JP2007238345A - Forming die, forming method and glass forming formed by using the forming die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and inexpensive forming die which can be used without modifying the conventional forming apparatus by improving the center alignment precision by the forming die itself since it becomes a problem particularly to align the centers of upper and lower dies with each other when a glass lens is formed by using a pair of upper and lower dies and when the conventional forming die using a drum die and upper and lower dies is used, the higher the requested precision of center alignment becomes, the smaller a clearance between the drum die and any of the upper and lower dies must be made. <P>SOLUTION: When the forming die is cooled quickly, a formed article is apt to strain thermally. Therefore, the forming die is surrounded by a heat insulating cylinder having low thermal conductivity, namely, is formed to have such a structure that the temperature changes slowly. The heat insulating cylinder is divided into three portions by two inclined planes inclined toward opposite directions to each other. Each of two inclined planes is formed into a low-friction sliding plane. When the heat insulating cylinder is engaged outside the drum die, each of the divided ones of the heat insulating cylinder moves to the lower side by its own weight along the sliding plane to align the upper and lower dies automatically with each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a mold for molding a lens or the like used in an electro-optical device by pressing a heat-softened glass material. In particular, the present invention relates to a configuration of a heat insulating cylinder that facilitates centering of a pair of molds.

When a glass lens is molded using a pair of upper and lower molds, the alignment of both molds is particularly problematic. If the centering is not performed correctly, the molded lens is decentered and the lens performance is deteriorated. In a conventional mold using a barrel mold and upper and lower molds, the clearance between the trunk mold and the upper and lower molds has to be made extremely small as the accuracy required for eccentricity increases (see, for example, Patent Document 1).
However, the smaller the clearance, the more the galling and the deformation due to it occurred.
In order to provide a clearance and satisfy the eccentricity accuracy, a mold structure having a positioning has been introduced (for example, see Patent Document 2). However, in these molds, it is difficult to easily change not only the molds but also the peripheral members of the molds and the control device.
Therefore, there is a demand for a compact and inexpensive molding die that can improve the eccentric accuracy with the molding die alone and can be used without changing the conventional molding apparatus.
Moreover, in the structure of only the trunk mold and the upper and lower molds, the heat conductivity of the upper and lower molds is high, so that heat can easily escape, and the heat is rapidly deprived during cooling. In order to prevent this, the temperature change is moderated by surrounding it with a heat insulating cylinder having low thermal conductivity.

JP 2005-231933 A JP 2005-238790 A

  Provided are a configuration and a method for producing an accurate glass lens without particularly reducing a clearance between a body mold and an upper mold and a mold having a special structure.

The invention according to claim 1 is a mold having upper and lower molds composed of a large-diameter part and a small-diameter part, a body mold, and a cylindrical heat insulating cylinder made of a material having lower thermal conductivity than each of the molds. The heat insulating cylinder has an inclined surface divided by two planes inclined in opposite directions with respect to the bus, and each of the heat insulating cylinders having the inclined surface has an inclined surface as a sliding surface, and the inclined surface is caused by its own weight. It is comprised so that it can move along.
According to a second aspect of the present invention, in the molding die according to the first aspect, a fitting portion for positioning in the circumferential direction is provided on each opposed inclined surface of the divided heat insulating cylinder. It is characterized by.
According to a third aspect of the present invention, in the molding die according to the second aspect, the fitting portion also serves as a stopper for preventing slipping.
According to a fourth aspect of the present invention, in the molding die according to any one of the first to third aspects, the inner periphery of at least one of the uppermost part and the lowermost thermal insulation cylinder of the divided thermal insulation cylinder is the Two flat portions that contact the large diameter portion of the mold are formed.
According to a fifth aspect of the present invention, there is provided the mold according to any one of the first to third aspects, wherein the divided heat retaining member has at least one of the upper mold, the lower mold, and the body mold, and a contact portion therewith. A shape for positioning in the circumferential direction is provided between the cylinder and the cylinder.

According to a sixth aspect of the present invention, in the molding die according to the fifth aspect, the shape for positioning is one flat portion provided in the large-diameter portion of the upper die or the lower die, and the heat retaining cylinder. It is a plane part provided in the inner peripheral part of the bus-line vicinity of minimum length of this.
According to a seventh aspect of the present invention, in the molding die according to the fifth aspect of the present invention, the shape for positioning includes the outer diameter of the upper mold, the large diameter portion of the lower mold or the body mold, and the inside of the heat retaining cylinder. It is the fitting part which consists of a protrusion and a ditch | groove formed in the bus-line direction of each circumference.
According to an eighth aspect of the present invention, in the molding die according to any one of the first to seventh aspects, between the outer periphery of at least one of the upper mold and the lower mold and the inner periphery of the barrel mold. A shape for positioning in the circumferential direction is provided.
According to a ninth aspect of the present invention, in the molding die according to the eighth aspect, the shape for positioning is formed in the direction of the generatrix of the small diameter portion of the upper die, the lower die and the inner periphery of the barrel die, respectively. It is the fitting part which consists of a protruding protrusion and a ditch | groove.

The invention according to claim 10 is a molding die having an upper and lower mold composed of a large-diameter portion and a small-diameter portion, a body mold, and a cylindrical heat insulation cylinder, and the bottom surface of the heat insulation cylinder is inclined at a predetermined angle with respect to the bus bar. The upper surface of the barrel mold is formed into an inclined surface having an angle coincident with the tilt angle of the lower surface of the heat insulating cylinder, and the lower surface of the barrel mold is opposite to the inclined lower plane. The upper surface of the large-diameter portion of the lower mold is formed as an inclined surface that matches the inclination angle of the lower surface of the body mold, and the heat insulation cylinder and the body mold are inclined. The surface is a sliding surface, and is configured to be movable along an inclined surface by its own weight.
The invention according to claim 11 is the molding die according to claim 10, wherein at least one of the inclined surfaces of the heat retaining cylinder and the barrel mold facing each other and the inclined surfaces of the barrel mold and the lower mold facing each other, A fitting portion for positioning in the circumferential direction is provided.
According to a twelfth aspect of the present invention, in the molding die according to the eleventh aspect, the fitting portion also serves as a stopper for preventing slipping.
According to a thirteenth aspect of the present invention, in the molding die according to any one of the tenth to twelfth aspects, two flat portions that are in contact with the large diameter portion of the upper die are formed on the inner periphery of the heat retaining cylinder. It is characterized by that.
According to a fourteenth aspect of the present invention, in the molding die according to any one of the tenth to twelfth aspects, a shape for positioning in a circumferential direction is provided between the upper die and the heat retaining cylinder. It is provided.

According to a fifteenth aspect of the present invention, in the molding die according to any one of the tenth to twelfth aspects, the circumferential positioning is performed between the barrel die and at least one of the upper die and the lower die. It is characterized in that it has a shape for performing.
According to a sixteenth aspect of the present invention, in the molding die according to the fifteenth aspect, the shape for positioning is a protrusion formed on the outer circumference of the die and the inner circumference of the heat retaining cylinder, respectively. It is a fitting part consisting of a strip and a groove.
According to a seventeenth aspect of the present invention, in the molding die according to any one of the tenth to sixteenth aspects, the upper and lower dies and the barrel die are formed of a molding material having a similar thermal conductivity, and the barrel is formed. A layer of a material having a thermal conductivity lower than that of the molding die material is provided on the outer periphery of at least one of the mold and the lower mold large-diameter portion.
The invention according to claim 18 is the molding die according to claim 17, characterized in that the material having low thermal conductivity is a material containing ceramic, chromium, nickel chromium or kovar as a component.
According to a nineteenth aspect of the present invention, in the molding die according to any one of the first to eighteenth aspects, at least a portion of the inner periphery of the barrel mold that contacts the molded product, a ridge or a groove, or the like. A position mark shape made of is formed.

The invention described in claim 20 is characterized in that, in the mold according to any one of claims 1 to 19, a porous material is used as a material having low thermal conductivity used for the heat insulating cylinder or the like. To do.
The invention according to claim 21 is the mold according to any one of claims 1 to 20, wherein the sliding surface is made of a material containing any of molybdenum disulfide, aluminum oxide, graphite, and tungsten disulfide. It is formed or a layer made of the material is formed.
According to a twenty-second aspect of the present invention, in the molding die according to any one of the first to twentieth aspects, one of the sliding surfaces is formed with fine irregularities, and the other is formed on a flat surface. Features.
A twenty-third aspect of the invention is characterized in that in the molding die according to any one of the first to twentieth aspects, a porous film is formed on the sliding surface.
A twenty-fourth aspect of the invention is characterized in that, in the mold according to the twentieth or twenty-third aspect, a lubricant is embedded in the hole of the porous film on the sliding surface.
According to a twenty-fifth aspect of the present invention, in the molding die according to the twenty-fourth aspect, the lubricant is molybdenum disulfide, tungsten disulfide, or graphite.

According to a twenty-sixth aspect of the present invention, in the molding die according to any one of the first to twentieth aspects, a sliding member is disposed on the sliding surface.
The invention according to claim 27 is the molding die according to claim 26, wherein the sliding member is a linear ball bearing or a linear roller bearing.
The invention according to claim 28 is the mold according to any one of claims 1 to 27, wherein the angle formed by the lower inclined surface of the two inclined surfaces with the horizontal plane is θ1, and the upper inclined The angle between the surface and the horizontal plane is θ2, the mass of the member mounted on the lower inclined surface is m1, the mass of the member mounted on the upper inclined surface is m2, and between the members in contact with the lower inclined surface When the coefficient of static friction is μ1 and the coefficient of static friction between members in contact with the upper inclined surface is μ2, θ1 and θ2 are
−m1sin θ1 + μ1 m1 cos θ1 + μ2 m2 cos θ2 · cos (θ1 + θ2)
<0
-M2sinθ2 + μ2m2cosθ2 <0
It is characterized by satisfying.

A twenty-ninth aspect of the invention is characterized in that the molding die according to any one of the first to twenty-eighth aspects is used and the upper and lower dies and the barrel die are automatically aligned.
In a thirty-third aspect of the present invention, the molding die according to any one of the first to twenty-eighth aspects is used, and an auxiliary cylinder having an inner diameter larger than the largest-diameter member of the mold and the heat retaining cylinder is covered with the lower mold. Then, the molding method is characterized in that the upper mold and the heat retaining cylinder are inserted into the auxiliary cylinder.
A thirty-first aspect of the invention is characterized in that, in the molding method according to the thirty-third aspect, the auxiliary cylinder is formed by combining semi-cylindrical members divided into two in the generatrix direction.
A thirty-second aspect of the invention is characterized by a glass molded body manufactured using the mold according to any one of the first to twenty-eighth aspects.
According to a thirty-third aspect of the present invention, there is provided an electro-optical device manufactured using the glass molded body according to the thirty-second aspect.

According to the present invention, the direction in which the upper and lower molds are made constant makes the eccentric direction of the molded body constant. This makes it easy to ensure the centering accuracy because the variation in eccentricity is reduced.
Further, the eccentric position can be easily stabilized by a molding machine using a conventional body mold.

FIG. 1 is a diagram for explaining the basic principle of the present invention. The figure (a) is a figure which shows the insertion process of a thermal insulation cylinder, and the figure (b) is a figure which shows the assembly completion state.
In the figure, reference numeral 1 is an upper mold, 2 is a lower mold, 3 is a barrel mold, 4 is a lower thermal insulation cylinder, 5 is an intermediate thermal insulation cylinder, 6 is an upper thermal insulation cylinder, 7 is a gob material, and A, B and C are thermal insulation cylinders. The moving direction of each is shown.
The configuration of the present invention is a molding die composed of an upper die, a barrel die, and a heat insulation cylinder. The upper and lower molds are aligned in one direction by moving in opposite directions with their own weight. Note that the upper and lower molds 1 and 2 may be simply referred to as molds below unless they are distinguished from each other.

Hereinafter, the assembly | attachment process of a type | mold and operation | movement of each member are demonstrated.
In FIG. 2A, a lower heat insulating cylinder 4 having an inner diameter slightly larger than the large-diameter base portion of the lower mold 2 fixed to a substrate (not shown) is placed so as to include the base portion. The lower heat insulating cylinder 4 has a cylindrical shape as its basic shape, but its upper surface is cut by a plane inclined at a predetermined angle with respect to the generatrix of the cylinder.
The small diameter portion of the lower mold 2 is formed concentrically with the base portion, and the upper surface thereof is an embossing surface concentric with the small diameter portion, and the gob material 7 which is a softened glass material is substantially at the center of the mold surface. Placed in.
A body mold 3 having an inner diameter slightly larger than the outer diameter of the small diameter portion is placed so that the bottom surface thereof is in contact with the upper surface of the large diameter portion so as to include the small diameter portion.
The small-diameter portion of the upper mold 1 having the large-diameter portion and the small-diameter portion having the same diameter and the same diameter as that of the lower heat insulating cylinder 4 is inserted into the body die 3 and concentric with the small-diameter portion on the lower surface of the small-diameter portion The mold surface formed on the gob material 7 is brought into contact with the gob material 7.

The middle heat insulating cylinder 5 has a shape in which the bottom surface is cut by a similar inclined plane at an angle that coincides with the upper surface of the lower heat insulating cylinder 4. When the inclined surface of the middle heat insulating cylinder 5 is made to coincide with the inclined surface of the lower mold 4 and is placed from above the lower heat insulating cylinder 4 (in the direction of arrow B), the intermediate heat insulating cylinder 5 has its own weight along the inclined surface of the lower heat insulating cylinder 4. Falling (in the direction of arrow B ′) occurs until the inner surface abuts on the outer periphery of the barrel die 3 and the barrel die 3 moves (in the direction of arrow B ″) until the inner circumference abuts on the outer periphery of the small-diameter portion of the lower die 2. Move to the lower side of the slope.
At this time, the lower heat retaining cylinder 4 also receives a force in the reverse direction (arrow A direction) due to the reaction force, and moves to a position where the inner diameter portion contacts the outer periphery of the base portion of the lower mold 2.
With respect to these movements, it is assumed that the contact portion with each other member is kept in a sufficiently low friction state. As a method for ensuring low friction, it is preferable to apply a lubricant to the sliding surface or to coat a lubricious material such as DLC. Alternatively, a component that improves lubricity, for example, molybdenum disulfide, may be included in the material of the heat insulating cylinder, or a lubricious material may be used for the material itself.

In FIG. 2B, an upper heat insulating tube 6 configured symmetrically with the lower heat insulating tube 4 is placed from above the middle heat insulating tube 5 (in the direction of arrow C). The middle heat insulating cylinder 5 is formed symmetrically in the vertical direction, and its upper surface is cut by a plane inclined in the direction opposite to the upper surface of the lower heat insulating cylinder 4. Therefore, the long-axis both ends of the inclined ellipse appearing on the upper and lower surfaces of the middle heat insulating cylinder 5 coincide with the same bus bar of the middle heat insulating cylinder 5, respectively. One of those buses is the maximum length bus and the other is the minimum length bus.
Although the absolute values of the inclination angles of the upper and lower surfaces do not have to coincide with each other, the inclination angle of the upper surface of the middle heat insulation cylinder 5 and the inclination angle of the bottom surface of the upper heat insulation cylinder 6 need to coincide with each other. It moves along the inclined surface of the middle heat insulating cylinder 5 (in the direction of arrow C ′), its inner peripheral surface comes into contact with the large diameter portion of the upper mold 1 and the upper mold 1 is moved (in the direction of arrow C ″). The outer periphery of the small diameter portion of the mold 1 abuts on the inner peripheral portion of the body mold 3.

In the assembled state of the molding die, the outer periphery of the small-diameter portion of the lower die 2 and the outer periphery of the small-diameter portion of the upper die 1 are both relative to the inner peripheral surface of the barrel die 3 supported in the vicinity of the center by the intermediate heat insulating cylinder 5. Since they abut on the same line, the upper and lower mold surfaces are in principle concentric. However, according to the present system, the upper and lower molds and the body mold are decentered in principle, so that a lens formed by embossing has a substantially constant decentering with respect to the outer diameter. However, since the amount of eccentricity is theoretically constant, the work in the subsequent process is also a typical work, and no special cost increase occurs.
The above assembly procedure has been described by disassembling the process for ease of understanding. However, as an actual work, the lower heat insulating cylinder 4, the middle heat insulating cylinder 5, and the upper heat insulating cylinder 6 are preliminarily stacked and held once. It is designed to be dropped around the body mold 3. As a result, all the movements in the directions indicated by the arrows are all completed in an instant. When there is a concern that the movement in the direction of the arrow is not sufficiently performed, for example, a slight vibration in the direction of the arrow A may be given. Thereby, the movement in all the arrow directions is completed. It is even better to select the resonance frequency of the heat insulating cylinder as the frequency to be applied.
In order to remove the mold after completion of molding, first, the heat insulating cylinders 4, 5, and 6 are pulled upward. Next, the upper mold 1 is removed upward by the suction means. Next, the molded product is taken out by an adsorbing means. The remaining body mold 3 and lower mold 2 are not removed except during cleaning.

FIG. 2 is a diagram for explaining a configuration for specifying the positional relationship between the upper and lower molds and the upper and lower heat insulation cylinders. The figure (a) is a figure which shows each end surface of the combination of an upper mold | type and an upper heat insulation cylinder, and the figure (b) each of the combination of a lower mold | type and a lower heat insulation cylinder.
In FIG. 5A, the inner side of the upper heat insulating cylinder 6 is not completely circular, but a part thereof is formed by combining a part of a V shape. That is, a part of the inner side of the upper heat insulating cylinder 6 has two flat portions 6a and 6b. Needless to say, the contact surface of the large-diameter portion of the upper mold 1 that is in contact with the upper heat insulating cylinder 6 and the vicinity thereof are reduced in friction. Therefore, when the upper heat insulating cylinder 6 contacts the upper mold 1 from the lateral direction, the flat portions 6a and 6b and the large diameter portion of the upper mold 1 come into contact with each other, and the center positions of both are automatically adjusted. If comprised in this way, even if the upper mold | type 1 was brought close to one direction by the said contact, it can be hold | maintained in the state in which both center positions substantially corresponded.
In FIG. 2B, the relationship between the lower heat insulating cylinder 4 and the lower mold 2 is configured in exactly the same manner.

FIG. 3 is a diagram for explaining another configuration for specifying the positional relationship between the upper and lower molds and the upper and lower heat insulating cylinders. The figure (a) is an up-and-down type, the figure (b) is an up-and-down heat insulation cylinder, and the figure (c) is a figure showing how to combine an upper mold and an upper insulation pipe.
This configuration is an example in which one inner peripheral surface of the heat insulating cylinder and one flat portion of the outer peripheral surface of the mold are formed. However, the flat surface portion of the inner surface of the heat insulating cylinder is the surface closest to the position where the length of the bus bar is minimum and orthogonal to the major axis of the ellipse appearing on the inclined end surface.
Even in this configuration, if the approximate positional relationship between the mold and the heat insulating cylinder is matched in advance, the contact between the mold and the heat insulating cylinder automatically causes surface contact between 6c and 1c or 4c and 2c, and in the circumferential direction. The relative positional relationship is uniquely determined.
With this configuration, the relative positional relationship between the upper mold 1 and the upper thermal insulation cylinder 6 is always kept constant. Similarly, the relative positional relation between the lower mold 2 and the lower thermal insulation cylinder 4 in the circumferential direction is always kept constant. Be drunk. Moreover, the center of a type | mold and a heat insulation cylinder can also be substantially corresponded like the structure shown in FIG. 2 by the way of taking a plane part. As a result, the sliding direction of the middle heat retaining cylinder 5 is regulated by the upper and lower heat retaining cylinders and settles to a specific position (the lowest position), so the inner circumference of the middle heat retaining cylinder 5 may be a simple circle. Therefore, the molded product is always molded with the same amount of eccentricity even if the number of presses is repeated.

FIG. 4 is a diagram for explaining an engaging portion that defines the relative positional relationship between the heat insulating cylinders.
FIG. 5 is a partial view showing details of the engaging portions of the lower and middle heat insulating cylinders. FIGS. 4A and 4C are partially enlarged views of the lower surface of the middle heat insulation cylinder, and FIGS. 2B and 2D are partially enlarged views of the upper surface of the lower heat insulation cylinder.
Two protrusions 5d extending in the radial direction are formed on the lower surface of the middle heat insulating cylinder 5 at a position corresponding to the maximum diameter of the elliptical end face formed by the inclined cross section. Corresponding to this, two concave long grooves 4e are formed on the upper surface of the lower heat retaining cylinder 4 in which the ridges 5d can be fitted and slid.
When the middle heat insulating cylinder 5 is placed on the lower heat insulating cylinder 4, the protrusion 5d and the long groove 4e engage with each other to restrict the movement in the circumferential direction and simultaneously slide in the maximum radial direction.
The cross-sectional shape of the protrusion 5d shown in the figure is a triangular shape, but other shapes such as an arc may be used as long as the combination of unevenness and sliding can be guaranteed. The ridges 5d are not formed in the entire thickness direction of the intermediate heat insulating cylinder 5, but are shortened within a range in which the engagement of the concave and convex portions is not disengaged as shown by the ridge 5d 'in FIG. You can also. Further, like the long groove 4e ′ shown in FIG. 4D, the groove length can be shortened within a range that does not hinder the use state. In the case of this configuration, the end of the long groove 4e ′ serves as a stopper with respect to the protrusion 5d ′, so that the middle heat retaining cylinder 5 may slide down with respect to the lower heat retaining cylinder 4 even when the heat retaining cylinder is stored. It is convenient that the combined shape can be maintained.
In both figures, a protrusion is provided in the middle heat insulating cylinder 5 and a long groove is provided in the lower heat insulating cylinder 4, but the protrusion and the long groove may be formed in reverse.
By forming a similar sliding portion between the middle heat insulating cylinder 5 and the upper heat insulating cylinder 6, all of the three heat insulating cylinders can maintain an accurate circumferential positional relationship with each other.

FIG. 6 is a view for explaining a configuration in which the lower heat insulating cylinder and the trunk mold are omitted.
In the figure, reference numeral 8 is an upper mold, 9 is a lower mold, 10 is a trunk mold, 11 is an upper heat insulating cylinder, and AT is an auxiliary cylinder.
In this configuration, the lower heat insulating cylinder is omitted, the outer diameter of the large-diameter portion of the lower mold is formed to be approximately the same as the outer diameter of the heat insulating cylinder, and the upper surface thereof is equivalent to the upper surface of the lower heat insulating cylinder 4 in FIG. It is an inclined surface. Further, the body mold 3 in FIG. 1 is also omitted, and the inner peripheral surface of the body mold 10 having the same shape as the middle heat insulating cylinder 5 serves as a body mold.
The body mold is made of the same material because the linear expansion coefficient must be the same as the upper and lower molds. For this reason, since it is expensive, it is possible to reduce the mold cost by adding the function of the body mold to the heat insulating cylinder.
The assembly order of this configuration is as follows. First, the gob material 7 is placed on the lower mold 9, the trunk mold 10 and the upper heat insulating cylinder 11 are sequentially stacked on the lower mold 9, and finally the upper mold 8 is inserted. As an auxiliary tool, a long auxiliary cylinder AT having an inner diameter slightly larger than the maximum diameter of the lower mold 9 is prepared, and after passing through the lower mold 9, the body mold 10 and the upper heat insulating cylinder 11 are inserted to facilitate assembly. is there. In addition, although description was abbreviate | omitted in FIG. 1, it is convenient to use an auxiliary tool also in the case of FIG.

However, in this method, since the length of the auxiliary cylinder AT becomes long, the movement amount at the time of removal becomes large. As a method for preventing this, focusing on the fact that the auxiliary cylinder AT does not require high accuracy, the cylinder of the auxiliary cylinder AT is vertically divided into two parts, and two members AT1 and AT2 having a semicircular cross section are combined. A method of using a cylindrical auxiliary cylinder AT can be used. The members AT1 and AT2 are made of a magnetic material, and both the split surfaces are magnetized with opposite polarities, so that the cylindrical auxiliary cylinder AT can be easily formed simply by bringing them close to each other. Moreover, if the magnetic force is small, the removal becomes very easy.
The auxiliary cylinder AT is also useful when storing the divided heat insulating cylinder.

FIG. 7 is a diagram for explaining a configuration during heating of the mold.
In the figure, reference numeral 12 denotes a plate, 13 denotes a heater, 14 denotes a substrate, and P denotes an arrow indicating the moving direction of the plate.
On the substrate 14, the lower mold 9 is installed in the hole 12 a of the plate 12 and all the molds are assembled thereon. Then, the plate 12 is slid in the direction of arrow P, and the bottom surface of the lower mold 9 is placed on the upper surface of the substrate 14. By sliding, the position is determined so that the lower die 9 is substantially aligned with the center of the heater 13. In this state, the heater 13 is energized to heat the lower mold.
In the structure of the upper and lower molds 8 and 9 and the body mold 10, the thermal conductivity of these members is set high, and as such, a sudden temperature change during cooling is added to the gob material, which is not preferable.
As a solution, there is known a method of enclosing the periphery with a member having good heat retention (low thermal conductivity).
For this reason, in order to give the body mold 10 the function of a heat insulating cylinder, it is necessary to prevent heat from being rapidly taken away when the upper and lower molds are cooled.
In order to carry out easily, it is realizable by forming a layer with a low heat conductivity in the outer periphery in a base material with a mold material.
Specifically, when the conventional heat insulation cylinder is made of stainless steel, the outer peripheral portion of the mold material is made of chromium, nickel chrome, etc. having the same thermal conductivity as the stainless steel. A method of coating the material is suitable. Other materials with low thermal conductivity include ceramic and kovar. If comprised in this way, the trunk | drum 10 can play the role similar to the middle heat insulation cylinder 5. FIG.
Further, in this structure, since the heat retaining effect on the side surface of the lower mold becomes insufficient, it is preferable to form the layer having the low thermal conductivity on the side surface of the lower mold.

Here, let us consider the conditions for the thermal insulation cylinder to slide down the slope with its own weight. For that purpose, it is necessary to consider the equation of motion when two objects are placed on a slope.
FIG. 8 is a view showing a state in which the middle heat insulation cylinder and the upper heat insulation cylinder overlap with the slope.
In the figure, g is the gravitational acceleration, m1 is the mass of the object K, m2 is the mass of the object L, α1 is the acceleration of the object K, α2 is the acceleration of the object L, μ1 is the static friction coefficient of the friction force acting on the object K, μ2 represents the static friction coefficient of the friction force with the object K acting on the object L, θ1 represents the angle formed by the inclined surface M with the horizontal direction, and θ2 represents the angle formed by the contact surface between the object K and the object L formed with the horizontal direction.
Here, the horizontal direction means a plane orthogonal to the central axis when the central axis of the mold or the heat insulating cylinder is arranged along the vertical line. Consider a motion in the case where the objects K and L having masses m1 and m2 are superimposed on the slope M whose angle with the horizontal direction is θ1.
Since the frictional force acting on the object L is proportional to the vertical drag of gravity m2g,
μ2m2g cos θ2.
The component in the slope direction between the gravitational bodies K and L is m2gsinθ2.
Accordingly, when the right direction in the figure is the positive direction, the force applied to the object L Fb = m2α2 = −m2gsinθ2 + μ2m2gcosθ2
Of the force applied to the object K, the component of the gravitational slope M direction is m1 g sin θ1,
The frictional force is μ1 m1 g cos θ1.

FIG. 9 is a diagram showing the relationship of forces related to the slope.
Here, of the frictional force applied to the object L, the component in the slope M direction is shown in FIG.
μ2m2g cos θ2 · cos (θ1 + θ2), and since this component is applied to the object K as a reaction, the force applied to the object K is
Fa = m1α2 = −m1gsinθ1 + μ1m1gcosθ1 + μ2m2gcosθ2 · cos (θ1 + θ2)
It becomes.
Here, consider the case of μ1 = μ2 = μ.
If Fa <0, the object K slides on the slope, and when this is solved, it can be seen that the angle should be equal to or greater than that shown in Table 1. The unit of angle is [°] (degree).

Next, consider the time when the object L slides on the slope.
Force applied to the object L Fb = m 2 α 2 = −m 2 g sin θ 2 + μ 2 m 2 g cos θ 2 <0
If it is good.
This is calculated as shown in Table 2.

FIG. 10 is a diagram illustrating the relationship between the lower limit values of θ1 and θ2 for each condition.
In the figure, a solid line indicates a case where the friction coefficient is 0.5, and a broken line indicates a case where the friction coefficient is 0.44.
As described above, the angle θ1 formed between the object K and the slope C must be set in consideration of the angle θ2 formed between the object L and the object K.

Next, the sliding surface of the slope will be described.
According to Coulomb's law of friction, the frictional force is irrelevant to the area of the sliding surface. The macro level finish has surface irregularities, and there is a part (true contact area) that is close to the distance that causes atomic level interaction. It is considered to be very limited because the apparent contact area has no meaning.
However, when viewed at the micro level, the frictional resistance is reduced by the micro bearing effect (micro wedge film effect) due to each particle on the surface.
If each surface particle is considered as a small bearing, dynamic pressure is generated due to the rust film effect. For this reason, it is possible to lower the coefficient of static friction by positively applying minute irregularities to the sliding surface. In order to realize this, application of a porous material or a film is effective. Further, by filling a fine hole with a lubricant such as molybdenum disulfide, the frictional resistance can be further reduced, and the wear resistance and adhesion of the lubricant can be improved. Other lubricants include aluminum oxide, graphite, tungsten disulfide and the like.

FIG. 11 is a diagram showing an example in which a bearing is mounted on a slope. The figure (a) is a perspective view of a lower thermal insulation cylinder, and the figure (b) is a front view of a bearing.
In the figure, reference numeral 15 denotes a bearing.
Instead of modifying the divided heat retaining sliding surface, a so-called bearing 15 such as a linear ball bearing or linear roller bearing may be disposed on one side of the sliding surface. In the figure, an example in which the bearing 15 is embedded in the lower heat insulating cylinder 4 is shown, but conversely, the bearing 15 may be embedded in the middle heat insulating cylinder 5. Similarly, a bearing can be interposed between the middle heat retaining cylinder 5 and the upper heat retaining cylinder 6.
This relationship can also be applied between the lower mold 9 and the middle heat insulating cylinder 10 in FIG.

12 and 13 are views showing a method for aligning the middle heat insulating cylinder and the barrel mold. FIG. 12A is a perspective view of the middle heat insulating cylinder, and FIG. 12B is an enlarged view of the F portion. FIG. 13A is a perspective view of the middle thermal insulation cylinder, and FIG. 13B is an enlarged view of the G section. A concave groove is formed in the generatrix direction of the portion of the middle thermal insulation cylinder 5 in contact with the body mold 3. In the case of FIG. 12, a concave groove 5f having a semicircular cross section is formed, and in the case of FIG. 13, a concave groove 5g having a triangular cross section is formed. Although not shown in the drawings, in order to fit into these concave grooves, protrusions having the same cross-sectional shape in the same busbar direction on the outer periphery of the corresponding barrel mold 3 are provided as fitting portions. The protrusions of the fitting part of the body mold 3 may be provided through from the top to the bottom, or may be provided only at the part in contact with the intermediate heat insulating cylinder 5. By doing so, the circumferential position of the body mold is always a constant position (orientation), so that the shape variation of the molded product is further reduced.
This relationship can also be applied to the configuration of FIG. That is, the same ditch | groove 11f, 11g is formed as a fitting part with respect to the middle heat insulation cylinder 11. FIG. In this case, since the middle heat insulating cylinder 11 is in contact with the upper mold 8 and the lower mold 9, it is preferable to provide a protrusion as a fitting portion corresponding to both of them. In addition, in the case of this configuration, the protrusions corresponding to the concave grooves 11f and 11g are also formed on the molded product and can be used as position marks. Therefore, the position of the molded product can be specified, and the centering operation becomes very easy. .

FIG. 14 is a view for explaining a method of applying a position mark to a molded product using a body mold. FIG. 4A is a perspective view of a body mold, and FIG. 4B is a partially enlarged view in the vicinity of a position mark.
On the outer periphery of the body mold 3, ridges 3h corresponding to the concave grooves 5f and 5g of the intermediate heat insulating cylinder 5 shown in FIGS. Further, a protrusion 3 h ′ is formed on the inner periphery of the body mold 3 in the generatrix direction at a position in contact with the upper mold 1 and the lower mold 2. However, the length in the generatrix direction of the ridge 3h ′ is a length that is in contact with only the molded product after molding, and the ridge 3h ′ is not formed on the portions that are in contact with the side surfaces of the upper mold 1 and the lower mold 2. Thereby, the position mark which consists of a ditch | groove is formed in a molded article. Instead of forming the protrusion 3h ′ from above to below, fitting grooves corresponding to the upper mold 1 and the lower mold 2 can be formed. In this case, since the upper mold 1, the lower mold 2 and the body mold 3 are all fixed in a predetermined positional relationship, the shape variation of the molded product is further reduced.
In addition, the cross-sectional shape of the position mark provided on the inner periphery of the body mold 3 is not limited to the triangular shape of the protrusion 3h ′, but may be a semicircular shape, or may be a concave groove instead of the protrusion. In this case, the position mark formed on the molded product is a ridge. In the case of the concave groove, the groove can be formed from the top to the bottom regardless of the upper mold 1 and the lower mold 2. Moreover, it does not need to be long like a ridge or a groove, but may be a convex or concave shape such as a conical shape or a cylindrical shape.
Similarly, the convex portions and the concave portions of the intermediate heat insulating cylinder 11 and the upper die 8 and the lower die 9 may be interchanged. Furthermore, the convex portion and the concave portion may be interchanged in the same manner with respect to the fitting portion between the middle heat insulating cylinder 5 and the body mold 3.

FIG. 15 is a diagram for explaining the effect when the present invention is used for manufacturing an aspherical lens. FIG. 4A is an aspherical die pressing using a conventional mold, FIG. 4B is the centering of the molded product, and FIG. 4C is an aspherical lens mold using the mold according to the present invention. FIG. 4C is a diagram for explaining the centering of the molded product.
The mold of the present invention is particularly effective in the production of aspherical lenses.
Problems of the conventional method will be described with reference to FIGS. In the case of an aspheric lens, there is an aspheric axis, and this deviation has a great influence on the optical performance. In the conventional method, since alignment of the upper mold 1 and the lower mold 2 is difficult, the respective aspherical axes may not be aligned on the same straight line. Therefore, when centering the molded product 7 ′ and adjusting the outer periphery to the position indicated by the broken line, a comprehensive optical axis generated by the synthesis of both aspheric surfaces is searched, and the outer periphery is shaped according to the optical axis. To do. As a result, the overall optical axis is shifted from the original aspherical axis, the optical performance is deteriorated, and the centering operation takes time.

The effects of the present invention will be described with reference to FIGS. According to the present invention, the upper mold 1 and the lower mold 2 are offset in the same direction with respect to the body mold 3, so that the upper and lower aspherical axes coincide in principle on the same straight line. Moreover, since the aspherical axis is parallel to the outer peripheral surface, it is very easy to mount the molded product 7 ″ when the centering operation of the molded product 7 ″ is performed to align the outer periphery with the position of the broken line.
Further, it is possible to omit the centering work of the molded product by matching the lens frame itself with the shape of the molded product by utilizing the fact that the molded product has less variation. In this case, if a position mark is given to the molded product, the lens frame is formed in a shape corresponding to it, and the position of the molded product that is not centered with the position mark of the lens frame as a mark. The lens frame is automatically centered by simply dropping it while aligning the marks.

It is a figure for demonstrating the basic principle of this invention. It is a figure for demonstrating the structure for pinpointing the positional relationship of an up-and-down type | mold and an up-and-down heat insulation cylinder. It is a figure for demonstrating the other structure for pinpointing the positional relationship of an up-and-down type | mold and an up-and-down heat insulation cylinder. FIG. 4 is a diagram for explaining an engaging portion that defines the relative positional relationship between the heat insulating cylinders. It is a fragmentary figure which shows the detail of the engaging part of a lower and middle heat insulation cylinder. It is a figure for demonstrating the structure which abbreviate | omitted the lower heat insulation cylinder and the trunk | drum. It is a figure for demonstrating the structure at the time of the heating of a type | mold. It is a figure which shows the state in which the middle heat insulation cylinder and the upper heat insulation cylinder have overlapped on the slope. It is a figure which shows the relationship of the force regarding a slope. It is a figure which shows the relationship between the lower limit of (theta) 1 and (theta) 2 according to conditions. It is a figure which shows the example which mounts a bearing on a slope. It is a figure which shows the method of aligning a middle heat insulation cylinder and a trunk | drum. It is a figure which shows the method of aligning a middle heat insulation cylinder and a trunk | drum. It is a figure for demonstrating the method of providing a position mark to a molded article using a trunk die. It is a figure for demonstrating the effect at the time of using this invention for manufacture of an aspherical lens.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 8 Upper mold | type 2,9 Lower mold | type 3,10 Body type | mold 4 Lower insulation cylinder 5 Middle insulation cylinder 6,11 Upper insulation cylinder 7 Gob material 15 Bearing

Claims (33)

  In a mold having an upper and lower mold composed of a large diameter part and a small diameter part, a body mold, and a cylindrical heat insulation cylinder made of a material having a lower thermal conductivity than each of the molds, Each of the heat insulation cylinders having an inclined surface divided by two planes inclined in the opposite direction is configured to be movable along the inclined surface by its own weight with the inclined surface as a sliding surface. A mold characterized by having   2. The mold according to claim 1, wherein a fitting portion for positioning in a circumferential direction is provided on each of the opposed inclined surfaces of the divided heat insulating cylinders.   The molding die according to claim 2, wherein the fitting portion also serves as a stopper for preventing slipping.   4. The molding die according to claim 1, wherein at least one inner circumference of the uppermost part and the lowermost thermal insulation cylinder of the divided thermal insulation cylinder is in contact with a large diameter part of the mold. A mold having two portions formed.   The molding die according to any one of claims 1 to 3, wherein at least one of the upper die, the lower die, and the barrel die and the divided heat insulating cylinder having a contact portion therewith are arranged in a circumferential direction. A forming die provided with a shape for positioning.   6. The molding die according to claim 5, wherein the shape for positioning includes an inner portion in the vicinity of a single flat surface portion provided on a large diameter portion of the upper die or the lower die and a minimum length bus bar of the heat insulating cylinder. A molding die characterized in that it is a flat portion provided on a peripheral portion.   6. The molding die according to claim 5, wherein the shape for positioning is formed in the generatrix direction of the outer diameter of the large-diameter portion or the barrel die of the upper mold, the lower mold, and the inner circumference of the heat retaining cylinder. A molding die characterized by being a fitting part composed of a ridge and a groove.   The molding die according to any one of claims 1 to 7, wherein positioning is performed in a circumferential direction between an outer circumference of at least one of the upper mold and the lower mold and an inner circumference of the barrel mold. A mold characterized by having a shape of   9. The molding die according to claim 8, wherein the shape for positioning is from a ridge and a groove formed in the direction of the generatrix of the small diameter portion of the upper die and the lower die and the inner circumference of the barrel die, respectively. A mold characterized by being a fitting part.   In a mold having an upper and lower mold, a body mold, and a cylindrical heat insulation cylinder composed of a large diameter part and a small diameter part, the bottom surface of the heat insulation cylinder has a shape cut by a plane inclined at a predetermined angle with respect to the bus bar. The upper surface of the body mold is formed as an inclined surface having an angle coincident with the inclination angle of the lower surface of the heat insulating cylinder, and the lower surface of the body mold is cut off by another plane inclined in a direction opposite to the inclined lower plane. The upper surface of the large-diameter portion of the lower mold is formed into an inclined surface having an angle coincident with the inclined angle of the lower surface of the body mold, and the heat insulating cylinder and the body mold have the inclined surface as a sliding surface, A molding die configured to be movable along an inclined surface.   11. The molding die according to claim 10, wherein positioning is performed in a circumferential direction on at least one of the inclined surfaces of the heat retaining cylinder and the barrel mold facing each other and the inclined surfaces of the barrel mold and the lower mold facing each other. A mold having a fitting portion.   12. The mold according to claim 11, wherein the fitting portion also serves as a stopper for preventing slipping.   The mold according to any one of claims 10 to 12, wherein two flat portions in contact with the large-diameter portion of the upper mold are formed on the inner periphery of the heat retaining cylinder.   13. The mold according to claim 10, wherein a shape for positioning in a circumferential direction is provided between the upper mold and the heat retaining cylinder. .   13. The molding die according to claim 10, wherein a shape for positioning in a circumferential direction is provided between the barrel die and at least one of the upper die and the lower die. A mold characterized by.   The molding die according to claim 15, wherein the shape for positioning is a fitting portion formed of a protrusion and a groove formed in the direction of the generatrix of the outer periphery of the die and the inner periphery of the heat retaining cylinder, respectively. A mold characterized by being.   The mold according to any one of claims 10 to 16, wherein the upper and lower molds and the body mold are formed of a mold material having similar thermal conductivity, and the body mold and the lower mold large-diameter portion are formed. A molding die characterized in that a layer of a material having a thermal conductivity lower than that of the molding die material is provided on at least one outer periphery.   18. The mold according to claim 17, wherein the material having low thermal conductivity is a material containing ceramic, chromium, nickel chromium or kovar as a component.   19. The molding die according to claim 1, wherein a position mark shape including a ridge or a groove is formed at least in a portion in contact with the molded product in an inner peripheral portion of the barrel die. A mold characterized by.   The mold according to any one of claims 1 to 19, wherein a porous material is used as a material having a low thermal conductivity used for the heat insulating cylinder or the like.   The mold according to any one of claims 1 to 20, wherein the sliding surface is formed of a material containing any of molybdenum disulfide, aluminum oxide, graphite, and tungsten disulfide, or depends on the material. A mold having a layer formed thereon.   21. The mold according to claim 1, wherein one of the sliding surfaces is formed with fine irregularities and the other is formed on a flat surface.   21. The mold according to claim 1, wherein a porous film is formed on the sliding surface.   The mold according to claim 20 or 23, wherein a lubricant is embedded in a hole of the porous film on the sliding surface.   25. The mold according to claim 24, wherein the lubricant is molybdenum disulfide, tungsten disulfide, or graphite.   21. The mold according to claim 1, wherein a sliding member is disposed on the sliding surface.   27. The mold according to claim 26, wherein the sliding member is a linear ball bearing or a linear roller bearing. The molding die according to any one of claims 1 to 27, wherein, of the two inclined surfaces, an angle formed by a lower inclined surface with a horizontal plane is θ1, and an angle formed by an upper inclined surface with a horizontal plane is θ2. , The mass of the member mounted on the lower inclined surface is m1, the mass of the member mounted on the upper inclined surface is m2, the coefficient of static friction between the members in contact with the lower inclined surface is μ1, the upper When the coefficient of static friction between members in contact with the inclined surface is μ2, θ1 and θ2 are
−m1sin θ1 + μ1 m1 cos θ1 + μ2 m2 cos θ2 · cos (θ1 + θ2)
<0
-M2sinθ2 + μ2m2cosθ2 <0
A mold characterized by satisfying   A molding method using the molding die according to any one of claims 1 to 28, wherein the upper and lower dies and the barrel die are automatically aligned.   The molding die according to any one of claims 1 to 28 is used, and an auxiliary cylinder having an inner diameter larger than that of the largest diameter member is placed on the lower mold among the mold and the thermal insulation cylinder, and then the upper mold and the thermal insulation cylinder are attached. A molding method comprising inserting into the auxiliary cylinder.   31. The molding method according to claim 30, wherein the auxiliary cylinder is formed by combining semi-cylindrical members divided into two in the generatrix direction.   A glass molded body produced using the mold according to any one of claims 1 to 28.   An electro-optical device manufactured using the glass molded body according to claim 32.

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