JP3389332B2 - Mold and molding method - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a molding die for compression molding.
And a molding method .

[0002]

2. Description of the Related Art For example, a molded product 2 shown in FIGS.
In the case of molding No. 1, conventionally, a molding die and a molding method shown in FIGS. 10 to 15 have been used.

The molded article 21 shown in FIGS. 8 and 9 is obtained by compression molding using a tetrafluoroethylene resin powder (PTFE powder) as a molding material by a molding die and a molding method described below. The two central portions 22 and 23 having different lengths L ₁ and L _{2 (} in the vertical direction in FIG. 9) are integrally provided, and specifically, a large central cylindrical portion 2 having a length L ₁ is provided.
2 and a small peripheral flange portion 23 having a length L ₂ are integrally provided, and the compression rates of the two portions 22 and 23 are set to be substantially equal.

The molding die and molding method shown in FIGS. 10 to 15 are as follows. First, as shown in FIG. 10, the molding material 24 necessary for molding the flange portion 23 of the molded product 21 and the lower portion of the cylindrical portion 22 having the same length as this is weighed, and this is molded into the mold body 2
The bottom portion of No. 5 is evenly filled, and the pressure jig 26 is used to slowly apply pressure by hand. Then, as shown in FIG. 11, the outer press piece 2
Insert 7 into the mold. Next, as shown in FIG. 12, the molding material 28 required for molding the upper portion of the cylindrical portion 22 is weighed and filled in the cavity in the outer press piece 27. Then, as shown in FIG. 13, the inner press piece 2
9. Insert the required number of flexible pads 30 and 31 and the upper end press piece 32 into the mold, place the pressing die 33 on the upper end press piece 32, and assemble the die thus assembled.
Place it between the platens of a hydraulic machine (not shown). Next, as shown in FIG. 14, the hydraulic machine is operated to slowly apply a predetermined molding pressure, hold it for a while, and then slowly depressurize. Then, the internal assembly with the molded product 21 still contained is pulled out from the mold body 25, and the screw ejector 34 is inserted into the groove 27a of the outer press piece 27 as shown in FIG.
And the internal press piece 29 is pushed by this screw ejector 34 to slowly eject the molded product 21.

However, the above conventional technique has the following problems. A. In the above molding method, since the molded product 21 has two portions 22 and 23 having different lengths L ₁ and L ₂ in the compression direction, it suffices to perform the above steps once, but three In the above case, the above steps or steps must be repeated. Therefore, in this case, since the number of steps is increased, it takes a lot of time to form. B. Since pads 30 and 31, which are consumable items, are required, the molding cost is high accordingly.

[0006]

In view of the above points, the present invention does not increase the number of steps even if there are three or more portions having different lengths in the compression direction, and thus the molding is easy. At the same time, there is no need for a pad, which is a consumable item.
Therefore, it is an object of the present invention to provide a molding die capable of reducing the molding cost.

In addition to this, as a result that the molded product has a plurality of portions having different lengths in the compression direction, as a result, the base portion directly projected by the die at the time of mold release, and the base portion. In contrast to the projection provided integrally with the part, the molded product can be easily released from the mold.
An object of the present invention is to provide a molding method capable of molding.

[0008]

In order to achieve the above object, the mold of the present invention is a mold for compression molding a molded article integrally provided with a plurality of portions having different lengths in the compression direction. Each part was provided with a pair of molds for sandwiching the molding material, the adjacent molds were made slidable, and the compression rates of the plurality of parts were made approximately equal by adjusting the slide stroke and urging by a spring. (Claim 1).

Further, the molding method of the present invention comprises the method according to claim 1.
A molding method using a mold, wherein the molded product has a base portion that is directly targeted for protrusion by the mold at the time of mold release,
The base part is provided with a protrusion integrally provided, and the mold release side end of the mold on the anti-release side in each pair is set with a height difference so as to form the protrusion when the molding material is filled. And the opposite side ends of the molds on the mold release side in each pair are arranged with a height difference so as to mold the protrusions when the compression is completed, and the protrusions are separated from the mold release side. It was decided to mold toward (claim 2).

[0010]

In the invention according to claim 1 having the above construction, it is possible to fill the molding material at a time without dividing the molding material into a plurality of times in terms of use and operation of the molding die. It is possible to compress all of the molding material at one time without pre-compressing a part of the molding material, and further, to use the pad, which is a consumable item, so that it is unnecessary.

According to the second aspect of the present invention, the molds are arranged so that the protrusions of the molded product are molded toward the release mold side when the molding material is filled in order to store the molding material in the cavity. Despite this, the arrangement of the molds is changed when the compression is completed, and in reality, the protrusion of the molded product is molded toward the mold release side. Therefore, at the same time when the protrusion of the base portion is completed, it is possible to finish the release of the entire molded product.

[0012]

Embodiments of the present invention will now be described with reference to the drawings.

The mold according to this embodiment is for molding the molded product 1 shown in FIGS. 1 and 2 by compression molding, has the structure shown in FIG. 3, and as shown in FIGS. Operate.

The molded article 1 shown in FIG. 1 and FIG. 2 is obtained by compression molding using tetrafluoroethylene resin powder (PTFE powder) as a molding material by a molding die and a molding method described below. (In the up-down direction in FIG. 2) integrally provided with three portions 2, 3 and 4 having different lengths L ₃ , L ₄ and L ₅ , specifically, a large central cylindrical portion having a length L _3. 2, an intermediate cylindrical portion 3 made in a length L _4, and integrally includes a flange portion 4 of the small becomes peripheral side of the length L _5, further compression of the three parts 2, 3, 4 The rates are set to be approximately equal. The compression ratio is represented by K = L '/ L, where K is the length, L'is the length before compression, and L is the length after compression.

As shown in FIG. 3, the molding die has the following structure.

That is, the above parts 2, 3, 4 of the molded article 1
A pair of molds 6, 7, 8, 9, for pressing the molding material 5 for each
10 and 11 are provided, and specifically, a substantially cylindrical first upper die 6 and a first lower die 7 are provided corresponding to the central cylindrical portion 2, and an intermediate cylindrical portion is provided. 3, a substantially cylindrical second upper mold 8 and a second lower mold 9 are provided, and a substantially cylindrical third upper mold 10 is provided corresponding to the flange portion 4 on the peripheral side. A third lower mold 11 is provided.

Below the upper moving part 12, a third upper mold 10 is provided.
Is fixed, and the second upper mold 8 is arranged on the inner peripheral side thereof,
The first upper mold 6 is arranged on the inner peripheral side thereof. The second upper mold 8 is slidable in the compression direction (vertical direction in the drawing) with respect to the third upper mold 10, but the step-like engaging portions 8a and 10a provided on the second upper mold 8 engage with each other. By
The third upper mold 10 is prevented from slipping downward and the downward sliding is stopped, and the upper end is brought into contact with the upper moving portion 12, whereby the upward sliding is stopped. The first upper mold 6 is
It is slidable in the compression direction with respect to the second upper mold 8, but can be pulled out downward from the second upper mold 8 by the engagement of the stepped engaging portions 6a, 8b provided on each. And the downward slide is stopped, and the upper end is brought into contact with the upper moving portion 12, whereby the upward slide is stopped. A spring 13 that elastically biases the upper die 6 downward is disposed between the upper moving portion 12 and the first upper die 6.

The first lower mold 7 is fixed to the upper side of the lower moving part 14, the second lower mold 9 is arranged on the outer peripheral side thereof, and the third lower mold 11 is arranged on the outer peripheral side thereof. ing. The second lower mold 9 is slidable in the compression direction with respect to the first lower mold 7, but has step-like engaging portions 7a, 9 provided on each of them.
When a is engaged, it is prevented from slipping upward from the first lower mold 7 and the upward sliding is stopped, and its lower end portion is brought into contact with the lower moving portion 14 so that it is directed downward. All slides are stopped. Further, the third lower mold 11 is slidable in the compression direction with respect to the second lower mold 9, but when the step-like engaging portions 9b and 11a provided on the third lower mold 11 engage with each other, It does not come out of the lower mold 9 upward, and the upward sliding is stopped, and the lower end is brought into contact with the lower moving portion 14, so that the downward sliding is stopped. Lower moving part 14 and third lower mold 11
A spring 14 for elastically urging the lower mold 11 upward is arranged between the two, and an outer mold 16 is arranged on the outer peripheral side of the third lower mold 11.

FIG. 3 shows a state in which the mold is opened and the cavity 17 above the lower molds 7, 9, 11 is filled with the uncompressed molding material 5. In the state of FIG. 3, the respective molds 6, 7, 8, 9, 10, 11 are arranged so that the compression ratios of the three parts 2, 3, 4 after compression are substantially equal for each pair. , 3, 4 are opened at a ratio according to the lengths L ₃ , L ₄ , L ₅ of the first and second upper molds 6, 8 respectively. It is located at the lower limit of the slide stroke due to its own weight, the lower ends of the first to third upper molds 6, 8 and 10 are flush with each other, and the second and third lower molds 9 and 11 are respectively the spring 1
It is located at the upper limit of the slide stroke due to the bias of 5.

When the upper moving part 12 or the lower moving part 14 is moved from the state shown in FIG. 3 to start compression, each mold 6,
As shown in FIG. 5, 7, 8, 9, 10, 11 compress the molding material 5 in pairs while sliding as shown in FIG. This compression is first started in the middle of the cylindrical portion 3 made in a large becomes the center of the cylindrical portion 2 and the length L ₄ of the length L _3, then the small consisting periphery side of the flange portion of the length L ₅ 4 Started at. In FIG. 4, which shows the progress in the specified time, the compression of the cylindrical portion 2 and the cylindrical portion 3 has already started, but the compression of the flange portion 4 has not yet started, and it will be started. In order to set such a time difference at the start of compression, in particular, the spring constant of the lower spring 15 is set to be small, and the initial load thereof is almost the same as the weight of the upper mold 11 supported by this spring. Is set to.

In the state shown in FIG. 5, the molding material 5 is completely compressed, and after a predetermined time, as shown in FIG. 6, the mold is opened and the molded product 1 is released.

As can be seen from the above description, according to the mold, even if the molded article 1 is provided with the three parts 2, 3 and 4, the molding material 5 is used a plurality of times because of its use and operation. It is not necessary to separately fill, and this may be filled at once, and it is not necessary to pre-compress a part of the molding material 5, but it is sufficient to compress all of it. Therefore, the number of steps does not increase unlike the above-mentioned conventional technique,
From the filling of the molding material 5 to the completion of compression, the molds 6, 7, 8,
To be performed by a series of movements of 9, 10, and 11,
The molding cycle is short. Therefore, molding can be performed more easily than before. Moreover, since the filling of the molding material 5 to the completion of compression are performed by a series of movements of the molds 6, 7, 8, 9, 10, and 11, the automation of molding is easy. Further, since the pad required in the above-mentioned conventional technique is not necessary, the molding cost can be reduced by a corresponding amount.

The molded product 1 shown in FIG. 1 and FIG. 2 has a shape in which three steps 2, 3 and 4 are provided on the upper surface thereof, which is a step of three steps in total, in other words, the length thereof. on a disk-shaped base portion 1a of the L _5, with a length of L ₃ -L _5, two stages of the projection 1b is provided.

Then, in the molding die for molding the molded article 1 having such upwardly projecting portions 1b, first, as shown in FIG. The lower ends of the upper molds 6, 8 and 10 are flush with each other, and the upper ends of the first to third lower molds 7, 9 and 11 are arranged in a stepwise manner. On the other hand, as shown in FIG. 5, when the compression is completed, on the contrary, the upper ends of the first to third lower molds 7, 9 and 11 are flush with each other, and the first to third upper molds are aligned. The lower ends of the molds 6, 8 and 10 are arranged in a step-like manner, whereby the protrusions 1b of the molded product 1 are formed into the molding material 5
However, as shown in FIG. 6, when the mold is released, the mold is molded upward in the mold release direction. Therefore, as shown in FIG. 6, it is possible to finish the mold release of the entire molded product 1 at the same time when the projection of the base portion 1a is completed, thereby facilitating the mold release of the molded product 1. You can

In the present invention, the number of parts of the molded product having different lengths in the compression direction is not limited to three, and a plurality of parts are widely included. Also, the shape of the molded product and the type of molding material are not limited as long as the present invention can be effectively used, and the shape or arrangement of each mold is appropriately changed as shown in FIG. To be done.

[0026]

The present invention has the following effects.

That is, first, in common with each claim, even if there are three or more portions of the molded product having different lengths in the compression direction, all of the molding material is filled in the mold at once. At the same time, since the whole molding material is compressed at one time, the number of steps does not increase, and since the molding material filling to the completion of compression are performed by a series of movements of the mold, the molding cycle can be shortened. Therefore, compression molding of this type of molded product can be performed more easily than before. Further, since the filling of the molding material to the completion of the compression are performed by a series of movements of the mold, the molding can be easily automated. Further, since the pad which has been conventionally required is not required, the molding cost can be reduced by a corresponding amount.

In the second aspect, as a result that the molded product has a plurality of portions having different lengths in the compression direction, as a result, the base portion directly projected by the die at the time of mold release, and the base portion. Since it has a protrusion integrally formed with the part, it is possible to finish the release of the entire molded product at the same time as the projection of the base part is completed, so the release of the molded product is easy. It can be anything.

[Brief description of drawings]

FIG. 1 is a perspective view of a molded product.

FIG. 2 is a cross-sectional view of the molded product.

FIG. 3 is a half-cut sectional view of a molding die according to an embodiment of the present invention.

FIG. 4 is a half-cut sectional view showing an operating state of the molding die.

FIG. 5 is a half-cut sectional view showing an operating state of the molding die.

FIG. 6 is a half-cut sectional view showing an operating state of the molding die.

FIG. 7 is a half-cut sectional view of a mold according to another embodiment of the present invention.

FIG. 8 is a perspective view of a molded product.

FIG. 9 is a sectional view of the same molded product.

FIG. 10 is an explanatory diagram according to a conventional example.

FIG. 11 is an explanatory diagram according to the conventional example.

FIG. 12 is an explanatory diagram according to the conventional example.

FIG. 13 is an explanatory diagram according to the conventional example.

FIG. 14 is an explanatory diagram according to the conventional example.

FIG. 15 is an explanatory diagram according to the conventional example.

[Explanation of symbols]

1 Molded Product 1a Base Part 1b Projections 2, 3, 4 Part 5 Molding Material 6, 8, 10 Upper Mold 6a, 7a, 8a, 8b, 9a, 9b, 10a, 11a
Engaging parts 7, 9, 11 Lower mold 12 Upper moving part 13, 15 Spring 14 Lower moving part 16 Outer mold 17 Cavity

Claims (2)

(57) [Claims] 1. Length in compression direction (L ₃ ) (L ₄ ) (L
_In a molding die for compression-molding a molded product (1) integrally provided with a plurality of parts (2), (3) and (4) different from each other, each of the parts (2), (3) and (4) is molded. A pair of molds (6, 7) (8, 9) (10, 11) sandwiching the material (5) is provided, and the molds (6, 8, 10) (7, 9, 1) adjacent to each other are provided.
It is characterized in that the compression ratios of the plurality of portions (2), (3) and (4) are made substantially equal to each other by adjusting the slide strokes and biasing the springs (13) and (15). Mold. 2. A molding method using the molding die according to claim 1.
Therefore , the molded product (1) has a base portion (1a) which is directly targeted for protrusion by the mold (11) at the time of releasing the mold product , and a protrusion (1b) integrally provided on the base portion (1a).
And the mold release side ends of the molds (7, 9, 11) on the opposite mold release side in each pair have a height difference so as to mold the protrusion (1b) when the molding material (5) is filled. Is set and arranged, and the height difference is set so that the ends of the molds (6, 8, 10) on the mold release side in each pair form the protrusions (1b) when the compression is completed. A molding method in which the protrusions (1b) are arranged side by side and are molded toward the mold release side.