JP4878321B2 - Mold press mold and method for producing molded body - Google Patents

Description

  The present invention relates to a mold press mold that can press-mold a molded body that requires high shape accuracy such as an optical element, and a method of manufacturing a molded body using such a mold press mold.

As a method of manufacturing an optical element such as an aspherical lens using a glass material, molding that is softened by heating with a pair of molds having molding surfaces facing each other corresponding to the shape of the molded product to be obtained A mold press method is known in which a material is press-molded and the molding surface of these molds is transferred.
Also, in order to prevent high-temperature deterioration of the molding surface of the mold used to carry out the mold press method and shorten the molding cycle time, the mold and the molding material are preheated separately and preheated molding is performed. A method is known in which a material is introduced into a mold and immediately press-molded.

These methods are disclosed in Patent Document 1, for example. In the method disclosed in Patent Document 1, the glass material and the mold are preheated, and after the glass material is supplied to the lower mold, the upper and lower molds are immediately closed to perform press molding. And a shaping | molding die is cooled to below a glass transition point, mold opening is performed, and it is trying to take out a glass forming body.
According to such a method, it is possible to form a glass molded body with excellent surface accuracy while shortening the cycle time and maintaining productivity.

Here, the clearance between the body mold and the sliding surface of the upper and lower molds guided thereby is set narrow so that the upper and lower molds are accurately coaxial. For this reason, if the upper and lower molds are slightly tilted with respect to the barrel mold when the mold is closed during press molding , rubbing and galling will occur at the sliding part between the barrel mold and the upper and lower molds, and an appropriate press Operation may be hindered.

JP-A-11-171564

Currently, optical elements used for small imaging devices and optical pickups have very high optical performance requirements. In order to produce a molded product that meets such requirements by mold press, the eccentric accuracy of the upper and lower molds, that is, good coaxiality and low relative inclination must be kept extremely high throughout the continuous pressing process. Is required. For example, the horizontal shift (shift) between the upper mold and the lower mold is within 10 μm, preferably within 5 μm, and the mutual tilt angle (tilt) is within 5 minutes, preferably within 2 minutes. Is required.
Therefore, the allowable clearance between the body mold and the upper and lower molds is 10 μm or less at the maximum, and the upper and lower molds must be surely continuously approached in this situation.

  However, it is generally difficult to perform continuous pressing hundreds to tens of thousands of times while maintaining sliding with such a narrow clearance. In particular, in the method disclosed in Patent Document 1, since the mold in the mold open state is preheated and the mold is closed in the preheated state, it is more difficult to maintain the coaxiality of the upper and lower molds in a high temperature environment. . That is, the upper mold and the lower mold are each supported by a support member, and either one is fixed to the main shaft of the mold closing mechanism so as to be movable up and down. When the upper die and the lower die are preheated to a temperature suitable for press molding in this state, the upper and lower die support members are thermally expanded and thermally deformed. For example, when the molding material is glass, it is preheated to a high temperature of 400 ° C. to 800 ° C., and in such a state, while maintaining high eccentric accuracy of the upper and lower molds, several hundred to several tens of thousands of times It is extremely difficult to perform continuous pressing.

Furthermore, in order to improve production efficiency, as disclosed in Patent Document 1, it is desirable to perform a plurality of press moldings simultaneously using a plurality of upper molds and lower molds.
However, when such an apparatus is used, the upper and lower molds are slightly displaced due to thermal deformation of the support member or the like. The amount of displacement varies depending on the distance of each die from the press spindle, and also varies depending on the press temperature selected depending on the type of molding material. Furthermore, if a plurality of upper molds and lower molds are supported by a single upper mold support member and a lower mold support member, the upper and lower support members have larger dimensions than the support members supporting the single mold. As a result, thermal deformation also increases. For this reason, it is extremely difficult to maintain a state in which each of the plurality of upper molds and lower molds arranged therein approaches and comes into close contact with the center axes accurately aligned through a continuous pressing process.

In mold press molding, if the coaxiality of the mold is not accurately maintained, rubbing or galling occurs between the lower mold and the barrel mold. Since a large load acts during pressing, if rubbing or galling occurs, the load that should be applied to the molded body is absorbed between the body mold and the lower mold, and the press pressure acts unevenly on the molded body, resulting in eccentricity accuracy and surface accuracy. Deterioration of wall thickness accuracy, damage to the trunk mold and lower mold, etc. occur.
Moreover, when the abrasion powder generated by rubbing or galling adheres to the molded body, the molded body has a poor appearance. Further, when such rubbing or galling occurs, the clearance between the trunk mold and the lower mold exceeds a predetermined range, and as a result, the position regulation of the lower mold by the trunk mold becomes loose. This means that the coaxiality between the upper mold and the lower mold is lost, and a horizontal shift (shift) between the upper mold and the lower mold and a relative inclination (falling) between the upper mold and the lower mold occur. . In particular, when the molded body is an optical element, serious performance degradation occurs.

  The present invention has been made in view of the above circumstances, and in order to press-mold the molded body with high accuracy, the eccentric accuracy of the upper and lower molds is maintained satisfactorily. An object is to provide a mold press mold that can be produced and a method for producing a molded body using such a mold.

The mold press mold according to the present invention includes a lower mold and an upper mold on which a molding surface of an arbitrary shape is formed, and the lower mold and the upper mold are arranged so as to face each other and are inserted coaxially. a cylinder type that, in a state where the upper die is inserted coaxially in the body mold, the upper mold holding member for holding the upper die with the body mold, the lower mold holding member for holding the lower die The lower mold has a shape in which a small diameter portion on which the molding surface is formed and a large diameter portion having a diameter larger than that of the molding surface are arranged coaxially, and a lower mold support base and a lower mother mold When holding the lower mold on the lower mold holding member, the lower mother mold has an inner peripheral surface whose upper side is a small-diameter inner peripheral surface and whose lower side is a large-diameter inner peripheral surface, and the small-diameter Between the annular step surface formed at the step portion between the inner peripheral surface and the large-diameter inner peripheral surface and the upper surface of the lower mold support base , The large-diameter portion of the lower die is held in loosely fitted, said the lower large-diameter portion of the lower surface or the curved surface of one of said lower die support the upper surface of the table, and the other as a plane, the lower and the lower die by the die holding member that is brought into contact via the curved surface, the lower mold holding member, when the lower mold is inserted into the barrel die, or after insertion, the lower die following the said curved surface Is configured to hold the lower mold while allowing the posture to be corrected.

In the mold press mold according to the present invention having such a structure, when the press molding operation is started and the lower mold is inserted into the barrel mold, the lower mold is positioned with respect to the upper mold and the trunk mold. Even if it is tilted, the lower mold is positioned along the curved surface (horizontal tilt or shaft) so that it is coaxial with the upper mold when inserted into the barrel mold or after insertion. It is inserted into the body mold while correcting itself (positional deviation in the center direction).
As a result, even if the clearance between the lower mold and the trunk mold is set to about several microns, the lower mold swings smoothly in the trunk mold without causing rubbing or galling between the lower mold and the trunk mold. The coaxiality between the lower mold and the upper mold can be secured to a high degree.

Further, in the mold press mold according to the present invention, the lower mold has a main body part including a small diameter part of the lower mold and a base part including a lower surface of the large diameter part of the lower mold, It can be set as the structure by which the several spherical member is arrange | positioned between the said base parts so that rolling is possible.
With such a configuration, when the spherical member rolls, the lower mold main body can move in the horizontal direction, and even if a small initial moment is generated, such movement is not caused. It will be done smoothly.
Therefore, the lower mold is inserted into the body mold while maintaining a high degree of coaxiality with the upper mold due to the correction of the tilt caused by the swing and the horizontal movement, and therefore the eccentricity accuracy (tilt and shift accuracy). Can be molded.

In addition, the mold press mold according to the present invention can be configured such that a concave portion that accommodates the spherical member is formed on at least one surface of the main body portion and the base portion facing each other with the spherical member interposed therebetween. .
With such a configuration, it is possible to prevent the spherical member from falling off when the molding die is assembled by accommodating the spherical member in the recessed portion.

In addition, the mold press mold according to the present invention preferably has a configuration in which the curved surface is formed by a spherical surface in consideration of swinging the lower mold .

Further, press-molding mold according to the present invention includes a resilient member for biasing the barrel die to the lower die, the molding material in said lower mold and the upper mold during the press forming, the lower mold It can be set as the structure by which the opening part end surface of the said trunk | drum type | mold of the side inserted is pressed by a part of said lower mold | type by the urging | biasing force of the said elastic member.
With such a configuration, at the time of press molding, the end face of the opening of the trunk mold is pressed against the lower mold by the biasing force of the elastic member, and the positional relationship between the lower mold and the trunk mold, in particular, the coaxiality is correctly defined. Thus, a molded article having excellent eccentricity accuracy can be obtained.
Further, in the mold press mold according to the present invention, the upper mold has a shape in which a small diameter portion on which the molding surface is formed and a large diameter portion having a diameter larger than the molding surface are arranged coaxially, When the upper mold is coaxially inserted into the barrel mold, the large-diameter portion of the upper mold is in contact with an annular step surface formed on the inner peripheral side of the trunk mold. be able to.
Further, in the mold press mold according to the present invention, an overhanging portion projecting in a radial direction is formed on the upper side of the body mold, and the body mold is formed on the upper mold holding member including an upper mold support base and an upper mother mold. In the state where the overhanging portion is held between the step surface formed on the inner periphery of the upper mother die and the upper die support base, the body die is held by the upper die holding member. It can be configured.

Further, the method for producing a molded body according to the present invention includes a lower mold and an upper mold on which a molding surface having an arbitrary shape is formed, and the lower mold and the upper mold are arranged so as to face each other so that the molding surfaces face each other. A body mold that is inserted into the body mold, an upper mold holding member that holds the upper mold together with the body mold, and a first mold that holds the lower mold. At least one mold holding member, and the lower mold has a shape in which a small-diameter portion in which the molding surface is formed and a large-diameter portion having a diameter larger than the molding surface are arranged coaxially, and the lower mold support In holding the lower mold on the lower mold holding member having a base and a lower mother mold, the lower mother mold has an inner peripheral surface in which the upper side is a small-diameter inner peripheral surface and the lower side is a large-diameter inner peripheral surface. An annular step surface formed at a step portion between the small-diameter inner peripheral surface and the large-diameter inner peripheral surface, and the lower mold support base The large-diameter portion of the lower mold is held in a loose fit between the surface, one of the lower surface of the large-diameter portion of the lower mold or the upper surface of the lower mold support base is a curved surface, the other is a plane, Using a mold press mold in which a lower mold and the lower mold support are brought into contact with each other through the curved surface, the lower mold is inserted into the body mold or after the lower mold is inserted. The molding material is supplied between the molding surfaces of the lower mold and the upper mold while being held by the lower mold holding member so that the posture can be corrected following the curved surface, and the lower mold and the upper mold The molding material is press-molded, and the shape of each molding surface is transferred to the molding material.
By setting it as such a method, since a pair of lower mold | type and upper mold | die which are facing can be maintained in a coaxial state with high precision, a molded object can be manufactured with sufficient precision.

In addition, the method for producing a molded body according to the present invention more specifically preheats the molding material prior to press molding, preheats the mold press mold, and preheats the molding material after preheating. It can be set as the method of supplying to the said said mold press shaping | molding die and performing press molding.
By setting it as such a method, a cycle time is shortened, production efficiency is high, and a highly accurate molded object can be manufactured.

A method of manufacturing a molded body according to the present invention, the lower mold includes a body portion including a small-diameter portion of the lower die, and a base portion including a bottom surface of the large diameter portion of the lower mold, the body portion The molding material can be press-molded by using a mold press mold in which a plurality of spherical members are arranged so as to roll between the base portion and the base portion.
With such a method, when the spherical member rolls, the lower mold main body can move in the horizontal direction, and even if a small initial moment is generated, such movement does not occur. It will be done smoothly. Therefore, the lower mold is inserted into the trunk mold with a high degree of coaxiality with the upper mold by correcting the posture following the curved surface and smooth horizontal movement by the spherical member. A molded body with good accuracy can be molded.

Further, in the method for producing a molded body according to the present invention, the molding material is formed by the lower mold and the upper mold using a mold press mold having an elastic member that biases the body mold toward the lower mold. In press molding, the end face of the opening of the body mold on the side where the lower mold is inserted can be pressed against a part of the lower mold by the urging force of the elastic member. .
With such a method, when the molding material is press-molded, the end face of the opening of the trunk mold is pressed against the lower mold by the biasing force of the elastic member, and the positional relationship between the lower mold and the trunk mold, in particular, both The degree of concentricity is correctly defined, and a molded body with better eccentricity can be obtained.

As described above, in the present invention, together with the lower mold and the lower mold holding member abuts via a curved surface, the lower mold holding member, when the lower mold is inserted into the body mold, or after being inserted, the curved surface since holding the lower mold while allowing the lower mold to correct the posture following the press forming operation is started, when the lower mold is inserted into the body mold, the upper mold and the trunk mold Even if the lower mold is inclined, the lower mold is positioned along the curved surface (horizontal direction) so that it is coaxial with the upper mold when inserted into the barrel mold or after insertion. (Inclination and misalignment in the axial direction) while correcting by itself. Thereby, the coaxiality of the lower mold and the upper mold can be highly secured without causing rubbing or galling during insertion.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[Mold press mold / first embodiment]
First, a first embodiment of a mold press mold (hereinafter referred to as “mold”) according to the present invention will be described.
1 and 2 are cross-sectional views showing an outline of the mold according to this embodiment. In these drawings, FIG. 1 shows a state in which a molding material G is supplied to a mold that has been opened. FIG. 2 shows a closed state.

The mold according to the present embodiment is an upper mold in which molding surfaces 11 and 21 having an aspherical shape or a spherical shape are formed based on the shape of an optical element (molded body) such as a glass lens to be molded. 10 and the lower mold 20. The upper mold 10 and the lower mold 20 are arranged so that the upper and lower molds 10 and 20 arranged facing each other so that the molding surfaces 11 and 21 face each other are close to each other in a state of being inserted into the body mold 30. The molding material G supplied between the two is press-molded.

In the illustrated example, the upper mold 10 is held by the upper mold holding member 15 together with the trunk mold 30, and the lower mold 20 is held by the lower mold holding member 25. These holding members 15 and 25 are both made of a magnetic material such as ambiloy, and are heated by high-frequency induction heating means (not shown) so that the heat is transmitted to the upper and lower molds 10 and 20 and the trunk mold 30. .

  In addition, a fixed shaft 40 is attached to the upper mold holding member 15 on the upper surface side. At the same time, a drive shaft 50 connected to an elevating mechanism such as an air cylinder (not shown) is attached to the lower surface side of the lower mold holding member 25. Accordingly, the lower mold 20 moves up and down along the axial direction with respect to the upper mold 10 so that the upper and lower molds 10 and 20 are close to and separated from each other. The drive shaft may be attached to the upper mold holding member 15 and the lower mold holding member 25 may be attached to the fixed shaft. A drive shaft may be separately attached to the upper mold holding member 15 and the lower mold holding member 25 so that both the upper and lower molds 10 and 20 move up and down along the axial direction.

The upper mold holding member 15 that holds the upper mold 10 together with the trunk mold 30 includes an upper mold support 16 and an upper mother mold 17. The upper mother die 17 has a cylindrical shape that surrounds the body die 30 coaxially, and is fixed to the lower surface of the upper die support 16.
A protruding portion 31 is formed on the upper side of the body mold 30 so as to project in the radial direction as shown in the figure. When the upper mother die 17 is fixed to the lower surface of the upper mold support base 16, It is sandwiched between a step surface 17 a formed on the inner periphery of the upper mold 17 and the lower surface of the upper mold support 16. The body mold 30 is held and fixed to the upper mold holding member 15 in a state where the overhanging portion 31 is sandwiched, and the movement in the horizontal direction and the axial direction is restricted.

  The upper die 10 has a shape in which a small-diameter portion 12 on which a molding surface 11 is formed and a large-diameter portion 13 having a diameter larger than that of the molding surface 11 are arranged coaxially, and is inserted coaxially into the body die 30. Held in the upper mold holding member 15. In the mold open state shown in FIG. 1, the lower surface of the large-diameter portion 13 of the upper mold 10 inserted into the trunk mold 30 is formed on an annular step surface 30 a formed on the upper inner peripheral side of the trunk mold 30. In contact with each other, a gap S is formed between the upper surface of the upper mold 10 and the lower surface of the upper mold support 16.

Therefore, the upper die 10 can be slid in the barrel die 30 in the axial direction by the gap S, but the upper die 10 was inserted into the barrel die 30 during the press molding operation. Since the state is maintained, the horizontal clearance C3 in the sliding portion between the upper mold 10 and the trunk mold 30 can be extremely small (for example, 5 μm or less, preferably 2 μm or less).

  When the lower mold 20 is raised and the mold is closed, the molding material G on the molding surface 21 of the lower mold 20 abuts on the molding surface 11 of the upper mold 10 and pushes up the upper mold 10. As a result, the upper mold 10 slides within the body mold 30 by the amount of the gap S and comes into contact with the lower surface of the upper mold support 16, and as shown in FIG. A gap is formed between the step surface 30 a of the body mold 30. The thickness of the molded body is once defined here, but after cooling, the upper mold 10 is slightly lowered by its own weight following the thermal contraction of the molded body, and the upper and lower molds 10 and 20 and the molded body. Cooling can be carried out while maintaining close contact with.

On the other hand, similarly to the upper mold 10, the lower mold 20 has a shape in which a small-diameter portion 22 formed with a molding surface 21 and a large-diameter portion 23 having a diameter larger than the molding surface 21 are arranged coaxially. It is held by a lower mold holding member 25 having a support base 26 and a lower mother mold 27 fixed to the upper surface of the lower mold support base 26. In the illustrated example, the lower mold holding member 25 is held. The lower surface of the large-diameter portion 23 of the lower mold 20 that is in contact with the lower mold support base 26 included in the lower mold 20 is a curved surface 24.

  The lower mother mold 27 provided in the lower mold holding member 25 has an upper side of the inner peripheral surface as a small-diameter inner peripheral surface 27a and a lower side as a large-diameter inner peripheral surface 27b. The lower mold 20 is formed so as to be sandwiched between an annular step surface 27 c formed at a step portion between the small diameter inner peripheral surface 27 a and the large diameter inner peripheral surface 27 b and the upper surface of the lower mold support base 26. The large-diameter portion 23 is configured to be loosely fitted between the lower mother die 27 and the lower die support base 26, which will be described later.

  Further, the lower mother die 27 opens upward as shown between the small-diameter inner peripheral surface 27a and the small-diameter portion 22 of the lower die 20 when the lower die 20 is disposed on the lower die holding member 25. An annular insertion groove 28 is formed. When the press molding operation is performed, the lower side of the body mold 30 is inserted into the insertion groove 28, and the small-diameter portion 22 of the lower mold 20 is inserted into the body mold 30 (see FIG. 2).

  When the small-diameter portion 22 of the lower mold 20 is inserted into the body mold 30, the inner peripheral surface of the body mold 30 comes into sliding contact with the upper and lower molds 10, 20, and thereby the coaxiality of the upper and lower molds 10, 20. Can be secured. At this time, if the clearance C4 between the outer peripheral surface of the small-diameter portion 22 of the lower mold 20 and the inner peripheral surface of the lower side of the body mold 30 is too large, the upper mold 10 and the lower mold 20 are misaligned, and tilt, shift, etc. The eccentricity of the upper and lower molds 10 and 20 becomes difficult to ensure. For this reason, the clearance C4 between the outer peripheral surface of the small-diameter portion 22 of the lower mold 20 and the inner peripheral surface on the lower side of the body mold 30 is 0.5 to 10 μm in consideration of the required eccentric accuracy of the optical element. And more preferably 1 to 5 μm.

As described above, in the illustrated example, the large-diameter portion 23 of the lower mold 20 is held loosely between the lower mother mold 27 and the lower mold support base 26. At this time, a predetermined clearance C1 is secured between the outer peripheral surface of the large-diameter portion 23 of the lower mold 20 and the large-diameter inner peripheral surface 27b of the lower mother die 27, and the large-diameter portion 23 of the lower mold 20 is secured. By securing a predetermined clearance C2 between the upper surface and the cross section 27c of the lower mother die 27, the lower die 20 is a curved surface formed on the lower surface of the large-diameter portion 23 within the range of the clearances C1 and C2. 24 is held by the lower mold holding member 25 so as to be allowed to swing along 24.
Here, considering that the lower mold 20 swings, the curved surface 24 formed on the lower surface of the large-diameter portion 23 is preferably a spherical surface, and the radius of curvature varies depending on the radius of the optical element to be molded. For example, it can be set to 100 mm to 500 mm.
In the illustrated example, the curvature of the curved surface 24 is exaggerated.

As described above, in the present embodiment, the curved surface 24 is formed on the lower surface of the large-diameter portion 23 of the lower mold 20, and the lower mold 20 and the lower mold holding member 25 are brought into contact with each other through the curved surface 24. In addition, the lower mold 20 is held by the lower mold holding member 25 so as to be swingable. By doing in this way, even if the lower mold 20 is inclined with respect to the upper mold 10 and the trunk mold 30 when the press molding operation is started and the lower mold 20 is inserted into the trunk mold 30, the lower mold 20 is inserted into the body mold 30 while correcting the posture (inclination in the horizontal direction and positional deviation in the axial direction) so as to be coaxial with the upper mold 10 following the curved surface 24. It has become. Further, at that time, the lower die 20 can move in the horizontal direction within the range of the clearance C1 (both sides) between the lower mother die 27 and the large-diameter inner peripheral surface 27b.
Thereby, in this embodiment, the coaxiality of the upper and lower molds 10 and 20 is highly secured.

That is, since the body mold 30 is held and fixed to the upper mold holding member 15 in a state where the movement in the horizontal direction and the axial direction is restricted, the press molding operation starts as shown in FIG. When the lower mold 20 is raised and inserted into the trunk mold 30 from the lower opening of the trunk mold 30, the axis C20 of the lower mold 20 does not coincide with the axis C10 of the upper mold 10. However, the lower mold 20 swings along the curved surface 24 while being inserted into the body mold 30, and as a result, an unreasonable force is not exerted on the lower mold 20 and the body mold 30, as shown in FIG. As shown, the posture of the lower mold 20 is corrected so that the upper mold 10 and the lower mold 20 are coaxial.
Thereby, even if the clearance C4 between the lower mold 20 and the trunk mold 30 is set to about several microns, the lower mold 20 swings without causing rubbing or galling between the lower mold 20 and the trunk mold 30. Thus, it can be smoothly inserted into the body mold 30 while correcting its own posture, and the coaxiality of the upper and lower molds 10 and 20 can be highly secured. In particular, even in a high temperature environment of 400 ° C. to 800 ° C., the lower mold 20 is inserted into the body mold 30 while correcting the posture by itself following the curved surface 24, so that no rubbing or galling occurs.

  In this way, in order to highly secure the coaxiality of the upper and lower molds 10 and 20, the guide part 32 that expands downward in a tapered shape is formed on the inner peripheral surface on the lower side of the trunk mold 30. It is preferable to leave. When the press molding operation is performed, if the peripheral portion of the small-diameter portion 22 of the lower die 20 is brought into contact with the guide portion 32, insertion of the lower die 20 into the body die 30 is not hindered. The lower mold 20 is smoothly inserted into the trunk mold 30 while being guided by the guide portion 32, and the posture of the lower mold 20 is corrected. The inclination angle θ of the guide portion 32 with respect to the axial direction is preferably 45 ° or less, more preferably 30 ° or less, and further preferably 10 ° or less.

Here, the range in which the lower mold 20 can swing, that is, the range in which the posture can be corrected by following the curved surface 24, is the outer peripheral surface of the large-diameter portion 23 of the lower mold 20 and the lower mother mold 27. It is defined by the clearance C1 with the large-diameter inner peripheral surface 27b and the clearance C2 between the upper surface of the large-diameter portion 23 of the lower mold 20 and the cross section 27c of the lower mother mold 27. If these clearances C1 and C2 are too small, In some cases, the clearance is lost due to the difference in thermal expansion between the lower mold 20 and the lower mother mold 27, and the swinging of the lower mold 20 may be hindered. Furthermore, when the press forming of a plurality of molds is performed, if the clearances C1 and C2 are too small, the allowable range of position accuracy of each mold is reduced, and galling may occur or the mold may not be closed.
On the contrary, if the clearances C1 and C2 are too large, the allowable swing range of the lower mold 20 becomes excessive, so that the body mold 30 comes into contact with the molding surface 21 of the lower mold 20 when closing the mold. There is a risk of damaging the molding surface 21 or making it impossible to close the mold.
Considering these, the clearance C1 is preferably 50 to 300 μm, and the clearance C2 is preferably 50 to 300 μm.

  In the molding die according to the present embodiment as described above, there is no limitation on materials used for the upper die 10, the lower die 20, the barrel die 30, and the like, for example, silicon carbide, silicon, silicon nitride, tungsten carbide, aluminum oxide, oxidation Cermet such as zirconium and titanium carbide, or a hard material whose surface is coated with diamond, refractory metal, noble metal alloy, carbide, nitride, boride, oxide or the like can be used. In addition, the portions that come into contact with the molding material G, such as the molding surfaces 11 and 21 of the upper and lower molds 10 and 20 and the inner peripheral surface of the barrel die 30, can be coated to prevent fusion with the molding surface. . Such a coating can be a noble metal film, a carbon film, a hydrogenated carbon film, or the like, and can be a film similar to a known release film. For example, a film containing carbon or hydrocarbon as a main component can be formed with a predetermined film thickness using a known means such as a vapor deposition method, a sputtering method, an ion plating method, or plasma CVD.

[Mold press mold / second embodiment]
Next, a second embodiment of the mold according to the present invention will be described.
FIG. 4 is a cross-sectional view schematically showing the molding die according to the present embodiment, and FIG. 4A shows a state in the middle of the press molding operation. FIG. 4B shows a state where the mold is closed.

  The mold according to this embodiment includes an elastic member 35 that urges the body mold 30 toward the lower mold 20. As such an elastic member 35, a coil spring or the like can be used. For example, as shown in the figure, a step portion 36 as a receiving seat is formed on the inner peripheral surface of the trunk mold 30, and By attaching an elastic member 35 between the cross-section 10 a formed at the step portion between the small diameter portion 12 and the large diameter portion 13 of the mold 10, the body mold 30 is biased toward the lower mold 20. Can be.

When the press molding operation is started and the lower mold 20 is raised and inserted into the body mold 30, the molding material G is press-molded between the upper and lower molds 10 and 20. In this press molding process, The opening end surface 33 on the lower mold 20 side of the body mold 30 is in contact with the upper surface of the large diameter section 23 of the lower mold 20. At this time, the trunk mold 30 is urged toward the lower mold 20 by the elastic member 35 and is pressed against the lower mold 20 in the middle of ascent.
Therefore, the position of the lower mold 20 and the trunk mold 30 is determined by setting the opening end surface 33 on the lower mold 20 side of the trunk mold 30 and the upper surface of the large-diameter portion 23 of the lower mold 20 to be orthogonal to the axial direction. It is possible to obtain a molded body having a relationship, in particular, a coaxiality that is correctly defined and having a better eccentric accuracy.

Further, in the present embodiment, an annular groove 16a that can accommodate the upper side edge of the trunk mold 30 is formed on the lower surface of the upper mold support base 16, and the upper and lower molds 10 and 20 are in a closed state. In some cases, the upper side edge of the body mold 30 protrudes upward from the upper surface of the upper mold 10 so as to fit in a groove 16 a formed on the lower surface of the upper mold support 16.
With this configuration, a long sliding distance of the trunk mold 30 with respect to the upper mold 10 and the lower mold 20 can be secured, and the inclination of the upper mold 10 and the lower mold 20 with respect to the trunk mold 30 can be suppressed to a minimum. Therefore, an optical element with higher eccentricity accuracy can be press-molded.

  Although this embodiment differs from 1st embodiment by the above point, since it is equipped with the structure similar to 1st embodiment other than that, detailed description about another structure is abbreviate | omitted.

[Mold press mold / third embodiment]
Next, a third embodiment of the mold according to the present invention will be described.
FIG. 5 is a cross-sectional view schematically showing the molding die according to the present embodiment, and FIG. 5A shows a state in the middle of the press molding operation. FIG. 5B shows a state where the mold is closed.

  In the mold according to the present embodiment, the lower mold 20 includes a main body 20a on which the molding surface 12 is formed, and a base 80 on which a curved surface 81 that contacts the lower mold holding member 25 (lower mold support base 26) is formed. have. And between the main-body part 20a and the base 80, the some spherical member 60 is arrange | positioned so that rolling is possible.

By doing so, the spherical member 60 rolls, so that the main body portion 20a of the lower mold 20 can move in the horizontal direction with respect to the base portion 80, and in addition, a minute initial moment is generated. However, such movement can be made smoothly.
Accordingly, the lower mold 20 is inserted into the body mold 30 while maintaining high coaxiality with the upper mold 10 by correcting the posture by the swing and the horizontal movement of the main body portion 20a. A molded article with good (tilt and shift accuracy) can be molded.

In consideration of the assembling property of the mold, it is preferable that a concave portion 80a is formed on the upper surface of the base portion 80 and the spherical member 60 is accommodated in the concave portion 80a as shown in the drawing. By doing so, it is possible to prevent the spherical member 60 from falling off when assembling the mold.
In order to accommodate the spherical member 60 and prevent its falling off, the recessed portion 80 a is formed on at least one surface of the main body portion 20 a and the base portion 80 that face each other with the spherical member 60 interposed therebetween. That's fine.

Here, as the spherical member 60, a diameter of 0.1 mm to 5 mm formed of a material having high heat resistance and high hardness such as Si ₃ N ₄ , SiC, Al ₂ O ₃ , cemented carbide, and other metals and ceramics. A true spherical member can be used.

  In addition, the number n of the spherical members 60 disposed between the main body 20a and the base 80 is such that the spherical member 60 can roll on the area a of the cross section passing through the center of the spherical member 60 and the base 80. The area of the range (in the example shown, the area of the bottom surface of the recess 80a) is determined according to A, and between these, 0.3 ≦ a × n / A ≦ 0.8, preferably 0.5 ≦ It is preferable to satisfy the relationship of a × n / A ≦ 0.7.

  If the number n of the spherical members 60 does not satisfy the above relationship, the main body portion 20a and the base portion 80 cannot be held in parallel when the arrangement of the spherical members 60 is biased. As a result, heat conduction from the lower mold 20 to the lower mold 20 becomes insufficient, and the lower mold 20 cannot be efficiently heated. On the other hand, if the number n of the spherical members 60 exceeds the above relationship, each spherical member 60 cannot freely roll and may hinder smooth horizontal movement of the main body 20a. .

  Although this embodiment differs from 2nd embodiment by the above point, since it has the structure similar to 2nd embodiment except that, detailed description about another structure is abbreviate | omitted.

[Press forming equipment]
Next, an example of a press molding apparatus suitable for press molding with the above mold will be described.

  FIG. 6 is a schematic plan sectional view of the press molding apparatus. As shown in this figure, the press molding apparatus 100 includes a heating chamber 120 and a molding chamber 130, and a passage 140 communicating between them.

  The internal space of the heating chamber 120, the molding chamber 130, and the passage 140 is a sealed space that is blocked from the outside, and the outer wall of the sealed space is formed by stainless steel, steel, or other members, and the hermeticity is improved by the sealing material. Guaranteed. The internal spaces of the heating chamber 120, the molding chamber 130, and the passage 140 are set to a non-oxidizing gas atmosphere such as nitrogen gas when the optical glass is molded.

  The heating chamber 120 is a region for preheating the supplied molding material G prior to pressing. In the heating chamber 120, a glass heating device 122, a molding material supply handler (hereinafter referred to as a supply handler 123), and a carry-in unit 121 for supplying the molding material G from the outside into the heating chamber 120 are installed. Yes. The carry-in unit 121 includes a carry-in chamber (not shown) in order to carry in the molding material G while maintaining hermeticity. The carry-in unit 121 carries in the molding material G supplied from the outside, and the inside is filled with non-oxidizing gas. After filling, the door on the heating chamber 120 side is opened, and the molding material G is sequentially carried into the interior.

  The supply handler 123 conveys the molding material G carried in from the carry-in part 121 to a heating region by the glass heating device 122 and conveys the heated molding material G to the molding chamber 130. The supply handler 123 includes a levitating dish 125 at the tip of the arm 124, and holds the molding material G while being floated by gas. In this example, the arm 124 including the levitating dish 125 is horizontally supported by the driving unit 123a fixed in the heating chamber 120, and the arm 124 is rotated in the horizontal direction with a rotation angle of approximately 90 °. In addition, the arm 124 is configured to be movable in and out in the radial direction with the drive unit 123 a as the center, and thereby, the held molding material G can be conveyed to the molding chamber 130.

  The glass heating device 122 is for heating the supplied molding material G to a temperature corresponding to a predetermined viscosity. In order to stably raise the molding material G to a certain temperature, it is preferable to use a heating device using resistance heating or high-frequency heating. As shown in the drawing, the glass heating device 122 is installed under the movement locus of the molding material G held on the arm 124, and can heat the molding material G while the molding material G is being conveyed by the arm 124. The arm 124 may be stopped on the glass heating device 122 for a predetermined time to heat the molding material G. These matters are determined according to the time required for heating the molding material G to be processed.

  On the other hand, the molding chamber 130 is an area for pressing the molding material G preheated in the heating chamber 120 to mold a molded body G1 having a desired shape. The molding chamber 130 includes a press device 133 and a molded body. A G1 carry-out handler (hereinafter referred to as a carry-out handler 132) and a carry-out section 131 for carrying out the press-formed molded body G1 to the outside are installed. The carry-out unit 131 includes a carry-out chamber (not shown) filled with a non-oxidizing gas in order to carry the molded body G1 to the outside while maintaining the airtightness of the molding chamber 130. The molded body G1 delivered from the carry-out handler 132 is once carried into the carry-out chamber and then carried out to the outside.

  The press device 133 receives the molding material G conveyed from the heating chamber 120 by the supply handler 123 and presses the molding material G to form a molded body G1 having a desired shape. The press device 133 includes the molding die M as described above, and presses the molding material G supplied between the upper and lower molds 10 and 20 by the molding surfaces 11 and 21 thereof. A mold heating device 134 for heating the mold M is installed around the mold M. A preferred embodiment of the mold heating device 134 is a heating method using high frequency induction. Prior to pressing the molding material G, the molding die M is heated by the mold heating device 134 and maintained at a predetermined temperature. The temperature of the molding die M at the time of pressing may be substantially the same as or lower than the temperature of the preheated molding material G.

  The carry-out handler 132 delivers the formed body G1 pressed by the press device 133 to the carry-out unit 131. The carry-out handler 132 includes a suction pad 132c at the tip of an arm 132b that is rotatably supported by the drive unit 132a. The suction pad 132c vacuum-sucks the optical glass on the lower mold of the mold M and enables the carry-out handler 132 to carry it. The molded body G1 adsorbed by the rotation of the arm 132b is conveyed under the carry-out part 131 and placed on a lifting / lowering means (not shown) installed here. After the arm 132b is retracted, the lifting / lowering means is raised and the molded body G1 is transferred to the carry-out section 131.

  The molding chamber 130 is provided with an opening / closing door 135 on the front side thereof, and the opening / closing door 135 is for an operator to access the inside of the molding chamber when the press molding apparatus 100 is maintained and inspected. A seal member 35a is provided around the open / close door 135, and airtightness in the molding chamber 130 is ensured with the open / close door 135 closed during pressing. The open / close door 135 includes a glass (for example, quartz glass) window 135b from which the press molding can be visually recognized from the outside.

  A passage 140 that connects the heating chamber 120 and the molding chamber 130 enables the supply handler 123 to transfer the molding material G from the heating chamber 120 to the molding chamber 130 and to exchange gas between the two chambers. To. Thereby, at the time of press molding, the atmospheric pressure, gas concentration, and temperature of the heating chamber 120 and the molding chamber 130 are made substantially constant. An airtight valve 141 is disposed in the passage 140. When the airtight valve 141 is closed, the heating chamber 120 and the molding chamber 130 are shut off in an airtight state. The airtight valve 141 is fully opened at the time of press molding, but is closed at the time of maintenance or inspection in the molding chamber 130 by an operator, and the airtight state on the heating chamber 120 side is maintained.

[Method for producing molded article]
Next, an embodiment to which the method for producing a molded body according to the present invention is applied will be described. The method for producing a molded body according to the present invention is press-molded using the mold as described above, and is preferably carried out by the press molding apparatus.
In the press molding apparatus, the molding material G is sequentially supplied from the carry-in portion 121 into the apparatus, and the molded body G1 is continuously press-molded. Here, focusing on the molding of one molding G1, The procedure will be described.

(A) Carry-in process Prior to molding, the gas inside the heating chamber 120 and the molding chamber 130 is gas-exchanged to a non-oxidizing gas. For example, a non-oxidizing gas is always supplied into the room and kept in a positive pressure state. In this non-oxidizing gas atmosphere, the glass heating device 122 and the mold heating device 134 are energized and maintained at a predetermined temperature. In this state, the airtight valve 141 of the passage 140 is opened.
In the first step, the molding material G is supplied to the heating chamber 120. Specifically, the molding material G is first placed in the carry-in chamber of the carry-in unit 121, and after being exhausted, the gas is replaced and then supplied to the heating chamber 120. At the time of supplying the molding material G, the arm 124 of the supply handler 123 is positioned below the carry-in portion 121, and the molding material G from the carry-in chamber is placed on the floating tray 125 of the supply handler 123.

(B) Molding Material Heating Step Upon receipt of the molding material G, for example, a spherical glass preform, the supply handler 123 immediately rotates its arm and moves the floating dish 125 onto the glass heating device 122. Here, the non-oxidizing gas is jetted from below to the floating dish 125, and thus the molding material G is heated and softened while floating on the floating dish 125. The molding material G is heated until the temperature reaches a temperature corresponding to a viscosity of 10 ⁶ to 10 ⁹ dPa · s.

(C) Mold heating step In addition, when the heated molding material G is supplied to the mold M, the temperature of the mold M corresponds to a temperature corresponding to a viscosity of 10 ⁸ to 10 ¹² dPa · s of glass. As shown, the mold M is preheated by induction heating by the mold heating device 134.
Here, the temperature setting values of the heated upper and lower molds 10 and 20 may be the same as the upper and lower molds 10 and 20 as described above, or a temperature difference may be provided. For example, the lower mold 20 can be made hotter than the upper mold 10 or the lower mold 20 can be made colder than the upper mold 10 depending on the shape and diameter of the molded body. When providing a temperature difference, it is desirable that the temperature difference between the upper and lower molds 10 and 20 be in the range of 2 to 15 ° C.

(D) Supply Step of Molding Material Thereafter, the supply handler 123 is driven to supply the molding material G to the molding surface 21 of the lower mold 20 of the press device 133 in the molding chamber 130. That is, the arm 124 is further rotated from the heating position and stopped when the floating tray 125 has reached the position facing the passage 140, and then the arm 124 is extended so that the floating tray 125 is in the mold open state in the press device 133. Extend to M, and drop the molding material G on the floating tray 125 onto the lower mold 20. Thereafter, the supply handler 123 moves the arm backward to move to the initial position, that is, below the carry-in unit 121, and waits to receive the next molding material G.
When the softened molding material G is transported and supplied to the lower mold 20, if the molding material G comes into contact with a member of the transport mechanism, the surface is likely to be defective. If the surface is defective, the surface shape of the molded body G1 to be molded is adversely affected. Therefore, using the supply handler 123 of this example that transports the softened molding material G in a state of being floated by gas and drops it to the lower mold is advantageous in preventing such adverse effects.

(E) Pressing Process When the molding material G is supplied to the lower mold 20 and the arm is retracted from the molding mold M, the mold closing (pressing operation) starts immediately. As shown in FIGS. 2 and 3, the lower mold 20 is raised and the molding material G is pressed between the upper mold 10 and a desired molded body G1 is molded. The stroke of the lower mold 20 for pressing is a preset value based on the thickness of the molded body G1 to be molded. In the cooling process of the next step, the stroke of the molded body G1 after molding is expected to shrink. The amount can be determined by. In general, the press molding speed is preferably 3 to 600 mm / min. In the case of molding a glass lens having a diameter of 15 mm or more, it is preferably 3 to 80 mm / min. The pressing procedure can be arbitrarily set according to the shape and size of the optical glass to be molded. For example, a procedure of performing multiple pressurizations such as performing secondary pressurization after releasing the load after initial pressurization may be employed.

Here, in the molding die M of this example, the lower die 20 is held by the lower die holding member 25 in a swingable state while the lower surface of the large diameter portion 23 is a curved surface 24. Therefore, even when the lower mold 20 is inclined with respect to the upper mold 10 when the mold is closed, when the lower mold 20 is inserted into the body mold 30, the lower mold 20 swings to correct its posture. The upper and lower molds 10 and 20 are aligned, and pressing is performed in this state.
Therefore, position correction is performed so that the lower mold 20 is coaxial with the upper mold 10 without causing rubbing and galling in the body mold 30 and the lower mold 20, and press molding can be performed with high accuracy.
Further, even after the lower mold 20 is inserted into the body mold 30 to some extent, the lower mold 20 corrects the posture following the curved surface 24, and the body mold so as to substantially coincide with the axis of the upper mold 10. Fits within 30.

  When the upper mold 10 and the lower mold 20 are closed, the opening end surface 33 on the lower mold 20 side of the body mold 30 is pressed against the upper end surface of the large-diameter portion 23 of the lower mold 20. Is preferred. Thereby, since the lower mold | type 20 and the trunk | drum 30 fix to concentric form, without mutually shifting position, a highly accurate molded object can be shape | molded stably.

(F) Cooling / mold release step At the same time as or after the start of pressing the molding material, the mold heating device 134 is turned off, and a non-oxidizing gas is allowed to flow into the molding die. It is also sprayed from the outside, whereby the mold M is cooled. And when the temperature of the shaping | molding die 150 becomes below the transition point of glass, the lower mold | type 20 is fall | descended and released, and the molded object G1 can be carried out.
Moreover, in order to prevent generation | occurrence | production of the crack of a molded object, and a radiation | damage damage, a cooling rate can be 50-200 degreeC / min as an average value from a cooling start to mold release. The cooling rate at the start of cooling is preferably smaller than the average cooling rate from the viewpoint of preventing cracking, and it is desirable to increase the cooling rate as the mold release temperature is approached. The mold release temperature can be not higher than the vicinity of the glass transition point Tg, but in general, it is desirable to set the value within the range from (Tg-50 ° C.) to Tg.

(G) Removal Step Next, the molded body G <b> 1 on the lower mold 20 is conveyed to the unloading unit 131 by the unloading handler 132. That is, as shown by an imaginary line in FIG. 6, the carry-out handler 132 is driven, the arm 132b is rotated, and the suction pad 132c at the tip is moved onto the lower mold. The molded body G1 on the lower mold is sucked by the suction pad 132c, the arm 132b is rotated, the arm 132b is conveyed to the lifting means below the carry-out portion 131, the suction of the suction pad 132c is released, and the molding is formed on the lifting means. Pass the body G1.

(H) Unloading step Next, the lifting / lowering means is raised and the formed body G1 is unloaded from the forming chamber 130 through the unloading chamber of the unloading portion 131. The mold heating device 134 is energized as soon as the molded body G1 is unloaded from the lower mold, and heats the mold to a predetermined temperature in preparation for the next press molding.
By repeatedly performing the above steps (a) to (h), the molded body G1 can be efficiently manufactured.
In addition, there is no restriction | limiting in particular about the shape of the optical glass of press molding object, A biconvex lens, a convex meniscus lens, a concave meniscus lens, a biconcave lens etc. can be shape | molded. The size of the molded body is not particularly limited, but generally a molded body having a diameter of about 2 mm to about 35 mm can be molded. This is because if the thickness is 2 mm or less, the glass material is likely to be cooled, so that it is easily broken, and if it is 35 mm or more, molding takes time and it is extremely difficult to obtain a good surface. Furthermore, the shape of the optical glass can be spherical, aspherical, or a combination thereof.

  While the present invention has been described with reference to the preferred embodiment, it is needless to say that the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. .

For example, in the above-described embodiment, an example of a mold having a pair of upper and lower molds 10 and 20 has been shown. However, as shown in FIG. 7, two pairs of upper and lower molds 10 and 20 may be provided. Further, although not particularly shown, three or more pairs of upper and lower molds 10 and 20 may be provided. By doing in this way, a plurality of formed objects can be simultaneously formed by one press forming operation.
Note that the example shown in FIG. 7 corresponds to a configuration in which two molds similar to those of the first embodiment described above are provided side by side and these are attached to a common fixed shaft 40 and drive shaft 50.

Further, in the embodiment described above, the curved surface 24 on the lower surface of the large diameter portion 23 of the lower mold 20, or although the example of forming a curved surface 81 on the lower surface of the base portion 80, and a lower die 20 and lower die support base 26 through a curved surface not good if it comes into contact.

For example, as shown in FIG. 8, a curved surface 28 can be formed on the lower mold support base 26 side.

  The present invention is applied to a mold press mold for press molding a molding material such as a glass preform, and a method for producing a molded body using such a mold press mold.

It is sectional drawing which shows the outline of 1st embodiment of the mold press molding die which concerns on this invention. It is sectional drawing which shows the outline of 1st embodiment of the mold press molding die which concerns on this invention. It is sectional drawing which shows the outline of 1st embodiment of the mold press molding die which concerns on this invention. It is sectional drawing which shows the outline of 2nd embodiment of the mold press molding die which concerns on this invention. It is sectional drawing which shows the outline of 3rd embodiment of the mold press molding die which concerns on this invention. It is a schematic plan view which shows an example of the press molding apparatus suitable for press-molding with the mold press-molding die concerning the present invention. It is sectional drawing which shows the outline of another embodiment of the mold press molding die which concerns on this invention. It is sectional drawing which shows the outline of another embodiment of the mold press molding die which concerns on this invention.

Explanation of symbols

10 Upper mold 11 Molding surface 15 Upper mold holding member 20 Lower mold 20a Main body 21 Molding surface 24 Curved surface 25 Lower mold holding member 30 Body mold 33 Opening end surface 35 Elastic member 60 Spherical member 80 Base 80a Recessed portion 81 Curved surface G Molding material

Claims (11)

A lower mold and an upper mold in which a molding surface of an arbitrary shape is formed;
The lower mold and the upper mold are arranged so as to face each other so that their molding surfaces face each other, and are inserted coaxially,
An upper mold holding member that holds the upper mold together with the trunk mold in a state where the upper mold is coaxially inserted into the trunk mold;
And a lower mold holding member for holding the lower mold,
Comprising at least
The lower mold has a shape in which a small-diameter portion on which the molding surface is formed and a large-diameter portion having a larger diameter than the molding surface are arranged coaxially, and includes the lower die support base and a lower mother die. In holding the lower mold on the holding member,
The lower mother die has an inner peripheral surface in which the upper side is a small-diameter inner peripheral surface and the lower side is a large-diameter inner peripheral surface, and is formed at a step portion between the small-diameter inner peripheral surface and the large-diameter inner peripheral surface. The large-diameter portion of the lower mold is held in a loose fit between the annular stepped surface and the upper surface of the lower mold support base,
And the lower large-diameter portion of the lower surface or the curved surface of one of said lower die support the upper surface of the table, and the other as a plane, by the said lower die support base and the lower mold that is brought into contact via the curved surface,
The lower mold holding member, when the lower mold is inserted into the barrel die, or after insertion, the lower mold holding the lower mold while allowing it to correct the posture following the said curved surface A mold press mold characterized in that The lower mold has a main body part including a small diameter part of the lower mold and a base part including a lower surface of the large diameter part of the lower mold ,
The mold press mold according to claim 1, wherein a plurality of spherical members are disposed between the main body and the base so as to be capable of rolling.   3. The mold press mold according to claim 2, wherein a concave portion for accommodating the spherical member is formed on at least one surface of the main body portion and the base portion facing each other through the spherical member.   The mold press mold according to any one of claims 1 to 3, wherein the curved surface is formed of a spherical surface. An elastic member for urging the body mold toward the lower mold ;
When press molding a molding material with the lower mold and the upper mold ,
The opening end face of the trunk mold on the side where the lower mold is inserted is pressed against a part of the lower mold by the urging force of the elastic member. Mold press mold. The upper mold has a shape in which a small-diameter portion where the molding surface is formed and a large-diameter portion whose diameter is larger than the molding surface are arranged coaxially,
The large diameter portion of the upper mold is in contact with an annular step surface formed on the inner peripheral side of the trunk mold when the upper mold is coaxially inserted into the trunk mold. The mold press molding die of any one of 1-5. An overhang portion is formed on the upper side of the body mold so as to project in the radial direction, and when the body mold is held by the upper mold holding member including an upper mold support base and an upper mother mold, In any one of Claims 1-6 which hold | maintained the said trunk | drum to the said upper mold | type holding member in the state clamped between the step surface formed in the inner periphery of the mother mold | type, and the said upper mold | type support stand. The mold press mold according to the description. A lower mold and an upper mold in which a molding surface of an arbitrary shape is formed;
The lower mold and the upper mold are arranged so as to face each other so that their molding surfaces face each other, and are inserted coaxially,
An upper mold holding member that holds the upper mold together with the trunk mold in a state where the upper mold is coaxially inserted into the trunk mold;
A lower mold holding member for holding the lower mold;
Comprising at least
The lower mold has a shape in which a small-diameter portion on which the molding surface is formed and a large-diameter portion having a larger diameter than the molding surface are arranged coaxially, and includes the lower die support base and a lower mother die. In holding the lower mold on the holding member,
The lower mother die has an inner peripheral surface in which the upper side is a small-diameter inner peripheral surface and the lower side is a large-diameter inner peripheral surface, and is formed at a step portion between the small-diameter inner peripheral surface and the large-diameter inner peripheral surface. The large-diameter portion of the lower mold is held in a loose fit between the annular stepped surface and the upper surface of the lower mold support base,
A mold press in which one of the lower surface of the large-diameter portion of the lower mold or the upper surface of the lower mold support is a curved surface and the other is a flat surface, and the lower mold and the lower mold support are brought into contact with each other via the curved surface Using a mold
The lower mold is held by the lower mold holding member so that the posture can be corrected following the curved surface when the lower mold is inserted into the body mold or after the lower mold is inserted. And supplying the molding material between the molding surfaces of the upper mold,
A method for producing a molded body, wherein the molding material is press-molded with the lower mold and the upper mold, and the shape of each molding surface is transferred to the molding material. Prior to pressing, thereby preheating the molding material, and preheating the mold press forming die, to claim 8 for press molding by supplying the molding material after preheating the mold press mold after preheating The manufacturing method of the molded object of description. The lower mold has a main body part including a small diameter part of the lower mold and a base part including a lower surface of the large diameter part of the lower mold ,
Using a mold press mold in which a plurality of spherical members are arranged to roll between the main body portion and the base portion,
The manufacturing method of the molded object of any one of Claims 8-9 which press-molds the said shaping | molding raw material. Using a mold press mold having an elastic member that urges the body mold toward the lower mold,
When press molding the molding material with the lower mold and the upper mold ,
Said barrel shaped opening end face of the side where the lower mold is inserted, according to any one of claims 8 to 10 which is to be pressed against the portion of the lower mold by the biasing force of the elastic member A method for producing a molded article.

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