JPH04275103A - Mold releasing method in dry press molding - Google Patents

Abstract

PURPOSE:To reduce remarkably the time for mold releasing by the operations of lowering a frame mold together with an upper mold for molding, lifting the upper mold, a molded body, and a lower mold after molding, and after extracting the molded body, lifting the frame mold to the same level with the lower mold. CONSTITUTION:In plain press molding process, a frame mold 3 and a lower mold 4 are placed at a level position, and a molded body 1 is moved from above the lower mold 4 and the frame mold 3 with a molded-body-pushing bar 5, and simultaneously a molding-powder-pushing bar 6 is moved to transfer the molding powder B above the lower mold 4. Then an upper mold 2 is lowered above the powder B to push the powder B, and at the same time, by bringing the lower surface of the upper mold 2 into contact with the upper surface of the frame mold 3, the frame mold 3 and the lower mold 4 are pushed against a reinforcing spring. At the end of molding in this way, the upper mold 2, the molded body 1, and the lower mold 4 are lifted up, and the molded body 1 is extracted while the frame mold 3 being kept at the lowered position. Then, the frame mold 3 is lifted up to the same level with the lower mold 4.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a demolding method in dry press molding for forming tile bases and the like.

0002

[Prior Art] In dry press molding, during the so-called demolding operation in which the molded product is pulled out from the frame mold after pressurization, the sides of the molded product are torn open and the corners of the molded product are broken. They are prone to defects such as breakage. Therefore, delicate adjustments to the operation of the mold and the detailed shape of the mold were required, and the stability of the equipment against defects was low. In the present invention, by changing the demolding operation from the conventional one, the occurrence of "sharpness" and "mog" is avoided and the stability of the product is improved.

0003

[Problem to be solved by the invention] “
The occurrence of "Moge" will be explained. The molded body is about 0 when demolded.
．． It expands by about 4 to 0.6%, but the lower part of the back side of the molded body
As shown in FIG. 5, when the mold is lifted up after molding, when a small amount remains in the frame, force is likely to be applied locally to the lower end, and as a result, moling is likely to occur. For this reason, as shown in Figure 3, in the case of conventional "insert molding", in order to smoothly release the expansion of the molded product, there is a
A chamfering process was performed as shown in FIG. However, in the case of "insert molding", partial wear of the frame is likely to occur due to sliding contact between the upper mold and the frame, and when partial wear occurs, resistance is generated in the part, causing moling. It was becoming more likely to occur. In addition, in the case of "flat press molding" shown in Fig. 4, it was impossible to chamfer the exit part of the frame mold as shown in Fig. 6, and a state where moling was likely to occur occurred. It is.

Next, the occurrence of "sharpness" on the side surface will be explained. In order to balance the above-mentioned expansion, the molded body 1 is
During demolding, it is pulled up while being sandwiched between the upper and lower molds. However, in this case, the demolding time should be as short as possible, and the clamping pressure should be maintained at a certain appropriate value. However, if the demolding speed is increased in order to shorten the demolding time using the hydraulic circuit, the fluctuations in the clamping pressure become large and "sharpness" occurs. For this reason, the demolding time cannot be shortened beyond a certain level,
Particularly when using raw materials that undergo large expansion during demolding,
was likely to occur. The present invention solves the above-mentioned problems of the prior art.

[0005]

[Means for Solving the Problems] The problems to be solved by the present invention are as described above, and next, the means for solving the problems will be explained. During molding, the frame mold 3 is lowered as the upper mold 2 is lowered, and after molding is completed, the upper mold 2, the molded body 1, and the lower mold 4 are raised, the frame mold 3 is maintained in the lowered position, and the molded body 1 is extracted. Afterwards, the frame mold 3 is raised to the same plane as the lower mold 4.

[0006]

[Operation] That is, in the state shown in Fig. 1-2, the molded body 1 and the lower mold 4 rise to a height of 2t, which is twice the thickness t of the molded body 1, as in the conventional case. Since the mold 3 does not rise, the molded body 1 actually separates from the side of the frame mold 3 when it rises by the thickness t, and the frame mold 3 and the molded body 1 separate in half the time compared to conventional methods. . Therefore, even if the rising speed of the molded body 1 is the same, the relationship between the two will be broken in half the time, so the expansion speed will be faster than the expansion speed of the molded body 1, and the "mog" shown in FIG. 5 will occur. This makes it possible to shorten the amount of time required for this, and avoid the occurrence of "mogé". In addition, even though the speed at which the frame 3 and the molded product 1 are cut has become faster, the rising speed of the molded product 1 remains the same, so the clamping state between the upper mold 2 and the lower mold 4 is This prevents the balance from being destroyed and prevents the occurrence of ``slip''.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The problems to be solved and the means and effects to be solved by the present invention are as described above. Next, the structure of an embodiment shown in the accompanying drawings will be explained. Figure 1 shows the "flat press molding" of the present invention.
Figure 2 is a side sectional view of the improved demolding mechanism in the conventional
Figure 3 is a side sectional view of the demolding mechanism in "Flat pressing molding".
4 is a side cross-sectional view showing the "flat press molding"mechanism; FIG. 5 is an enlarged cross-sectional view of the frame 3 and lower mold 4 in "flat press molding" just before they become horizontal. ,
Figure 6 is a side cross-sectional view of the frame 3 and lower mold 4 in "insert molding" just before they become horizontal, and Figure 7 shows that after molding is completed, the molded body 1 is transported to the next process, and the molding material powder B is poured into the lower mold. FIG.

First, in FIG. 2, the conventional "flat press molding"
The vertical movement of the upper mold 2, lower mold 4, and frame mold 3 will be explained. First, the frame mold 3 and the lower mold 4 are in a horizontal position as shown in FIG. 2-4, and as shown in FIG. While moving from above, the molding material powder extrusion rod 6 is simultaneously moved to move the molding material powder B onto the lower mold 4. The upper mold 2 is lowered onto the molding material powder B that has been moved onto the lower mold 4, and the volume is reduced from the state of the molding material powder B to about half, as shown in FIG. 2-1. Push it to a certain state. At the same time as the upper mold 2 presses in, the lower surface of the upper mold 2 comes into contact with the upper surface of the frame mold 3, and the frame mold 3 is pushed in against the urging spring applied from below. Furthermore, as the upper die 2 is pushed in, the lower die 4 is also pushed in against the biasing spring. This state is the state shown in FIG. 2-1. When molding is completed in this state, the upper mold 2 returns to the state shown in Figure 2-2.
to rise. At the same time, the lower mold 4 is also raised by a hydraulic cylinder, and the frame mold 3 is also raised by the same hydraulic cylinder. In this case, if the upper die 2 and the lower die 4 are not lifted in a balanced state, the molded article 1 will become "sharp." From the state of Figure 2-1, Figure 2-2
By the time the molded body 1 has completed its open expansion,
First, the frame 3 rises from Figure 2-1 to the state shown in Figure 2-2,
Furthermore, the molded body 1 must rise by 2t, which is twice the thickness t of the molded body 1, until it comes off from the upper end of the frame mold 3. Next, the upper mold 2 reaches the state shown in Figure 2-3.
is separated and rises, and the molded body 1 is also expanded upward. Next, the upper mold 2 moves up and retreats to the position shown in FIG. 2-4, and as shown in FIG. and the following molding material powder B
This is the movement that takes place.

In the above conventional technology, at the stage shown in FIG. 2-2, just before the lower mold 4 and frame mold 3 become flush with each other, only the back corner of the molded body 1 slightly hangs on the frame mold 3. In this state, there is a high possibility that "mog" will occur at the corners of the lower surface of the molded body 1. That is, the molded body 1
If the speed at which the molded object 1 expands by about 0.4 to 0.6% during demolding is faster than the speed at which the side surface of the mold 3 separates from the frame 3, "molding" occurs. It's put away. In order to solve this situation, the present invention makes the speed at which the side surface of the molded body 1 separates from the frame 3 faster than the speed at which the molded body 1 expands, so that the molded body 1 and the frame 3 are separated at once. This causes the contact state between the two to be separated. However, if the actual rising speed of the molded body 1 is increased, the balance between the upper mold 2 and the lower mold 4 will be lost, so the speed cannot be increased, and the rising speed of the molded body 1 in the past The speed at which the frame mold 3 and the molded body 1 cut together was increased.

Next, the main part of the present invention will be explained with reference to FIG. The molding material powder B transferred onto the lower mold 4 by the molding material powder extrusion rod 6 is pressed and molded by lowering the upper mold 2, and the lower mold 4 and frame mold 3 are also lowered at the same time. This is the same as the conventional method, and the molding ends in the state shown in FIG. 1-1. next,
The molded body 1 is raised to the state shown in Figure 1-2, but at this time, the frame mold 3 that has been lowered to the state shown in Figure 1-1 does not rise together when the upper mold 2 and the lower mold 4 are raised. It is structured like this. That is, in the state shown in FIG.
However, since the frame 3 does not rise at this time, the molded body 1 actually separates from the side of the frame 3 when it rises by the thickness t. Therefore, the frame mold 3 and the molded body 1 can be separated in half the time compared to the conventional method. Therefore, even if the rising speed of the molded body 1 is the same, the relationship between the two will be broken in half the time, so the expansion speed will be faster than the expansion speed of the molded body 1, and the "mog" shown in FIG. 5 will occur. This makes it possible to shorten the amount of time required for this, and avoid the occurrence of "mogé". In addition, even though the speed at which the frame 3 and the molded product 1 are cut has become faster, the rising speed of the molded product 1 remains the same, so the clamping state between the upper mold 2 and the lower mold 4 is Without losing balance,
It is also possible to prevent the occurrence of sharpness. Next, the upper mold 2 rises and separates as shown in Figure 1-3, then the upper mold 2 further rises as shown in Figure 1-4, and at the same time, a separate operating cylinder is used to raise the lower mold 4. The frame 3, which is lifted by the operating cylinder, rises, the lower mold 4 and the frame 3 become on the same plane, and the molded object extrusion rod 5 and molding material powder extrusion rod 6 begin to transfer as shown in FIG. .

[0011]

[Effects of the Invention] Since the present invention is constructed as described above, the following effects are achieved. First, when the molded body 1 expands, the lower mold 4 rises above the frame mold 3, so that it becomes difficult to apply unreasonable force to the lower part of the back surface of the molded body 1. Moreover, even if the exit portion of the frame mold 3 is partially worn, it can now be used without causing "mog" to a certain extent. Second, compared to the conventional method, the upper stroke required to demold the molded body 1 is only half, so the demolding time can be shortened while the demolding speed remains the same. It was possible. Thirdly, since the speed at which the molded body 1 is raised is the same as before, the upper mold 2 and the lower mold 4
The balance of the molded object 1, which rises while maintaining its balance while being held between the two, is not lost, and the occurrence of "sharpness" can also be avoided.

[Brief explanation of the drawing]

FIG. 1 is a sectional side view of an improved demolding mechanism in "flat press molding" of the present invention.

FIG. 2 is a side sectional view of a demolding mechanism in conventional "flat press molding".

FIG. 3 is a side cross-sectional view showing the "insert molding" mechanism.

FIG. 4 is a side sectional view showing a "flat press molding" mechanism.

FIG. 5 is an enlarged cross-sectional view of the frame die 3 and the lower die 4 just before becoming horizontal in "flat press molding".

FIG. 6 is a side sectional view of the frame die 3 and the lower die 4 just before they become horizontal in "insertion molding".

FIG. 7 is a side cross-sectional view of a state in which the molded body 1 is transported to the next step and the molding material powder B is transported onto the lower die 4 after molding is completed.

[Explanation of symbols]

B Molding material powder 1 Molded object 2 Upper mold 3 Frame type 4 Lower mold 5 Molded body extrusion rod 6 Molding material powder extrusion rod

Claims (1)

[Claims] Claim 1: During molding, the frame is lowered as the upper mold is lowered, and after molding is completed, the upper mold, the molded body, and the lower mold are raised, the frame is maintained in the lowered position, and after the molded body is extracted, A demolding method in dry press molding that is characterized by raising the frame mold to the same plane as the lower mold.