JP4665361B2 - Method and apparatus for assembling mold for molding - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an assembling method and an assembling apparatus for a molding mold for molding a plastic lens.
[0002]
[Prior art]
A conventional method for assembling a mold for molding is as disclosed in JP-A-4-148906. FIG. 4 shows a process flow diagram and FIG. 5 shows a schematic diagram until cavity formation. First, in the conventional assembling method, after the centering of the molding die 16 that defines the field on the visual field side and the molding die 17 that defines the surface on the eyeball side, the non-molding surface side of the two molding dies is held. The center 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 and 19b are transferred by the first transfer means 11a and 11b so that the centers of the two molds are on the same axis. Thereafter, a calculation process is performed based on the height data of the center of the two molds with respect to a predetermined reference position, and the mold holding means 19a so that the molding surfaces of the two molds are at a predetermined interval 13. , 19b are transferred by the second transfer means 12a, 12b. Finally, the adhesive tape 15 is wound around the outer peripheral surfaces of the two molds one or more times to form a cavity.
[0003]
In the post-injection apparatus, a plastic lens material is filled into a cavity formed by two molds and an adhesive tape. In the case of a spectacle lens, there is an astigmatism prescription, so as shown in FIG. 6, molds having different radii of curvature (R1 and R2) are used in the orthogonal axial directions. For this reason, the molding surface interval of the outer periphery of the molding die is not uniform in the circumferential direction. However, conventionally, since the molding die has not been placed in the axial direction, injection is performed by inserting an injection needle at an arbitrary position in the circumferential direction of the molding mold.
[0004]
[Problems to be solved by the invention]
In the conventional method for assembling a molding mold, there are more than 500 combinations of two molds. Therefore, the combinations are wrong, different molds are mixed in the lot, or the upper and lower molds are If the mold holding means 19a, 19b are moved so that the molding surface of the mold is at a predetermined interval 13, the molds may interfere with each other. FIG. 7 shows an example when interference occurs due to a mistake in the mold. In this example, the mold 14 is not a regular mold. When the mold holding means 19a is moved so that the second transfer means 12a has a predetermined interval 13, the outer periphery of the mold 14 hits the other outer periphery of the mold before the predetermined interval 13 is obtained. At this time, an excessive force is applied to the second transfer means 12a and 12b of the mold, and mechanical displacement occurs in the second transfer means 12a and 12b. The mechanical deviation of the second transfer means 12a, 12b is a relative deviation of the mold holding parts 19a, 19b at the tip of the transfer means, and corresponds to a parallelism and a deviation of the core. Parallelism and misalignment greatly affect prism accuracy, which is the basic accuracy of plastic lenses. If the mold is assembled with parallelism and misalignment, the plastic lens after molding becomes a defective prism. End up. In addition, when the mechanical displacement of the second transfer means 12a, 12b occurs due to interference, the prism inspection can be performed only after the plastic lens is cured and the mold is peeled off. become. Since a plastic lens takes about 20 hours to cure, if a mold interference cannot be detected, the number of defects produced during that time will be enormous. Furthermore, once the mechanical displacement of the second transfer means 12a, 12b due to the interference of the mold occurs, the accuracy is severe, and a great deal of time is spent on the restoration work. In addition, if the mold itself is scratched by interference, the scratch is 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 crack and become unrecyclable.
[0005]
Even if barely no interference occurs, when the molding surface interval of the outer periphery of the mold is smaller than the predetermined interval, the injection needle cannot be inserted into the cavity by an injection device in a later process, and the plastic lens raw material is It may spill. If the plastic raw material adheres to the movable part of the injection device, it solidifies and causes abnormal operation.
[0006]
In a molding mold for a convex lens with a narrow space between the outer periphery of the mold, 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. Filling). Since the polymerization initiator is added to the plastic lens raw material, the viscosity increases with time. In order to suppress the occurrence of chipping defects, it is preferable that the viscosity is low. Therefore, it is necessary to provide time constraints from the preparation of the raw material to the injection. As a result, a large amount of plastic lens raw materials cannot be prepared at a time, resulting in a production loss. Also, if the injection device stops due to some trouble, the viscosity of the plastic lens raw material may increase and become unusable. For these reasons, there is a growing demand to enable injection of plastic lens raw materials that have increased in viscosity by injecting even as little as possible from the wide interval of the outer periphery of the mold. There is a method of heating the raw material in order to lower the viscosity of the plastic lens raw material, but depending on the type of the plastic lens raw material, there is a method in which the reaction is rapidly accelerated and cannot be heated. In addition, since the heating of the raw material uses a heater, it has a problem that it is disadvantageous from the viewpoint of energy saving.
[0007]
The present invention relates to an assembling method and an assembling apparatus for detecting the interference between two molding dies in advance and simultaneously directing the molding mold so that the injection needle can be inserted at a position where the distance between the outer peripheral portions of the molding dies is widest. The purpose is to provide.
[0008]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventor measured the distance between the molding surfaces of the outer periphery of the molding die before positioning the two molding die molding surfaces at a predetermined interval. By comparing the measured value with the total transfer amount of each mold until the interval between the molding surfaces of the two molds reaches a predetermined distance from the measured position, the interference between the molds is detected in advance. Was found to be effective.
[0009]
By detecting the interference between the molds in advance, mechanical misalignment of the second transfer means can be avoided, and the restoration work that has conventionally required several hours can be avoided, reducing the stop loss of the apparatus. Contribute to. Further, it is possible to prevent mass production of plastic lenses having defective prisms by preventing interference of the mold, and cracks and scratches on the molding surface due to interference of the mold.
[0010]
In addition, mold interference detection simultaneously detects differences in mold combinations, mixing of different molds in a lot, and the difference between upper and lower molds. Differences in mold types that could not be found can be found at the time of assembly work, so that it is possible to avoid making defects. Further, if the difference in the molds can be detected during the assembly operation, there is an advantage that it is not necessary to check all types of molds in the lot as in the case where an abnormality is found in the intermediate inspection.
[0011]
Furthermore, since the minimum dimension of the molding surface interval at the outer periphery of the molding die is secured, the injection needle does not interfere with the molding die when the injection needle is inserted by a subsequent injection device. As a result, stable operation of the apparatus and shortening of the cleaning time can be realized without spilling the plastic lens raw material.
[0012]
In addition, by supplying the assembled molding mold to the post-injection device while maintaining the circumferential position of the molded mold that has been directed, it is possible to start from the position where the molding surface spacing on the outer periphery of the molding mold is the widest. It becomes possible to inject. As a result, even if a plastic lens raw material having an increased viscosity is injected, overflow from the injection port does not occur, which is effective in reducing defective chips. In addition, since the plastic lens raw material having an increased viscosity can be injected, the plastic lens raw material can be prepared in a large amount at a time, and the number of preparations and the number of preparation operations can be greatly reduced.
[0013]
Therefore, the invention described in the first aspect is to center each mold in a casting molding method in which an adhesive tape is wound around two molds to form a cavity, and a plastic lens material is filled in the cavity and then cured. A step, a step of holding a non-molding surface of each mold, a step of detecting a mark placed in an axial direction of at least one mold or a predetermined position of the mold, and a mold based on the detected result A step of performing an axial direction, a step of measuring the height of the center of each mold surface relative to a predetermined reference position, a step of aligning the center of each mold with the same axis, The step of measuring the molding surface interval, the step of comparing the measured value and the total transfer amount of each molding die until the interval between the two molding die molding surfaces reaches a predetermined interval from the measured position, 2 Sheet molding mold A step of spacing surfaces at predetermined intervals to provide a method of assembling forming mold, characterized by comprising the step of forming a cavity winding an adhesive tape to the mold outer peripheral surface.
[0014]
Further, the invention described in the form 2 centripets each mold in a casting molding method in which a cavity is formed by winding an adhesive tape around two molds, and a plastic lens material is filled in the cavity and then cured. Positioning means, holding means for holding the non-molding surface of each mold, detection means for detecting a mark placed in the axial direction of at least one mold or a predetermined position of the mold, and the mold axis An axial direction rotating means for rotating the mold so as to be an angle, a first measuring means for measuring the height of the center portion of each mold surface relative to a predetermined reference position, and the center of each mold Two molds from a first transfer means that is aligned with the same axis, a second measurement means that measures the molding surface interval of the outer periphery of the mold, and a value measured by the second measurement means and the measured position Molding surface A determination means for comparing the total amount of transfer of each mold until the interval reaches a predetermined interval, and a second unit that moves each mold so that the interval between the two mold surfaces is a predetermined interval. There is provided a molding mold assembling apparatus comprising a transfer means and an adhesive tape winding means for winding an adhesive tape around an outer peripheral surface of a mold to form a cavity.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Although embodiments of the present invention will be described below, the present invention is not limited to the following embodiments. FIG. 1 is an assembly process flow diagram of a molding mold according to the present invention. In this embodiment, the axial direction detection and the axial direction are performed following the non-molding surface holding step of the molding die, but the molding surface interval measuring step of the outer periphery of the molding die after the non-molding surface holding step of the molding die. If it was before, there is no problem at any timing. First, centripetal operation is performed on a mold that defines the field on the visual field side and a mold that defines the surface on the eyeball side. Next, the non-molding surface of each mold in the centered state is held. The holding means is equipped with a suction pad having a rotation stop mechanism inside the cup and holds it by vacuum suction. An anti-rotation mechanism for the suction pad is attached to prevent the mold and the cup from shifting during taping. Then, detection of a mark placed in the axial direction of at least one mold or a predetermined position of the mold is performed. As a method for detecting the axial direction, a method for detecting the axis of the astigmatism mold using an auto lens meter is desirable from the viewpoint of cost and accuracy. As a method for detecting a marking attached to a predetermined position of the mold, there are an image processing using a CCD camera, a method using an optical sensor, and the like. When the detection of the axial direction or the mark is completed, the position where the thickness of the outer peripheral portion of the astigmatic mold is maximized becomes the measurement position of the second measuring means for measuring the molding surface interval of the outer periphery of the mold. Perform axial out. As shown in FIG. 6, since the astigmatic molds have different outer peripheral thicknesses, the positions 20 at which the molding surface interval between the outer peripheral parts of the molds becomes the minimum, that is, the molds contact each other first. This is because the position interval needs to be measured. However, the spherical mold does not detect the axial direction because the outer peripheral portion has a uniform thickness and does not need to be projected in the axial direction. Thereafter, the height of the center portion of each mold surface relative to the reference height is measured by the first measuring means. And it conveys with a 1st transfer means so that the center of two molds may be on the same axis | shaft. In this state, the molding surface interval between the outer peripheral portions of the two molding dies is measured. As the method for measuring the molding surface interval of the outer periphery of the molding die, a method using an area sensor shown in FIG. 2, a method using image processing (non-contact) using a CCD camera shown in FIG. A physical (contact type) method may be mentioned. When the area sensors 1a and 1b are used, the outermost peripheral portion of the mold has an end face position that varies depending on the roundness, outer diameter accuracy, and centripetal accuracy of the mold. It is better to measure. In addition, the area sensor is preferably of a type that uses a laser beam with high light straightness as a light source. When the CCD camera 3 is used, the illumination 4 is used to make the image clear. Here, the measurement value 2 of the molding surface interval of the outer periphery of the molding die is compared with the total transfer amount of each molding die until the interval between the two molding die molding surfaces reaches a predetermined interval from the measured position, By giving an error when the total transfer amount ≧ measured value, it is possible to prevent the mold from interfering.
[0016]
Further, if control is performed to generate an error under the condition of the total transfer amount ≧ (measured value−α), α can be secured as the molding surface interval 21. The value of α is the lens minimum 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, interference between the mold and the injection needle can be prevented in advance, and the stable operation of the apparatus and shortening of the cleaning time can be realized without spilling the plastic lens raw material.
[0017]
Thereafter, the second transfer means transfers the two molds so as to have a predetermined interval. Finally, the molding mold is completed by sticking the adhesive tape to the outer peripheral surfaces of the two molding dies.
[0018]
In this embodiment, the circular mold has been described, but there is no problem even if the mold has a non-circular shape.
[0019]
The direction of the molding die is measured in order to measure the distance between the molding surfaces of the outer peripheral portion at the position where the molding dies first contact each other, and at the same time, the position 21 at which the molding surface interval of the outer peripheral portion of the molding die is maximized The purpose is to match. The injection needle can be inserted at a position where the molding surface interval of the outer periphery of the molding die is maximized by supplying it to an injection device in a subsequent process while maintaining the orientation of the molding mold that is directed.
[0020]
【The invention's effect】
By using the method and apparatus for assembling the molding mold of the present invention, it is possible to detect the interference between the two molding dies in advance, and inject in such a direction that the injection can be performed at the position where the molding surface interval of the outer periphery of the molding die is the widest. It can be supplied to the device. By detecting the interference of the mold, it is possible to avoid the occurrence of mechanical deviation of the assembling apparatus. As a result, it is possible to prevent the occurrence of prism defects and scratch defects, and the mold does not crack, which greatly contributes to cost reduction. In addition, since the difference in the molds can be detected at the same time, it is possible to suppress the occurrence of power failure and to remove the wrong mold on the spot. Furthermore, since interference of the injection needle can be suppressed, it leads to stable operation of the post-injection device and shortening of the cleaning time.
[0021]
Since the plastic lens raw material can be injected from the place where the molding surface interval of the outer periphery of the mold is widest, it is possible to prevent chipping defects caused by unfilling. Further, since it is possible to inject even a plastic lens material having an increased viscosity, a large amount of plastic lens material can be prepared at a time, and the number of preparations and preparation work steps can be greatly reduced.
[Brief description of the drawings]
FIG. 1 is an assembly process flow diagram of a molding mold of the present invention.
FIGS. 2A and 2B are diagrams showing a method for measuring an interval between molding surfaces of a molding die outer periphery using an area sensor, wherein FIG. 2A is a plan view and FIG. 2B is a side view.
FIGS. 3A and 3B are diagrams illustrating a method for measuring a distance between molding surfaces of a molding die outer periphery using image processing, where FIG. 3A is a plan view and FIG. 3B is a side view.
FIG. 4 is an assembly process flow diagram of a conventional molding mold.
FIG. 5 is a schematic view until a cavity is formed with a normal mold.
FIG. 6 is a shape diagram of an astigmatism mold.
FIG. 7 is a schematic view showing a state where the wrong mold is assembled and interfered.
[Explanation of symbols]
1a, 1b ··· Area sensor 2 ··· Molding surface interval 3 at the outer periphery of the mold ··· CCD camera 4 ··· Illumination 10a and 10b .. First measuring means 11a, 11b .. First transfer means 12a, 12b .. Second transfer means 13... 15 ........ Adhesive tape 16 ........ Molding die 17 that defines the field on the visual field side ........ Molding die 18a, 18b that defines the surface on the eyeball side..Reference Height 19a, 19b ··· Mold holding means 20 ··············································································· Maximum position

Claims (2)

A casting 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 in the cavity and then cured .
Holding the non-molded surface of each mold;
Detecting a mark placed in the axial direction of at least one mold or a predetermined position of the mold;
A step of axially shaping the mold based on the detected result;
A step of measuring the height of the center of each molding surface relative to a predetermined reference position;
Aligning the center of each mold with the same axis;
Measuring the molding surface interval of the outer periphery of the mold, and
A step of comparing the measured value with the total transfer amount of each mold until the distance between the centers of the two molds from the measured position to a predetermined distance;
A step of setting a predetermined interval between the centers of the two mold forming surfaces;
Winding an adhesive tape around the outer peripheral surface of the mold to form a cavity ;
Including
The step of performing the axial direction performs the axial direction so that the position where the thickness of the outer periphery of the mold is maximized is the measurement position in the step of measuring the molding surface interval.
A method for assembling a mold for molding. An apparatus for assembling a mold for casting molding, 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 .
Holding means for holding the non-molding surface of each mold;
Detecting means for detecting a mark placed in an axial direction of at least one mold or a predetermined position of the mold;
Axial direction extending means for rotating the mold so that the axis of the mold is at a predetermined angle;
First measuring means for measuring the height of the center portion of each molding surface relative to a predetermined reference position;
First transfer means for aligning the center of each mold with the same axis;
A second measuring means for measuring the molding surface interval of the outer periphery of the molding die;
Determining means for comparing the value measured by the second measuring means with the total transfer amount of each mold until the distance between the centers of the two molding dies from the measured position to a predetermined distance; ,
A second transfer means for moving the respective molds so that the distance between the centers of the two mold surfaces is a predetermined distance;
An adhesive tape winding means for winding an adhesive tape around the outer peripheral surface of the mold to form a cavity;
An apparatus for assembling a mold for molding.

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