JP5222990B2 - Injection molding apparatus and injection molding method - Google Patents

Description

  The present invention relates to an injection molding apparatus and an injection molding method in which an intermediate mold is disposed between a first mold and a second mold.

  Conventionally, in order to simultaneously mold two or more resin products, an injection molding apparatus including a mold called a stack mold (tandem mold) has been widely used.

  This type of injection molding apparatus generally includes an intermediate mold disposed between a fixed mold and a movable mold, and the mold is in a closed state between the fixed mold and the intermediate mold. In addition, a first cavity is formed, and a second cavity is formed between the movable mold and the intermediate mold.

  As such an injection molding apparatus, the molten resin guided from the first passage formed in the fixed mold is circulated through the second passage formed in the intermediate mold to be fed into the first cavity and the second cavity. A technical idea of molding a desired resin product by supplying the resin product has been proposed (for example, see Patent Document 1).

JP 2004-122589 A

  However, in the prior art described in Patent Document 1 described above, since the second passage (manifold) through which the high-pressure molten resin (molten material) flows is formed in the intermediate mold, the intermediate mold is large and Becomes heavy. If the intermediate mold is heavy in this way, a mechanism (for example, a support base) for supporting the intermediate mold is required in addition to the diver and the guide pin, and there is a problem that the injection molding apparatus becomes large. .

  The present invention has been made in view of such problems, and can reliably supply the molten material to the first cavity and the second cavity, and reduce the size and weight of the intermediate mold. Therefore, an object of the present invention is to provide an injection molding apparatus and an injection molding method that can be miniaturized.

[1] An injection molding apparatus according to the present invention is arranged between a first mold and a second mold, which are opposed to each other so as to be close to and away from each other, and between the first mold and the second mold. A first cavity formed between the first mold and the intermediate mold in a closed state, and between the second mold and the intermediate mold. In the injection molding apparatus capable of filling the second cavity formed with a molten material, the intermediate mold includes a surface facing the first mold and a surface facing the second mold. A through-hole that is open is formed, a first nozzle part that is provided in the first mold and supplies the molten material to the first cavity, and the first nozzle that is insertable into the through-hole. A second nozzle portion provided in the mold and for supplying the molten material to the second cavity; A seal member that is slidable on the wall surface, and the seal member faces the side on which the first mold is located and contacts the second nozzle portion, and the second A pressure receiving portion that faces the side where the mold is located and contacts the molten material led out from the second nozzle portion is formed.

  According to the injection molding apparatus of the present invention, the through hole into which the second nozzle portion can be inserted is formed in the intermediate mold. Therefore, the 1st nozzle part which supplies molten material to a 1st cavity, and the 2nd nozzle part which supplies molten material to a 2nd cavity can be provided in a 1st metal mold | die. Thereby, since it is not necessary to form the molten material flow path having a manifold function in the intermediate mold, the intermediate mold can be reduced in size (thinned) and reduced in weight. Therefore, the injection molding apparatus can be reduced in size.

  In addition, since the pressure receiving portion is formed on the seal member slidable on the wall surface constituting the through hole, when the molten material is led out from the second nozzle portion, the pressure receiving portion is made of the first metal by the molten material. It will be pressed to the side where the mold is located. Accordingly, the contact portion of the seal member can be pressed against the second nozzle portion, so that the molten material derived from the second nozzle portion has a gap between the second nozzle portion and the wall surface forming the through hole. It is possible to prevent leakage. Therefore, the molten material can be reliably supplied to the first cavity and the second cavity.

[2] The injection molding apparatus may further include a pressing unit that presses the seal member toward the side where the first mold is located.

  According to such a configuration, since the sealing member can be pressed to the side where the first mold is located by the pressing means, the contact of the sealing member in a state before the molten material is led out from the second nozzle portion. The portion can be pressed against the second nozzle portion. Thereby, when the derivation of the molten material from the second nozzle portion is started (before the pressure receiving portion is pressed by the molten material), the molten material is formed between the second nozzle portion and the wall surface forming the through hole. It is possible to prevent leakage into the gap between them.

[3] In the injection molding apparatus, a hole is formed in a portion of the second mold facing the seal member, and the hole is displaceable along a pressing direction of the pressing means. The pressing member may further include a receiving member disposed in the portion, and the pressing unit may press the seal member through the receiving member in a state of being provided in the hole.

  According to such a configuration, since the pressing means is disposed in the hole of the second mold, the intermediate mold can be further reduced in size and compared with the case where the pressing means is provided in the intermediate mold. The weight can be reduced. In addition, since the pressing means presses the sealing member via the receiving member, the pressing force of the pressing means acts on the sealing member reliably even when the pressing means is disposed in the hole. Can be made.

[4] In the above injection molding apparatus, the seal member is formed with a hole through which the second nozzle portion can be inserted or through which the molten material led out from the second nozzle portion flows. The contact portion is formed on a first wall surface extending in a radial direction from an end portion of the hole where the first mold is located, and the pressure receiving portion is located in the hole where the second mold is located. You may form in the 2nd wall surface extended in radial direction from the edge part on the side to do.

According to such a configuration, since the contact portion is formed on the first wall surface and the pressure receiving portion is formed on the second wall surface, the pressing force received by the pressure receiving portion from the molten material is passed through the contact portion. Can be efficiently transmitted to the second nozzle portion.

[5] In the above injection molding apparatus, the receiving member may be capable of contacting the second wall surface .

According to this structure, since the receiving member is contactable with the second wall surface, the pressing force of the pressing means can be applied to the second wall. Thereby, the pressing force of the pressing means can be efficiently transmitted to the contact portion of the seal member. Therefore, the contact portion of the seal member can be reliably pressed against the second nozzle portion before the molten material is led out from the second nozzle portion.

[6] In the above injection molding apparatus, the seal member is used, the number and the seal member body said hole is formed, and a flange portion extending radially outward of said second nozzle portion from the sealing member main body, the And the said receiving member may be able to contact the said collar part.

According to such a structure, since a receiving member can contact the collar part of a sealing member, the pressing force of a press means can be made to act on the collar part. Thus, when the molten material from the second nozzle portion is derived, since the second wall so that only the pressing force from the molten material is applied, said second wall is pressed excessively There is nothing. Therefore, it is possible to suitably suppress the said second wall is damaged.

[7] The injection molding method according to the present invention is arranged between the first mold and the second mold, which are opposed to each other so as to be able to approach and separate, and between the first mold and the second mold. And an intermediate mold in which a through-hole opened in a surface facing the first mold and a surface facing the second mold is formed, and a first nozzle portion provided in the first mold And a second nozzle part. An injection molding method using an injection molding apparatus comprising: the second nozzle part in the through hole by bringing the first mold and the second mold close to each other. A mold closing step of forming a first cavity between the first mold and the intermediate mold and forming a second cavity between the second mold and the intermediate mold; A first supply step of supplying a molten material to the first cavity at the first nozzle portion; and the second nozzle portion at the first supply step. A second supply step for supplying the molten material to the cavity, and in the second supply step, the melt led out from the second nozzle portion to a seal member slidable on the wall surface constituting the through hole. By contacting the material, the seal member is pressed against the side where the first mold is located and pressed against the second nozzle portion.

  According to the injection molding method of the present invention, in the mold closing process, the second nozzle portion is inserted into the through hole of the intermediate mold to form the first cavity and the second cavity, and in the first supply process, the first cavity is formed. A molten material is supplied to the first cavity by a first nozzle portion provided in one mold, and the second cavity is provided in the second cavity by a second nozzle portion provided in the first mold in a second supply step. Molten material is supplied. Thereby, since it is not necessary to form the molten material flow path having a manifold function in the intermediate mold, the intermediate mold can be reduced in size (thinned) and reduced in weight. Therefore, the injection molding apparatus can be reduced in size.

  Further, in the second supply step, the molten material led out from the second nozzle portion is brought into contact with a seal member slidable on the wall surface constituting the through hole, whereby the seal member is placed on the side where the first mold is located. Since the molten material led out from the second nozzle portion leaks into the gap between the second nozzle portion and the wall surface constituting the through hole. Can be prevented. Therefore, the molten material can be reliably supplied to the first cavity and the second cavity.

[8] In the injection molding method, in the mold closing step, the seal member may be pressed against the second nozzle portion by pressing the seal member toward the side where the first mold is located.

  According to such a method, since the sealing member is pressed against the second nozzle portion by the pressing means in the mold closing step, the sealing member is pressed against the second nozzle portion by the molten material at the start of the second supply step. Before being melted), the molten material can be prevented from leaking into the gap between the second nozzle part and the wall surface forming the through hole.

  As described above, according to the present invention, the intermediate mold is disposed between the first mold and the second mold, and the first nozzle part and the second nozzle part are provided on the first mold. Thus, a through-hole through which the second nozzle portion can be inserted is formed in the intermediate mold. Therefore, in the mold closed state, the molten material can be supplied to the first cavity by the first nozzle portion, and the molten material can be supplied to the second cavity by the second nozzle portion. Thereby, since an intermediate metal mold | die can be reduced in size and weight, size reduction of an injection molding apparatus can be achieved.

  In addition, since the sealing member slidable on the wall surface constituting the through-hole is pressed against the second nozzle portion by the molten material derived from the second nozzle portion, the molten material is surely attached to the first cavity and the second cavity. Can be supplied to.

It is a partial cross section explanatory view showing the state where molten resin was filled into the 1st cavity and the 2nd cavity formed in the injection molding device concerning a 1st embodiment of the present invention. FIG. 2 is a partially omitted enlarged longitudinal sectional view showing a mold opening state of the injection molding apparatus of FIG. 1. FIG. 3 is a partially omitted perspective view of the movable mold, the pressing mechanism, and the movable platen shown in FIG. 2. FIG. 3 is an explanatory plan view of the movable mold shown in FIG. 2. It is a plane explanatory view for explaining the 1st pressure receiving part and the 2nd pressure receiving part which are formed in the seal member shown in FIG. It is a flowchart for demonstrating the injection molding method which concerns on 1st Embodiment of this invention. It is a perspective view of the press mechanism in the state before a receiving member and a sealing member contact. FIG. 8 is a perspective view of a state where the mold closing operation is completed in FIG. 7. FIG. 2 is a partially omitted enlarged longitudinal sectional view showing a mold closed state of the injection molding apparatus of FIG. 1. FIG. 10 is a cross-sectional view taken along line XX in FIG. 9. It is a graph which shows the relationship between an injection molding process and sealing force. FIG. 6 is a partially omitted enlarged cross-sectional view showing a mold opening state of an injection molding apparatus according to a second embodiment of the present invention. It is a plane explanatory view for explaining the 1st pressure receiving part and the 2nd pressure receiving part which are formed in the seal member shown in FIG. FIG. 13 is a partially omitted enlarged cross-sectional view showing a closed state of the injection molding apparatus of FIG. 12.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an injection molding method according to the present invention will be described in detail with reference to the accompanying drawings by exemplifying preferred embodiments in relation to an injection molding apparatus that performs the injection molding method.

(First embodiment)
First, an injection molding apparatus 10A according to the first embodiment will be described with reference to FIGS. The injection molding apparatus 10A according to the present embodiment is an apparatus including a so-called stack mold. That is, the injection molding apparatus 10A includes an intermediate mold 20 disposed between the fixed mold 16 and the movable mold 22 as shown in FIG. And filling the molten resin (melting material) into the first cavity 204a formed between the intermediate mold 20 and the second cavity 204b formed between the movable mold 22 and the intermediate mold 20. Thus, two or more resin products are formed simultaneously.

  Specifically, as shown in FIGS. 1 and 2, the injection molding apparatus 10 </ b> A is fixed to the fixed platen 12 and each corner of the fixed platen 12 and extends in the thickness direction of the fixed platen 12. A plurality of (for example, four) divers 14, a fixed mold (first mold) 16 fixed to the fixed platen 12, an injection mechanism 18 provided in the fixed mold 16, and the fixed mold An intermediate mold 20 supported so as to be movable with respect to the plurality of divers 14 so as to face 16, and a movable mold disposed on the opposite side of the fixed mold 16 of the intermediate mold 20 ( (Second mold) 22, a movable plate 24 fixed to the movable mold 22 and supported to be movable with respect to the plurality of divers 14, a seal mechanism 26, and a control unit 28.

  One surface of the fixed mold 16 is fixed to the other surface of the fixed platen 12. A first runner 200a and a first gate 202a as a molten resin flow path, and a molding space for a resin product, between the other surface of the fixed mold 16 and one surface of the intermediate mold 20 in the mold closed state. As a first cavity 204a (see FIGS. 1 and 9).

  The first runner 200a and the first gate 202a are flow paths for guiding the molten resin guided from the injection mechanism 18 (first nozzle part 36 described later) to the first cavity 204a.

  The injection mechanism 18 includes an injection unit 30 (see FIG. 1) that injects molten resin at a predetermined pressure, and an introduction unit that is disposed so as to penetrate the fixed platen 12 and that guides the molten resin injected from the injection unit 30. 32, a manifold part 34 connected to the introduction part 32 in a state of being provided inside the fixed mold 16, and a first nozzle part 36 and a second nozzle part 38 connected to the manifold part 34. .

  The manifold part 34 distributes the molten resin guided from the introduction part 32 to the first nozzle part 36 and the second nozzle part 38.

  The first nozzle portion 36 is for supplying the molten resin guided from the manifold portion 34 to the first cavity 204a, and includes a nozzle body 40 extending along the thickness direction of the fixed mold 16, and the nozzle body. The nozzle heater 42 is mounted on the outer peripheral surface of the nozzle 40 and the head portion 44 is provided on the tip surface of the nozzle body 40.

  The nozzle heater 42 is for maintaining the temperature of the molten resin flowing through the nozzle body 40 substantially constant by heating the nozzle body 40. The front end surface of the head portion 44 is exposed on the other surface of the fixed mold 16. In addition, the resin flow path formed inside the head portion 44 communicates with the first runner 200a in a mold-closed state.

  The second nozzle portion 38 is for supplying the molten resin guided from the manifold portion 34 to a second cavity 204b described later, and is a long nozzle body 46 extending along the thickness direction of the fixed mold 16. And a plurality of (for example, three) nozzle heaters (heating means) 48 mounted around the outer peripheral surface of the nozzle body 46 and a head portion 50 provided on the front end surface of the nozzle body 46. The tip end side of the nozzle body 46 protrudes from the other surface of the fixed mold 16.

  The intermediate mold 20 is connected to the movable mold 22 by a tensile link (not shown). Thus, when the mold is opened, the intermediate mold 20 is separated from both the fixed mold 16 and the movable mold 22 simply by moving the movable platen 24 to the side opposite to the side where the fixed mold 16 is located. Can be made.

  A through hole 52 extending along the thickness direction is formed in the intermediate mold 20. The through-hole 52 includes a large-diameter hole 54 opened on one surface of the intermediate mold 20 (a surface facing the fixed mold 16 in the intermediate mold 20), and a medium-diameter hole 56 communicating with the large-diameter hole 54. And a small-diameter hole 58 that communicates with the medium-diameter hole 56 and opens in the other surface of the intermediate mold 20 (the surface facing the movable mold 22 in the intermediate mold 20). The through hole 52 is formed so that the distal end side of the second nozzle portion 38 can be inserted in a mold-closed state (see FIGS. 1 and 9).

  The other surface of the intermediate mold 20 is between the one surface of the movable mold 22 and the second runner 200b and the second gate 202b as a molten resin flow path, and a molding space for the resin product. As a second cavity 204b (see FIGS. 1 and 9). The second runner 200b and the second gate 202b are flow paths for guiding the molten resin guided from the injection mechanism 18 (second nozzle portion 38) to the second cavity 204b.

  As shown in FIGS. 2 to 4, a portion of one surface of the movable mold 22 facing the small-diameter hole 58 of the intermediate mold 20 has a runner groove 206 constituting a part of the second runner 200 b, A gate groove 208 that communicates with the runner groove 206 and forms a part of the second gate 202b is formed. The runner groove 206 includes a long groove 210 extending in one direction and a pair of recesses 212 formed on both sides of the long groove 210 at a position substantially in the center in the longitudinal direction of the long groove 210.

A gate groove 208 communicates with both ends of the long groove 210 in the longitudinal direction. The groove depth of the long groove 210 is formed deeper than the groove depth of the gate groove 208. Each recess 212 extends along the long groove 210 and communicates with the long groove 210. The depth of each recess 212 is shallower than the depth of the long groove 210 (see FIG. 2). The gate groove 208 extends along the extending direction of the long groove 210.

  In addition, the movable mold 22 is provided with an arrangement hole 60 penetrating in the thickness direction. The arrangement hole 60 includes a pair of communication holes 62 that open to the side of the pair of recesses 212 constituting the runner groove 206 on one surface of the movable mold 22 (see FIG. 4), and the other of the movable mold 22. And a cylindrical hole 64 that opens to the surface and communicates with the pair of communication holes 62. Each communication hole 62 communicates with a pair of recesses 212.

  On one surface of the movable platen 24, a protruding portion 66 that fits into an opening of a cylindrical hole 64 formed on the other surface of the movable mold 22 is formed.

  The sealing mechanism 26 prevents the molten resin led out from the second nozzle portion 38 from leaking into the gap V (see FIG. 9) between the wall surface constituting the through hole 52 and the second nozzle portion 38. belongs to.

  The seal mechanism 26 includes a seal member 68 disposed in the through hole 52, the above-described arrangement hole 60, and the arrangement member 60 disposed on the arrangement hole 60 to press the seal member 68 toward the side where the fixed mold 16 is located. And a pressing mechanism 70.

  The seal member 68 includes a seal member main body 72 formed in a bottomed cylindrical shape, and a flange portion 74 protruding outward from one end of the seal member main body 72 (outside in the radial direction of the second nozzle portion 38).

  The seal member main body 72 is formed with a large-diameter hole 76 that opens to one end face thereof, and a small-diameter hole 78 that communicates with the hole 76 and opens to the other end face of the seal member main body 72. In addition, a surface (contact portion) 80 capable of being in liquid-tight contact with the head portion 50 of the second nozzle portion 38 is formed at a boundary portion between the hole 76 and the hole 78.

  The hole 78 of the seal member main body 72 is located coaxially with the axis of the seal member main body 72. The hole 78 may be a tapered hole whose diameter increases toward the other surface. In this case, the hole 78 can be used as a cold sprue.

  A predetermined clearance CL is formed between the seal member main body 72 and the wall surface forming the small diameter hole 58 in a mold open state (a state before the nozzle main body 46 of the second nozzle portion 38 is heated by the nozzle heater 48). Has been. The clearance CL is such that when the seal member 68 is thermally expanded by receiving heat from the second nozzle portion 38 or the like, the seal member 68 comes into contact with (is slidable to) the wall surface forming the small diameter hole 58. Set to dimensions.

  Thereby, it is possible to suitably suppress the thermally expanded seal member 68 from being squeezed to the wall surface constituting the small diameter hole 58 and to prevent the molten resin from leaking between the wall surface and the seal member 68. be able to. In FIG. 2, the dimension of the clearance CL is exaggerated for easy understanding.

  Such a seal member 68 is preferably made of a material having a good sliding property with respect to the wall surface constituting the small-diameter hole 58 and a small thermal expansion coefficient. This is because the clearance CL can be easily set. In the present embodiment, the seal member 68 is made of stainless steel.

  As understood from FIG. 2, the seal member 68 slightly protrudes from the through hole 52 toward the movable mold 22 in the mold open state.

  Displacement of the seal member 68 on the fixed mold 16 side is limited by a stopper portion 82 fixed to a step portion formed at the boundary portion between the large diameter hole 54 and the medium diameter hole 56 of the intermediate mold 20. Thereby, it can suppress that the sealing member 68 is pressed against the 2nd nozzle part 38 excessively. Therefore, it is possible to prevent the second nozzle portion 38 from being damaged.

  The pressing mechanism 70 constituting the sealing mechanism 26 includes a receiving member 84 that can contact the sealing member 68, a column 86 interposed between a bottom portion of the runner groove 206 and the protruding portion 66 of the movable platen 24, and the receiving member. A plurality (for example, four) of disc springs (pressing means) 88 and an adjustment ring 90 are provided between the member 84 and the protrusion 66.

  The receiving member 84 is formed in a substantially cylindrical shape, and has an outer diameter that is substantially the same as the outer diameter of the seal member main body 72 (see FIG. 2). In addition, the receiving member 84 is disposed in the arrangement hole 60 so as to be slidable with respect to the wall surface constituting the arrangement hole 60.

  On one end surface of the receiving member 84, a disposition groove 92 is formed in which a wall portion constituting the runner groove 206 is disposed. That is, the receiving member 84 includes a pair of convex portions 94 constituting the groove side portion of the arrangement groove 92, and a connecting portion 96 constituting the groove bottom portion of the arrangement groove 92 by connecting the convex portions 94. .

  The receiving member 84 is movable in a state in which a wall portion constituting the runner groove 206 is disposed in the disposition groove 92 (a state where the wall portion constituting the runner groove 206 and the groove bottom surface of the disposition groove 92 are in contact). It protrudes to the intermediate mold 20 side from the other surface of the mold 22 (see FIGS. 2 and 7).

  The connecting portion 96 is formed with a hole 98 through which the column 86 can be inserted. Therefore, the receiving member 84 can be relatively displaced with respect to the support column 86 along the extending direction of the support column 86.

  The plurality of disc springs 88 press (bias) the receiving member 84 toward the side where the intermediate mold 20 is located. The adjustment ring 90 is for adjusting the amount of displacement of the receiving member 84.

  In the sealing mechanism 26 configured as described above, as shown in FIG. 5, the other surface of the sealing member main body 72 is in contact with the portion where the end surfaces of the pair of convex portions 94 constituting the receiving member 84 are in contact (broken line cross). Part indicated by hatching: hereinafter referred to as first pressure receiving part 100) and part constituting part of second runner 200b (part indicated by solid cross hatching: hereinafter referred to as second pressure receiving part 102) , Will be formed.

  That is, the first pressure receiving part 100 is pressed to the fixed mold 16 side by the receiving member 84 pressed by the disc spring 88, and the second pressure receiving part 102 is pressed to the fixed mold 16 side by the molten resin of the second runner 200b. Pressed. In the following description, the pressing force acting on the first pressure receiving portion 100 is referred to as a first sealing force, and the pressing force acting on the second pressure receiving portion 102 is referred to as a second sealing force.

  Then, when the first sealing force (second sealing force) acts on the seal member 68, the surface 80 of the seal member 68 can be pressed against the head portion 50 of the second nozzle portion 38 in a liquid-tight manner.

  Incidentally, the first sealing force can be adjusted according to the type and number of the disc springs 88. The second sealing force can be adjusted by the shape of the long groove 210 and the pair of recesses 212. These sealing forces are arbitrarily set according to the type of molten resin, the injection pressure of the molten resin, the material of the sealing member 68, and the like.

  In the present embodiment, the second sealing force is set to be larger than the first sealing force. Specifically, the first sealing force is obtained when the molten resin is led out from the second nozzle portion 38 (before the second sealing force acts on the sealing member 68) and the surface 80 of the sealing member 68 and the second nozzle. The size (first sealing force value P1) is set such that the molten resin does not leak from between the portion 38 and the head portion 50.

  As the second sealing force, a sealing force (synthetic sealing force) obtained by combining the first sealing force and the second sealing force is used to fill the second runner 200b, the second gate 202b, and the second cavity 204b with molten resin. In a completed state, the size is set such that the molten resin does not leak from between the surface 80 and the head portion 50 (second sealing force value P2).

  The control unit 28 includes an injection control unit 104, a heating control unit 106, and a movable platen drive control unit 108 (see FIG. 1). The injection control unit 104 drives and controls the injection unit 30 to inject a predetermined amount of molten resin to the first nozzle unit 36 and the second nozzle unit 38 by a predetermined amount.

  The heating control unit 106 drives and controls the nozzle heater 42 of the first nozzle unit 36 to heat the nozzle body 40. In addition, the heating control unit 106 drives and controls the plurality of nozzle heaters 48 of the second nozzle unit 38 to heat the nozzle body 46. The movable platen drive control unit 108 moves the movable platen 24 along the extending direction of the diver 14.

  The injection molding apparatus 10A according to the present embodiment is basically configured as described above. Next, an injection molding method using the injection molding apparatus 10A will be described. In the following description, the mold open state is the initial state.

  As shown in FIG. 6, first, a mold closing operation is started (step S1). That is, the movable platen drive control unit 108 drives the movable platen 24 and moves it to the intermediate mold 20 side. Then, first, the movable mold 22 contacts the intermediate mold 20 and the pair of convex portions 94 of the receiving member 84 contacts the first pressure receiving portion 100 of the seal member 68 (step S2). At this time, the seal member 68 is pushed by the convex portion 94 of the receiving member 84 and moves in the through hole 52 to the fixed mold 16 side.

  Next, when the movable platen 24 is further moved to the intermediate mold 20 side, the movable mold 22 and the intermediate mold 20 are integrally moved to the fixed mold 16 side, and the surface 80 of the seal member 68 is second. It contacts the head part 50 of the nozzle part 38 (step S3).

  Then, the receiving member 84 is displaced in the arrangement hole 60 to the movable platen 24 side, and the receiving member 84 pressed by the action of the disc spring 88 presses the seal member 68 to the fixed mold 16 side (step S4, FIG. 7 and FIG. 8). That is, since the first sealing force acts on the first pressure receiving portion 100 of the seal member 68 (see FIG. 11), the surface 80 of the seal member 68 is pressed against the head portion 50 of the second nozzle portion 38.

  Thereafter, in step S5, the mold closing operation is completed. At this time, as understood from FIGS. 9 and 10, the one end surface of the pair of convex portions 94 constituting the receiving member 84 and the other surface of the seal member 68 are the intermediate mold 20 and the movable mold 22. Located on the parting line (PL surface).

  At this stage, the first runner 200 a, the first gate 202 a, and the first cavity 204 a are formed between the fixed mold 16 and the intermediate mold 20, and between the intermediate mold 20 and the movable mold 22. The second runner 200b, the second gate 202b, and the second cavity 204b are formed. The front end surface of the head portion 44 of the first nozzle portion 36 faces the first runner 200a, and the hole 78 of the seal member 68 communicates with the second runner 200b.

  When the mold closing operation is completed, the first sealing force reaches the sealing force value P1 (see FIG. 11). For this reason, it is preferable to appropriately prevent the molten resin from leaking into the gap V between the wall surface forming the through hole 52 and the second nozzle portion 38 when the supply of the molten resin to the second runner 200b is started. it can.

  Thereafter, the heating control unit 106 drives the nozzle heater 42 of the first nozzle unit 36 and drives the nozzle heater 48 of the second nozzle unit 38 (step S6). As a result, the temperature of the nozzle body 40 of the first nozzle portion 36 is raised to a predetermined temperature, and the temperature of the nozzle body 46 of the second nozzle portion 38 is raised to a predetermined temperature.

  At this time, the seal member 68 is thermally expanded by the heat received from the second nozzle portion 38. In the present embodiment, since the predetermined clearance CL is formed in advance between the seal member main body 72 and the wall surface forming the small diameter hole 58, the thermally expanded seal member 68 forms the small diameter hole 58. Contact the wall (slidable). Thereby, when the sealing member 68 is thermally expanded, the sealing member 68 can be suitably suppressed from being squeezed into the wall surface constituting the small diameter hole 58.

  Subsequently, the injection control unit 104 drives the injection unit 30 to inject a predetermined amount of molten resin from the injection unit 30 by a predetermined amount (step S7). Then, the molten resin injected from the injection part 30 is guided to the manifold part 34 via the introduction part 32 and distributed to the first nozzle part 36 and the second nozzle part 38.

  The molten resin guided to the first nozzle portion 36 is led out from the head portion 44 and supplied to the first cavity 204a via the first runner 200a and the first gate 202a.

  On the other hand, the molten resin guided to the second nozzle portion 38 is led out from the head portion 50 and supplied to the second runner 200 b through the hole 78 of the seal member 68. That is, the molten resin led out from the head portion 50 flows into the long groove 210 of the runner groove 206 and then enters the pair of concave portions 212 and flows into the gate groove 208.

  At this time, since the second pressure receiving portion 102 of the seal member 68 contacts the molten resin supplied to the second runner 200b, the seal member 68 is pressed by the molten resin to the side where the intermediate mold 20 is located. . In other words, since the second sealing force acts on the second pressure receiving portion 102 of the sealing member 68, the surface 80 of the sealing member 68 has the second nozzle portion with a combined sealing force obtained by combining the first sealing force and the second sealing force. 38 heads 50 are pressed.

  The molten resin flowing into the gate groove 208 is guided to the second cavity 204b. As a result, the first cavity 204a and the second cavity 204b are filled with the molten resin (step S8, see FIG. 1).

  At this stage, the combined sealing force reaches a sealing force value P2 (see FIG. 11). Thereby, even when the molten resin of the second runner 200b has a relatively high pressure, it is preferable to suppress the molten resin from leaking into the gap V between the wall surface forming the through hole 52 and the second nozzle portion 38. be able to.

  Then, after the filled molten resin is sufficiently solidified, a mold opening operation is performed (step S9). That is, the movable platen drive control unit 108 drives the movable platen 24 to move the movable die 22 to the side opposite to the side where the fixed die 16 is located. As a result, the movable mold 22 is separated from the intermediate mold 20, and then the intermediate mold 20 connected to the movable mold 22 by a tension link (not shown) is pulled to the movable mold 22, thereby fixing the fixed mold. 16 apart.

  Thereafter, the resin product is taken out (step S10). At this stage, the injection molding according to the present embodiment is completed.

  According to this embodiment, the through hole 52 is formed in the intermediate mold 20. Therefore, the first nozzle part 36 that supplies the molten resin to the first cavity 204 a and the second nozzle part 38 that supplies the molten resin to the second cavity 204 b can be provided in the fixed mold 16.

  That is, in the present embodiment, since it is not necessary to form a molten resin flow path having a manifold function in the intermediate mold 20, the intermediate mold 20 can be reduced in size (thinned) and reduced in weight. Thereby, size reduction of 10 A of injection molding apparatuses can be achieved.

  In addition, since the second pressure receiving portion 102 is formed on the other surface of the seal member 68 slidable on the wall surface constituting the through hole 52, when the molten resin is led out from the second nozzle portion 38, the second pressure receiving portion 102 is formed. The two pressure receiving portions 102 are pressed to the side where the fixed mold 16 is located by the molten resin. As a result, the surface 80 of the seal member 68 can be pressed against the head portion 50 of the second nozzle portion 38, so that the molten resin forms a gap V between the second nozzle portion 38 and the wall surface constituting the through hole 52. Leakage can be prevented. Therefore, the molten resin can be reliably supplied to the first cavity 204a and the second cavity 204b.

  In the present embodiment, the pressing force (elastic force, spring force) of the disc spring 88 is received by the first pressure receiving portion 100 of the seal member 68 via the member 84 in the mold closed state (the state before injecting the molten resin). By acting, the surface 80 of the seal member 68 is pressed against the head portion 50 of the second nozzle portion 38. Accordingly, when the derivation of the molten resin from the second nozzle portion 38 is started (before the second pressure receiving portion 102 of the seal member 68 is pressed by the molten resin), the molten resin leaks into the gap V. This can be prevented.

  Further, since the disc spring 88 is disposed in the arrangement hole 60 formed in the movable mold 22, the intermediate mold 20 is further layered compared to the case where the disc spring 88 is disposed in the intermediate mold 20. It can be reduced in size and weight. Even in such a case, since the receiving member 84 is provided, the pressing force of the disc spring 88 can be reliably applied to the seal member 68.

  In the present embodiment, a surface 80 that contacts the second nozzle portion 38 is formed on one surface of the walls constituting the hole 78 through which the molten resin led out from the second nozzle portion 38 flows, and the wall portion A first pressure receiving portion 100 and a second pressure receiving portion 102 are formed on the other surface of the first pressure receiving portion. Therefore, the first sealing force and the second sealing force can be efficiently transmitted to the head portion 50 of the second nozzle portion 38 via the surface 80. Therefore, the surface 80 of the seal member 68 can be reliably pressed against the second nozzle portion 38.

(Second Embodiment)
Next, an injection molding apparatus 10B according to a second embodiment of the present invention will be described with reference to FIGS. In the injection molding apparatus 10B according to the second embodiment, elements having the same or similar functions and effects as those of the injection molding apparatus 10A according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. To do. 12 and 14, the illustration of the stationary platen 12 and the stationary mold 16 is omitted.

  As shown in FIG. 12, the injection molding apparatus 10 </ b> B according to the present embodiment includes a seal mechanism 150 instead of the seal mechanism 26.

  The seal mechanism 150 includes a seal member 152, a pair of holes 154 formed in the intermediate mold 20, a pair of arrangement holes 156 formed in one surface of the movable mold 22, and the pair of arrangement holes 156. And a pressing mechanism 158 provided.

  The seal member 152 includes a seal member main body 160 formed in a bottomed cylindrical shape, and a flange portion 162 projecting outward from one end portion of the seal member main body 160. The outer diameter dimension of the seal member main body 160 is set to be smaller than the outer diameter dimension of the seal member main body 72 described in the first embodiment.

  Each hole 154 communicates with the medium diameter hole 56 and opens on the other surface of the intermediate mold 20. Each placement hole 156 penetrates the movable mold 22 in the thickness direction and faces each of a pair of holes 154 formed in the intermediate mold 20. Each arrangement hole 156 has a smaller hole diameter on the other side. Each of the pair of projecting portions 163 formed on the other surface of the movable platen 24 is fitted into each opening portion of the arrangement hole 156 on one surface of the movable mold 22.

  The pressing mechanism 158 includes a receiving member 164 disposed in each arrangement hole 156 so as to be in contact with the flange 162, and a coil spring (pressing means) 166 that presses the receiving member 164 toward the flange 162. Have.

  Each receiving member 164 includes a pin 168 extending in the thickness direction of the movable mold 22 and a spring receiving member 170 fixed to the pin 168 so as to be slidable on the wall surface constituting the arrangement hole 156.

  Each spring receiving member 170 can come into contact with a step portion formed on one side of each arrangement hole 156. Thereby, it can prevent suitably that each spring receiving member 170 slips out from each arrangement | positioning hole 156. FIG. The coil spring 166 is interposed between the protrusion 163 of the movable platen 24 and the spring receiving member 170.

  In the sealing mechanism 150 configured as described above, as shown in FIG. 13, a first pressure receiving portion 174 is formed on the other surface of the flange portion 162 so that one end surface of the pin 168 constituting the receiving member 164 contacts. A second pressure receiving portion 176 constituting a part of the second runner 200b is formed on the other surface of the seal member main body 160.

  In the present embodiment, as described above, the outer diameter of the seal member main body 160 is smaller than the outer diameter of the seal member main body 72 described in the first embodiment. Is smaller than the area of the second pressure receiving portion 102.

  Thereby, the bending stress which the 2nd sealing force gives to the sealing member main body 160 can be decreased. Therefore, it can suppress suitably that the sealing member 152 is damaged.

  In the injection molding apparatus 10 </ b> B configured as described above, when the mold closing operation is started, first, the movable mold 22 contacts the intermediate mold 20 and one end surface of the pair of pins 168 is the other surface of the flange portion 162. To touch. At this time, the seal member 152 is pushed by the pair of pins 168 and moves in the through hole 52 to the fixed mold 16 side.

  Next, when the movable platen 24 is further moved to the intermediate mold 20 side, the movable mold 22 and the intermediate mold 20 are integrally moved to the fixed mold 16 side, and the surface 80 of the seal member 152 is second. It contacts the head part 50 of the nozzle part 38.

  Then, each receiving member 164 is displaced in the arrangement hole 156 toward the movable platen 24, and the pin 168 of the receiving member 164 pressed by the action of the coil spring 166 presses the seal member 152 toward the fixed mold 16. That is, the first sealing force acts on the first pressure receiving portion 174 formed on the flange portion 162.

  As a result, the surface 80 of the seal member 152 is pressed against the head portion 50 of the second nozzle portion 38, so that the wall surface constituting the through hole 52 and the second nozzle portion when the supply of molten resin to the second runner 200b is started. It is possible to suitably prevent the molten resin from leaking into the gap V between the first and second members 38.

  And when molten resin is supplied from the 2nd nozzle part 38, 2nd sealing force acts on the 2nd pressure receiving part 176 formed in the other surface of the sealing member main body 160 by this molten resin. Thereby, even if it is a case where a high voltage | pressure molten resin is supplied to the 2nd cavity 204b, it can suppress that this molten resin leaks into the said clearance gap V. FIG.

  According to this embodiment, since the pin 168 constituting the receiving member 164 can contact the flange portion 162, the first sealing force can be applied to the flange portion 162. Thereby, when the molten resin is led out from the second nozzle portion 38, only the second sealing force acts on the wall portion constituting the hole 78, so that the wall portion is excessively pressed. There is no. Therefore, it can suppress suitably that this wall part is damaged.

  The present invention is not limited to the above-described embodiment, and it is naturally possible to adopt various configurations without departing from the gist of the present invention.

  For example, in the present invention, the seal members 68 and 152 may be provided in the second nozzle portion 38. Further, the pressing means is not limited to the disc spring 88 or the coil spring 166. That is, a cylinder mechanism or the like may be used as the pressing means.

  The first nozzle part 36 and the second nozzle part 38 may be provided in the movable mold 22 instead of the fixed mold 16.

  Further, the sealing members 68 and 152 may form holes through which the second nozzle portion 38 is inserted instead of the holes 78 through which the molten resin led out from the second nozzle portion 38 flows. In this case, the amount of heat received from the molten resin by the sealing members 68 and 152 can be reduced.

10A, 10B ... Injection molding device 16 ... Fixed mold (first mold)
20 ... Intermediate mold 22 ... Movable mold (second mold)
36 ... 1st nozzle part 38 ... 2nd nozzle part 52 ... Through-hole 60, 156 ... Arrangement hole (hole part)
68, 152 ... sealing member 88 ... disc spring (pressing means)
72, 160 ... Sealing member main body 74, 162 ... collar 80 ... surface (contact part) 84, 164 ... receiving member 100, 174 ... first pressure receiving part 102, 176 ... second pressure receiving part 166 ... coil spring (pressing means) 204a ... 1st cavity 204b ... 2nd cavity CL ... Clearance

Claims (8)

A first mold and a second mold, which are opposed to each other in a state where they can be closely spaced from each other;
An intermediate mold disposed between the first mold and the second mold,
In a mold closed state, it melts into a first cavity formed between the first mold and the intermediate mold and a second cavity formed between the second mold and the intermediate mold. In injection molding equipment that can be filled with materials,
In the intermediate mold, a through-hole is formed in each of a surface facing the first mold and a surface facing the second mold,
A first nozzle part provided in the first mold for supplying the molten material to the first cavity;
A second nozzle part provided in the first mold in a state of being insertable into the through hole, and for supplying the molten material to the second cavity;
A seal member slidable on the wall surface constituting the through hole,
The seal member faces the side on which the first mold is located, and a contact portion that contacts the second nozzle portion;
An injection molding apparatus, characterized in that a pressure receiving portion that faces the side on which the second mold is located and that contacts the molten material led out from the second nozzle portion is formed. The injection molding apparatus according to claim 1, wherein
An injection molding apparatus further comprising pressing means for pressing the seal member toward the side where the first mold is located. The injection molding apparatus according to claim 2,
The second mold has a hole formed in a portion facing the seal member,
A receiving member disposed in the hole in a displaceable manner along the pressing direction of the pressing means;
The injection molding apparatus according to claim 1, wherein the pressing means presses the seal member through the receiving member in a state of being provided in the hole. The injection molding device according to claim 3,
The seal member is formed with a hole through which the second nozzle part can be inserted or through which the molten material led out from the second nozzle part flows.
The contact portion is formed on a first wall surface extending in a radial direction from an end portion of the hole where the first mold is located,
The pressure-receiving portion is formed on a second wall surface extending in a radial direction from an end portion of the hole where the second mold is located . The injection molding apparatus according to claim 4, wherein
The injection molding apparatus, wherein the receiving member is capable of contacting the second wall surface . The injection molding apparatus according to claim 4, wherein
The seal member includes a seal member body in which the hole is formed;
Has a flange portion extending radially outward of said second nozzle portion from the sealing member main body,
The injection molding apparatus according to claim 1, wherein the receiving member is capable of contacting the flange portion. A first mold and a second mold, which are opposed to each other in a state where they can be closely spaced from each other;
An intermediate formed between the first mold and the second mold and having a through-hole opened in a surface facing the first mold and a surface facing the second mold Mold,
An injection molding method using an injection molding apparatus comprising a first nozzle part and a second nozzle part provided in the first mold,
By bringing the first mold and the second mold close to each other, the second nozzle portion is inserted into the through hole, and a first cavity is formed between the first mold and the intermediate mold. And a mold closing step of forming a second cavity between the second mold and the intermediate mold,
A first supply step of supplying a molten material to the first cavity at the first nozzle portion;
A second supply step of supplying the molten material to the second cavity at the second nozzle portion, and
In the second supply step, the molten metal led out from the second nozzle portion is brought into contact with a sealing member slidable on a wall surface constituting the through hole, so that the first mold is attached to the sealing member. An injection molding method, wherein the injection molding method is characterized by pressing against the second nozzle portion by pressing toward the position. The injection molding method according to claim 7,
In the mold closing step, the injection molding method is characterized in that the sealing member is pressed against the second nozzle portion by pressing the sealing member toward the side where the first mold is located.

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