JP2023116977A - Mold, and molded product formed using the same - Google Patents

Abstract

To easily perform disassembling of a core and take out a molded product while suppressing generation of parting lines even if the molded product has an undercut part.SOLUTION: A plate squeeze mechanism 20 that is pushed down by an upper mold 2 and presses down a core retaining plate 7 in an axial direction of plate driving is provided. The plate squeeze mechanism 20 has: a first push rod 21 in which one end abuts against the core retaining plate 7 at the time of mold clamping and other end is continuous with the upper mold 2 or abuts against the upper mold 2 at the time of mold clamping; and a first push rod insertion hole 3a provided in a lower mold 3 so that the first push rod 21 is inserted through. Tt the time of mold clamping, a length L2 of the first push rod 21 is longer than a distance L1 from a top surface of the core retaining plate 7 corresponding to the first push rod insertion hole 3a to a top surface of the lower mold 3 (L2>L1).SELECTED DRAWING: Figure 2A

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for molding a molded article having an undercut portion and a molded article molded by the mold.

For example, as disclosed in Japanese Unexamined Patent Application Publication No. 2002-100031, there is known a slide core advancing/retreating mechanism having an angular pin for sliding a slide core and a guide portion for guiding the angular pin. In this slide core advancing/retreating mechanism, the guide portion has an inner member formed with a pin insertion hole through which the angular pin is passed, and an outer member formed with an inner insertion hole through which the inner member is inserted. The axial direction is inclined with respect to the axial direction of the inner member, the axial direction of the inner insertion hole is inclined with respect to the axial direction of the outer member, and the axial direction of the inner member and the axial direction of the inner insertion hole are substantially aligned. In addition, the axial direction of the pin insertion hole substantially coincides with the axial direction of the outer member.

Japanese Patent Application Laid-Open No. 2020-82450

Conventionally, the core is divided into a piece structure, and after molding, the piece is manually taken out by an operator and disassembled.

However, if the operator performs these operations each time molding is performed, it takes time before the next molding is performed. Moreover, if it takes a long time to reach the next step, the core will cool down, so the temperature of the core must be raised before the next step is started, and it takes time to raise the temperature.

Moreover, the core is often heated to 100° C. or more, and it is difficult for workers to touch it with bare hands.

Furthermore, in the case of a large-sized molding die, the core may weigh more than 10 kg, and the work of disassembling the core is hard work.

The volume of the divided core is not constant, and there is a difference in the easiness of cooling for each core component. Attempting to assemble core component parts with different temperatures may result in damage to the core due to thermal expansion or the like, resulting in improper assembly.

On the other hand, in the slide core structure as in Patent Document 1, although continuous molding can be performed, the parting line enters in the mold opening direction. There's a problem.

The present invention has been made in view of this point, and its object is to easily disassemble the core while suppressing the occurrence of parting lines even in a molded product having an undercut portion. to take out the molded product.

In order to achieve the above object, the present invention provides a core retainer plate that retains the core fixing pin at the locked position and can be opened at the open position.

Specifically, the first invention includes an upper mold, a lower mold, and a core that faces the cavity between the upper mold and the lower mold and is composed of a plurality of core components, and the undercut part is formed. For the mold that molds the molded product that has
The above mold is
a core fixing pin for fixing each of the plurality of core components;
A core removal which has a plurality of fixing pin insertion slits for inserting the core fixing pins, locks the core fixing pins at a locked position, and can be opened at an open position where the core fixing pins are rotationally or horizontally moved from the locked position. a stop plate;
a plate driving mechanism for rotating or horizontally moving the core retainer plate;
a plate squeeze mechanism that is pressed down by the upper die to press the core retainer plate in the axial direction of the plate drive;
The plate squeeze mechanism is
a first push rod, one end of which abuts against the core retainer plate during mold clamping and the other end of which is continuous with the upper mold or abuts against the upper mold during mold clamping;
a first push rod insertion hole provided in the lower mold so that the first push rod is inserted;
The length of the first push rod at the time of clamping the mold is longer than the distance from the upper mold side surface of the core retainer plate corresponding to the first push rod insertion hole to the upper mold side surface of the lower mold. It's long.

According to the above configuration, when the mold is clamped, one end of the first push rod abuts against and presses against the core retaining plate, and the core retaining plate is sufficiently pressed. is reliably prevented from occurring. Then, by releasing the plate squeeze function that presses the plate in the axial direction by opening the mold, the core retainer plate rotates or moves horizontally, and moves to the open position where the core fixing pin can be released. , a plurality of core components can be disassembled to remove the molded product without disassembling the entire mold.

In the second invention, in the first invention,
The first push rod is divided into two or more pieces, and the entire length of the divided first push rod corresponds to the first push rod insertion hole at the time of clamping the mold. longer than the distance from the upper mold side surface of the lower mold to the upper mold side surface of the lower mold.

According to the above configuration, the core retainer plate or the first push rod wears due to deterioration over time, etc., and the total length of the first push rod and the core corresponding to the first push rod insertion hole at the time of mold clamping are removed. Even if the difference between the distance from the upper die side surface of the stop plate to the upper die side surface of the lower die becomes smaller, if part of the divided first push rod is replaced with a longer one, Since an appropriate difference can be maintained, it becomes easy to secure the pressing force without correcting the mold side.

In a third invention, in the first or second invention,
A first permanent magnet is provided at one end of the first push rod, or the entire first push rod including the one end is a permanent magnet,
At least one of the upper mold and the lower mold with which the one-side end abuts is provided with a second permanent magnet that repels the first permanent magnet.

According to the above configuration, the core retainer plate or the first push rod wears due to deterioration over time, etc., and the total length of the first push rod and the core corresponding to the first push rod insertion hole at the time of mold clamping are removed. Even if the difference between the distance from the upper die side surface of the stop plate to the upper die side surface of the lower die becomes smaller, the pressing force can be secured by using the repulsive force of the magnet through which repels, so the mold It becomes easy to secure the pressing force without correcting the side. The first push bar may be the first permanent magnet as a whole, or may be the first permanent magnet only at one end of the mold.

In a fourth invention, in any one of the first to third inventions,
The plate drive mechanism includes a drive plate provided below the core retaining plate for rotating or horizontally moving the core retaining plate,
The plate squeeze mechanism is
the first push rod;
a second push rod that is pushed down by the upper mold to control driving of the drive plate;
a first biasing member provided on the lower surface side of the drive plate and biasing the drive plate toward the upper mold;
a second biasing member provided on the upper surface side of the drive plate and pushing up the second push rod;
The first timing at which the first push rod releases the function of pressing the core retainer plate in the axial direction of the plate drive coincides with the second timing at which the second push rod releases the drive control of the drive plate. Or earlier than the second timing.

According to the above configuration, not only the first push rod but also the second push rod may be provided. By driving the drive plate after canceling the function of pressing the plate in the axial direction of the plate drive, the core retainer plate can be moved to the open position.

In the fifth invention, in the fourth invention,
The plate drive mechanism has a rotary drive unit that rotates the core retainer plate when the plate squeeze mechanism is released from pressing the plate drive in the axial direction,
The rotary drive portion is a ball member provided between the center rotation shaft of the drive plate and the center hole of the core retainer plate through which the center shaft of the drive plate is inserted,
A ball member accommodating recess for accommodating the ball member is formed in the center hole of the core retainer plate,
A driving groove in which the ball member can move is spirally formed in the central axis of the driving plate.

According to the above configuration, when the drive plate is pushed up by the first biasing member in a state in which the pressing of the plate drive in the axial direction by the plate squeeze mechanism is released, the ball member moves along the spiral groove. , the core retainer plate rotates by opening and closing the mold accordingly. Thereby, the core fixing pin is moved to the open position to enable disassembly of the core components.

In the sixth invention, in the fourth invention,
The plate drive mechanism has a rotary drive unit that rotates the core retainer plate when the plate squeeze mechanism releases the pressing force,
The rotation drive part is a protrusion provided on the central axis of the drive plate,
The core retainer plate has a central hole through which the central shaft of the drive plate is inserted, and a drive groove formed spirally on the inner peripheral surface thereof into which the protrusion is inserted.

According to the above configuration, when the drive plate is pushed up by the first urging member in a state where the pressing force by the plate squeeze mechanism is released, the protrusion of the center shaft of the drive plate moves along the spiral groove and moves along the spiral groove. Since the core retainer plate is pushed up, the core retainer plate rotates accordingly. Thereby, the core fixing pin is moved to the open position to enable disassembly of the core components.

In the seventh invention, in the fifth or sixth invention,
The core retainer plate is formed with an arc-shaped second push rod insertion slit through which the second push rod is inserted.

According to the above configuration, the rotation of the core retainer plate is not hindered by providing the slit for inserting the second push rod.

In the eighth invention, in the fifth invention,
The plate driving mechanism has a horizontal driving section that horizontally moves the core retaining plate when the pressing of the plate driving in the axial direction by the plate squeeze mechanism is released,
The horizontal drive unit is
an inclined surface provided on one of the drive plate and the core retainer plate;
A protrusion is provided on the other of the drive plate and the core retainer plate and contacts the inclined surface.

According to the above configuration, the core retainer plate can be horizontally moved and the lock of the core fixing pin can be released with a simple configuration.

The molded article of the ninth invention has an undercut portion on at least one of the inner surface and the outer surface, and is molded by the mold of any one of the first to eighth inventions, which has no intersecting parting line on the surface. It is a molded product.

According to the above configuration, it is possible to obtain a molded product that has an undercut portion and no intersecting parting lines and has a good appearance and high marketability.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, even a molded product having an undercut portion can be easily disassembled and taken out while suppressing the occurrence of a parting line.

1 is a cross-sectional view showing a mold in a clamped state according to Embodiment 1 of the present invention; FIG. FIG. 2 is a cross-sectional view corresponding to FIG. 1 in a state where the force of the first push rod to push the core retainer plate is reduced; 2B is a partially enlarged cross-sectional view of FIG. 2A according to Modification 2 of Embodiment 1. FIG. 2B is a partially enlarged cross-sectional view of FIG. 2A according to Modification 3 of Embodiment 1. FIG. FIG. 2B is a partially enlarged cross-sectional view of FIG. 2A according to Modification 4 of Embodiment 1; 2B is a partially enlarged cross-sectional view of FIG. 2A according to Modification 5 of Embodiment 1. FIG. 2B is a partially enlarged cross-sectional view of FIG. 2A according to Modification 6 of Embodiment 1. FIG. FIG. 2 is a cross-sectional view corresponding to FIG. 1 in a state in which the force with which the second push rod pushes the drive plate is reduced; FIG. 2 is a sectional view equivalent to FIG. 1 showing how a first biasing member pushes up a drive plate; FIG. 4 is a plan view showing the core retainer plate and its surroundings in a state where the first biasing member pushes up the drive plate; It is a perspective view which expands and shows a drive plate. FIG. 2 is a cross-sectional view corresponding to FIG. 1 showing how a core retainer plate is rotated by a driving plate; 4C is a plan view equivalent to FIG. 4B showing how the drive plate rotates the core retaining plate and the core fixing pin rotates. FIG. FIG. 2 is a cross-sectional view corresponding to FIG. 1 showing a state in which the upper mold is largely separated from the lower mold; FIG. 2 is a cross-sectional view equivalent to FIG. 1 showing how the core and the product are separated from the lower mold; FIG. 2 is a sectional view equivalent to FIG. 1 showing how the third core component is separated from the first core component, the second core component and the product; FIG. 2 is a sectional view equivalent to FIG. 1 showing how the second core component is separated from the first core component and the product; FIG. 7 is a cross-sectional view showing the mold in a clamped state according to Embodiment 2 of the present invention. FIG. 10 is a cross-sectional view showing a mold in a clamped state according to a modified example of Embodiment 2 of the present invention; 4(a) to 4(c) are cross-sectional views respectively showing modified examples of molds according to other embodiments.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a mold 1 of Embodiment 1 of the present invention, and this mold 1 includes, for example, a rectangular parallelepiped upper mold 2, a box-shaped lower mold 3, and a mold between the upper mold 2 and the lower mold 3. A mold for molding a molded product 5 facing a cavity 50, including a core 4 composed of a plurality of (three in this embodiment) core components 4a, 4b, and 4c, and having an undercut portion 5a. . Note that the number of core components may be two or four or more. The upper die 2 and the lower die 3 are made of carbon steel for machine structural use, such as S45C and S55C.

As shown in FIG. 4B, the mold 1 includes a total of six core fixing pins 6 that fix three core components 4a, 4b, and 4c, respectively, and six core fixing pins 6 through which the six core fixing pins 6 are inserted. and a core retainer plate 7 which has four fixing pin insertion slits 8 and can rotate to open the core fixing pin 6 at the open position. The core retainer plate 7 is disc-shaped and has a central hole 7a formed in the center.

The fixing pin insertion slit 8 of the core retainer plate 7 has a width WA narrower than the maximum diameter Dmax of the core fixing pin 6 at the locked position A (WA<Dmax), and a width WB at the open position B of the core. It is wider than the maximum diameter Dmax of the fixed pin 6 (WB>Dmax). For example, in the range of the locked position A, the fixing pin insertion slit 8 is formed with a retainer portion 8a that is narrower than the open position B. As shown in FIG. As described above, in this embodiment, the core fixing pin 6 can be released at the open position B and the core fixing pin 6 can be retained at the lock position A with a simple configuration. Further, the core retainer plate 7 is formed with an arc-shaped second push rod insertion slit 7c through which the second push rod 22 is inserted.

The mold 1 also includes a plate drive mechanism 10 that rotates the core retainer plate 7 . The plate drive mechanism may be a motor or an angular pin.

The plate drive mechanism 10 includes a drive plate 11 provided below the core retainer plate 7 for rotating the core retainer plate 7 . As shown in FIG. 4C, the drive plate 11 has a disk shape and a cylindrical shaft 11a extending vertically from the center.

The mold 1 further includes a plate squeeze mechanism 20 which is pushed down by the upper mold 2 to press the core retainer plate 7 in the axial direction of the plate drive.

The plate squeeze mechanism 20 includes, for example, a cylindrical first push rod 21 that is pushed down by the upper mold 2 to hold down the core retainer plate 7 in the axial direction of the plate drive, and a drive plate 11 that is pushed down by the upper mold 2. and a cylindrical second push rod 22 for driving the . A circular first push rod insertion hole 3a is formed in the lower die 3 so that the first push rod 21 can be inserted therethrough.

The plate squeeze mechanism 20 is also provided on the lower surface side of the drive plate 11 and biases the drive plate 11 toward the upper mold 2. A first biasing member 23 made of, for example, a compression coil spring and a second biasing member 24 made of, for example, a compression coil spring for pushing up the second push rod 22 . In this embodiment, the first push rod 21 is made of, for example, a round bar made of bearing steel (SUJ2) with high abrasion resistance, and is pressed by the mold clamping force of the molding machine without providing an urging member. The first biasing member 23 and the second biasing member 24 may not be compression coil springs, and may be plate springs, disc springs, air cylinders, or the like.

The first timing at which the first push rod 21 releases the pressing of the core retainer plate 7 in the axial direction of the plate drive coincides with the second timing at which the second push rod 22 starts driving the drive plate 11. Alternatively, it is set to be earlier than the second timing.

The plate drive mechanism 10 further includes a rotation drive unit 12 that rotates the core retainer plate 7 when the plate squeeze mechanism 20 is released from pressing the plate drive in the axial direction.

As shown in FIG. 1A or FIG. 4A, for example, the rotation drive portion 12 is formed by a shaft 11a of the drive plate 11 and a center hole 7a of the core retainer plate 7 through which the shaft 11a of the drive plate 11 is inserted. It is the ball member 13 provided in between. As shown in FIG. 1, the center hole 7a of the core retainer plate 7 is formed with a ball member accommodating recess 7b in which the ball member 13 is accommodated.

On the other hand, as shown in FIG. 4C, the shaft 11a of the drive plate 11 is spirally formed with a drive groove 11b in which the ball member 13 can move.

As shown in FIG. 1A or FIG. 4A, the core 4 includes an upper core component 4a having a larger outer diameter at the upper end than the outer diameter at the lower end, and a central through hole through which the lower side of the upper core component 4a is inserted. and a lower core component 4b having an outer diameter at its upper end larger than that at its lower end. In this embodiment, a ring-shaped outer core component 4c covers the lower outer periphery of the lower core component 4b. An undercut portion 5a of the molded product 5 is formed in a cavity 50 between the upper core component 4a, the lower core component 4b, and the outer core component 4c.

Next, the operation of the mold 1 according to this embodiment will be described in order using the drawings.

In the clamped state shown in FIG. 1, for example, a rubber product as the molded product 5 is formed from the silicone rubber in the cavity 50. As shown in FIG. Silicon rubber has a low viscosity of 20 to 5000 Pa·S before heating, and easily leaks out from the gaps of the cavity 50 to form burrs.

However, in this embodiment, as shown in FIG. 2A, the distance L1 from the upper surface of the core retainer plate 7 corresponding to the first push rod insertion hole 3a to the upper surface of the lower mold 3 during mold clamping is greater than the distance L1. 1 Since the length L2 of the first push rod 21 is long (L2>L1), the lower end of the first push rod 21 contacts and presses the upper surface of the core retainer plate 7 when clamping the mold, so that the entire mold 1 has a gap. This makes it difficult for burrs to occur, thereby reliably preventing the occurrence of burrs.

Then, as shown in FIG. 2A, the mold opening process is started. First, when the upper die 2 is slowly raised, the upper die 2 is slightly separated from the lower die 3 and the force of the first push rod 21 pushing against the core retainer plate 7 is weakened. As a result, the axial pressing of the core retainer plate 7 in the plate driving direction is released at the first timing.

Next, as shown in FIG. 3, when the upper die 2 is further raised, the force with which the second push rod 22 presses the drive plate 11 via the second biasing member 24 is weakened. As a result, the drive plate 11 starts rotating at the second timing. Note that the second timing may be the same as the first timing.

Next, as shown in FIGS. 4A and 4B, the first biasing member 23 pushes the drive plate 11 up. As the drive plate 11 moves upward, the core retainer plate 7 rotates while the ball member 13 moves within the drive groove 11b. Specifically, the ball member 13 rotates the core retainer plate 7 in the direction of the arrow shown in FIG. 4B by moving the drive groove 11b shown in FIG. 4C from the lower side to the upper side. At this stage, each core fixing pin 6 is in the range of the lock position A, so that it is retained by the narrow retaining portion 8a of the fixing pin insertion slit 8. As shown in FIG. By providing the second push rod insertion slit 7c, the rotation of the core retainer plate 7 is not hindered.

Further, as shown in FIGS. 5A and 5B , the drive plate 11 is pushed up by the first biasing member 23 to further rotate the core retainer plate 7 and move the core fixing pin 6 to the open position B. . At the open position B, the core fixing pin 6 can be pulled out upward. Although not shown in detail, an ejector plate on which an ejector rod is erected vertically is provided below the lower die 3, and is operated in the direction of the upper die 2 to push up the core fixing pins 6 and eject the product. may be demolded from the core 4.

Next, as shown in FIG. 6, by moving the upper mold 2 away from the lower mold 3, the core 4 can be accessed from above.

Next, as shown in FIG. 7, the core 4 as a whole is separated from the lower mold 3 together with the molded product 5 . The core fixing pin 6 is lifted with each core component.

Then, as shown in FIG. 8, the outer core component 4c is removed from below. The molded product is a rubber product such as silicon rubber, and the undercut portion 5a is deformable, so that the molded product 5 is not damaged even if it is removed.

Next, as shown in FIG. 9, the lower core component 4b is removed from below.

Finally, the molded product 5 is removed from the upper core component 4a. In this way, when the drive plate 11 is pushed up by the first biasing member 23 in a state in which the plate squeeze mechanism 20 is released from pressing the plate drive in the axial direction, the drive plate 11 is pushed up along the spiral drive groove 11b. Since the ball member 13 moves, the core retainer plate 7 rotates accordingly. Thereby, the core fixing pin 6 is moved to the open position B, and the core components 4a, 4b, 4c can be disassembled.

Conversely, in order to reassemble the mold 1 that has been disassembled, the operations described above may be performed in reverse order. During assembly, when the core retainer plate 7 is set so that the core fixing pin 6 is at the open position B and the upper die 2 is placed thereon and pushed in, the core retainer plate 7 is pushed by the first push rod 21. As a result, the mold 1 is assembled with the core fixing pin 6 relatively moved to the lock position A and retained.

After assembly, it is preferable to use a communication passage (not shown) that communicates with the cavity 50 to fill the molded product 5 with a molding material. Since the mold 1 can be easily disassembled without taking much time, the core components are difficult to cool down and the difference in thermal expansion is small, so that the cores can be assembled normally.

Thus, in this embodiment, by sequentially releasing the first push rod 21 and the second push rod 22 that have been pushed down by the upper die 2, the core retainer plate 7 is moved in the axial direction of the plate drive. By driving the drive plate 11 after the pressing is released, the core retainer plate 7 can be rotated to the open position B. As shown in FIG. Then, when the core fixing pin 6 is moved to an open position where it can be opened, the plurality of core components 4a, 4b, 4c can be disassembled and the molded product 5 can be taken out without disassembling the entire mold.

In the present embodiment, even if the molded product 5 has ribs on the inner peripheral surface that will serve as the undercut portions 5a, the molded product 5 can be removed after molding without disassembling the mold 1 as a whole. Therefore, according to the mold 1 according to the present embodiment, even with the molded product 5 having the undercut portion 5a, the core can be easily disassembled and the molded product 5 can be taken out while suppressing the occurrence of the parting line. be able to.

-Modification 1-
Although not shown in detail, the configuration of the plate driving mechanism 10 is not limited to that of the first embodiment. For example, the rotation drive part 12 is a protrusion provided on the shaft 11a of the drive plate 11, and the core retainer plate 7 is inserted with the shaft 11a of the drive plate 11 and has a protrusion on the inner peripheral surface. The drive groove 11b to be inserted may have a spirally formed center hole 7a. In short, the concave-convex relationship is opposite to that of the above-described embodiment.

In this case as well, when the drive plate 11 is pushed up by the first biasing member 23 in a state in which the plate squeeze mechanism 20 is released from pressing the plate drive in the axial direction, the protrusion of the shaft 11a of the drive plate 11 is pushed up. Since the core retainer plate 7 is pushed up while relatively moving along the spiral groove, the core retainer plate 7 rotates accordingly. Thereby, the core fixing pin 6 is moved to the open position B, and the core components 4a, 4b, 4c can be disassembled.

-Modification 2-
In Embodiment 1, the first push rod 21 made of a single round bar is placed on the side of the lower mold 3, but as shown in FIG. 2B, the first push rod 21b is fixed to the lower surface of the upper mold 2 You may Also in this case, the length L2 of the first push rod 21b is longer than the distance L1 from the upper surface of the core retainer plate 7 corresponding to the first push rod insertion hole 3a to the upper surface of the lower die 3.

-Modification 3-
In Embodiment 1 described above, the first push rod 21 is composed of a single round bar, but as shown in FIG. 2C, the first push rod 21c may be divided into a plurality of pieces. For example, it may be divided into two parts, the lower part of which is screwed to the core retainer plate 7 and the upper part of which is placed on top of the plate so that the upper end protrudes from the surface of the lower mold 3 . Also in this case, the total length L2 of the first push rod 21c is longer than the distance L1.

By doing so, for example, when the first push rod 21c or the lower surface of the upper mold 2 is weakened, by increasing the length of the upper part of the first push rod 21c, it is possible to continue without machining the mold side. can be molded as

-Modification 4-
In Modification 3, the lower side of the first push rod 21c divided into two parts is screwed to the core retainer plate 7, but as shown in an enlarged view of FIG. 2 may be fixed, and the lower side may be placed on the core retainer plate 7 .

-Modification 5-
In Embodiment 1, the first push rod 21 is made of a round bar, but as shown in an enlarged view in FIG. 2E, the first push rod 21e may be made of a bar-shaped compression coil spring. In that case, it is desirable that the compression coil spring have a degree of resilience that overcomes the pressure of the filling material. Also in this case, the total length L2 of the first push rod 21e is longer than the distance L1.

-Modification 6-
As shown in FIG. 2F, a first permanent magnet 26 is provided on the upper end of the first push rod 21f, and a second permanent magnet 25 that repels the first permanent magnet 26 is provided on the lower surface of the upper die 2 with which the upper end abuts. may In this case, since the repulsive force of the pair of magnets 25 and 26 can be used, the total length L2 of the first push rod 21e need not necessarily be longer than the distance L1, but it is advantageous if it is longer.

Although not shown, the entire first push rod 21f including one end portion may be a permanent magnet, and the first push rod 21f, which is the first permanent magnet, may repel the first push rod 21f, which is the first permanent magnet, toward the core retaining plate 7 side. Two permanent magnets 25 may be provided.

By configuring in this way, the core retainer plate 7 or the first push rod 21e wears due to deterioration over time, etc. Even if the difference between the distance L1 from the upper surface of the core retainer plate 7 corresponding to 3a to the upper surface of the lower die becomes small, the pressing force can be secured by utilizing the repulsive force between the repelling magnets 25 and 26. Therefore, it becomes easy to secure the pressing force without correcting the mold side.

(Embodiment 2)
FIG. 10 shows Embodiment 2 of the present invention, which differs from Embodiment 1 in that the core retainer plate does not rotate but moves horizontally. In the following embodiment 2 and its modification, the same parts as those in FIGS. 1 to 9 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the mold of this embodiment (only the lower mold 103 portion is shown), the plate drive mechanism 10 pushes the core retainer plate 107 when the plate squeeze mechanism 20 releases the pressing force of the plate drive in the axial direction. It has a horizontal drive for horizontal movement. Although not shown in detail, this horizontal driving part is provided on one of the driving plate and the core retainer plate 107 on an inclined surface, and on the other of the drive plate and the core retainer plate 107 and contacts the inclined surface. Including contacting protrusions.

Also in this embodiment, the core retainer plate 107 can be moved horizontally from the locked position to the open position with a simple structure, and the core fixing pin 6 can be locked and unlocked.

-Modification-
FIG. 11 shows a mold according to a modification of Embodiment 2 of the present invention (only the lower mold 103' portion is shown), which differs from Embodiment 2 in that the core retainer plate 107' is divided into four parts.

In this case, it is preferable to move the core fixing pin 6 from the locked position to the open position by moving the two pairs of core retaining plates 107' away from each other. For example, two pairs of inclined surfaces and two pairs of protrusions may be provided.

(Other embodiments)
Embodiments of the present invention may be configured as follows.

That is, in the embodiment, the undercut portion 5a of the molded product 5 has a rib shape provided on the inner peripheral surface side, but it may be a rib shape provided on the outer peripheral surface side. In this case, the shape and arrangement of the core components may be changed according to the shape of the undercut portion. The core fixing pins may also be provided according to the shape and arrangement of the core components.

For example, modifications simply shown in FIGS. 12(a) to 12(c) can be considered. That is, as shown in FIG. 12(a), the inner peripheral surface of the undercut portion 205a of the molded product 205 may be formed by the projecting portions of the upper core component 204a and the lower core component 204b. As shown in FIG. 12(b), the inner peripheral surface of the undercut portion 205a of the molded product 205 may be formed by the projecting portion of the lower core component 204b, or as shown in FIG. 12(c), The inner peripheral surface of the undercut portion 205a of the molded product 205 may be formed by the projecting portion of the upper core component 204a.

In each of the above-described embodiments, the molded product 5 is a rubber product such as silicon rubber, but may be an elastomer having elasticity, or may be a thermoplastic resin material or a thermosetting resin material.

The above embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its applications, or uses.

1 mold
2 upper die
3 lower die
3a First push rod insertion hole
4 core
4a upper core component
4b lower core component
4c outer core component
5 molded product
5a Undercut part
6 Core fixing pin
7 Core retainer plate
7a central hole
7b ball member housing recess
7c Second push rod insertion slit
8 Slit for fixing pin insertion
8a retaining part
10 plate drive mechanism
11 drive plate
11a axis
11b drive groove
12 rotary drive
13 ball member
20 Plate squeeze mechanism
21, 21b, 21c, 21d, 21e, 21f first push rod
22 second push rod
23 first biasing member
24 second biasing member
25 second permanent magnet
26 first permanent magnet
50 cavity 103, 103' lower mold 107, 107' plate 204a upper core component 204b lower core component 205 molded product 205a undercut

Claims (9)

A mold for molding a molded product having an undercut portion, comprising an upper mold, a lower mold, and a core facing a cavity between the upper mold and the lower mold, and composed of a plurality of core components. ,
a core fixing pin for fixing each of the plurality of core components;
A core removal which has a plurality of fixing pin insertion slits for inserting the core fixing pins, locks the core fixing pins at a locked position, and can be opened at an open position where the core fixing pins are rotationally or horizontally moved from the locked position. a stop plate;
a plate driving mechanism for rotating or horizontally moving the core retainer plate;
a plate squeeze mechanism that is pressed down by the upper die to press the core retainer plate in the axial direction of the plate drive;
The plate squeeze mechanism is
a first push rod, one end of which abuts against the core retainer plate during mold clamping and the other end of which is continuous with the upper mold or abuts against the upper mold during mold clamping;
a first push rod insertion hole provided in the lower mold so that the first push rod is inserted;
The length of the first push rod at the time of clamping the mold is longer than the distance from the upper mold side surface of the core retainer plate corresponding to the first push rod insertion hole to the upper mold side surface of the lower mold. A mold characterized by a long length. A mold according to claim 1,
The first push rod is divided into two or more pieces, and the entire length of the divided first push rod corresponds to the first push rod insertion hole at the time of clamping the mold. The mold is longer than the distance from the upper mold side surface of the lower mold to the upper mold side surface of the lower mold. The mold according to claim 1 or 2,
A first permanent magnet is provided at one end of the first push rod, or the entire first push rod including the one end is a permanent magnet,
A mold, wherein at least one of the upper mold and the lower mold with which the one-side end abuts is provided with a second permanent magnet that repels the first permanent magnet. A mold according to any one of claims 1 to 3,
The plate drive mechanism includes a drive plate provided below the core retaining plate for rotating or horizontally moving the core retaining plate,
The plate squeeze mechanism is
the first push rod;
a second push rod that is pushed down by the upper mold to control driving of the drive plate;
a first biasing member provided on the lower surface side of the drive plate and biasing the drive plate toward the upper die;
a second biasing member provided on the upper surface side of the drive plate and pushing up the second push rod;
The first timing at which the first push rod releases the function of pressing the core retainer plate in the axial direction of the plate drive coincides with the second timing at which the second push rod releases the drive control of the drive plate. Or a mold characterized in that it is earlier than the second timing. A mold according to claim 4,
The plate drive mechanism has a rotary drive unit that rotates the core retainer plate when the plate squeeze mechanism is released from pressing the plate drive in the axial direction,
The rotary drive portion is a ball member provided between the center axis of the drive plate and the center hole of the core retainer plate through which the center axis of the drive plate is inserted,
A ball member accommodating recess for accommodating the ball member is formed in the center hole of the core retainer plate,
A mold, wherein a driving groove in which the ball member can move is spirally formed in the central axis of the driving plate. A mold according to claim 4,
The plate drive mechanism has a rotary drive unit that rotates the core retainer plate when the plate squeeze mechanism is released from pressing the plate drive in the axial direction,
The rotation drive part is a protrusion provided on the central axis of the drive plate,
The core retainer plate has a central hole through which the central shaft of the drive plate is inserted, and a drive groove formed spirally on the inner peripheral surface thereof into which the projection is inserted. type. The mold according to claim 5 or 6,
A mold, wherein the core retainer plate is formed with an arc-shaped second push rod insertion slit through which the second push rod is inserted. A mold according to claim 5,
The plate driving mechanism has a horizontal driving section that horizontally moves the core retaining plate when the pressing of the plate driving in the axial direction by the plate squeeze mechanism is released,
The horizontal drive unit is
an inclined surface provided on one of the drive plate and the core retainer plate;
A mold, characterized in that it is a protrusion provided on the other of the drive plate and the core retainer plate and abutting against the inclined surface. 9. A molded article molded by the mold according to any one of claims 1 to 8, having an undercut portion on at least one of the inner surface and the outer surface, and having no intersecting parting line on the surface.