIG. 1 has the predetermined spacing 13, the outer peripheral portion of the molding die 14 hits the outer peripheral portion of the other molding die before the predetermined spacing 13 is obtained. At this time, the second transfer means 12 of the forming die
Unreasonable force is applied to a and 12b, and the second transfer means 12
Mechanical deviation occurs in a and 12b. Second transfer means 12
The mechanical deviations of a and 12b are relative deviations of the mold holding portions 19a and 19b at the tip of the transfer means, and correspond to parallelism and misalignment of the cores. Parallelism and misalignment of cores greatly affect the prism accuracy, which is the basic accuracy of plastic lenses, so if a mold is assembled with parallelism and misalignment of cores, the plastic lens after molding will have a defective prism. Will end up. Further, when the mechanical displacement of the second transfer means 12a and 12b occurs due to the interference, the prism inspection can be performed only after the plastic lens is cured and the molding die is peeled off. Therefore, the prism defective lens should be continuously produced after the interference. become. Since it takes about 20 hours to cure a plastic lens, if the interference of the mold cannot be detected, the number of defects produced during that period will be enormous.
In addition, the second transfer means 1 once by the interference of the molding die
When the mechanical deviations of 2a and 12b occur, the accuracy is severe, and a great deal of time is required for the restoration work. In addition, if the molding die itself is scratched due to interference, the scratches are transferred to the plastic lens, and the plastic lens itself becomes defective. If the depth of the scratch is shallow, it can be reused by polishing the mold again, but if the impact at the time of interference is strong, the expensive mold will be cracked and cannot be regenerated.

Further, even if the interference does not occur barely, if the molding surface interval of the outer periphery of the mold becomes smaller than the predetermined interval, the injection needle cannot be inserted into the cavity by the injection device in the subsequent step, and the plastic is not formed. The lens material may be spilled. If the plastic material adheres to the moving parts of the injection device, it will solidify and lead to abnormal operation.

In a molding mold for a convex lens having a narrow outer periphery of a molding die, when a high-viscosity plastic lens raw material is injected, the raw material overflows from the injection port before the cavity is filled with the plastic raw material. It becomes defective (not filled). Since the polymerization initiator is added to the plastic lens raw material, the viscosity increases with time.
Since it is preferable that the viscosity is low in order to suppress the occurrence of chipping defects, it is necessary to set a time constraint from the preparation of the raw materials to the injection. As a result, a large amount of plastic lens raw materials cannot be mixed at once, resulting in a loss in production. In addition, if the injection device stops due to some trouble, the viscosity of the plastic lens raw material may increase and the plastic lens may become unusable. For these reasons, there is an increasing demand for injection even from a plastic lens raw material having an increased viscosity by injecting from a place having a wide outer peripheral portion of the molding die. There is also a method of heating the raw material in order to reduce the viscosity of the plastic lens raw material, but depending on the type of the plastic lens raw material, the reaction may be rapidly accelerated and heating may not be possible. Further, since the heater is used for heating the raw material, there is a problem that it is disadvantageous from the viewpoint of energy saving.

The present invention is an assembling method in which interference between two molding dies is detected in advance, and at the same time, the molding mold is oriented so that the injection needle can be inserted into a position where the outer periphery of the molding dies has the widest interval. And an assembling apparatus.

[0008]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the present inventor has found that the outer peripheral portion of the molding die is positioned before the two molding surfaces are positioned so that the molding surfaces have a predetermined distance. By measuring the distance between the molding surfaces and comparing the measured value with the total amount of transfer of each mold until the distance between the two molding dies from the measured position reaches the specified interval, We have found that it is effective to detect interference between molds.

By detecting the interference between the molding dies in advance, it is possible to avoid the mechanical displacement of the second transfer means, and it becomes unnecessary to carry out the restoration work which conventionally took several hours. Contributes to reduction of stop loss. In addition, it is possible to prevent the molding die from interfering with the production of a large number of plastic lenses with defective prisms, and prevent cracks and scratches on the molding surface due to the interference of the molding die.

Further, since the detection of the interference of the molding dies is also to detect the difference of the combination of the molding dies, the mixing of different molding dies in the lot, and the misalignment of the upper and lower molding dies, the conventional intermediate inspection after the molding is completed. Differences in mold types that could only be caught can be found during assembly work and defects can be avoided. Further, if the difference between the molding dies can be detected during the assembling work, there is also an advantage that it is not necessary to check all the types of the molding dies in the lot as when an abnormality is found in the intermediate inspection.

Furthermore, since the minimum dimension of the molding surface distance at the outer peripheral portion of the molding die is ensured, the injection needle does not interfere with the molding die when the injection needle is inserted by the injection device in the subsequent step. As a result, stable operation of the apparatus and reduction of cleaning time can be realized without spilling the plastic lens raw material.

Further, by supplying the assembled molding mold to the injection device in the subsequent step while maintaining the circumferential position of the molding die which has been oriented, the molding surface distance at the outer peripheral portion of the molding die is minimized. It is possible to inject from a wide position. As a result, even if the plastic lens material having an increased viscosity is injected, overflow from the injection port does not occur, which is also effective in reducing chipping defects. Also, since it becomes possible to inject the plastic lens raw material whose viscosity has increased, a large amount of plastic lens raw material can be prepared at once,
It is possible to significantly reduce the number of times of mixing and the number of steps of mixing work.

Therefore, according to the first aspect of the invention, the adhesive tape is wound around the two molds to form the cavity,
In a cast molding method in which a plastic lens raw material is filled into the cavity and then cured, a step of centriping each molding die, a step of holding a non-molding surface of each molding die, and an axial direction of at least one molding die or molding The step of detecting the mark placed at a predetermined position of the mold, the step of axially extending the molding die based on the detected result, and the height of the center of each molding die molding surface with respect to the predetermined reference position The step of measuring, the step of aligning the center of each mold with the same axis, the step of measuring the molding surface distance on the outer periphery of the molding die, the measured value and the distance between the two molding surfaces from the measured position Is compared with the total transfer amount of each mold until the predetermined distance is reached, a step of setting the distance between the two molding surfaces of the mold to a predetermined distance, and wrapping the adhesive tape around the outer peripheral surface of the mold. Forming a cavity Provides a method of assembling forming mold, characterized in that it consists of that process.

Further, the invention according to claim 2 is a cast molding method in which an adhesive tape is wound around two molding dies to form a cavity, and a plastic lens raw material is filled into the cavity and then cured. Positioning means for centering the mold, holding means for holding the non-molding surface of each molding die, and detection means for detecting a mark provided on at least one molding die in the axial direction or at a predetermined position of the molding die,
An axial direction-extracting means for rotating the forming die so that the axis of the forming die has a predetermined angle, and a first measuring means for measuring the height of the center portion of each forming surface of the forming die with respect to a predetermined reference position, First transfer means for aligning the centers of the respective molding dies with the same axis, second measuring means for measuring the molding surface distance of the outer peripheral portion of the molding dies, and values measured by the second measuring means and the measured positions. And a determining means for comparing the total transfer amount of each mold until the distance between the two molding surfaces becomes a predetermined distance, and the distance between the two molding surfaces becomes a predetermined distance. An apparatus for assembling a molding mold, comprising: a second transfer means for moving each molding die; and an adhesive tape winding means for winding an adhesive tape around an outer peripheral surface of the molding die to form a cavity.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments. FIG. 1 is a flow chart of an assembling process of a molding mold according to the present invention. In the present embodiment, the axial direction detection and the axial direction extraction are performed subsequent to the step of holding the non-molding surface of the molding die, but after the step of holding the non-molding surface of the molding die, the molding surface distance measuring step of the outer peripheral portion of the molding die is performed. There is no problem at any time before. First, centering of a molding die that defines the field-side surface and a molding die that defines the eyeball-side surface are performed. Next, the non-molding surface of each molding die in the centripetal state is held. The holding means is equipped with a suction pad having a rotation stopping mechanism inside the cup and holds it by vacuum suction. The rotation stop mechanism of the suction pad is attached to prevent the mold and the cup from shifting during taping. Then, at least one of the molding dies is detected in the axial direction or at a predetermined position of the molding dies. As a method of detecting the axial direction, a method of detecting the axis of the astigmatism molding die using an auto lens meter is preferable from the viewpoint of cost and accuracy. As a method of detecting the marking attached to a predetermined position of the molding die, there are a method of image processing using a CCD camera, a method of using an optical sensor, and the like, but other methods can be used as long as the mark can be detected. After the detection of the axial direction or the mark is completed, the position where the thickness of the outer peripheral portion of the astigmatism molding die is maximum is the second position at which the molding surface interval of the outer peripheral portion of the molding die is measured.
The axial direction is adjusted so that the measurement position of the measurement means is reached.
This is because, as shown in FIG. 6, since the astigmatism forming molds have different outer peripheral thicknesses, the positions 20 at which the molding surface intervals of the outer peripheral parts of the forming molds are minimized, that is, the forming molds first contact each other. This is because it is necessary to measure the distance between positions. However,
The spherical mold does not detect the axial direction because the thickness of the outer peripheral portion is uniform and it is not necessary to project the axial direction. After that, the height of the central portion of each molding surface with respect to the reference height is measured by the first measuring means. Then, the two molds are conveyed by the first transfer means so that the centers of the two molds are on the same axis. In that state, the molding surface distance between the outer peripheral portions of the two molding dies is measured. As the method for measuring the molding surface interval of the outer peripheral portion of the molding die, a method using the area sensor shown in FIG. 2, a method by image processing using a CCD camera shown in FIG. 3 (non-contact), a displacement sensor, or the like was used. A physical (contact type) method can be mentioned. When the area sensors 1a and 1b are used, the outermost peripheral portion of the molding die has an end face position that varies depending on the roundness and outer diameter accuracy of the molding die and the centripetal accuracy of the molding die.
It is better to measure the inside. Further, the area sensor is preferably of a type that uses laser light having a high linearity of light as a light source in terms of accuracy. When the CCD camera 3 is used, the illumination 4 is used to make the image clear. Here, the measured value 2 of the molding surface distance at the outer peripheral portion of the molding die is compared with the total transfer amount of each molding die from the measured position until the distance between the two molding die molding surfaces reaches a predetermined distance, When the sum of the transfer amounts ≧ measured value, an error is issued to prevent the mold from interfering.

Further, if control is performed so that an error occurs under the condition of the total transfer amount ≧ (measured value−α), the molding surface interval 21 becomes α.
Can be secured. The value of α is the minimum lens edge thickness dimension which is the specification of the plastic lens product itself. The outer diameter of the injection needle needs to be α or less in consideration of the insertion accuracy of the injection needle. As a result, it is possible to prevent interference between the molding die and the injection needle when it is inserted, prevent the plastic lens raw material from spilling, and realize stable operation of the device and reduction of the cleaning time.

After that, the two transfer molds are transferred by the second transfer means so that the two molds have a predetermined interval. Finally, the adhesive tape is attached to the outer peripheral surfaces of the two molding dies to complete the molding mold.

In this embodiment, the circular mold is described, but there is no problem even if the mold has a non-circular shape.

The orientation of the molding dies is performed to measure the molding surface spacing of the outer peripheral portions at the positions where the molding dies first come into contact with each other, and at the same time, the position 21 where the molding surface spacing of the outer peripheral portions of the molding dies becomes maximum. It is also intended to align with a certain direction. By supplying the injection mold in the subsequent step while maintaining the orientation of the molding mold that has been oriented, the injection needle can be inserted into a position where the molding surface interval of the outer peripheral portion of the molding die is maximized.

[0020]

EFFECTS OF THE INVENTION By using the method and apparatus for assembling a molding mold of the present invention, interference between two molding dies can be detected in advance, and further, injection is performed at the position where the molding surface spacing of the outer periphery of the molding dies is the widest. It will be possible to supply to the injection device in the direction that can perform. Since the interference of the molding dies can be detected, the mechanical deviation of the assembling apparatus can be avoided. As a result, it is possible to prevent the occurrence of defective prisms and defective scratches, and to prevent the mold from cracking, which greatly contributes to cost reduction. Further, since the difference between the molding dies can be detected at the same time, it is possible to prevent the occurrence of the frequency defect, and it is possible to remove the wrong molding dies on the spot. Further, since interference of the injection needle can be suppressed, stable operation of the injection device in the subsequent process and shortening of cleaning time can be achieved.

Since the plastic lens raw material can be injected from the place where the molding surface spacing is widest on the outer periphery of the molding die, chipping defects caused by unfilling can be prevented. Further, since it is possible to inject even the plastic lens raw material having an increased viscosity, a large amount of plastic lens raw material can be blended at one time, and the number of blending operations and the number of blending work steps can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a flow chart of an assembly process of a molding mold of the present invention.

FIG. 2 is a diagram showing a method for measuring an interval between molding surfaces of a molding die outer peripheral portion using an area sensor, FIG.
(B) is a side view.

3A and 3B are diagrams showing a method for measuring an interval between molding surfaces of a molding die outer peripheral portion using image processing, FIG. 3A is a plan view, and FIG. 3B is a side view.

FIG. 4 is a flow chart of an assembly process of a conventional molding mold.

FIG. 5 is a schematic view of forming a cavity in a normal mold.

FIG. 6 is a shape diagram of an astigmatism forming die.

FIG. 7 is a schematic view showing a state where they are assembled by a wrong mold and interfere with each other.

[Explanation of symbols]

1a, 1b .... Area sensor 2 .... Molding surface spacing on the outer periphery of the mold 3 ... CCD camera 4 ... Illumination 10a, 10b ..First measuring means 11a, 11b..first transfer means 12a, 12b..second transfer means 13 ........ predetermined interval 14 ........ abnormal forming mold 15 --- Adhesive tape 16 --- Molding die that defines the field-side surface 17 --- Molding die 18a and 18b that defines the eye-side surface-Reference Height 19a, 19b ··· Mold holding means 20 ··· · Position where the molding surface spacing on the outer periphery of the molding die is minimum 21 ··· Maximum position

Claims (2)

[Claims] 1. A cast molding method in which an adhesive tape is wound around two molds to form a cavity, and a plastic lens raw material is filled in the cavity and then cured.
Centering each mold, holding the non-molding surface of each mold, detecting a mark on at least one of the molds in the axial direction or at a predetermined position on the mold, and the detected result Based on the above, a step of axially extending the mold, a step of measuring the height of the center of each mold surface with respect to a predetermined reference position, and a step of aligning the center of each mold with the same axis , The step of measuring the molding surface distance of the outer peripheral portion of the molding die, and the total of the transfer amount of each molding die from the measured value and until the distance between the molding surfaces of the two molding die reaches a predetermined distance. A method of assembling a molding mold, comprising: a step of comparing, a step of setting a distance between two molding surfaces of a molding die to a predetermined distance, and a step of forming a cavity by winding an adhesive tape around an outer peripheral surface of the molding die. . 2. A casting molding method in which an adhesive tape is wound around two molds to form a cavity, and a plastic lens raw material is filled in the cavity and then cured, and positioning means for centripetalizing each mold and Holding means for holding the non-molding surface of the molding die, detection means for detecting a mark provided on at least one molding die in the axial direction or at a predetermined position of the molding die, and so that the shaft of the molding die has a predetermined angle. Axially extending means for rotating the mold, first measuring means for measuring the height of the center of the molding surface of each mold with respect to a predetermined reference position, and aligning the center of each mold with the same axis The first transfer means, the second measuring means for measuring the molding surface distance of the outer peripheral portion of the molding die, the value measured by the second measuring means and the distance between the two molding surfaces from the measured position. For a predetermined period Determination means for comparing the total amount of transfer of each mold until it becomes, and second transfer means for moving each mold so that the interval between the two molding surfaces of the mold becomes a predetermined interval, An apparatus for assembling a molding mold, comprising: an adhesive tape winding means for winding a tape around an outer peripheral surface of a molding die to form a cavity.