JP2015193224A - Method and mechanism for demolding molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a demolding method for tearing a resin product off from a forming mold, capable of reliable demolding using a simple mechanism, without damaging the molded product.SOLUTION: A columnar hole is provided in the surface of a forming mold. During forming, the columnar hole is closed with a first pin having a tip shape along the cross section of the hole. During demolding, the first pin is retracted in the inward direction of the mold, such that the molded product is communicated with a first gas supply path disposed inside the hole. The first pin is then moved forward, so that the gas present in the columnar hole is compressed to increase the pressure. The compressed gas then enters between the molded product and the forming mold, so that the molded product can be torn off.

Description

  The present invention relates to a technique for effectively peeling from a mold without damaging a resin molded product.

  In the resin molding process, a liquid resin is cured along the shape of the molding die to obtain a molded product with a desired shape, but the cured resin often adheres firmly to the molding die. A mechanism for forcibly peeling the product from the mold, that is, a demolding mechanism is required.

  Conventionally the most commonly used demolding mechanism is a configuration in which an elongated cylindrical movable pin is loaded into a mold and protrudes from the mold in the direction of the molded product when demolding Is known (for example, Patent Document 1). However, when projecting the pin, the space generated when the molded product is separated from the molding die is in a vacuum state, and the force acts in the direction of preventing demolding, and the shape of the corner of the tip of the pin is the molded product In order to prevent unnecessary protrusions from being provided, the pin has a sharp shape, which often causes problems such as scratching the molded product or bending the molded product if it is severe. Occur.

  As a countermeasure against this, rather than projecting the pins, the pins are retracted in the direction of the inside of the mold, the molded product is connected to an air supply source connected to the back of the hole, and the molded product is molded by the force of air. It has been proposed to peel it off (for example, Patent Document 2). However, the pressure of air that can be applied using a general pneumatic device is at most about 1 MPa (10 atm), and particularly when the molded product has high bending rigidity (for example, fiber reinforced resin), or In the case of using a resin having a strong adhesive force to the mold (for example, a thermosetting resin such as epoxy), it may not be possible to obtain a sufficient force to push up and peel off the molded product.

  As a method of increasing the force to push up the molded product, a method of increasing the diameter of the pin can be considered, but in this case, the contact area between the pin and the mold, that is, the area where the pin is bonded to the mold by the resin is increased, As a result, a large amount of force is required to pull the pin out of the mold, and a heavy mechanism corresponding to the force is required, which raises a new problem of increasing the cost of the demolding mechanism and thus the entire mold. It will be.

JP 2003-53803 A JP 59-140019 A

  In view of the above situation, the present invention provides a demolding method for a molded product and a demolding mechanism for a molded product that can be reliably demolded without damaging the molded product while using a simple mechanism. .

  As means for solving the above-described problems, the present invention has the following configuration. That is, a demolding method in which a resin molded product is peeled off from a molding die, wherein a columnar hole is formed on the surface of the molding die, and at the time of molding, a first pin having a tip shape along the cross-sectional shape of the columnar hole When the mold is removed, the first pin is retracted along the hole, and the first gas supply path connected to the hole is communicated to allow the gas to flow into the hole. The first pin is moved forward, the gas filled in the hole is compressed, the compressed gas is allowed to enter between the molded product and the mold, and the molded product is peeled off. This is a method for demolding products.

  Further, it is a demolding mechanism for peeling off the resin molded product from the mold, and in at least one mold constituting the mold, a columnar hole connected to the surface of the mold and a depth of the columnar hole The first gas supply path that communicates, the first pin having a tip shape that follows the cross-sectional shape of the columnar hole, and the gap between the hole and the first pin are sealed at the tip portion of the first pin. A sealing mechanism, the first pin, a first position where the tip of the first pin closes the columnar hole and forms a part of the surface shape of the mold, and the first pin Retreating from the surface of the mold, and having a pin drive mechanism capable of reciprocating between a second position where the surface of the mold communicates with the first gas supply path through the columnar hole, The first pin is retracted to the second position so that the columnar hole communicates with the first gas supply path, and the first pin is again connected to the first position. Positioned is advanced to compress the gas present in columnar hole, and wherein the peeling from the forming die a molded type product by gas having the compressed, a demolding mechanism of the molded article.

  According to the method for demolding a molded product of the present invention, there is provided a demolding method for a molded product and a demolding mechanism for the molded product that can be reliably demolded without damaging the molded product while using a simple mechanism. be able to. Specifically, since the molded product is peeled off from the mold by the pressure of air, not only does it cause unnecessary damage to the molded product, but also a high level of air is efficiently generated by a simple mechanism installed in the mold. Since it can be compressed to a pressure, even a molded product that is particularly difficult to peel off can be surely removed by the air reliably entering the gap between the molded product and the mold.

It is a schematic sectional drawing which shows the steady state of the mold release mechanism which concerns on the 1st Embodiment of this invention. It is a schematic sectional drawing which shows the state of the "first step of demolding" of the demolding mechanism which concerns on the 1st Embodiment of this invention. It is a schematic sectional drawing which shows the state of "the 2nd step of demolding" of the demolding mechanism which concerns on the 1st Embodiment of this invention. It is the figure which summarized the demolding step of this invention. It is a schematic sectional drawing which shows the steady state of the mold release mechanism which concerns on the 2nd Embodiment of this invention. It is a schematic sectional drawing which shows the steady state of the mold release mechanism which concerns on the 3rd Embodiment of this invention. It is a schematic sectional drawing which shows the steady state of other embodiment of the mold release mechanism which concerns on the 3rd Embodiment of this invention.

  Next, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a steady state in which the demolding mechanism does not particularly work in this embodiment. In this description, a lower mold 2 (hereinafter simply referred to as an upper mold 1) opposite to an upper mold 1 (hereinafter simply referred to as an upper mold 1). The liquid resin is supplied to the space between the lower mold 2 and the liquid resin is cured, and the molded product 3 is completed. The lower mold 2 is provided with a cylindrical hole 4, and first gas supply paths 5 a and 5 b are connected to the back of the hole 4. In this embodiment, the first gas supply path 5a is connected to the hole 4 and is a region in which the diameter of the cylinder is slightly larger than the hole 4, and the first gas supply path 5b is the first gas supply path. It is an elongate hole connected to 5a, extends to the side opposite to the molded product side of the lower mold 2, and is finally connected to the air supply source 6 outside the lower mold 2.

  A first pin 7 is inserted into the hole 4, and a tip portion of the first pin 7 forms a part of the product surface shape of the lower mold 2. The outer diameter of the tip portion of the first pin 7 is slightly smaller than the inner diameter size of the hole 4. Specifically, when the inner diameter of the hole 4 is φ8 mm, the outer diameter of the tip portion of the first pin 7 is preferably made smaller by about 5 to 30 μm than the inner diameter of the hole 4. Further, O-rings 8 made of a rubber-like elastic body are respectively mounted in the grooves 9 as a sealing mechanism on the outer periphery so that the holes 4 can be closed and sealed. Although the thickness and number of O-rings 8 depend on the size of the first pin 7, it is preferable to provide a cross-sectional diameter of 0.5 to 0.8 mm and the number of 2 to 4. Moreover, the groove | channel 9 can provide the width | variety per 0.6-1.2mm and the depth in the range of 0.4-0.7mm according to the thickness of the O-ring 8. FIG.

  A pin driving mechanism 10 is connected to the rear end side of the first pin 7 via a connecting member 11. In the present invention, as shown in FIG. 1, the position where the first pin 7 blocks the hole 4 is referred to as the “first position” of the first pin 7.

  FIG. 2 shows the first step of the demolding operation, that is, the “first step of demolding” following the state of FIG. In FIG. 2, the upper mold 1 is lifted upward by a mold opening / closing mechanism (not shown), and a gap 15 is formed between the upper mold 1 and the molded article 3 sticking to the lower mold 2. Here, the first pin 7 is retracted from the surface of the lower mold 2 by the pin driving mechanism 10, and the surface of the molding die is connected to the first gas supply paths 5 a and 5 b through the holes 4. The position where the first pin 7 is retracted is referred to as the “second position” of the first pin 7.

  As a result, air is supplied to the hole 4 from the air supply source 6, and the hole 4 is not in a vacuum state but is in a pressurized state higher than the atmospheric pressure or the atmospheric pressure according to the pressure of the air supply source 6. When the pressure setting of the air supply source 6 is in a pressurized state, the molded product 3 can be pushed up in a direction away from the lower mold 2, and if the molded product 3 can be removed from the lower mold 2 at this time, After the first step of demolding, it becomes unnecessary, but in the case where the molded article 3 has a particularly high rigidity (for example, fiber reinforced resin) or a resin having a strong adhesive force to the mold (for example, thermosetting such as epoxy) In the case of using (resin), the molded product 3 cannot be removed even if the pressure applied to the air supply source 6 is the maximum pneumatic pressure (for example, 1 MPa (10 atm)) supplied from a general pneumatic device. There are many cases.

Therefore, next, the process proceeds to a “second step of demolding” as shown in FIG. 3, where the first pin 7 is closed by the operation of the pin driving mechanism 10 to close the hole 4. Move forward again towards. As long as the sealing mechanism between the first pin 7 and the hole 4 is sufficiently functioning, the air inside the hole 4 is greatly compressed during the advancement process of the first pin 7, and the pin driving mechanism 10. The pressure can be increased up to a point until it balances with the force that advances the first pin 7. For example, when the pin drive mechanism 10 is composed of a general air cylinder mechanism, and the bore diameter of the cylinder is φ25 mm and an air pressure of 1 MPa (10 atm) is applied thereto, the inside of the hole 4 having an inner diameter of φ8 mm The maximum pressure generated in this is “1 MPa (10 atm) × (25 mm / 8 mm) ² ≈10 MPa (100 atm)”, which is an extremely small and simple mechanism that is not easily used in general pneumatic equipment. A high air pressure is generated, and the force can be used as a force for peeling the molded product 3 from the lower mold 2. Actually, before reaching the high pressure as in the above calculation example, the air breaks the adhesion between the molded product 3 and the lower mold 2 and enters between them, and the molded product 3 is peeled off from the lower mold 2. If the area where this adhesion is broken is sufficient at this stage as the required demolding function, the demolding operation ends here.

  However, if the mold cannot be sufficiently removed even after the second step of demolding, the process can be shifted to the “third step of demolding”. In the third step of demolding, the hole 4 is supplied with air through the first gas supply paths 5a and 5b when the first pin 7 is moved back to the “second position” again, as in the state of FIG. Reconnected to the source 6. If the pressure of the air supply source 6 is set to a pressurized state higher than atmospheric pressure, for example, 0.5 to 1 MPa (5 to 10 atmospheres), which is a level supplied from a general pneumatic device, the molded product 3 Is pushed up by air pressure. At this time, the action of the air pushing up the molded product 3 is greatly different from the above-described “first step of demolding”. That is, by performing the “second step of demolding”, the molded product 3 has already been peeled off from the lower mold 2 to some extent, and air can easily enter this gap. Since the air pressure acts at an equal pressure over a much larger area than the “first step of demolding”, the total force that pushes up the molded product 3 becomes much larger, and finally demolding Complete. After this, the first pin 7 is finally returned to the “first position” again as “the fourth step of demolding”, and the resin molding can be started again, that is, the steady state as the demolding mechanism. It becomes.

  The above demolding steps are summarized as shown in FIG. The greatest point of the present invention is that in the “second step of demolding”, the air in the hole 4 is compressed by the first pin 7, and the force by which the compressed air pushes up the molded product 3 is driven by a pin. The mechanism 10 is equivalent to the force that advances the first pin 7, which is implemented through the air layer instead of projecting the hard demolding pin from the mold surface as in the prior art. It can also be said. Since the molded product 3 is not a hard pin but is pressed by air, which is a fluid, the risk of scratching the molded product 3 during the demolding process can be avoided, and not the air provided from the simple air supply source 6 but the pin. Since a high thrust by a mechanical mechanism such as the drive mechanism 10 can be directly applied to the molded product 3 through air, a high demolding capability is realized. Furthermore, the “third step of demolding” allows the action of air pressure over a large area and ensures demolding over the entire molded article 3. From the two characteristics of not scratching and high demolding ability, the diameter of the first pin 7 can be set smaller than that of the conventional method, and as a result, the entire demolding mechanism can be designed to be small. The merits are also born. If the demolding mechanism is small, the degree of freedom of the place where the demolding mechanism is attached is increased, and the degree of freedom of design of the molded product is expanded.

  The first embodiment of the present invention has been described above, but the present invention is not limited to this. For example, FIG. 5 discloses a second embodiment of the present invention. FIG. 5 particularly shows a steady state of the demolding mechanism, that is, a state in which the first pin 7 is in the first position in the first embodiment, and the pin driving mechanism 10 ′ has the first piston 12 by air pressure. The first piston 7 'is integrally formed with the first piston 12, and the compressed air for reciprocating the first piston 12 is switched from the air supply source 6'. The air is supplied to the air chambers 14a and 14b via the valve 13 via the first gas supply paths 5c and 5d, respectively. A particularly important point is that the air chamber 14a is connected to the hole 4 '. By adopting this configuration, the air supply source is obtained by the action of the switching valve 13 in the "first step of demolding". The air supplied from 6 'to the air chamber 14a through the first gas supply path 5c causes the first piston 12 to retreat by the pressure, and the tip of the first pin 7' comes out of the hole 4 '. At the same time, it plays the role of supplying air to the hole 4 '. The subsequent demolding steps are the same as those shown in the first embodiment. By adopting such a configuration, the entire demolding mechanism can be designed in a compact form.

  FIG. 6 discloses a third embodiment of the present invention. FIG. 6 particularly shows a steady state of the demolding mechanism, that is, a state in which the first pin 7 ″ is in the first position in the first embodiment, and is formed integrally with the first pin 7 ″. The first piston 12 'has a pressure amplifying chamber 18, and the pressure amplifying chamber 18 stores an air chamber 14c for retracting the first piston 12' and a first gas supply. It communicates with the path 5e. The second pin 16 can be inserted into the pressure amplification chamber 18. Further, the second pin 16 is formed integrally with the second piston 17, and the air supplied from the air supply source 6 ″ through the second gas supply path 5f and the repulsion of the spring 19 opposed thereto. A particularly important point is that air is introduced from the second gas supply path 5f and the second pin 16 is inserted into the pressure amplifying chamber 18 so that the first gas supply path 5e can be moved. The supplied air is greatly compressed to increase the pressure in the pressure amplifying chamber 18 and the air chamber 14c, and this compressed air creates a large force for retracting the first piston 12 ', and the first pin 7 " Even if the inner wall of the hole 4 ″ or the molded product 3 ″ is strongly fixed, the first pin 7 ″ is peeled off from the fixing without using a hydraulic pressure or a large air cylinder, so that it can be operated. Can However, since the state in which the second pin 16 is inserted into the pressure amplification chamber 18 is inconvenient for completely pulling out the first pin 7 ″ from the hole 4 ″, the second step is the second step. The gas supply path 5f is evacuated and the second pin 16 is retracted to the steady state as shown in FIG. 6. The first pin 7 ″ is not fixed and the operation is possible. As a result, the demolding operation can be performed in the same procedure as the method disclosed in the second embodiment. In the above-described embodiment, it is preferable that the volume of the air chamber 14c be as small as possible because the effect of pressure amplification is large. To that end, the surface of the first piston 12 'facing the air chamber 14c is opposed to the surface. It is preferable that the distance from the inner surface on the opposite side constituting the air chamber 14c is made to be extremely small with the first pin 7 "fully advanced, but they are in complete contact with each other. And the air chamber 14c cannot be formed, and the force pushing the first piston 12 'cannot be generated, so that it is necessary to leave a slight gap.

  FIG. 7 discloses another embodiment of the third embodiment of the present invention. As shown in FIG. 7, the pressure amplification chamber 18, the air chamber 14 c, the second pin 16, the second piston 17, and the first piston 17 are connected to the inside of the pin driving mechanism 10 connected to the first pin 7 via the coupling member 11. Even if the gas supply paths 5d and 5e are provided, the same effect can be exhibited.

  In the above-described embodiment, the air supplied to the air supply sources 6, 6 ′, 6 ″ has been described as the atmosphere in the natural environment, but the present invention is not limited to air, and nitrogen, oxygen, carbon dioxide, argon It is possible to select from any gas such as methane, etc. However, it is preferable to use ordinary air in terms of economy.

  Further, in the above-described embodiment, the demolding mechanism has been disclosed that is always incorporated in the lower molds 2, 2 ′, 2 ″. However, these demolding mechanisms are configured as a single unit and molded. It can be made detachable from the mold, so that when the mold removal mechanism causes trouble, the unit can be replaced by a unit, which is convenient in terms of maintenance.

  The shape of the holes 4, 4 ′, 4 ″ may be a round hole as in the above-described embodiment as long as it is a columnar shape having an equal cross-sectional shape in the longitudinal direction, other squares, hexagonal polygons, rectangles Or a cross-sectional shape such as an ellipse, etc. In practice, a round hole that is easy to process is desirable, but as shown in the above embodiment, the positions of the holes 4, 4 ′, 4 ″ are the positions of the mold. If the hole 4, 4 ', 4 "is not formed in the normal direction even though it is not present in the flat part of the product surface or is present in the flat part, It is also meaningful to make the holes 4, 4 ′, 4 ″ not round but other non-circular, such as an ellipse, as a function of stopping around the pin to enter.

1, 1 ′, 1 ″: Upper mold 2, 2 ′, 2 ″: Lower mold 3, 3 ′, 3 ″: Molded product 4, 4 ′, 4 ″: Holes 5a, 5b, 5c, 5d, 5e : First gas supply path 5f: second gas supply path 6, 6 ', 6 ": air supply source 7, 7', 7": first pin 8: O-ring 9: groove 10, 10 ' 10 ": Pin drive mechanism 11: Connecting member 12, 12 ': First piston 13: Switching valves 14a, 14b, 14c: Air chamber 15: Gap 16: Second pin 17: Second piston 18: Pressure amplification Chamber 19: Spring

Claims (6)

A demolding method in which a resin molded product is peeled off from a mold, and a columnar hole is formed on the surface of the mold and is closed by a first pin having a tip shape along the cross-sectional shape of the columnar hole at the time of molding. When removing the mold, the first pin is retracted along the hole, and the first gas supply path connected to the hole is communicated to allow the gas to flow into the hole. The first pin is advanced, the gas filled in the hole is compressed, the compressed gas is introduced between the molded product and the mold, and the molded product is peeled off. Demolding method. After the first pin has been advanced, the first pin is again retracted along the hole, the hole and the first gas supply path are connected again, and the molded product is pulled by the gas pressure. The method for demolding a molded product according to claim 1, wherein the molded product is peeled off. A pressure amplifying chamber provided in a part of a hole penetrating the inside of the first piston formed integrally with the first pin and forming a part of the first gas supply path has a second By inserting a pin, gas flows into an air chamber communicating with the pressure amplification chamber, and by compressing air, the pressure in the pressure amplification chamber and the air chamber is increased, and the first pin is moved backward, 3. The molded product removal according to claim 1, wherein the first pin is advanced, the gas filled in the hole is compressed, and the molded product is peeled off by the compressed gas. 4. Mold method. A demolding mechanism for peeling a resin molded product from a mold, and communicating with a columnar hole connected to the surface of the mold and at the back of the columnar hole in at least one mold constituting the mold A first gas supply path, a first pin having a tip shape that follows the cross-sectional shape of the columnar hole, and a seal mechanism that seals a gap between the hole and the first pin at the tip portion of the first pin The first pin, a first position where the tip of the first pin closes the columnar hole and forms a part of the surface shape of the mold, and the first pin is the mold A pin drive mechanism that retreats from the surface of the mold and is capable of reciprocating between a second position where the mold surface communicates with the first gas supply path via a columnar hole, The first pin is retracted to the second position so that the columnar hole communicates with the first gas supply path, and the first pin is again connected to the first position. Compressing the gas present in the allowed columnar hole in advanced location, wherein the peel the molded type products from forming die by a gas obtained by the compression, molded articles demolding mechanism. The first pin driving mechanism comprises a mechanism for reciprocating the first piston in the cylinder by gas pressure, and the first pin is integrally connected to the first piston, and the first piston The mold release mechanism according to claim 4, wherein the gas pressure for retreating is supplied from the first gas supply path. An air chamber provided in a peripheral portion of the first pin, the first piston formed integrally with the first pin, a second pin, and formed integrally with the second pin. A pressure amplifying chamber for amplifying an air pressure for retreating the first piston composed of the first pin by inserting a second piston and a second pin into the inside, the pressure amplifying chamber being 6. The method according to claim 4, wherein the pressure amplification chamber is provided in a part of a hole penetrating the inside of the first piston, and forms a part of the first gas supply path. Demolding mechanism for molded products.

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