JP2003251650A - Molding apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding apparatus capable of performing highly accurate molding in spite of a simple constitution. <P>SOLUTION: Air being a pressure transmission medium applies a pressure difference at least in the axial line direction in the gap between a lower mold fitting and holding member 8 and a slider 10 when the slider 10 is inclined with respect to the lower mold fitting and holding member 8 so as to generate a moment for correcting the inclination of the slider 10. Therefore, the inclination of the slider 10 can be suppressed with respect to the lower mold fitting and holding member 8 and a highly accurate molded article can be formed by properly positioning a mold at the time of molding. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding apparatus using a molding die, and for example, improves the eccentricity accuracy and axial accuracy of a molded product such as an optical element without using a complicated mechanism, and realizes highly accurate molding. The present invention relates to a molding device that enables stable production of products.

[0002]

2. Description of the Related Art Usually, a member forming a cavity for molding a high-precision component such as an optical element has a molding surface and is a pair of die parts (also referred to as core parts or insert parts) or a pair of die parts. It consists of a die part and a barrel part that forms the outer periphery of the molding surface. The eccentricity of this pair of die parts must be regulated with extremely high precision in order to obtain a highly accurate molded product, but pressure is transmitted to the fitting part for performing the press operation and opening / closing the molding cavity during molding. By supplying the medium, non-contact holding can be realized,
As a result, highly accurate and highly reproducible eccentricity regulation with extremely few variations can be realized.

[0003]

If the centers of the molding surfaces of a pair of die parts are eccentric to each other due to the parts machining accuracy and assembly accuracy, this is a deviation error, so the non-contact fitting part If the pressure distribution of the pressure transmission medium supplied to the entire circumference is given a bias distribution in the circumferential direction, highly accurate shift eccentricity adjustment of 1 μm or less can be easily performed. Regarding the molding die and the molding apparatus having such a function, the principle thereof has already been described in detail in JP 2001-341134 based on the invention of the same inventors as the present application. In addition, the mechanism using the pressure transmission medium to realize this high precision molding has a very simple structure,
No mention is made of a simpler and more practical form, or a mechanism for replacing a mold part whose molding surface is deteriorated or damaged by repeated molding.

In view of the above points of the present invention, it is an object of the present invention to further develop the useful idea of the prior application and to provide a molding apparatus capable of performing highly accurate molding in spite of its simple structure.

[0005]

According to a first aspect of the present invention, there is provided a molding apparatus including a moving member for holding a mold for forming a molding cavity for molding a molded article, and a movable member that includes the moving member and is relatively movable. And a supply means for supplying a pressure transmission medium to a gap between the movable member and the fixed member, wherein the pressure transmission medium moves the movable member with respect to the fixed member. While maintaining the non-contact state, when the moving member is tilted with respect to the fixed member, a pressure difference is given at least in the axial direction in the gap so as to generate a moment that corrects the tilt. The inclination of the moving member with respect to the fixed member can be suppressed, and the molding die can be formed with high precision by appropriately positioning the molding die during molding. The present invention will be described later with reference to FIG.

Here, when molding is performed by a pair of molding dies having molding surfaces facing each other, with respect to the eccentricity between the molding dies, if the machining accuracy of the molding dies and the mounting members thereof is high to some extent, both of them are formed by a pressure transmission medium. There is no need for non-contact support.
For example, the fitting gap through which the pressure transmission medium flows is set to, for example, 10 μm.
If it is set to about m, this means that the shift adjustment range is up to plus or minus 10 μm. A moving differential member that takes a large supply differential pressure at a 180-degree position where the blowout port of the pressure transmission medium faces the axis is taken, and finally holds and moves the molding die, is separated via the pressure transmission medium. This is because the shift adjustment range is until the contact with the fixed member. Applying this mechanism to both molds facing each other relatively gives a shift adjustment range of ± 20 μm. However, as long as the machining accuracy of the mold is at least 10 μm or less, it is not necessary to support both of the facing molds in a non-contact manner, and only one mold can move during the pressing operation and opening / closing of the mold cavity. Since it suffices to support one of the molds, it is possible to halve the pipes and valves for the pressure transmission medium by fixing one of the molds, resulting in a very simple structure.

In the molding apparatus according to the second aspect, it is preferable that the gap is within 20 μm (more specifically, around 10 μm) because the movable member can be easily positioned with respect to the fixed member with high accuracy.

The molding apparatus according to claim 3, wherein when the molding die is placed at a molding position, a midpoint of the moving direction of a surface of the moving member which is supported in a non-contact manner by the pressure transmitting medium, If the distance between the thickness center of the molding cavity of the molding die in the moving direction is ± 300 mm or less, even if the pressure difference of the pressure transmission medium in the gap at least in the axial direction is small, This is preferable because the moving member can be easily positioned with respect to the fixed member with high accuracy. Here, for example, + 300m
m is the midpoint of the moving direction of the moving member,
The case is 300 mm above the thickness center of the molding cavity of the molding die in the moving direction, and -300 mm means that the midpoint of the moving direction of the moving member is the moving direction of the molding cavity of the molding die. It refers to the case of being 300 mm below the thickness center.

In the molding apparatus according to the fourth aspect, when a holding member that holds the counter molding die that opposes the molding die is fixed to the fixing member, with respect to the fixed counter molding die, Since the molding die attached to the moving member may be positioned using the pressure transmission medium, the configuration is simplified.

In the molding apparatus of the fifth aspect, at least one of mounting the molding die and the moving member and mounting the opposing molding die and the holding member is performed by taper surface fitting. With this, the molding die or the opposing molding die can be positioned more accurately.

In the molding apparatus according to the sixth aspect of the present invention, if a cooling means for cooling at least one of the moving member and the fixed member is provided, it is possible to suppress uneven thermal expansion of the moving member and the fixed member. Higher precision molding can be performed.

In the molding apparatus according to the seventh aspect, when the fixing member is arranged at a position for containing the molding die during molding, the effect of suppressing the inclination of the moving member by the pressure transmitting medium is further enhanced. be able to.

In the molding apparatus according to the eighth aspect, when the optical element is molded by molding using the molding die, a highly accurate optical element can be molded. As an optical element,
For example, lens, prism, diffraction grating optical element (diffraction lens, diffraction prism, diffractive plate), optical filter (spatial low pass filter, wavelength band pass filter, wavelength low pass filter, wavelength high pass filter, etc.), polarization filter (analyzer, optical rotator) , A polarization separation prism, etc.) and a phase filter (phase plate, hologram, etc.) are conceivable, but not limited thereto.

According to a ninth aspect of the present invention, there is provided a molding apparatus having a fixing member for supporting a molding die forming a molding cavity for molding a molded article so as to be relatively movable, and the molding die has the fixing member. On the other hand, since it is supported by the pressure transmission medium interposed in the gap between the molding die and the fixing member, it is possible to support the molding die with low friction, and by utilizing the gap, Positioning in the direction orthogonal to the axis and adjustment of the inclination with respect to the axis can be performed. The “molding die” referred to in the present invention is the lower die 12 in the embodiment of FIG.
And the lower die fixed support 11 and the slider 10 correspond to each other, and in the embodiment of FIG. 3, the lower die 12, the lower die fixed support 11 and the slider 10 ′ correspond to each other. However, in the embodiment of FIG. 4, the upper die 5, the upper die fixed support member 23,
The plate 23a and the slider 20 'are equivalent, but not limited to them.

According to a tenth aspect of the present invention, there is provided a molding device according to the tenth aspect, wherein a fixing member for movably supporting a molding die forming a molding cavity for molding a molded product and the fixing member is fixed to the fixing member. And a holding member for holding an opposing molding die facing the molding die, the molding die being supported by a pressure transmission medium interposed in a gap between the molding die and the fixing member with respect to the fixing member. Therefore, the mold can be supported with low friction, and the gap can be used to position the mold in the direction orthogonal to the axis and adjust the inclination with respect to the axis. In the embodiment of FIG. 1, the “molding die” referred to in the present invention is the lower die 12 and the lower die fixed support 11.
And the slider 10 correspond to each other. In the embodiment of FIG. 3, the lower mold 12, the lower mold fixing support 11 and the slider 10 'correspond to each other, and the embodiment of FIG. Then, the upper mold 5, the upper mold fixed support member 23, the plate 23a, and the slider 20 'correspond, but the invention is not limited thereto. Other terms are associated with each other according to the description of the embodiments described later (hereinafter, the same).

[0016] A molding apparatus according to a eleventh aspect of the present invention is a moving member that holds a molding die that forms a molding cavity for molding a molded product, a fixed member, and is fixed to the fixed member and faces the molding die. And a holding member for holding the opposed molding die, wherein the moving member is provided with respect to the fixed member.
Since the movable member is supported so as to be relatively movable by the pressure transmission medium interposed in the gap between the moving member and the fixed member, the moving member can be supported with low friction, and the molding is performed by using the gap. Positioning of the mold in the direction orthogonal to the axis and adjustment of the inclination with respect to the axis can be performed.

According to a twelfth aspect of the present invention, in a molding apparatus, a first holding member for holding a molding die for forming a molding cavity for molding a molded product, and a first holding member for holding an opposing molding die facing the molding die are provided. And a second holding member, and the first holding member is supported so as to be relatively movable with respect to the second holding member by a pressure transmission medium interposed in a gap therebetween, so that low friction is achieved. It is possible to support the molding die with the use of the gap, and use the gap to perform positioning of the molding die in the direction orthogonal to the axis and adjustment of the inclination with respect to the axis. The "first holding device" in the present invention corresponds to the assembly of the lower die fixed support 11 and the slider 10 in the embodiment of FIG. 1 and the lower die support in the embodiment of FIG. Mold fixed support 11
And the slider 10 ′ correspond to each other, and in the embodiment of FIG. 4, the upper die fixing support member 23, the plate 23a, and the slider 20 ′ correspond to each other, while the “second holding device” corresponds to
The embodiment of FIG. 1 corresponds to an assembly of the lower mold fitting support member 8, the frame 1, and the upper mold fixing support member 3.
In the embodiment of FIG. 4, it corresponds to an assembly of the lower mold fitting support member 8 ′, the frame 1, the intermediate plate 14, the upper lid 2, and the upper mold fixing support member 3, and in the embodiment of FIG. An assembly of the lower die fixed support 21, the plate 22, and the lower die fitting support member 28 corresponds, but is not limited thereto.

According to a thirteenth aspect of the present invention, there is provided a molding device according to the thirteenth aspect of the present invention, in which a movable member for holding a mold for forming a molding cavity for molding a molded article is fixedly mounted, and the fixed member is fixed to the fixed member. A holding member for holding an opposite molding die facing the die so as to be attachable, wherein the moving member is a pressure transmission medium interposed between the moving member and the moving member in a gap between the moving member and the fixed member. Therefore, at least one of the mounting of the molding die and the moving member, and the mounting of the opposing molding die and the holding member is performed by taper surface fitting, The movable member can be supported with low friction, and the gap can be utilized to position the molding die in a direction orthogonal to the axis and adjust the inclination with respect to the axis, and further, to form the molding die and / or Countercurrent mold can be more accurately positioned.

According to a fourteenth aspect of the present invention, there is provided a molding device including: a moving member that holds a molding die that forms a molding cavity for molding a molded product; and a fixed member that includes the moving member and holds the moving member so as to be relatively movable. Supply means for supplying a pressure transmission medium to a gap between the moving member and the fixed member, the pressure transmission medium being provided in at least one of the moving member and the fixed member. The discharge port is configured to discharge toward the other side, and the plurality of discharge ports are provided at the same position in the axial direction and along the circumferential direction in at least one of the moving member and the fixed member. Since they are individually arranged, it is possible to support the moving member with low friction, and by utilizing the gap,
The molding die can be positioned in the direction orthogonal to the axis, and the inclination with respect to the axis can be determined.

According to a fifteenth aspect of the present invention, in the molding apparatus, after the pressure transmission medium is discharged from the blow-out port, the pressure transmission medium is directed in a direction opposite to the axial direction, and is interposed between the moving member and the fixed member. It is adapted to escape from one escape position to the outside, and the blowout port is preferably arranged at a midpoint in the axial direction of the two escape positions. It should be noted that rather than displacing the blowout port in the axial direction, it is better to place the blowout port at the same position in the axial direction because the pressure gradient of the pressure transmission medium becomes symmetrical about the blowout port in the axial direction. The advantage that the pressure of the pressure transmission medium discharged from each outlet is easily adjusted can be obtained, but the present invention is not limited to this.
Further, a plurality of outlets may be provided in the axial direction, and the outlets may be arranged rotationally symmetrically with respect to the axis on each holding surface. In this case, the pressure transmitting medium discharged from the outlets arranged in the axial direction may be By independently adjusting the supply pressure, the inclination of the molding die with respect to the axis and the moment rigidity thereof can be improved.

According to a sixteenth aspect of the present invention, there is provided a molding device comprising: a moving member that holds a molding die that forms a molding cavity for molding a molded product; and a fixed member that includes the moving member and holds the moving member so as to be relatively movable. Supply means for supplying a pressure transmission medium to a gap between the moving member and the fixed member, the pressure transmission medium being provided in at least one of the moving member and the fixed member. A plurality of blow-out ports are arranged in the axial direction in at least one of the moving member and the fixed member, and are discharged in the circumferential direction from the blow-out port of the means. Since a plurality of rollers are arranged rotationally symmetrically with respect to the axis, the moving member can be supported with low friction, and the molding die can be positioned in the direction orthogonal to the axis by utilizing the clearance. Further, allows an adjustment of the inclination with respect to the axis of the mold by adjusting the supply pressure of the pressure transmitting medium ejected from the outlet disposed axially independently.

According to a seventeenth aspect of the present invention, there is provided a molding device, wherein a moving member for holding a molding die for forming a molding cavity for molding a molded product, a fixed member, and a fixed member fixed to the fixed member are opposed to the molding die. And a holding member for holding the opposed molding die, wherein the moving member is provided with respect to the fixed member.
By the pressure transmission medium interposed in the gap between the moving member and the fixed member, is supported so as to be relatively movable,
When the molding die is arranged at a molding position, a midpoint of the moving direction of a surface of the moving member which is supported in a non-contact manner by the pressure transmission medium, and a thickness center of the molding cavity of the molding die in the moving direction. However, since the distance is ± 300 mm or less, the moving member can be supported with low friction, and even if the pressure difference of the pressure transmitting medium in the gap at least in the axial direction is small, the fixing member is small. On the other hand, there is an advantage that the moving member can be easily positioned with high accuracy.

According to a eighteenth aspect of the present invention, there is provided a molding device, wherein a moving member for holding a molding die for forming a molding cavity for molding a molded product, a fixed member, and a fixed member fixed to the fixed member are opposed to the molding die. A holding member for holding the opposing molding die, and a retractable shield member connecting the moving member and the fixed member, wherein the moving member has the moving member and the fixed member with respect to the fixed member. The movable member is supported so as to be relatively movable by a pressure transmission medium interposed in a gap between the movable member and the member. Since the shielding member shields at least the periphery of the mold at the time of molding, it supports the movable member with low friction. At the same time, the gap can be utilized to perform positioning in the direction orthogonal to the axis of the molding die and adjustment of the inclination with respect to the axis, and moreover, by the shielding member, the moving member and the fixing member can be kept at high temperature. By thermally isolated from the shape atmosphere, it can be avoided thermal expansion problems.

For example, when molding glass or the like, the molding atmosphere generally has a high temperature of about 500 to 600 ° C., so that the gap between the moving member to which the pressure transmitting medium is supplied and the fixed member is about. When it is as narrow as 10 μm, when there is a local temperature deviation between the moving member and the fixed member, the change in the amount of gap due to thermal expansion is several tens%.
Due to the change, the holding rigidity may be remarkably reduced, and in some cases, the gap may become zero, causing galling of the member. On the other hand, as in the present invention,
By thermally isolating the moving member and the fixed member from the high temperature molding atmosphere by using the shielding member, the temperature can be maintained at 100 ° C. or less, for example, and the temperature gradient of each member is gentle. As a result, unnecessary thermal expansion can be suppressed, and smooth operation of the molding apparatus can be ensured.
A metal bellows or the like is conceivable as the "extendable and retractable shield member", but is not limited thereto.

The molding apparatus according to claim 19, wherein the pressure transmission medium is room temperature pressurized air at -10 ° C or higher (to prevent dew condensation) and 30 ° C or lower (to suppress reduction in rigidity). Since it is a medium normally used in the above, special piping and the like are not required, and it can be obtained at low cost, which is preferable.
Also, when water or oil is used as a pressure transmission medium adjacent to a high-temperature molding atmosphere, instantaneous vaporization (explosive vaporization) may occur, so it is necessary to take measures to prevent this. However, if it is air at room temperature and pressure, it can be said that handleability is excellent from this point of view.

In the molding apparatus according to the twentieth aspect, a moving member for holding a mold for forming a molding cavity for molding a molded product, a fixed member, and a member fixed to the fixed member and facing the mold. A holding member for holding the opposing molding die, and a cooling unit for cooling at least one of the moving member and the fixed member, wherein the moving member has the moving member and the fixed member with respect to the fixed member. It is characterized in that it is supported so as to be relatively movable by a pressure transmission medium interposed in a gap between the and.

As described above, the molding atmosphere for molding glass or the like is usually 500 to 600 ° C.
Since the temperature becomes high, the gap between the moving member to which the pressure transmitting medium is supplied and the fixed member is about 10 μm.
In the case where the distance is as narrow as m, when there is a local temperature deviation between the moving member and the fixed member, the change in the gap amount changes by several tens of percent due to thermal expansion, so that the holding rigidity is significantly reduced. However, in some cases, the gap becomes zero, which may cause the member to be scratched. In contrast,
As in the present invention, by cooling at least one of the moving member and the fixed member by the cooling means, if the temperature can be maintained within a predetermined temperature range (for example, 100 ° C. or less), the temperature gradient of each member is gentle. As a result, unnecessary thermal expansion can be suppressed, and smooth operation of the molding apparatus can be ensured.

If the shielding member or the cooling means is used, for example, in order to improve the positioning accuracy, when the molding die is placed at the molding position, the surface of the moving member which is supported by the pressure transmission medium in a non-contact manner is supported. Even when the midpoint of the moving direction and the thickness center of the molding cavity of the molding die in the moving direction are arranged at a distance of ± 300 mm or less, the moving member and the moving member and the At least one of the fixing members can be thermally isolated from the hot molding atmosphere, which contributes to downsizing of the apparatus.

However, it is also possible to use the shielding member and the cooling means together. In such a case, the cooling medium of the cooling means is prevented from being overheated, so that the cooling efficiency thereof is enhanced. In some cases, water, oil or the like can be used as the pressure medium.

In a molding apparatus according to claim 21, when an optical element is molded by molding using the molding die,
A highly accurate optical element can be molded.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a molding apparatus according to this embodiment. This molding apparatus is applied to a hot press molding mechanism. In FIG. 1, an upper die fixing support member 3 is fixedly arranged on an upper portion of a sturdy frame 1 via an upper lid 2. The upper mold fixing and supporting member 3, which is a holding member, has an upper mold retainer 4 and an upper mold (opposing mold) 5 attached thereto by tapered surface fitting (described later). A heater 6 and a thermocouple 7 are inserted inside the upper mold 5. The lower die 12 is also the lower die retainer 1 like the upper die 5.
3 is attached to the lower mold fixing support member 11 by taper surface fitting (described later), the heater and the thermocouple are inserted into the lower mold 12, and the lower mold fixing support member 11 is coupled to the slider 10. It can move up and down as a unit.

At the bottom of the frame 1, a cylindrical lower die fitting support member 8 is attached. The lower die fitting support member 8 as a fixing member is connected to the internal passage 8a and the inner passage 8a, and is located at the center of the inner peripheral surface of the lower die fitting support member 8 in the axial direction and at equal intervals in the circumferential direction. 4 (only two are shown in FIG. 1) are provided. A pipe 9 communicating with an external air source (not shown) is connected to the internal passage 8a.

A slider 10 is arranged inside the lower mold fitting support member 8. The slider 10 has a cylindrical shape and is fitted to the inner periphery of the lower mold fitting support member 8, and the gap between them is about 10 μm. A lower die fixed support 11 is attached to the upper end of the slider 10, and a lower die (molding die) 12 is attached to the upper portion of the lower die fixed support 11 by a tapered surface fitting (described later) via a lower die retainer 13. It is installed. The slider 10 and the lower die fixed support 11 constitute a moving member.

A cylindrical heat insulating wall 15 is arranged between the intermediate plate 14 attached to the frame 1 and the upper die fixing support member 3 so as to surround the lower outer periphery of the upper die 5. . Further, on the outside of the lower die fixed support 11,
A metal for maintaining the molding atmosphere between the intermediate plate 14 and the slider 10 regardless of the movement of the slider 10 and thermally isolating the slider 10 and the lower die fitting support member 8 from the molding atmosphere. The bellows 16 is arranged as a shield member so as to be expandable and contractible.

In the present embodiment, from the outside air source, through the pipe 9 and the internal passage 8a, from the orifice outlet (also simply referred to as outlet) 8b on the inner peripheral surface of the lower die fitting support member 8, Air at room temperature (air pressure of 5 atm) is blown as a pressure transmitting medium, thereby supporting the slider 10 in a non-contact state with the lower die fitting support member 8. At the time of molding, the slider 10 and the lower die fixed support 11 move upward in accordance with the pressing force from below, and the upper die 5
A material such as glass in a molten state conveyed between the mold and the lower mold 12 is pressed between them to obtain an optical element having a shape corresponding to the mold. An air source (not shown) and the pipe 9
The internal passage 8a and the outlet 8b constitute a supply means. Further, although the lower die fitting support member 8 and the slider 10 and their fitting surfaces are cylindrical in this example, they may be square pillars or the like in order to self-regulate the rotation around the movable axis. Further, in order to increase the rigidity, a servo mechanism such as a spool valve or a diaphragm valve may be incorporated in the circuit of the air outlet or the pressure transmitting medium.

Here, the inside of the heat insulating wall 15 (molded portion A)
Is maintained in an atmosphere of, for example, a high temperature inert gas (nitrogen, argon, etc.) in order to perform appropriate molding. On the other hand, the space between the lower mold fitting support member 8 and the slider 10 needs to be precisely maintained at a gap of about 10 μm over the entire circumference by the air at room temperature discharged from the air outlet 8b. In order to suppress the competition of parts due to expansion, the lower mold fitting support member 8 is preferably arranged as far away as possible from the high temperature atmosphere.

However, it has been found that when the lower die fitting support member 8 is separated from the molding section A, the following problems occur. This problem is solved by the lower die fitting support member 8 and the slider 1.
It will be described with reference to FIG. Incidentally, FIG.
In the drawing, the lower die fitting support member 8 is depicted as being inclined, but this is relative, and in fact, the slider 10 is inclined with respect to the lower die fitting support member 8, The restoring force is also given to the slider 10.

Generally, in the non-contact fitting support by the pressure transmitting medium, the static rigidity in the direction perpendicular to the fitting surface can be made very high, and a certain restoring force (moment) can be applied to the moment rigidity such as tilting. Can occur. This is because, as shown in FIG. 2, when a moment acts on the slider 10 for some reason, the midpoint B of the fitting length (the slider 10 as the moving member and the lower die fitting support member 8 as the fixing member). It rotates around a midpoint between two escape positions C and D where air, which is a pressure transmission medium, escapes from the gap between the two, and the air outlet 8b is provided here). The area where the spreading pressure decreases (left in FIG. 2) and the area where the gap narrows and the pressure increases (right in FIG. 2) have the same area, and the total static rigidity in the direction perpendicular to the mating surface. Keeps this state because
The restoring force of the slider 10 can be obtained by a moment that is obtained by simply applying a very short distance from the midpoint B of the fitting length to the pressure difference of the pressure transmission medium between the portion where the gap is widened and the portion where the gap is narrowed. However, it can be said that the restoring force does not become sufficiently large depending on the conditions.

As a comparative example, this is shown by specific numerical values. As a comparative example, the distance between the center of the thickness in the pressing direction of the molding cavity (the center of the thickness of the optical element at the time of molding) and the center of the tilt center at the time of molding (in FIG. 1). Δ) is about 430 mm, and the fitting length (axial direction length of the lower die fitting support member 8) is 160 mm. Assuming that the shift force acts in the molding cavity, the moment is 430/80 = about 5.
The pressure transmitting medium must generate a quadruple restoring moment. Assuming that the shift of the lower die 12 must be suppressed to 1 μm or less when a shift force is applied during molding, the gap change amount at the end of the lower die fitting support member 8 is 1 μm.
m / 5.4 = 0.19 μm. If the lower die fitting support member 8 has a static rigidity of 1000 N / μm, the resulting restoring moment is 0.19 μm × 1000 N / μm × 8.
It becomes 0 mm = 15200 Nmm. Actually this is the lower mold 1
How much is equivalent to the shift force of 2 is 1
5200Nmm / 430mm = only about 35N. A force of only 35 N acts on the lower die 12 in a direction perpendicular to the movable axis direction (sideways direction), and a shift eccentricity of 1 μm occurs between the upper die 5 and the lower die 12. As described above, the non-contact support by the pressure transmission medium has a drawback that the low moment rigidity tends to affect the eccentricity between the molds.

Therefore, as a result of earnest research, the present inventor suppresses the distance Δ between the thickness center of the molding cavity in the pressing direction (the thickness center of the optical element at the time of molding) and the tilt center position at the time of molding within 300 mm. It was found that the slider 10 can increase the restoring moment (force) acting on the lower mold 12 to suppress the eccentricity between the molds.

FIG. 3 is a sectional view of a molding apparatus showing an embodiment obtained by further improving the above-mentioned embodiment.
The same components as those in the embodiment of FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. The main improvement in the embodiment of FIG. 3 is that the shift force acting on the die (lower die 12 in the case of FIG. 3) that moves in the non-contact state acts as a large moment on the non-contact support portion (slider 10 ′ outer peripheral surface). In order not to work, the distance Δ from the vicinity of the lower mold 12 (the center of the molding cavity in the thickness direction) to the center of the movement direction of the non-contact support portion is reduced to about 300 mm. In the present embodiment, four (two only shown in the figure) are arranged at equal intervals in the axial center of the outer peripheral surface of the slider 10 ′ via the pipe 9 and the internal passage 10a ′ of the slider 10 ′ from an external air source. ) Air at room temperature (air pressure of 5 atm) is blown as a pressure transmission medium from the arranged blow-out port 10b ', thereby supporting the slider 10' in a non-contact state with the lower die fitting support member 8 '. It is configured to be. Therefore, an air source (not shown), the pipe 9, the internal passage 10a ', and the outlet 10b' constitute a supply means.

Compared with the comparative example, the arm length ratio of the restoring moment is 300/80 = 1.5 times, and the gap change at the end of the non-contact supporting part when the shift of the lower mold 12 is suppressed to 1 μm or less. The amount is 1 μm / 2.5 = 0.40 μm, and if the static rigidity is 1000 N / μm, the restoring moment generated is 0.40 μm × 1000 N / μ.
m × 80 mm = 32000 Nmm. As the shift force of the corresponding lower die 12, 32000 Nmm / 300 m
Since m = about 107 N, it is possible to endure a shift force that is three times or more that of the comparative example.

However, regarding the thermal influence which was the greatest reason for separating the non-contact supporting portion from the molding portion A as described above, in the embodiment of FIG.
A cooling passage 19 as cooling means is provided in the lower die fitting support member 8'and the slider 10 ', and a cooling medium such as water is caused to flow through the cooling passage 19 to allow the slider 10' and the lower die fitting support member to be molded. 8'and cooled so that the distance Δ is 300m
Even within m, it is possible to suppress heating from the molding portion A, avoid the influence of thermal expansion, and maintain the gap between them substantially constant. In addition, the lower die fixed support 11
2 is exactly the same as in FIG. 2 and is kept long in order to suppress heat conduction from the lower mold 12 to the slider 10 ′.

FIG. 4 is a sectional view of a main part of a molding apparatus according to still another embodiment. In the present embodiment,
At the upper end of the cylindrical slider 20, the upper die fixed support member 23
The upper die 5 is attached via the plate 23a. On the other hand, a support 21 is attached to the lower end of a lower mold fitting support member 28, which is attached to a frame (not shown) and contains the slider 20, via a plate 22.

In the present embodiment, the upper die 5 is a forming die, the lower die 12 is an opposing forming die, and the upper die fixing support member 2 is used.
3, the plate 23a, the slider 20 is a moving member,
The lower die fixed support 21 is a holding member, and the plate 22,
The lower die fitting support member 28 is a fixed member. In the present embodiment, the lower die fitting support member 2 is supplied from an external air source via the pipe 9 and the internal passage 28a of the lower die fitting support member 28.
Room temperature air (air pressure 5 atm) is blown out as a pressure transmission medium from four blowout ports 28b (only two are shown) arranged at equal intervals in the axial center of the outer peripheral surface of No. 8, thereby fitting the lower mold. The slider 20 is maintained in a non-contact state with the support member 28.
An air source (not shown), the pipe 9, the internal passage 28a,
The outlet 28b constitutes a supply means.

Before and after molding, the upper die 5 and the lower die 12 are separated from each other by moving the slider 20 in the axial direction with respect to the lower die fitting support member 28, as shown in FIG. 4 (b). Then, the molten material can be conveyed to the inside and the molded processed product can be conveyed to the outside through the window 20a provided on the side surface of the slider 20.

According to the present embodiment, at the time of molding shown in FIG. 4A, the lower mold 4 is at a position to be contained in the lower mold fitting support member 28, and more specifically, in the thickness direction of the molding cavity. The distance from the center to the axial midpoint of the non-contact support portion (lower die fitting support member 28) is almost zero. Thus, the distance between the center of the thickness of the molding cavity and the midpoint of the non-contact supporting portion is ideally set to zero, but if the distance is about 300 mm or less, the allowable shift of the movable die is 1 μm.
The shift force that can be set to m or less can be relatively easily set to 100 N or more, which is preferable. If the distance between the center of the thickness of the molding cavity and the midpoint of the non-contact support part is set to a value other than zero, the position of the midpoint of the non-contact support part may be above or below the thickness center of the molding cavity. Generally, it is easier to design the mechanism by moving the upper die.

By the way, the molding surface of the molding die may be scratched, the surface roughness may be deteriorated, or may be chipped due to repeated molding. Therefore, it is important that the molding surface be easily maintained. Is. Therefore, in order to perform such maintenance, it is preferable that the upper mold 5 and the lower mold 12, which are molding dies (or counter molding dies), can be easily attached to and detached from the molding device. Further, since the molding die may be remade and replaced with a new part as necessary, a small and simple form is preferable so that the material cost and the processing cost do not increase.

On the other hand, since the member for holding the mold during the pressing operation and the opening / closing operation of the molding cavity uses the pressure transmitting medium, the rigidity thereof is proportional to the area. It is advantageous. Further, since the wide fitting surface requires relatively high accuracy, the processing cost tends to increase. Therefore, since the characteristics of the moving member obviously conflict with the conditions required for the molding die itself, it is better not to provide the molding die itself with a fitting portion for performing a pressing operation or opening and closing the molding cavity. Can be said. That is, the moving member that moves the molding surface in a non-contact state using the pressure transmission medium and the molding die should be separate bodies in the embodiment.

A problem that arises when the molding die is small and easy to attach and detach is the reproducibility of eccentricity between the molding die and the fitting member when attaching and detaching. Each time the mold is attached and detached, its position changes due to shifting and tilting of the molding surface with respect to the mating surface.Even if the mold is the same, eccentricity adjustment is performed each time the mold is attached and detached. There must be. Since this eccentricity adjustment is for high-precision molded products, it is a micro value on the order of μm, so it is difficult to measure it directly mechanically, and the eccentricity is actually measured from the molded product. There is no choice but to use a fairly time-consuming method of determining and correcting. Therefore, it is very important for practical use that the reproducibility of eccentricity due to attachment and detachment of the molding die is sufficiently high.

The normal machining accuracy of the abutting surface is about 1 μm in terms of flatness and dimensional accuracy. Therefore, considering that the molding die is fixedly held by hole fitting, unless the fitting portion is close to the molding surface, a shift of several μm easily occurs due to the inclination, and reproducibility cannot be expected with this. On the other hand, when the molding die is fixed by face-to-face contact, the tilt of the eccentricity can be reduced to almost zero, but the shift cannot be regulated at all. Therefore, as described in Japanese Patent Application No. 2001-236348 by the present inventors, a method of fitting tapered surfaces to each other (referred to as taper surface fitting) is most suitable for fixing the mold. It can be seen that it meets the purpose of high-precision molding, which is the essence of, and exhibits its effect. The machining accuracy of the taper abutting part with a cylindrical grinder is about 1 μm, but even if the taper angle has an error to that extent, it will fit on the circumference by abutting, so shift And the tilt can be regulated surely.

In practice, the mold material is silicon carbide (Si
C), when the fixed holding member is made of Macor, two kinds of taper apex angles of 40 degrees and 60 degrees are prepared respectively, and the reproducibility of abutting and fitting is improved on the molding apparatus having the non-contact supporting portion of the present invention. Confirmed with an auto collimator. As long as the orientation of the molding die and the orientation of the fixed holding member are matched, the tilt reproducibility is 20 times or more.
It entered within 0 seconds.

In FIG. 1, FIG. 3 and FIG. 4, the taper abutting reference surface 5 is added to the molding apparatus having the non-contact supporting portion of the present invention.
An upper mold 5 and a lower mold 12 having a, 12a are shown. The pressers 4 and 13 of the molds 5 and 12 are both made of a material using a heat resistant elastic material, and the molds 5 and 12 are fixed to the taper abutting surface 3a (23a) of the fixed holding member 3 (23) and the lower mold. Tapered butting surface 11 of support 11 (21)
It is pressed against a (21a), that is, fixed by using a tapered surface fitting.

In the conventional molding apparatus, a guide having mechanical contact such as an easy cross roller guide is used for moving the movable die during hot pressing and opening / closing of the molding cavity. Since it was about 1 to 2 μm at most, even if the taper surface abutment of the molding die was used as the reference surface for attachment / detachment, the positioning effect was almost buried in the variation, and as described above, it took less than 20 seconds. It did not appear as an effect that it must be reproduced. In other words, as in the present invention, the mold attaching / detaching method using the taper abutment as the reference surface is the first to be performed by combining the mold with a structure that movably supports the mold in a non-contact manner and has a structure having extremely high rigidity against external force. It is now possible to make use of it in actual high precision molding.

Although the present invention has been described above with reference to the embodiments, the present invention should not be construed as being limited to the above embodiments, and it goes without saying that appropriate modifications and improvements are possible. is there.

[0056]

As described above, according to the present invention, it is possible to provide a molding apparatus which can perform highly accurate molding despite having a simple structure.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a molding device according to a first embodiment.

FIG. 2 is a diagram schematically showing a lower mold fitting support member 8 and a slider 10.

FIG. 3 is a sectional view of a molding apparatus according to a second embodiment.

FIG. 4 is a cross-sectional view of a molding device according to a third embodiment.

[Explanation of symbols]

1 frame 3, 23 Upper die fixed holding member 5 Upper mold 8, 28 Lower die fitting holding member 10, 20 slider 12 Lower mold

Claims (21)

[Claims] 1. A moving member that holds a molding die that forms a molding cavity for molding a molded product, a fixed member that includes the moving member and holds the moving member so as to be relatively movable, the moving member and the fixed member. Supply means for supplying a pressure transmission medium to a gap between the pressure transmission medium and the fixed member, the pressure transmission medium maintaining the movable member in a non-contact state with respect to the fixed member. A molding apparatus, wherein a pressure difference is applied at least in the axial direction in the gap so that the inclination is corrected when the moving member is inclined. 2. The molding apparatus according to claim 1, wherein the gap is within 20 μm. 3. A midpoint of the moving direction of a surface of the moving member which is supported in a non-contact manner by the pressure transmitting medium when the molding die is placed at a molding position, and the movement of the molding cavity of the molding die. Direction thickness center is ± 300
2. The distance is less than or equal to mm.
Or the molding apparatus according to 2. 4. The molding apparatus according to claim 1, wherein a holding member that holds an opposing molding die facing the molding die is fixed to the fixing member. 5. The taper surface fitting is used for at least one of mounting of the molding die and the moving member and mounting of the opposing molding die and the holding member. 5. The molding apparatus according to any one of 4 to 4. 6. The molding apparatus according to claim 1, further comprising a cooling unit that cools at least one of the moving member and the fixed member. 7. The molding apparatus according to claim 1, wherein the fixing member is arranged at a position where the molding die is included during molding. 8. The molding apparatus according to claim 1, wherein the optical element is molded by molding using the molding die. 9. A fixing member for movably supporting a molding die forming a molding cavity for molding a molded product, wherein the molding die has the molding die and the molding die with respect to the fixing member. A molding apparatus, which is supported by a pressure transmission medium interposed in a gap between the fixing member and the fixing member. 10. A fixing member for movably supporting a molding die forming a molding cavity for molding a molded product, and an opposed molding die fixed to the fixing member and facing the molding die. And a holding member for holding the molding die, wherein the molding die is supported on the fixing member by a pressure transmission medium interposed in a gap between the molding die and the fixing member. . 11. A moving member that holds a molding die that forms a molding cavity for molding a molded product, a fixed member, and a holding member that holds an opposed molding die that is fixed to the fixed member and faces the molding die. A member, wherein the moving member is movably supported relative to the fixed member by a pressure transmission medium interposed in a gap between the moving member and the fixed member. Molding equipment. 12. A first holding member for holding a molding die that forms a molding cavity for molding a molded product, and a second holding member for holding an opposing molding die facing the molding die. The molding apparatus is characterized in that the first holding member is movably supported by the second holding member by a pressure transmission medium interposed in a gap between the second holding member and the second holding member. 13. A moving member for holding a molding die for forming a molding cavity for molding a molded article, a fixed member, and an opposed molding die fixed to the fixed member and facing the molding die. And a holding member that holds the moving member, the moving member being movably supported relative to the fixed member by a pressure transmission medium interposed in a gap between the moving member and the fixed member. At least one of the mounting of the molding die and the moving member and the mounting of the opposed molding die and the holding member is performed by taper surface fitting. 14. A moving member that holds a molding die that forms a molding cavity for molding a molded product, a fixed member that includes the moving member and holds the moving member so as to be relatively movable, the moving member and the fixed member. And a supply means for supplying a pressure transmission medium to a gap between the pressure transmission medium and the other side of the outlet of the supply means arranged in at least one of the moving member and the fixed member. It is designed to be discharged toward
The molding device is characterized in that a plurality of the blowout ports are arranged at the same position in the axial direction and along the circumferential direction in at least one of the moving member and the fixed member. 15. The pressure transmitting medium, after being discharged from the outlet, heads in directions opposite to each other in the axial direction, and escapes from two escape positions to the outside via a space between the moving member and the fixed member. The molding apparatus according to claim 14, wherein the blowout port is arranged at a midpoint in the axial direction of the two escape positions. 16. A moving member that holds a molding die that forms a molding cavity for molding a molded product, a fixed member that includes the moving member and holds the moving member so as to be relatively movable, the moving member and the fixed member. And a supply means for supplying a pressure transmission medium to a gap between the pressure transmission medium and the other side of the outlet of the supply means arranged in at least one of the moving member and the fixed member. It is designed to be discharged toward
At least one of the moving member and the fixed member has a plurality of the air outlets arranged in the axial direction, and a plurality of the air outlets arranged in a rotationally symmetrical manner with respect to the axial line along the circumferential direction. apparatus. 17. A moving member that holds a molding die that forms a molding cavity for molding a molded product, a fixed member, and a holding member that holds an opposed molding die that is fixed to the fixed member and faces the molding die. A member, the moving member is supported so as to be movable relative to the fixed member by a pressure transmission medium interposed in a gap between the moving member and the fixed member, When placed at the molding position, the midpoint of the moving direction of the surface of the moving member that is supported in a non-contact manner by the pressure transmission medium and the thickness center of the moving direction of the molding cavity of the molding die are ± A molding apparatus having a distance of 300 mm or less. 18. A moving member that holds a molding die that forms a molding cavity for molding a molded product, a fixed member, and a holding member that holds an opposed molding die that is fixed to the fixed member and faces the molding die. A movable member and a fixed member, and the movable member is interposed in a gap between the movable member and the fixed member with respect to the fixed member. A molding apparatus, which is movably supported by a pressure transmission medium, and which shields the periphery of the mold at least during molding. 19. The molding apparatus according to claim 18, wherein the pressure transmission medium is room temperature pressurized air at −10 ° C. or higher and 30 ° C. or lower. 20. A moving member that holds a molding die that forms a molding cavity for molding a molded product, a fixed member, and a holding member that holds an opposed molding die that is fixed to the fixed member and faces the molding die. And a cooling unit that cools at least one of the moving member and the fixed member, wherein the moving member is interposed in a gap between the moving member and the fixed member with respect to the fixed member. A molding apparatus, which is supported by a pressure transmission medium so as to be relatively movable. 21. The molding apparatus according to claim 9, wherein an optical element is molded by molding using the molding die.