JP5114280B2 - Molding method of molding material - Google Patents

Description

  The present invention relates to a molding material molding method for molding a molding material set in a mold set including a pair of pressing dies without waste from the beginning of the molding process.

  Conventionally, for example, as seen in Patent Document 1, preheating, pressing and cooling processes are performed on a plurality of mold sets (blocks) composed of a pair of pressing molds by a plurality of molding shafts (stages) arranged in the order of the molding processes. A molding method has been proposed in which the molding material (optical element material) set in the mold set is sequentially molded.

  4 (a), 4 (b), and 4 (c) are diagrams illustrating such a conventional molding process. FIG. 2A shows the mold set 1, FIG. 2B shows the molding part 2, and FIG. 1C shows the molding process. In the drawing, the illustration of the mold set conveyance system is omitted.

  As shown in FIG. 1 (a), the mold set 1 is first formed into a basically cylindrical upper mold 3 having a flange at the top and a molding convex part at the center of the lower surface, and molded at the center of the upper surface. A recess 4 is formed, and a lower mold 4 having two step portions on the peripheral surface is provided.

  A cylindrical sleeve 5 is engaged with the lower step portion of the lower mold 4 so as to be erected, and a flange is provided inside the upper portion of the step portion on the lower mold 4 inside the sleeve 5. An annular outer peripheral die 6 is engaged and erected. A molding material 7 is placed and set in the molding recess at the center of the upper surface of the lower mold 4.

  Further, as shown in FIG. 4B, the molding portion 2 is provided with three molding shaft portions 8 (8a, 8b, 8c) in order of steps from left to right. The forming shaft portion 8a serving as the first shaft is a shaft portion for the preheating process, the forming shaft portion 8b serving as the second shaft is the shaft portion for the pressing process, and the forming shaft portion 8c serving as the third shaft is the cooling process. It is a shaft part for.

  Each molding shaft portion 8 is fixed to the lower frame 9 of the molding apparatus main body at the lower part, and includes a fixed heat plate 12 with a built-in heater 11, and a movable heat plate 13 with a built-in heater 11 at the upper part. ing. The movable heat plate 13 is fixed to the lower end portion of the piston 15 that moves up and down from a cylinder device (not shown) fixed to the upper frame 14 of the molding apparatus main body.

  When the forming material 7 is formed, as shown in FIG. 4 (c), the mold set 1 is continuously carried into the forming portion 2 in the order of (1), (2), (3). The mold set 1 means that the molding shaft portion 8a in the shaft preheating step, the molding shaft portion 8b in the second shaft pressing step, and the molding shaft portion 8c in the third shaft cooling step are sequentially conveyed and molded. Further, (4), (5),... Are successively carried into the molding unit 2 and repeatedly produced as a molded product 7-1.

  By the way, as in Patent Document 1, when a plurality of mold sets such as the first mold set, the next mold set, and the next mold set are successively carried into the molding section, the temperature is set to a high temperature in the press process. The temperature of the heat plates 12 and 13 of the molding shaft portion 8b is lowered during the first molding by the first mold set 1 (1).

  Immediately after the molding process (pressing process) by the first mold set 1 (1), when the next mold set 1 (2) is carried into the molding shaft portion 8b of the pressing process, the temperature is lower than at the start of the first molding. Therefore, the next mold set 1 (2) cannot be molded under the same conditions as the first mold set 1 (1). Therefore, it becomes necessary to stabilize the molding conditions to a certain level.

  5 (a) and 5 (b) are diagrams for explaining a method for stabilizing the molding conditions to be constant with the configuration of the molding unit 2 described above. FIGS. 9A and 9B both show the temperature of the forming shaft portion 8b in the pressing process in the vertical direction, and show the passage of time in the horizontal direction.

  As a preparatory process for stabilizing the molding conditions at a constant level, all the preheating, pressing and cooling processes are first repeated within the same time interval. This shows the case of high-temperature molding in which the mold set is deformed while being heated in the pressing step. FIG. 6A shows the temperature H0 in the first heat treatment 17-0 of the molding shaft 8b in the pressing process, the temperature H1 in the first molding 17-1, the temperature H2 in the second 17-2, the temperature H2 in the third 17th. -3 gradually decreases to the temperature H3 and stabilizes somewhere (becomes constant).

  FIG. 5A shows that when the fourth molding 17-4 is completed, the temperature has decreased to the temperature of the molding condition value of the stable high temperature molding of temperature H4. Thereafter, no matter how many times the preheating, pressing, and cooling steps are repeated, the molding temperature of the molding shaft portion 8b in the pressing step does not drop from the temperature H4.

That is, the case (a) in the figure shows an example in which a stable temperature H4 which is an appropriate temperature for high-temperature molding is obtained by repeating the molding process four times when the preheating temperature H0 is set.
Figure (b) also shows a preparation process in which all the preheating, pressing, and cooling processes are repeated within the same time interval. This is a pressing process in the case of intermediate temperature molding that deforms while cooling the mold set. Is shown. In this case, the case where the molding is performed at an appropriate molding condition value temperature is shown. In this case, from the temperature h0 in the first heat treatment 17-0 of the molding shaft portion 8b in the pressing step, the temperature h1 in the first molding 17-1, the temperature 17 in the second 17-2, the temperature h2 in the third 17-3. It gradually rises with temperature h3 and stabilizes somewhere (becomes constant).

  FIG. 5B shows that the temperature h4 has reached the temperature of the stable molding condition value of the medium temperature molding at the stage when the fourth molding 17-4 is completed. Thereafter, no matter how many times the preheating, pressing, and cooling steps are repeated, the molding temperature of the molding shaft portion 8b in the pressing step does not rise from the temperature h4.

That is, in the case of FIG. 5B, when the preheating temperature h0 is set, an example is shown in which a stable temperature h4 that is an appropriate temperature for intermediate temperature molding is obtained by repeating the molding process four times.
In addition, when the molding apparatus stops due to some accident, the above-mentioned stabilized temperature changes. In this case, preparation for repeating the molding several times until the stabilized state of the original molding conditions is obtained. It takes a process.
JP 2001-058837 A

  By the way, in the above example, an example in which a stable temperature, which is an appropriate temperature for molding, can be obtained by repeated molding of the preparation process four times. Usually, until the temperature of the pressing process becomes constant until the stabilization of molding conditions. Repeating the preparation process requires 4 to 10 repetitions.

  And by this preparatory process, since the molded product discharged | emitted by one repetition is not a good product, it is discarded. If the molded product is a mass-produced product, the occurrence of 4-10 defective products will not have a significant adverse effect on the yield, but if the molded product is produced in a small amount, 4-10 defective products will be generated. Even if this is the case, the yield cannot be ignored.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a molding material molding method for molding a molding material set in a mold set without waste from the beginning of the molding process. And

 In order to achieve the above object, a molding material molding method of the present invention includes a plurality of a pair of pressing dies with respect to a plurality of molding shafts each having a heated heat plate and arranged in the order of the molding process. The molding material set in the mold set by sequentially moving the mold set and sequentially performing the temperature control process, pressing process and slow cooling process on the mold set at the molding shafts arranged in the molding process order. In the molding method of the molding material to be molded, the plurality of mold sets are moved while leaving every other molding shaft portion.

  According to the present invention, the molding material set in the mold set can be used because the empty time zone of the molding shaft part that is vacated every other time can be used for the time for the molding shaft part to recover to a temperature at which pressing can be started. It is possible to provide a molding material molding method for molding without waste from the beginning of the molding process.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIGS. 1A and 1B and FIGS. 2A, 2B, and 2C are diagrams for explaining a molding process in the first embodiment. FIG. 1A shows a state in which the mold set 21 (1) has already been carried into the preheating molding shaft portion 23 a of the molding chamber 22.

  The configuration of the mold set 21, the molding chamber 22, the molding shaft portion 23 (the molding shaft portions 23a, 23b, and 23c in the preheating step, the pressing step, and the slow cooling step) and the molding material 24 in this example are shown in FIG. The configuration of the mold set 1, the molding part 2, the molding shaft part 8 (the molding shaft part 8a in the preheating process, the molding shaft part 8b in the pressing process, the molding shaft part 8c in the cooling process) and the molding material 7 shown in FIG. An example is shown.

Therefore, the description of the configuration and functions in FIG. In FIGS. 1 (a), (b) and FIGS. 2 (a), (b), (c), only the portions necessary for explanation are given numbers.
In the following description, the molding shaft portions 23a, 23b, and 23c in the preheating step, the pressing step, and the slow cooling step are simply referred to as a heating shaft 23a, a molding shaft 23b, and a slow cooling shaft 23c.

  In each of these three axes, there is a movable heat plate 25 with a built-in heater on the top and a fixed heat plate 26 with a built-in heater on the bottom, as in the case of FIG. The mold set 21 is sequentially transported to these three axes as indicated by arrows a, b, and c, and the finished molded product is discharged out of the molding portion 2 as indicated by the arrow d.

In this example, the temperature of the shaft is initially set to medium temperature, high temperature, and low temperature in the order of the heating shaft 23a, the forming shaft 23b, and the slow cooling shaft 23c.
In the following, a method of forming the forming material 24 as a non-defective product from the first one in the three-axis configuration of heating → molding → slow cooling in the molding chamber 22 of the molding machine in this example will be described.

  First, as shown in FIG. 1 (a), the first mold set 21 (1) at room temperature is conveyed as indicated by an arrow a and supplied to the heating shaft 23a. The piston 27 of the heating shaft 23a is lowered and the movable heat plate 25 presses the upper surface of the upper mold 28 of the mold set 21 (1) to transmit heat to the upper mold 28 to heat the upper mold 28, and is fixed at the lower part. The heat plate 26 is in close contact with the lower surface of the lower mold 29 of the mold set 21 (1) and transfers heat to heat the lower mold 29.

  Thereby, the first mold set 21 (1) receives heat from the upper and lower heat plates 25 and 26 of the heating shaft 23a, is preheated, and approaches the intermediate temperature. This preheating time is, for example, 1 minute in this example. In this one minute, the heat plates 25 and 26 of the heating shaft 23a are deprived of heat by the mold set 21 (1) and become a temperature lower than the intermediate temperature.

  During this time, the pistons 27 of the forming shaft 23b and the slow cooling shaft 23c are retracted to the upper standby position, so that the movable heat plate 25 is in the upper standby position, and the fixed heat plate 26 and the movable heat plate 25 is formed with a gap sufficient to convey the mold set 21 (1).

  Next, as shown in FIG. 1 (b), the movable heat plate 25 of the heating shaft 23a moves upward to release the pressure and release the mold set 21 (1). The first mold set 21 (1) that has been released due to a rise in temperature in the vicinity of the intermediate temperature is transferred to the hot fixed heat plate 26 of the molding shaft 8b as indicated by an arrow b.

  Here, the piston 27 of the molding shaft 8b advances downward, and the high-temperature movable heat plate 25 presses while heating the upper mold of the mold set 21 (1). From the lower part, a high-temperature fixed heat plate 26 is brought into close contact with the lower surface of the lower mold 29 of the mold set 21 (1) to heat the lower mold 29.

  As a result, the mold set 21 (1) receives heat from the upper and lower heat plates 25 and 26 and approaches the high temperature. Then, the molding material 24 is pressed from above and below and is compressed and deformed. In this example, the compression deformation processing time is, for example, 2 minutes.

Further, during the molding deformation time of 2 minutes, the temperature of the upper and lower heat plates 25 and 26 on the molding shaft 23b is 60 ° C. lower than that before molding.
Following the above, the movable heat plate 25 of the molding shaft 23b moves upward to release the pressure and release the mold set 21 (1). The first mold set 21 (1) is almost completely deformed and raised to a temperature close to a high temperature, and is conveyed from the molding shaft 23b to the slow cooling shaft 23c as shown by an arrow c, and is gradually cooled. It is transferred onto the fixed heat plate 26 of the cold shaft 23c.

  The first mold set 1 (1) completes the deformation while performing the final deformation while being gradually cooled for 1 minute while the temperature is lowered at an appropriate temperature difference on the slow cooling shaft 23c. The molding material 24 is cooled until the shape is hardened due to the temperature drop.

The first mold set 1 (1) cooled until the shape is solidified is discharged from the cooling shaft 23c to the outside of the molding chamber as indicated by an arrow d.
At the same time, as shown in FIG. 2 (a), the next mold set 21 (2) is supplied to the heating shaft 23a as shown by the arrow a, as described in FIG. 1 (a). The next mold set 21 (2) is preheated for 1 minute by the heating shaft 23a.

  Further, during this one minute, the forming shaft 23b is an empty shaft. Then, the heating plates 25 and 26 on the upper and lower sides of the molding shaft 23c are heated by built-in heaters during the one-minute free time zone of the molding shaft 23c, and the first mold set 21 (1) is molded. The temperature at which the heat is lost and the temperature is lowered by 60 ° C. is restored to the first temperature at which molding can be started (pressing start).

  The state shown in FIG. 2 (b) is merely the replacement of the first mold set 21 (1) and the next mold set 21 (2), which is the same as the state shown in FIG. 1 (b). . In the state shown in FIG. 2 (c), the next mold set 21 (2) and the third mold set 21 (3) are interchanged, and the first mold set 21 (1) and the next mold set 21 (2 ) Are simply replaced, which is the same as the state shown in FIG.

  FIG. 3 (a) shows the first set of the mold set 21 by the molding procedure shown in FIGS. 1 (a), (b) and FIGS. 2 (a), (b), (c). FIG. 3 is a diagram for explaining that the molding process can be repeated with the molding temperature condition of the molding shaft 23b kept constant, and FIG. 3 (b) is a diagram showing another example.

3 (a) and 3 (b) show the change in temperature of the heat plates 25 and 26 above and below the forming shaft 23b in the vertical direction and the passage of time in the horizontal direction.
As shown in FIG. 3 (a), the temperature of the molding shaft 23b reaches the molding start temperature Ha in the initial heating step 27-0 (see FIG. 1 (a)), and the first molding step 27-1 (FIG. 3). 1 (b)) to the stable molding temperature Hb. However, in the next temperature recovery period 27-2 (see FIG. 2 (a)), the molding start temperature Ha is recovered, and in the second molding step 27-3 (see FIG. 2 (b)), the stable molding temperature Hb is reached again. Then, in the next temperature recovery period 27-4 (see FIG. 2 (c)), the molding temperature is recovered again.

  Thereafter, the molding process 27-1, the temperature recovery period 27-2, the molding process 27-3, and the temperature recovery period 27-4 are repeated to produce good molded articles continuously from the first one. Can do.

  As in the conventional example shown in FIG. 4 (c), if the next mold set 1 (2) is put immediately after the first mold set 1 (1) in the molding shaft part 8b, the molding shaft part is obtained. Since the recovery of the temperature of 8b is not in time, it is necessary to allow the molding shaft portion 8b to recover the temperature and then insert the next mold set 1 (2) into the molding shaft portion 8b for molding.

  In this example, as described above, in order to ensure the time for temperature recovery of the molding shaft portion 8b, the mold set 21 is divided into three axes with the mold sets 21 (1), (2), (3),. Instead of transporting the whole area, it is transported by leaving every other shaft part. When the vacant space becomes the vacant space of the molding shaft portion 8b, the vacant time zone is used for the time for recovering the temperature of the molding shaft 23b.

In this way, if the temperature fluctuated in the molding is recovered and molding is performed, the molding procedure for the non-defective product can be set from the first time, and the second molding and subsequent molding can be continuously performed as molding of the non-defective product.
In addition, although there is a difference in the heat transfer relationship between the axes, the occurrence of this difference is a common condition for all of the heating axis, the forming axis, and the slow cooling axis. When the molding shaft 23b is in the process of the molding process, the other shafts are vacant, and the other shafts can recover the changed temperature during this idle time zone.

  In addition, if the time to be used for the temperature recovery time becomes longer, not limited to every other interval as described above, the original condition is reproduced for all axes by appropriately setting two or more intervals. And can be molded.

  FIG. 3 (b) is a diagram showing a temperature change pattern when the temperature settings of the three axes of the heating axis, the forming axis, and the slow cooling axis shown in FIGS. 1 (a) to 2 (c) are different from the above. . In the case of this example, the initial set temperature is set to a high temperature, a medium temperature, and a low temperature in the order of the heating shaft 23a, the forming shaft 23b, and the slow cooling shaft 23c.

  The molding method will be briefly described for this example. In this example, the temperature setting is different from the case of FIG. 3 (a) as described above, and the conveyance mode of the mold set 21 with respect to the molding chamber 22 is as shown in FIGS. 1 (a), 1 (b) and 2 (a). ), (b), (c).

  Referring again to FIG. 1 (a), the room temperature mold set 21 (1) is placed on the heating shaft 23a, and the heat of the fixed heat plate 26 is conducted to the mold set 21 (1). The upper heat plate 25 is also lowered and brought into contact with the mold set 21 (1) to conduct heat.

  The mold set 21 (1) receives heat from the heat plate and approaches a high temperature, and the molding material 24 becomes soft. The heat plates 25 and 26 of the heating shaft 23a are deprived of heat by the mold set 21 and become a temperature lower than the high temperature.

  In FIG. 1 (b), the mold set 21 (2) in which the molding material 24 inside is sufficiently softened is transferred onto the fixed heat plate 26 of the medium temperature molding shaft 23b. The upper movable heat plate 25 is also lowered and pressed to cool the molding material 24 in the mold set 21 (1) while deforming it.

  The mold set 21 (1) transfers heat to the heat plates 25 and 26 of the molding shaft 23b and approaches the intermediate temperature, and the molding material 24 is solidified. At this time, the temperature of the heat plates 25 and 26 above and below the forming shaft 23b is increased by heat transfer from the mold set 21 (1).

  In FIG. 2 (a), the mold set 21 (1) is almost completely deformed, and at a temperature in the vicinity of the intermediate temperature, that is, at a temperature that still has room for deformation, a fixed hot plate of the low-temperature slow cooling shaft 23c. 26 is transferred.

  Within the slow cooling shaft 23c, the mold set 21 (1) completes the deformation while performing the final deformation while further lowering the temperature. The molding material 24 is cooled until the shape is hardened due to the temperature drop. The molding material 24 cooled until it hardens is discharged from the cooling shaft 23c to the outside of the molding chamber.

  The initial heating step 28-0, the first molding step 28-1, the temperature return period 28-2, the second molding step 28-3, and the temperature return period 28-4 in FIG. The relationship between a), (b) and FIGS. 2 (a), (b), (c) is as follows: initial heating step 27-0 in FIG. 3 (a), first molding step 27-1, temperature return period 27-2, the second step 27-3 of molding, and the temperature return period 27-4, and the same relationship with FIGS. 1 (a), (b) and FIGS. 2 (a), (b), (c) It is.

The high temperature used in the above-described molding step is a temperature at which the molding material 24 is softened and can be easily deformed by pressing, and refers to a temperature between the “transition point” and the “sagging point”.
Further, the intermediate temperature refers to a temperature at which the deformation can be managed, and refers to a temperature between “transition point” and “transition point −10 ° C.”.

The low temperature is a temperature at which the molding material is solidified and does not deform, and includes an effect of preventing rapid cooling.
In addition, this invention is not limited to the said embodiment, In the implementation stage, it can change variously in the range which does not change the summary.

(a), (b) is a figure (the 1) explaining the shaping | molding process in 1st Embodiment. (a), (b), (c) is a figure (the 2) explaining the shaping | molding process in 1st Embodiment. (a), (b) is a figure explaining that the molding process can be repeated by stabilizing the molding temperature condition of the molding shaft from the first one of the mold set in the molding process in the first embodiment. It is. (a), (b), (c) is a figure explaining the conventional shaping | molding process. (a), (b) is a figure explaining the method for stabilizing molding conditions uniformly with the structure of the conventional shaping | molding part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Type set 2 Molding part 3 Upper mold 4 Lower mold 5 Sleeve 6 Peripheral mold 7 Molding material 8 (8a, 8b, 8c) Molding shaft part 9 Molding apparatus main body lower frame 11 Heater 12 Fixed heat plate 13 Movable heat plate 14 Molding Upper body frame 15 Piston 17-0 Heat treatment 17-1 First molding 17-2 Second molding 17-3 Third molding 17-4 Fourth molding H0, h0 Heating temperature H1, H2, H3, H4, h1, h2, h3, h4 Temperature at the time of press process molding 21 Mold set 22 Molding chamber 23 Molding shaft 23a Heating shaft 23b Molding shaft 23c Slow cooling shaft 24 Molding material 25 Movable heat plate 26 Fixed heat plate

Claims (1)

A plurality of mold sets each consisting of a pair of pressing dies are sequentially moved to a plurality of molding shafts each having a heated heat plate and arranged in the order of the molding process, and the molding shafts arranged in the order of the molding process. In the molding material molding method for molding the molding material set in the mold set by sequentially performing a preheating process, a pressing process, and a cooling process on the mold set.
The molding shaft part is composed of three axes, a preheating process shaft part, a pressing process shaft part, and a cooling process shaft part,
There line movement of a plurality of said mold set while leaving every other one of said shaped shaft portion,
The free time zone of the pressing process shaft portion is devoted to a recovery period that is a time for the pressing process shaft portion to recover to a temperature at which pressing can be started,
The temperature of the heat plate during the recovery period of the pressing step shaft portion recovers from the lower to the higher molding condition temperature,
The time of the pressing step in the pressing step shaft and the time during the recovery period are set independently,
The time of the preheating process in the shaft portion for the preheating process and the time of the cooling process in the shaft portion for the cooling process are the same.
A molding material molding method characterized by the above.