JPH0586515U - Mold - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a molding die that prevents burrs from being cut when a molded product is released. [Structure] A cavity 6 is formed by an upper mold 1 having an injection hole 4, a middle mold 2 and a lower mold 3. The upper mold 1 and the lower mold 3 form a flow passage 5 that connects the injection hole 4 and the cavity 6 to each other. A hole 7 communicating with the flow passage 5 is formed in the lower mold 3,
The pin 8 is inserted into the hole 7 so as to be vertically movable. The pin 8 has a lid 9 that opens and closes the opening of the hole 7. Pin 8 in hole 7
There is a gap e between and. The molded product molded in the cavity 6 is molded integrally with the burr formed in the flow passage 5 in a connected state. When the molded product is taken out after opening the upper mold 1, when the molded product is pulled up, the pin 8 moves upward and the lid 9 opens the hole 7. Then, the external air is introduced into the space between the burr and the lower mold 3 through the gap e, and the burr is smoothly separated from the lower mold 3 together with the molded product. Become.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a molding die, and more particularly to a molding die used when molding a molding material such as an elastic material.

[0002]

[Prior art and its problems]

 Conventionally, there is a mold as shown in FIG. 3 as a mold for molding rubber to obtain an oil seal.

That is, the molding die shown in FIG. 3 includes an upper die 21, a middle die 22 and a lower die 23, which can come into contact with each other and separate from each other, and cooperate with each other to form a cavity 26. The injection hole 24 into which the elastic material is injected, the upper mold 21 and the lower mold 23 in cooperation with each other, and the flow passage 25 for guiding the elastic material from the injection hole 24 to the cavity 26 are formed. When the unvulcanized elastic material is injected from the injection hole 24, the elastic material is guided to the cavity 26 through the flow passage 25, and is vulcanized and molded in the cavity 26 to a predetermined position. A shaped molded product 33 is obtained.

In FIG. 3, the upper mold 21 has an injection hole 24 formed in the center thereof, and an unvulcanized elastic material as a molding material is injected into the injection hole 24. There is.

The upper mold 21 can contact and separate from the middle mold 22, and the middle mold 22 can contact and separate from the lower mold 23, so that the middle mold 22 can be separated from the upper mold 21 and the lower mold. The molds 21, 22, 23 are brought into contact with each other while being interposed between them, so that the molds 21, 22, 23 cooperate with each other to form an annular cavity 26 inside. ..

The middle mold 22, which can be brought into contact with and separated from the upper mold 21, has a through hole 22a inside thereof. Further, the lower mold 23 that can be brought into contact with and separated from the middle mold 22 is formed with a convex portion 23a at the center thereof, and when the middle mold 22 and the lower mold 23 are aligned with each other, the middle mold 2 2 Are fitted in a state of being separated from each other at a required interval.

When the upper mold 21 is further matched with the middle mold 22 in a state where the middle mold 22 and the lower mold 23 are matched with each other, the end surface of the convex portion 23 a of the lower mold 23 faces the bottom surface of the upper mold 21. As a result, a cavity 26 is formed between the molds 21, 22, and 23.

At this time, a molding material flow passage 25 is formed between the facing surfaces of the bottom surface of the upper mold 21 and the convex portion 23 a of the lower mold 23 with a slight distance therebetween. The injection hole 24 of the mold 21 and the cavity 26 formed between the molds 21, 22, and 23 are electrically connected.

By configuring the molding die as described above, first, the middle die 22 and the lower die 23 are aligned with each other, and the metal ring 31 is arranged at a predetermined position in the space formed between the two and 23. After that, by further fitting the upper mold 21, the metal ring 31 is positioned in the cavity 26 formed between the molds 21, 22 and 23.

Next, when the unvulcanized elastic material is injected into the injection hole 24 of the upper die 21, the elastic material flows through the flow passage 25 into the cavity 26 to fill the cavity 26.

After that, the elastic material is vulcanized, so that the rubber portion 32 made of the elastic material is integrally molded inside the metal ring 31 as shown in FIG. An annular molded product 33 is obtained.

When the molded product 33 is taken out of the molding die, the upper die 21 is first opened, and then the middle die 22 is pulled upward to open the die. Then, the molded product 33 comes to be pulled up integrally with the middle mold 22, whereby the molded product 33 is separated from the lower mold 23.

However, in such a conventional mold, when the molded product 33 is separated from the lower mold 23, the burr 14 formed integrally with the molded product 33 is cut. was there.

That is, the molded product 33 is molded in a state in which the rubber portion 32 is connected and integrated with the burr 34 formed by the injection hole 24 and the flow passage 25 of the upper mold 21. Since the burr 34 is in close contact with the lower mold 23 when the mold is opened, when the molded product 33 is separated from the lower mold 23, as the molded product 33 is raised, the molded product 33 and the burr 34 are separated from each other. The connecting part was sometimes elongated and eventually cut.

That is, when the molded product 33 is pulled up while the burr 34 and the lower mold 23 are in close contact with each other, as shown in FIG. As a result, the molded part 33 rises on the one hand, and the bar 34 on the other hand acts such that the vacuum force of the vacuumed space 20 pulls it down. As a result, the connecting portion between the molded product 33 and the burr 34 is stretched and largely deformed, and finally, it exceeds the limit and is cut so as to be torn.

When the burr 34 is cut when the molded product 33 is released in this way, the burr 34 is left in the lower mold 23, so that deburring work is required later and production It was a sexual problem.

Further, in this case, there is a possibility that the molded product 33 itself may be damaged due to the extension of the connecting portion between the molded product 33 and the burr 34. It was also a problem in terms of quality.

The present invention solves the above problems and prevents the burr from being cut off when the molded product is released from the mold, thereby improving the productivity and the quality of the molded product. It is intended to provide a molding die.

[0019]

[Means for solving problems]

 In order to solve the above-mentioned problems, the present invention is a molding die comprising a plurality of dies that can be brought into contact with each other and separated from each other, and cooperate with each other to form a cavity. A flow passage is formed between the upper mold and the lower mold, which is formed in the upper mold and guides the molding material injected into the injection hole to the cavity, and the lower mold is formed with a hole communicating with the flow passage. Further, it has a structure in which a pin having a lid portion for opening and closing the opening portion of the hole is provided movably in a state where there is a gap in the hole.

[0020]

[Action]

 This invention adopts the above means. When a molding material is injected through the injection hole of the upper mold, the molding material is guided to the cavity through the flow passage and then vulcanized, whereby a molding product of a predetermined shape is formed. Is obtained.

Then, after the mold is opened, the molded product can be released from the mold by pulling up the molded product. At this time, the molded product is connected with the burr formed by the injection hole and the flow passage. It is integrally molded in this state, and when removing the molded product, the burr is also pulled up together.

Here, in this invention, the burr is prevented from being cut when the molded product is separated.

First, after the mold is opened, the molded product is pulled up to take out the molded product. As the molded product rises, a vacuum state is created between the burr and the lower mold with which the burr is in close contact. Vacancies will be formed.

Then, the vacuum force of the void moves upward so that the pin is pulled up, and the lid part of the pin opens the opening part of the lower die hole, whereby external air is formed in the hole. It is supplied to the void between the burr and the lower mold through the gap between the pin and the pin, and the vacuum state of this void is released.

Therefore, conventionally, when the molded product is pulled up, the burr is stretched because the burr is pulled down to the lower mold side by the vacuum force in the space between the burr and the lower mold. However, in the present invention, when the molded product is pulled up, the vacuum state in the space between the burr and the lower mold is released, so The force that pulls down the burr does not act, and as a result, extension and cutting of the burr are prevented.

[0026]

【Example】

 Embodiments of the present invention shown in the drawings will be described below.

FIG. 1 is a diagram showing an embodiment of a molding die according to the present invention. That is, the mold shown in FIG. 1 is composed of an upper mold 1, a middle mold 2, and a lower mold 3, which can come into contact with and separate from each other and cooperate with each other to form a cavity 6. It has a hole 4 and a flow passage 5 that is formed between the upper mold 1 and the lower mold 3 and guides the elastic material from the injection hole 4 to the cavity 6. A lid which forms a hole 7 communicating with the passage 5 and which is vertically movably inserted into the hole 7 of the lower mold 3 in a state where a gap e is formed, and the vertical movement of which opens and closes the opening of the hole 7. A pin 8 having a portion 9 is provided.

When the unvulcanized elastic material is injected through the injection hole 4, the elastic material is guided to the cavity 6 through the flow path 5 and then vulcanized and molded. A molded product 13 having a predetermined shape can be obtained.

In FIG. 1, the upper mold 1 has an injection hole 4 formed in the center thereof, and an unvulcanized elastic material as a molding material is injected into the injection hole 4. There is.

The upper mold 1 can contact and separate from the middle mold 2, and the middle mold 2 can contact and separate from the lower mold 3. When they match, an annular cavity 6 is formed inside. In this case, the molds 1, 2 and 3 are brought into contact with each other while the middle mold 2 is interposed between the upper mold 1 and the lower mold 3, whereby the respective molds 1, 2 and 3 cooperate to form the cavity 6 Will be formed.

The middle mold 2, which can be brought into contact with and separated from the upper mold 1, has a through hole 2a inside thereof. In addition, the lower mold 3 which can be brought into contact with and separated from the middle mold 2 is formed with a convex portion 3a at the center thereof, and when the middle mold 2 and the lower mold 3 are aligned with each other, the middle mold 2 is not It is designed to be fitted in a state of being separated at a required interval.

Therefore, when the upper mold 1 is further matched with the middle mold 2 in a state where the middle mold 2 and the lower mold 3 are matched with each other, the end surface of the convex portion 3 a of the lower mold 3 faces the bottom surface of the upper mold 1. As a result, the cavity 6 is formed between the molds 1, 2, and 3.

At this time, the bottom surface of the upper mold 1 and the end surface of the convex portion 3a of the lower mold 3 are positioned so as to be slightly separated from each other, whereby the upper mold 1 and the lower mold 3 are positioned. A flow path 5 for the molding material is formed between the surfaces facing each other. The flow passage 5 communicates with the injection hole 4 of the upper mold 1 on the one hand and the cavity 6 formed between the molds 1, 2 and 3 on the other hand, and as a result, the injection of the upper mold 1 is performed. The hole 4 is connected to the cavity 6 through the flow passage 5.

The lower die 3 which forms the flow passage 5 in cooperation with the upper die 1 has a hole 7 formed at the center thereof which opens downward and communicates with the flow passage 5, and a pin 8 is formed in the hole 7. It is inserted so that it can move up and down.

At this time, due to the processing dimensional tolerance of the hole 7 and the pin 8 of the lower mold 3, an annular surface formed slightly apart between the facing surfaces of the inner peripheral surface of the hole 7 and the outer peripheral surface of the pin 8. The gap e 1 is present. The existence of the gap e allows the flow passage 5 formed by the upper mold 1 and the lower mold 3 to be electrically connected to the outside of the molding die through the gap e.

In addition, the pin 8 has a disk-shaped lid portion 9 formed at the end portion on the upper die 1 side and having a size capable of closing the hole 7 of the lower die 3. The lid 9 opens and closes the opening of the hole 7 in accordance with the vertical movement of the.

In this case, in a normal state, the lid portion 9 of the pin 8 is in a state of being engaged with the step portion 7a formed in an annular shape at the opening portion of the hole 7 of the lower die 3 on the upper die 1 side. The lid 9 of the pin 8 closes the opening of the hole 7, thereby preventing communication between the gap e and the flow passage 5.

A stopper 15 is mounted on the outer peripheral surface of the lower end portion of the pin 8, so that when the pin 8 moves upward, the stopper 15 engages with a part of the lower mold 3 and It prevents the above movement.

Next, the operation of the above will be described.

By constructing this molding die as described above, first, the middle die 2 and the lower die 3 are aligned with each other, and the metal ring 11 is arranged at a predetermined position in the space formed between the two and 3. After that, when the upper mold 1 is further fitted, the metal ring 11 is positioned in the cavity 6 formed between the molds 1, 2 and 3.

Next, when an unvulcanized elastic material which is a molding material is injected into the injection hole 4 of the upper mold 1, this elastic material flows into the cavity 6 through the flow passage 5 and fills the cavity 6. It becomes

At this time, in the hole 7 communicating with the flow passage 5, the lid 9 of the pin 8 is in close contact with the stepped portion 7 a of the opening, and the hole 7 is closed by the lid 9. Therefore, the elastic material flowing through the flow passage 5 is prevented from flowing out into the gap e formed between the lower die 3 and the pin 8, and thus the elastic material is prevented from leaking to the outside. There is.

After the elastic material fills the cavity 6, the elastic material is vulcanized, whereby the rubber portion 12 made of the elastic material is integrally molded inside the metal ring 11, and is also shown in FIG. As a result, a molded product 13 having an annular shape as a whole is obtained.

When the molded product 13 is taken out from the molding die, the upper mold 1 is first opened, and then the middle mold 2 is pulled upward to open the mold. Then, the molded product 13 comes to be pulled up integrally with the middle mold 2, whereby the molded product 13 is separated from the lower mold 3.

Here, in this molding die, when the molded product 13 is detached, the burr 14 integrally molded in the state of being connected to the molded product 13 is not cut.

That is, the burr 14 integrally molded with the molded product 13 is in a state of being in close contact with the lower mold 3 at the time of molding, and this molding die is molded when the molded product 13 is separated from the lower mold 3. The pin 8 moves upward as the product 13 rises, and the lid 9 opens the opening of the hole 7 of the lower mold 3, so that air is supplied between the burr 14 and the lower mold 3. As a result, the burr 14 can be easily taken out from the lower mold 3 together with the molded product 13.

First, when the elastic material is vulcanized inside the mold, the rubber part 12 of the molded product 13 molded in the cavity 6 is formed by the injection hole 4 and the flow passage 5 of the upper mold 1. The burr 14 is connected to and integrated with the burr 14. At this time, the burr 14 is in close contact with the lower mold 3.

Next, when the molded product 13 is pulled up, the burr 14 integrally connected to the molded product 13 also rises as the molded product 13 rises, and the space 10 in the vacuum state between the burr 14 and the lower mold 3 is raised. However, at this time, the vacuum force of the void 10 causes the pin 8 to be lifted and moved upward.

Then, the lid portion 9 of the pin 8 opens the opening portion of the hole 7 of the lower die 3, and as a result, the space 10 between the burr 14 and the lower die 3 becomes the flow passage 5, and It is electrically connected to the outside through a gap e between the lower die 3 and the pin 8.

Then, due to the vacuum force between the burr 14 and the lower die 3, the air existing outside is sucked into the void 10 between the lower die 3 and the pin 8 through the gap e and the flow passage 5. As a result, the vacant space 10 is released from the vacuum state and becomes the atmospheric pressure.

Therefore, when the molded product 13 is pulled up from the lower mold 3, the connection between the molded product 33 and the burr 34 is conventionally caused by the vacuum force of the space 20 formed between the burr 34 and the lower mold 23. However, in the molding die having the above-mentioned configuration, the vacuum state of the space 10 between the burr 14 and the lower mold 3 is released, so that the burr is The unit 14 and the molded product 13 are smoothly lifted together with the molded unit 13 and can be easily detached from the lower mold 3.

As a result, the molded product 13 can be taken out from the lower mold 3 with the burr 14 being connected without being cut.

[0053]

[Effect of the device]

 As described above, according to the present invention, the pin having the lid portion for opening and closing the hole is inserted into the hole formed so as to communicate with the flow path of the molding material so that the pin can be moved up and down. When the pin is removed, the pin lid opens the opening of the hole, and there is a space formed between the burr that is integrally molded with the molded product in the flow passage and the mold to which this burr is in close contact. The vacuum state can be released.

Therefore, when the molded product is released from the mold, it is possible to prevent the burr formed in a state of being connected to the molded product from being deformed so as to be stretched, whereby the burr is cut. Can be prevented.

As a result, after the molded product was released from the mold, the burr was conventionally cut on the way, so that a cut piece of the burr remained in the mold, and it was necessary to peel off the burr. In the molding die according to the present invention, the burr can always be taken out integrally with the molded product, so that deburring work is unnecessary and therefore the productivity can be improved.

Further, in the past, since the burr was cut so as to be torn off when the molded product was detached, the molded product was liable to be scratched and the quality was likely to be unstable. According to the invention, it is possible to reduce the occurrence of defects such as scratches on the molded product by preventing the burrs from being cut off when the molded product is separated as described above. The effect is that the quality of the molded product as a product can be stabilized.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a view for explaining the operation of this invention.

FIG. 3 is a diagram showing a conventional example.

FIG. 4 is a diagram illustrating a defect of a conventional example.

[Explanation of symbols]

 1, 21 ... upper mold 2, 22 ... middle mold 2a, 22a ... through hole 3, 23 ... lower mold 3a, 23a ... convex portion 4, 24 ... injection hole 5, 25 ... flow passage 6, 26 ... Cavity 7 ... Hole 7a ... Step 8 ... Pin 9 ... Lid 10, 20 ... Vacancy 11, 31 ... Metal ring 12, 32 ... Rubber part 13, 33 ... Molded product 14, 34 ... Burr 15 ... Stopper e ... Gap

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B29C 45/26 7179-4F // B29K 21:00

Claims (1)

[Scope of utility model registration request] 1. A mold comprising a plurality of molds (1), (2) and (3) which can come into contact with each other and separate from each other and cooperate with each other to form a cavity (6). The material injection hole (4) is formed in the upper mold (1), and the injection hole (4) is formed.
A flow passage (5) for guiding the molding material injected into the cavity (6) is formed between the upper mold (1) and the lower mold (3), and the flow passage (5) is formed in the lower mold (3). A pin (8) having a hole (7) communicating with 5) and further having a lid (9) for opening and closing the opening of the hole (7) is provided in the hole (7) with a gap (e). ) Is provided so as to be movable in the state of having a).