JPH07715U - Mold - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a molding die capable of preventing material leakage during molding. [Structure] The upper mold 1, the middle mold 4, and the lower mold 5 form a cavity 11. The first ring 9 and the second ring 10 are arranged in the cavity 11. The upper mold 1 has a pot 12 and an injection hole 6. The piston 8 is inserted through the pot 12. Upper mold 1
Is formed by the upper mold body 2 and the movable mold 3 which can be divided between the facing surfaces of the first ring 9 and the second ring 10. Upper mold body 2
An elastic member 7 is provided between the movable mold 3 and the movable mold 3. When the mold is clamped, the upper mold body 2 presses the first ring 9 and the movable mold 3 presses the second ring 10 due to the material pressure. Since the upper mold body 2 and the movable mold 3 operate independently, the variations of the rings 9 and 10 are absorbed, and the space between the first ring 9 and the second ring 10 is sealed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a molding die, and more particularly to a molding die in which a product such as a torsion damper is obtained by integrally molding a rubber-like elastic material with a ring member.

[0002]

[Prior art and its problems]

 Conventionally, as this type of molding die, one shown in FIG. 6 is known. That is, the forming die shown in FIG. 6 includes an upper die 41, a middle die 44, a lower die 45 that cooperate to form an annular cavity 51, and a piston 48 provided in the upper die 41. The upper die 41 has a pot 52 that opens upward and allows the dough to be placed thereon, and an injection hole 46 that guides the dough in the pot 52 to the cavity 51. The piston 48 can move up and down in the pot 52. Is inserted into. When the first ring 49 and the second ring 50 are concentrically arranged in the cavity 51 and then the mold is clamped, the dough is molded while being interposed between the first ring 49 and the second ring 50. It has become.

In FIG. 6, the upper mold 41, the middle mold 44, and the lower mold 45 are combined with each other to form an annular cavity 51 between the respective molds 41, 44, 45. Here, the first ring 49 and the second ring 50, which are integrally formed, can be concentrically arranged in the cavity 51. When the molds 41, 44, 45 are combined in that state (when the molds are closed), one end surface of the first ring 49 and the second ring 50 is the upper mold 41, and the other end surface is The lower molds 45 are brought into contact with each other.

In this case, a second ring 50 can be fitted in the central portion of the lower die 45, and a cylindrical protrusion having a height equal to or shorter than the length of the second ring 50. 45a has been formed. As a result, the second ring 50, which is a molded part, is positioned at a predetermined position in the cavity 51 by fitting the second ring 50 into the convex portion 45a of the lower mold 45.

Further, the middle die 44 has an inner diameter larger than the outer diameter of the convex portion 45 a of the lower die 45 and is capable of fitting the first ring 49 therein, and is the same as or longer than the length of the first ring 49. It also has a short height. As a result, the first ring 49, which is a molded component, is fitted into the middle mold 44 and positioned at a predetermined position in the cavity 51.

Therefore, the first ring 49 and the second ring 50 are positioned, so that the first ring 49 is positioned outside and the second ring 50 is positioned with a predetermined gap between the facing surfaces. The rings 50 are arranged concentrically on the inside and are housed in the cavities 51.

A pot 52 and an injection hole 46 are formed in the upper mold 41. The pot 52 is formed so as to open upward at the center of the upper mold 41, and an unvulcanized material made of a rubber-like elastic material is placed on the bottom surface of the pot 52. . A plurality of the injection holes 46 are equally opened on the bottom surface of the pot 52 to conduct the pot 52 downward. The injection holes 46 allow the dough placed on the pot 52 to be placed on the cavity 51. The first ring 49 and the second ring 50 are guided into an annular space formed between them.

The upper mold 41 is provided with a piston 48 that is vertically movably inserted into a pot 52 of the upper mold 41. When the ram pressure of a press machine (not shown) is applied after the mold is closed, the piston 48 moves downward to apply pressure to the material in the pot 52.

This molding die is configured as described above, so that the first ring 49 and the second ring 50 are placed at predetermined positions in the cavity 51, and then the respective dies 41, 44, 45 are combined. After that, by performing mold clamping, the first ring 49 and the second ring 50 are formed integrally with the rubber-like elastic body.

First, by aligning the lower mold 45 and the middle mold 44, fitting the second ring 50 on the convex portion 45 a of the lower mold 45, and fitting the first ring 49 inside the middle mold 44, The first ring 49 and the second ring 50 are arranged at predetermined positions. Then, the upper mold 41 is combined with the middle mold 44 and the lower mold 45 to close the mold, so that the first ring 49 and the second ring 50 are separated from each other by a predetermined distance and the upper mold 41 and the lower mold 41 are separated. It is sandwiched with the mold 45.

Next, when the dough is placed on the pot 52 of the upper die 41 and the die is clamped by a press machine (not shown), the piston 48 presses the dough in the pot 52. Then, the dough in the pot 52 is guided to the cavity 51 through the injection hole 46 by the pressing force of the piston 48, and the annular space between the first ring 49 and the second ring 50 is filled with the raw material. Will be done.

Then, the dough is vulcanized in the cavity 51 in that state, whereby the dough is molded integrally with the first ring 49 and the second ring 50. As a result, with the rubber-like elastic body interposed between the first ring 49 and the second ring 50, a molded product having an annular shape as a whole can be obtained.

However, in such a conventional molding die, there is a risk that a burr formation may occur due to a phenomenon called a so-called material surrounding at the time of molding.

That is, when the mold is closed, the upper end surfaces of the first ring 49 and the second ring 50, which are molded parts, are brought into close contact with the upper mold 41, so that the space between the first ring 49 and the second ring 50 is closed. Since the place is sealed, the length of the first ring 49 or the second ring 50 is not as designed, or the upper end surface of the first ring 49 or the second ring 50 is formed horizontally. If not, a gap will be formed between the upper end surface of the first ring 49 or the second ring 50 and the upper die 41. Therefore, the mold may not be closed properly.

For example, when the first ring 49 is formed according to the design dimension and the second ring 50 is formed shorter than the design dimension, as shown in FIG. An annular gap is created between the end surface and the upper mold 41.

That is, the above-mentioned ones are designed so that each of the first ring 49 and the second ring 50 is clamped by the upper mold 41 and the lower mold 45 at the same time so that each ring 49, 50 and both molds 41, 45 and 45, respectively, so that the space between the first ring 49 and the second ring 50 is sealed. For this reason, the first ring 49 and the second ring 50 cannot be held between the upper mold 41 and the lower mold 45 when the mold is closed unless the length is formed according to the design dimension. Therefore, if there is variation in the length dimension of the first ring 49 or the second ring 50, the variation in the dimension cannot be properly absorbed and dealt with. As a result, in the case shown in FIG. 7, when the mold is closed, both end surfaces of one first ring 49 are in close contact with the mating mold, but the other second ring 50 has a slightly shorter dimension. In addition, the upper end surface is separated from the upper mold 41 to form a gap.

As described above, when a gap is formed between the upper end surface of the second ring 50 and the upper die 41, when the dough is filled, the dough flows out inward from the gap, so that a so-called swirl around the dough occurs. By performing vulcanization in this state, burrs are formed on the molded product. Further, in this case, since the second ring 50 is not completely sandwiched between the upper mold 41 and the lower mold 45, the holding in the cavity 51 is unstable, and therefore, the injection of the dough during the molding is performed. The second ring 50 may move due to the pressure, which may cause defective molding.

Further, as another example, when the upper end surface of the first ring 49 is formed parallel and the upper end surface of the second ring 50 is formed slightly oblique, as shown in FIG. An annular gap is created between the upper end surface of the 2 ring 50 and the upper die 41.

That is, the first ring 49 and the second ring 50 cannot be brought into close contact with the upper mold 41 and the lower mold 45 when the molds are closed unless the upper end surfaces thereof are formed in parallel. Therefore, if the parallelism of the upper end surface of the first ring 49 or the second ring 50 has a variation, the variation in the parallelism cannot be properly absorbed and dealt with. As a result, in the case as shown in FIG. 8, when the mold is closed, both end faces of the one first ring 49 are in close contact with the mating mold, while the other second ring 50 has the upper end face formed obliquely. Therefore, only a part of the upper end surface comes into contact with the upper mold 41, and the other parts are separated from the upper mold 41 to form a gap.

In this way, when a gap is formed between the upper end surface of the second ring 50 and the upper die 41, when the dough is filled, the dough flows out inward from the gap, so-called a dough surrounding area occurs. By performing vulcanization in this state, burrs are formed on the molded product.

The present invention solves the above problems, and aims to provide a molding die that prevents so-called dough rotation from occurring during molding and prevents burrs from being formed on a molded product. To do.

[0022]

[Means for solving problems]

 In order to solve the above-mentioned problems, the present invention comprises, as a first invention, an upper die, a middle die and a lower die which cooperate to form an annular cavity, and a first ring integrally formed in the cavity. And the second ring are arranged concentrically, and then an upper mold having an injection hole at a corresponding portion between the both rings is arranged in contact with the upper surfaces of the two rings, and the injection hole is inserted through the injection hole. A mold for filling and molding a space in a space formed between the two rings by dividing the upper mold at a portion corresponding to the opposing surface between the first ring and the second ring. It is said that the upper die body and the movable die are provided with a holding means provided between the upper die body and the movable die to hold the movable die in a vertically movable state with respect to the upper die body. It has a structure. As a second invention including the first invention, the holding means is a rubber-like elastic member that holds the movable die movably in a direction orthogonal to the axis. As a third device including the first device, the holding means is a biasing member capable of adjusting the upper and lower positions of the movable die.

[0023]

[Action]

 By adopting the above-mentioned means, this invention can prevent the so-called cloth rotation. That is, the upper die is divided at the portion corresponding to the opposing surfaces of the first ring and the second ring, which are integrally formed, and is formed by the upper die body and the movable die. When the mold is clamped, each ring is pressed independently to make close contact. As a result, even if there is variation in each ring, each ring will be in close contact with its mating mold, and will reliably seal the void between the first ring and the second ring in which the dough is filled. As a result, the material leakage during molding is prevented, and burrs are not formed on the molded product.

When the holding means for holding the movable die vertically movable with respect to the upper die body is formed of a rubber-like elastic member that allows the movable die to move in the axial direction, the movable die is moved upward. Since it can be displaced in three dimensions with respect to the mold body, it becomes possible to more flexibly deal with dimensional variations of each ring.

Further, when the holding means is formed of a biasing member capable of adjusting the vertical position of the movable die, the biasing force for each ring can be arbitrarily changed by the adjusting operation. Even if the dimensional variation of each ring is in a high range, it will be possible to flexibly deal with it.

[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 molding die shown in FIG. 1 includes an upper die 1, a middle die 4, a lower die 5 in which the respective dies cooperate with each other to form an annular cavity 11, and a piston 8 provided in the upper die 1. It is equipped with. The upper mold 1 has a pot 12 that opens upward and allows the dough to be placed thereon, and an injection hole 6 that guides the dough in the pot 12 to the cavity 11. A piston 8 is inserted into the pot 12 so as to be vertically movable. To be done. When the first ring 9 and the second ring 10 are concentrically arranged in the cavity 11 and then the mold is clamped, the dough is molded with the material interposed between the first ring 9 and the second ring 10. It has become. At this time, the upper die 1 is formed by an upper die body 2 and a movable die 3 which are separable at a portion between the facing surfaces of the first ring 9 and the second ring 10, and the movable die 3 is movable between the two. An elastic member 7 for holding the die 3 in a vertically movable state with respect to the upper die body 1 is provided.

In FIG. 1, the upper mold 1, the middle mold 4, and the lower mold 5 are combined with each other to form an annular cavity 11 between the molds 1, 4, and 5. Here, the first ring 9 and the second ring 10, which are integrally formed, can be arranged concentrically in the cavity 11. When the molds 1, 4, and 5 are combined in that state (when the molds are closed), one end face of the first ring 9 and the second ring 10 is the upper mold 1, and the other end face is the lower mold. The molds 5 are brought into contact with each other.

In this case, the second ring 10 can be fitted in the central portion of the lower mold 5 and the cylindrical protrusion having a height equal to or shorter than the length of the second ring 10. 5a is formed. As a result, the second ring 10, which is a molded component, is positioned at a predetermined position in the cavity 11 by fitting the second ring 10 into the convex portion 5a of the lower mold 5.

Further, the middle die 4 has an inner diameter larger than the outer diameter of the convex portion 5 a of the lower die 5 to which the first ring 9 can be fitted, and at the same time as the length of the first ring 9. It has an annular shape with a shorter height. As a result, the first ring 9, which is a molded component, is positioned in the cavity 11 at a predetermined position by being fitted into the middle mold 4.

Therefore, the first ring 9 and the second ring 10 are positioned so that the opposing surfaces are separated from each other by a predetermined distance, and the first ring 9 is located outside and the second ring 10 is separated. 10 are arranged concentrically inside and housed in the cavity 11.

A pot 12 and an injection hole 6 are formed in the upper mold 1. The pot 12 is formed so as to open upward in the central portion of the upper mold 1. The unvulcanized material made of rubber-like elastic material is placed on the bottom surface of the pot 12. is there. The injection holes 6 have a plurality of openings and are evenly opened on the bottom surface of the pot 12 to conduct the pot 12 downward. The injection holes 6 allow the dough placed on the pot 12 to be cavitated. It is adapted to be guided into an annular space formed between the first ring 9 and the second ring 10 arranged at 11.

The upper die 1 is formed by an upper die body 2 and a movable die 3 which are separable between the facing surfaces of the first ring 9 and the second ring 10. The upper mold body 2 has an annular shape as a whole, and the disk-shaped movable mold 3 having the injection holes 6 is inserted inside the upper mold body 2 at a predetermined interval. As a result, the movable die 3 can move up and down with respect to the upper die body 2.

An elastic member 7 as a holding means is integrally provided between the inner peripheral surface of the upper mold body 2 and the outer peripheral surface of the movable mold 3 facing each other. The elastic member 7 is made of hard rubber having heat resistance and formed in an annular shape. By interposing the elastic member 7 between the upper mold body 2 and the movable mold 3, the movable mold 3 is moved vertically and horizontally with respect to the upper mold body 2 by the elastic force of the elastic member 7. Will be held in a movable state.

The upper mold 1 is provided with a piston 8 which is vertically inserted into a pot 12 of the upper mold 1. Then, after closing the mold, when the ram pressure of a press machine (not shown) is applied, the piston 8 moves downward to apply pressure to the dough in the pot 12.

Next, the operation of the above will be described. Since this molding die is configured as described above, the first ring 9 and the second ring 10 are placed at predetermined positions in the cavity 11, and then the respective molds 1, 4, 5 are combined, After that, by performing mold clamping, the first ring 9 and the second ring 10 are formed integrally with the rubber elastic body.

First, by aligning the lower mold 5 and the middle mold 4, fitting the second ring 10 to the convex portion 5 a of the lower mold 5, and fitting the first ring 9 inside the middle mold 4, The first ring 9 and the second ring 10 are arranged at predetermined positions in the cavity 11. Then, the upper die 1 is combined with the middle die 4 and the lower die 5 to close the die, so that the first ring 9 and the second ring 10 are separated from each other by a predetermined distance, and the upper die 1 and the lower die 5 are separated from each other. It is sandwiched between and.

Next, when the dough is placed on the pot 12 of the upper mold 1 and the die is clamped by a press machine (not shown), the piston 8 presses the dough in the pot 12. Then, the dough in the pot 12 is guided to the cavity 11 via the injection hole 6 by the pressing force of the piston 8, and the dough is filled in the annular space between the first ring 9 and the second ring 10. Will be done.

Then, the dough is vulcanized in the cavity 11 in that state, whereby the dough is molded integrally with the first ring 9 and the second ring 10. As a result, a molded product having an annular shape as a whole can be obtained with the rubber-like elastic body interposed between the first ring 9 and the second ring 10.

In addition, in the above-mentioned molding die, a phenomenon called so-called dough rotation does not occur during molding.

That is, since the upper mold 1 is formed by the upper mold body 2 and the movable mold 3, and the elastic member 7 is provided between the upper mold body 2 and the movable mold 3, the upper mold 1 is clamped at the time of mold clamping. Since the main body 2 and the movable mold 3 independently press the first ring 9 and the second ring 10, respectively, even if there is some variation in the first ring 9 or the second ring 10, the upper mold 1 It is possible to ensure close contact between the ring and each ring 9, 10.

For example, when the first ring 9 is formed according to the designed size and the second ring 10 is formed shorter than the designed size, when the molding pressure acts, as shown in FIG. The upper mold body 2 presses the first ring 9, and the movable mold 3 presses the second ring 10. Then, the upper mold body 2 comes into close contact with the upper end surface of the first ring 9 and the movable mold 3 comes into close contact with the upper end surface of the second ring 10, respectively, so that the upper die main body 2 is placed between the first ring 9 and the second ring 10. The formed void is sealed so that so-called dough surrounding does not occur.

First, in the normal state, the upper mold 1 is held by the elastic force of the elastic member 7 with the upper mold body 2 and the movable mold 3 having their lower surfaces aligned with each other. Then, as described above, in the case where the second ring 10 is formed shorter than the design size, each mold 1, with the first ring 9 and the second ring 10 being arranged at a predetermined position of the cavity 11. When the dies 4 and 5 are combined to close the mold, the upper mold body 2 contacts the first ring 9, but the movable mold 3 does not contact the upper end surface of the second ring 10.

When the piston 8 is pressed from this state and pressure is applied to the material in the pot 12, the molding pressure causes the upper mold body 2 to press the first ring 9 into close contact, and at the same time, to move the movable mold. 3 moves downward against the elastic force of the elastic member 7 until it comes into close contact with the upper end surface of the second ring 10. Therefore, when the molding pressure is applied, the first ring 9 is sandwiched between the upper mold body 2 and the lower mold 5, and the two mating molds 2 and 5 are in close contact with each other, and the second ring 10 is movable. Since it is sandwiched between 3 and the lower mold 5 and the mating molds 3 and 5 come into close contact with each other, the space between the first ring 9 and the second ring 10 is sealed. As a result, when the mold is clamped, the material filled in the space between the first ring 9 and the second ring 10 is prevented from leaking to the outside.

That is, in the above, the upper die main body 2 that presses the first ring 9 and the movable die 3 that presses the second ring 10 operate independently by the molding pressure during mold clamping. Therefore, even if there is some variation in the length dimension of the first ring 9 or the second ring 10, the variation in the dimension is absorbed, and the upper end surface of each ring 9, 10 adheres to the upper mold 1. It can be molded in the state where it is left.

Further, in the above case, since the second ring 10 formed to be short is also completely sandwiched between the upper mold 1 and the lower mold 5, it is possible to stabilize the holding in the cavity 11. Therefore, it is possible to prevent the second ring 10 from moving due to the injection pressure of the dough at the time of molding and obtain a good molded product.

As another example, in the case where the upper end surface of the first ring 9 is formed in parallel and the upper end surface of the second ring 10 is formed slightly oblique, when the molding pressure acts, As shown in FIG. 3, the upper die body 2 presses the first ring 9 and the movable die 3 presses the second ring 10. Then, the upper mold body 2 comes into close contact with the upper end surface of the first ring 9 and the movable mold 3 comes into close contact with the upper end surface of the second ring 10, so that the space between the first ring 9 and the second ring 10 is close. The vacant space formed in the area is sealed so that so-called dough surrounding does not occur.

First, in the normal state, the upper mold 1 is held by the elastic force of the elastic member 7 with the upper mold body 2 and the movable mold 3 having their lower surfaces aligned. Then, as described above, when the upper end surface of the second ring 10 is formed in a slightly slanted state, the first ring 9 and the second ring 10 are arranged at predetermined positions in the cavity 11. When the molds are closed by combining the molds 1, 4, and 5 in this state, the upper mold body 2 abuts on the first ring 9, but the movable mold 3 is only on a part of the upper end surface of the second ring 10. It will be in a contact state.

From this state, when the piston 8 is pressed to apply pressure to the material in the pot 12, the molding pressure causes the upper mold body 2 to press the first ring 9 to be in close contact with the movable mold. 3 deforms the elastic member 7 until it comes into close contact with the upper end surface of the second ring 10 and inclines obliquely. Therefore, when the molding pressure is applied, the first ring 9 is sandwiched between the upper mold body 2 and the lower mold 5, and the mating molds 2 and 5 are in close contact with each other, and the second ring 10 is movable. Since it is sandwiched between the mold 3 and the lower mold 5 and the mating molds 3 and 5 come into close contact with each other, the space between the first ring 9 and the second ring 10 is sealed. . As a result, when the mold is clamped, it is possible to prevent the material filled in the space between the first ring 9 and the second ring 10 from leaking to the outside.

That is, in the above, the upper die main body 2 that presses the first ring 9 and the movable die 3 that presses the second ring 10 operate independently of each other by the molding pressure during mold clamping. Therefore, even if there are many variations in the parallelism of the upper end surfaces of the first ring 9 or the second ring 10, the variations in the parallelism are absorbed and the upper end surfaces of the rings 9 and 10 are placed in the upper mold. It can be molded in the state of being in close contact with 1.

Next, another embodiment will be described with reference to FIGS. 4 and 5. That is, the forming dies shown in FIGS. 4 and 5 are an upper die 21, a middle die 24, a lower die 25, and a spool provided on the upper die 21, which are mutually combined to form an annular cavity 31. It is equipped with a board 28. The upper die 21 has an injection hole 26, and the spool board 28 has a spool 33. A runner gate 32 for guiding the dough from the spool 33 to the injection hole 26 is formed between the upper mold 21 and the spool board 28. When the first ring 29 and the second ring 30 are concentrically arranged in the cavity 31 and then the mold is clamped, the dough is molded with the material interposed between the first ring 29 and the second ring 30. It has become. At this time, the upper die 21 is formed of an upper die body 22 and a movable die 23 which are divisible at a portion between the facing surfaces of the first ring 29 and the second ring 30, and between the two 22 and 23, A biasing member 27 is provided for holding the movable die 23 in a vertically movable state with respect to the upper die body 21.

In FIGS. 4 and 5, the upper mold 21, the middle mold 24, and the lower mold 25 are combined with each other to form an annular cavity 31 between the respective molds 21, 24, 25. Here, the first ring 29 and the second ring 30, which are integrally formed, can be arranged concentrically in the cavity 31. When the molds 21, 24, 25 are combined in that state (when the molds are closed), one end surface of the first ring 29 and the second ring 30 is the upper mold 21, and the other end surface is the lower mold surface. The molds 25 are brought into contact with each other.

In this case, the second ring 30 can be fitted in the central portion of the lower mold 25, and a cylindrical protrusion having a height equal to or shorter than the length of the second ring 30. 25a has been formed. As a result, the second ring 30, which is a molded part, is positioned at a predetermined position in the cavity 31 by fitting the second ring 30 into the convex portion 25a of the lower mold 25.

Further, the middle die 24 has an inner diameter larger than the outer diameter of the convex portion 25 a of the lower die 25 so that the first ring 29 can be fitted therein, and the length of the first ring 29 is equal to or longer than that of the first ring 29. It also has a short height. As a result, the first ring 29, which is a molded part, is positioned in the cavity 31 at a predetermined position by being fitted into the middle mold 24.

Therefore, the first ring 29 and the second ring 30 are positioned, so that the first ring 29 and the second ring 30 are positioned outside with the predetermined distance between the facing surfaces. The rings 30 are arranged concentrically on the inside and are housed in the cavities 31.

A spool board 28 is provided on the upper surface of the upper mold 21. A spool 33 is formed in the center of the spool board 28, and an unvulcanized material made of a rubber-like elastic material is injected from the outside to the spool 33.

A runner gate 32, which is a flow path for the cloth, is formed between the spool board 28 and the upper die 21, and the runner gate 32 is attached to the spool 33 of the spool board 28 and the upper die 21. The injection hole 26 formed is electrically connected.

As shown in FIG. 5, the injection holes 26 of the upper die 21 are formed at equal intervals on the circumference centered on the spool 33 of the spool board 28. The dough flowing through 32 is guided into an annular space formed between the first ring 29 and the second ring 30 in the cavity 31. In this case, the runner gate 32 is formed in a groove shape so that the spool 33 of the spool board 28 and each of the injection holes 26 of the upper die 21 are electrically connected to each other, and as shown in FIG. It is designed to

The upper die 21 is composed of an upper die body 22 and a movable die 23, which are separable at a portion located outside the injection hole 26 between the facing surfaces of the first ring 29 and the second ring 30. It is formed. The upper die main body 22 has a disc shape as a whole, and has a columnar slide guide portion 22a protruding downward at the center thereof. Further, the movable die 23 has an annular shape, and the movable die 23 is fitted on the slide guide portion 22a of the upper die body 22 so as to be vertically movable.

A biasing member 27 is provided between the upper end surface of the movable mold 23 and the facing surface of the upper mold body 22 as a holding means for biasing the two and 23 so as to separate them from each other in the axial direction. Since the biasing member 27 is a combination of a pair of disc springs facing each other here, the biasing members 27 are provided at equal intervals. The biasing force of the disc spring 27, which is the biasing member, is adjusted by operating the shoulder bolt 34. The shoulder bolt 34 holds the disc spring 27 at a predetermined position by axially penetrating the upper die main body 22 and screwing the upper die main body 22 into the movable die 23. The distance between the facing surfaces of the main body 22 and the movable die 23 is adjusted. As a result, by interposing the biasing member 27 between the upper mold body 22 and the movable mold 23, the movable mold 23 can move up and down with respect to the upper mold body 22 by the elastic force of the biasing member 27. It will be retained in the state.

Next, the operation of the above will be described. This molding die is configured as described above, so that the first ring 29 and the second ring 30 are placed at a predetermined position in the cavity 31, and then the respective molds 21, 24, 25 are assembled, and then this mold is assembled. By performing mold clamping, the first ring 29 and the second ring 30 are formed integrally with the rubber-like elastic body. Here, for example, when a sleeve is used as the first ring 29 and a vibrating ring is used as the second ring 30, a so-called bush type torsional damper is obtained as a product.

First, by aligning the lower mold 25 and the middle mold 24, fitting the second ring 30 into the convex portion 25 a of the lower mold 25, and fitting the first ring 29 inside the middle mold 24, The first ring 29 and the second ring 30 are arranged at predetermined positions in the cavity 31. Then, by combining the upper mold 21 with the middle mold 24 and the lower mold 25 and closing the mold, the first ring 29 and the second ring 30 are separated from each other by a predetermined distance, and the upper mold 21 and the lower mold 25 are separated from each other. It is sandwiched between and.

Next, when the dough is ejected from the spool 33 of the spool board 28 in the mold closed state, the dough is guided by the injection pressure to the cavity 31 through the runner gate 32 and the injection hole 26, and The dough is filled in the annular space between the first ring 29 and the second ring 30.

Then, the dough is vulcanized in the cavity 31 in that state, whereby the dough is molded integrally with the first ring 29 and the second ring 30. As a result, with the rubber-like elastic body interposed between the first ring 29 and the second ring 30, a molded product having an annular shape as a whole can be obtained.

In addition, in the above-mentioned molding die, a phenomenon called so-called dough rotation does not occur during molding.

That is, the upper die 21 is formed by the upper die body 22 and the movable die 23, and the biasing member 27 is provided between the upper die body 22 and the movable die 23, so that the upper die 21 is movable at the time of molding. Since the mold 23 and the upper mold body 22 independently press the first ring 29 and the second ring 30, respectively, there is some variation in the dimensional accuracy of the first ring 29 or the second ring 30 during mold clamping. Even if there is, the upper mold 21 and each ring 29, 30 can be surely brought into close contact with each other.

For example, when the first ring 29 is longer than the designed size and the second ring 30 is formed according to the designed size, the movable mold 23 is attached to the first ring 29, and The upper mold bodies 22 are pressed against the two rings 30, respectively. Then, since the movable mold 23 and the upper mold body 22 come into close contact with the upper end surface of the first ring 29 and the upper end surface of the second ring 30, respectively, the first ring 29 and the second ring 30 are contacted with each other. The vacant space formed between is closed so that the so-called dough surrounding does not occur.

First, in the normal state, the upper mold 21 is held by the elastic force of the biasing member 27 with the upper mold body 22 and the movable mold 23 having their lower surfaces aligned. Then, as described above, in the case where the first ring 29 is formed longer than the designed size, each mold 21, with the first ring 29 and the second ring 30 arranged in a predetermined position of the cavity 31, When the molds are closed by combining 24 and 25, the movable mold 23 contacts the first ring 29, but the upper mold body 22 does not contact the upper end surface of the second ring 30.

From this state, when the spool plate 28 is provided on the upper surface of the upper mold 21 to perform mold clamping, the movable mold 23 presses the first ring 29 to be in close contact with the mold clamping force, and at the same time, the upper mold main body. The element 22 moves downward against the urging force of the urging member 27 until it comes into close contact with the upper end surface of the second ring 30. Therefore, when the mold clamping force is applied, the first ring 29 is sandwiched between the movable mold 23 and the lower mold 25 so that the mating molds 23, 25 come into close contact with each other, and the second ring 30 moves upward. Since it is sandwiched between the mold body 22 and the lower mold 25 and the mating molds 22 and 25 come into close contact with each other, the space between the first ring 29 and the second ring 30 is sealed. Becomes As a result, it is possible to prevent the dough filled in the space between the first ring 29 and the second ring 30 from leaking outside during molding.

That is, in the above, the movable die 23 that presses the first ring 29 and the upper die body 22 that presses the second ring 30 operate independently by the molding pressure when the die is clamped. Therefore, even if there is some variation in the length dimension of the first ring 29 or the second ring 30, the variation in the dimension is absorbed and the upper end surface of each ring 29, 30 is brought into close contact with the upper mold 21. It will be possible to mold in an open state.

Further, in the above case, the second ring 30, which is relatively shorter than the first ring 29 due to the design dimension, is completely sandwiched between the upper die 21 and the lower die 25. Therefore, it is possible to stabilize the retention in the cavity 31, and therefore, it is possible to prevent the second ring 30 from moving due to the injection pressure of the dough at the time of molding and obtain a good molded product. it can.

Further, in the above molding die, it is possible to improve the quality of the molded product.

That is, by providing the runner gate 32 for individually conducting the connection between the spool 33 of the spool board 28 and each of the plurality of injection holes 26 formed in the upper mold 21, the spout 33 is ejected. The pressure of the dough does not act on the upper mold 21 significantly.

That is, although the pressure of the cloth ejected from the spool 33 acts on the upper mold 21 in proportion to the size of the pressure receiving area, the above-mentioned one has a groove between the spool plate 28 and the upper mold 21. By providing the runner gate 32 having a shape, the pressure receiving area of the upper mold 21 against the injection pressure of the cloth can be reduced. This is compared with the case where the gate that connects the spool 33 and the injection hole 26 is a so-called film gate, that is, when the gate is formed by a circular recess that connects the spool 33 and all the injection holes 26. The pressure receiving area of the upper mold 21 with respect to the material pressure can be reduced.

Therefore, since the injection pressure acts on the groove bottom surface of the runner gate 32, the pressure receiving area for the material pressure is reduced, and accordingly, the total mold clamping force can be made relatively small. As a result, it becomes possible to use a press machine having a relatively low mold clamping pressure.

Further, in the above-mentioned one, since the upper end surface of the upper die body 22 contacts the spool board 28, the runner gate 32 is formed between the upper die 21 and the spool board 28. The dimension of the runner gate 32 in the groove depth direction does not change during molding. As a result, even if the injection pressure of the cloth acts on the runner gate 32, the cross-sectional area of the flow passage in the runner gate 32 can always be kept constant. Therefore, the molding pressure acting on the cavity 51 via the upper mold 21 can be made constant, so that the quality of the obtained molded product can be improved.

Moreover, by forming the groove-shaped runner gate 32, the volume of the flow path from the spool 33 to the injection hole 26 can be reduced as compared with the case where the gate is formed by a circular recess. Therefore, the yield of the fabric can be improved.

[0077]

[Effect of device]

 As described above, according to the present invention, in the molding die in which the space between the first ring and the second ring is filled with the material and these are integrally molded, the upper die is connected to the first ring. Holding means for dividing the upper die body and the movable die at a portion corresponding to a surface facing the second ring and for holding the movable die in a vertically movable manner between the upper die body and the movable die. By providing, even if there is variation in the dimensional accuracy of the first ring or the second ring, it is possible to flexibly deal with this variation.

In other words, in the upper die, the upper die main body and the movable die independently press each ring and closely contact each other during molding, so that the inter-ring gap is maintained regardless of the dimensional variation of each ring. The empty space can be reliably sealed. As a result, it is possible to prevent the material from leaking from the cavity and to prevent the formation of burrs on the molded product, which eliminates the need for deburring work and improves the productivity.

Also, by preventing the material from leaking from the cavity during molding, it is possible to secure the internal pressure of the cavity, so that problems such as air entering the molded product and insufficient material injection can be prevented. This has the effect of improving the quality of the molded product.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of a molding die according to the present invention.

FIG. 2 is a diagram illustrating a first example of the operation of the molding die shown in FIG.

FIG. 3 is a diagram illustrating a second example of the operation of the molding die shown in FIG.

FIG. 4 is a view showing another embodiment of the molding die according to the present invention.

5 is a diagram showing a positional relationship among a spool, an injection hole, and a runner gate, taken along line XX in FIG.

FIG. 6 is a diagram showing a conventional example.

FIG. 7 is a diagram illustrating a first example of the operation of the molding die shown in FIG.

FIG. 8 is a diagram illustrating a second example of the operation of the molding die shown in FIG.

[Explanation of symbols]

 1, 21, 41 ... upper mold 2, 22 ... upper mold body 3, 23 ... movable mold 4, 24, 44 ... middle mold 5, 25, 45 ... lower mold 5a, 25a, 45a ... convex portion 6, 26, 46 ... Injection hole 7 ... Elastic member (holding means) 8, 48 ... Piston 9, 29, 49 ... First ring 10, 30, 50 ... Second ring 11, 31, 51 ... ... Cavity 12, 52 ... Pot 22a ... Slide guide section 27 ... Biasing member (holding means) 28 ... Spool board 32 ... Runner gate 33 ... Spool 34 ... Shoulder bolt

Claims (3)

[Scope of utility model registration request] 1. Cooperated annular cavities (11) (3)
1) forming upper mold (1) (21), middle mold (4) (2)
4), the lower mold (5) (25), and the cavity (1
1) First ring (9) (2) integrally molded with (31)
9) and the second ring (10) (30) are arranged concentrically, and then the both rings (9) (29), (10) (3)
The upper molds (1) and (21) provided with the injection holes (6) and (26) at the corresponding positions between 0) are the rings (9) (29),
(10) Arranged in contact with the upper surfaces of (30), and through the injection holes (6) (26), the rings (9) (2).
9), a molding die for molding by filling the space formed between (10) and (30) with a cloth, the upper die (1) (2)
1) is divided at the portion corresponding to the facing surface between the first ring (9) (29) and the second ring (10) (30), and the upper mold body (2) (22) and the movable mold are divided. (3) (23) and the upper mold body (2) (22) and the movable mold (3)
Holding means (7) (27) for holding the movable molds (3) (23) in a vertically movable state with respect to the upper mold bodies (2) (22) is provided between the movable molds (3) and (23). Molding die characterized by the following. 2. The rubber-like elastic member (7) for holding the movable die (3) so as to be movable in the direction orthogonal to the axis.
The molding die according to claim 1, wherein 3. The holding means is a biasing member (27) capable of adjusting the vertical position of the movable die (23).
Mold described.