JP2011156758A - Injection molding mold and injection molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an injection molding mold, wherein a resin flow in the mold is controlled so that a weld line is restrained from being created according to the properties of a resin constituting a molding and to provide an injection molding method. <P>SOLUTION: The injection molding mold 10 includes: a cavity 21 having at least two flow paths which are connected to each other at the ends; and resin injector 31, 51 for injecting the resin into the flow paths, respectively; and resin flow controllers 32, 33, 41, 52, 53 for controlling at least one of a shape of the tip surface of a leading edge portion of the resin flowing in one flow path and another shape of the tip surface of the leading edge portion of the resin flowing in the other flow path according to the properties of the resin flowing in the flow path when the resin flowing in one flow path begin to merge with the resin flowing in the other flow path so that the resin can flow along the wall surface of a flow passage formed by the resin in the vicinity of a resin merging portion since the resin flowing in one flow path begin to merge with the resin flowing in the other flow path until the resin is solidified. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an injection mold and an injection molding method for injection molding a molded body having a predetermined shape with a resin.

  2. Description of the Related Art Conventionally, there is an injection molding method in which a cavity having a predetermined shape is provided therein, and an injection molding method for molding a molded body having a shape corresponding to the predetermined shape by injecting a molten resin into the cavity. Proposed. When the molded body is molded, the resin injected and injected into the cavity advances (flows) in the cavity while filling the cavity. That is, the cavity corresponds to a resin flow path. In other words, the cavity is constituted by a resin flow path. Hereinafter, for convenience, “injection injection” is also simply referred to as “injection”, and “resin flow path” is also simply referred to as “flow path”.

  For example, when the cavity is constituted by a plurality of flow paths and two of the plurality of flow paths are connected to each other at their end portions (for example, one flow path has a plurality of flow paths). And when two of the branched flow paths merge again), when resin is injected into the cavity, the resin flowing in the two flow paths is The two flow paths meet at a position where they are connected to each other (hereinafter, the position where the resin flowing in the flow path meets will be referred to as “meeting position” for convenience). As is well known, a molded body formed by an injection mold having such a cavity may have a “region where the resin is not sufficiently mixed” around the portion corresponding to the meeting position.

  The region is generally considered to be generated by a layer including a solidified resin being formed on the surface of the leading portion of the resin flowing in the flow path. More specifically, when the resin streams having the layer containing the solidified resin associate with each other, the layers containing the solidified resin come into contact with each other. At this time, since the layers already contain a solidified resin, the layers cannot be mixed sufficiently. Further, since the layers cannot be mixed sufficiently, the resin existing around the layers cannot be mixed sufficiently. These regions are believed to result in these areas.

  In the said area | region, since the layers containing the solidified resin are not fully mixed, the boundary surface (contact surface) is formed between these layers. Further, since the flow rate of the resin rapidly decreases around the boundary surface, the characteristics of the resin in the region (for example, density and orientation) are different from the properties of the resin in the region other than the region. There is a case. That is, there may be a “bias in resin characteristics”. As a result, the region is visually recognized from the outside of the molded body as “a portion having a different appearance characteristic from other regions (so-called weld line)”.

  On the other hand, for the purpose of improving the aesthetics of the molded body, a bright body may be contained in the resin used for injection molding. The luminous body used for this purpose generally has an ellipsoidal shape (for example, a rugby ball shape). Due to this shape, the reflectance of the luminous body in the axial direction of the luminous body is different from the reflectance of the luminous body in the direction perpendicular to the axial direction of the luminous body. Further, due to this shape, when the resin containing the luminous body flows in the flow path, the luminous body is oriented so that the axial direction thereof coincides with the flow direction of the resin.

  When the resins flowing in the flow path meet, the resin flows collide with each other at the meeting position. Therefore, the resin flowing direction changes significantly around the meeting position. Therefore, the resin flow direction at positions around the meeting position and the resin flow direction at positions other than the vicinity of the meeting position are greatly different. As a result, when the molded body is molded with the resin containing the luminous body, the orientation direction of the luminous body around the part corresponding to the meeting position of the molded body, and the orientation direction of the luminous body in the part other than this part, Different. That is, “the deviation of the orientation direction of the luminous body” occurs. Therefore, when the molded body is molded with a resin containing a luminous body, the above-mentioned “region where the resin is not sufficiently mixed” is also included in the “orientation direction of the luminous body” in addition to the “resin characteristics” described above. , Different from other areas. As described above, when the orientation direction of the luminous body is different, the reflectance of light by the luminous body is different. Therefore, when a molded body is molded with a resin containing a bright body, the weld line is more clearly visible.

  Since the weld line is a factor that impairs the appearance of the molded body, it is desired to suppress the weld line from being visually recognized as much as possible. Therefore, one of the conventional injection molds (hereinafter referred to as “conventional mold”) is made up of two flow paths (specifically, annular flow paths) connected to each other at the end. And a discharge port for discharging the resin and a resin reservoir for storing the resin discharged from the discharge port.

  When a resin containing a luminous body is injected into the cavity of the conventional mold, the resin flowing in one of the two channels is provided with the discharge port before reaching the meeting position. Pass through the position. At this time, the resin passing through the vicinity of the discharge port among the resin flowing in the one flow path is discharged to the resin reservoir through the discharge port. Therefore, on the downstream side of the position where the discharge port is provided, the amount of resin flowing through the “position close to the discharge port” in one flow path is more than the amount of resin flowing through the “position away from the discharge port”. Less. As a result, the leading portion of the resin flowing in the one flow path has a “shape that protrudes in the flow direction as the distance from the discharge port” (see, for example, the resin flow F2 in FIG. 2A). On the other hand, the leading portion of the resin flowing through the other of the two flow paths has a “shape in which the approximate center position of the flow path protrudes in the flow direction” (for example, the resin flow in FIG. 2A). See F1.)

  Therefore, at the time when the head portions having the above-described shapes start to associate with each other, there is a “space not filled with resin” between the head portions (see, for example, FIG. 2B). Then, between the beginning of the beginning parts and the time when the resin is solidified, the beginning parts flow in the respective flow directions so as to fill the “space not filled with resin” (for example, FIG. (See 2 (c) and FIG. 2 (d).)

  As described above, in the conventional mold, the leading portions can flow in the respective flow directions after the leading portions of the flow of the resin start to associate with each other and until the resin solidifies. Therefore, it is possible to prevent the resin flow rate from rapidly decreasing around the meeting position. Therefore, the occurrence of “bias in resin characteristics” around the meeting position is suppressed. Furthermore, it is possible to prevent the resin flow direction from changing significantly around the meeting position. Therefore, the occurrence of “bias in the orientation direction of the luminous body” around the meeting position is suppressed. As a result, the conventional mold can suppress the weld line from being visually recognized (see, for example, Patent Document 1).

JP 2008-188855 A

  As described above, the conventional mold suppresses the weld line from being visually recognized by providing the discharge port and the resin reservoir at a predetermined position of the cavity. However, in order to prevent the weld line from being visually recognized, characteristics of the resin (for example, viscosity and elastic modulus), characteristics of the luminous body (for example, shape, size, light reflectance, etc.), and A discharge port having an “appropriate shape (for example, aperture)” needs to be provided at an “appropriate position” corresponding to the content of the luminous body relative to the resin. Therefore, in order to suppress the weld line from being visually recognized by the concept adopted in the conventional mold, it is used to mold the molded body even if the shape of the molded body to be molded is the same. If the properties of the molding material (resin and luminous body, etc.) to be formed are different, the mold itself must be remade. That is, the conventional mold has a problem that even if the shape of the molded body is the same, it is necessary to remake the mold according to the characteristics of the material to be molded.

  In view of the above problems, the object of the present invention is to ensure that a weld line is visually recognized by a single mold even when a molded body having a predetermined shape is injection-molded with a molding material having any characteristics. An object of the present invention is to provide an injection mold and an injection molding method that can be suppressed.

First, an “injection mold” according to the present invention for achieving the above-described object will be described.
The mold for injection molding of the present invention is
An injection molding die for injection molding a molded body having a predetermined shape with a resin, comprising a cavity, a resin injection means, and a resin flow control means.

More specifically, the cavity is
A cavity having a shape corresponding to the predetermined shape of the molded body, and having at least two flow paths connected to each other at an end portion.

Furthermore, the resin injection means includes
Resin injecting means for injecting the resin constituting the molded body into the flow path, wherein the resin flows into the flow path so that the resin flowing in the flow paths meet at a portion where the flow paths are connected to each other. inject.

  Here, the resin injection means includes a member involved in injecting resin into the flow path. Specifically, as the resin injection means, for example, a resin injection port through which the resin injected into the flow path passes, an opening / closing member that opens and closes the resin injection port, and the resin injection port pass through per unit time Examples include an adjustment member that adjusts the amount of resin. Further, the resin injection means may include a resin injection device that melts and pressurizes the resin and injects and injects the resin into the flow path, and may not include the resin injection device.

In addition, the resin flow control means includes
“The resin can flow along the wall surface defining the flow path in the vicinity of the site where the resin meets after the resin flowing in the flow path starts to solidify until the resin solidifies. "When the resin flowing in the flow path begins to associate," the shape of the leading end surface of the resin flowing in one flow path "and" the tip of the leading portion of the resin flowing in the other flow path " At least one of “the shape of the surface” is “controlled” in accordance with the properties of the resin flowing in the flow paths.

  As described above, the resin flows in the flow direction of the resin (in other words, the flow path is defined in the vicinity of the portion where the resin meets after the resin flowing in the flow path starts to solidify until the resin solidifies. If it can flow (along the wall surface), the resin flow rate can be prevented from abruptly decreasing, so that “unevenness of resin characteristics” is suppressed in the vicinity of the site where the resin meets. . As a result, the weld line is suppressed from being visually recognized.

  Further, the resin flow control means controls the shape of the front end surface of the leading portion of the resin flowing in the flow path “depending on the properties of the resin”. Here, “resin properties” are properties that affect the visibility of the weld line among the properties of the resin itself, such as the viscosity and elastic modulus of the resin, when the molding material is only the resin. including. On the other hand, “resin properties” means that when the molding material is a mixture of a resin and another substance (such as a luminous body), for example, the properties of the resin itself, the shape and size of the other substance, and the light It includes properties that affect the visibility of the weld line among the properties of other materials such as reflectance and the content of other materials relative to the resin.

  As described above, the injection mold according to the present invention has the shape of the tip surface of the leading portion of the resin flowing in the flow path so as to prevent the weld line from being visually recognized “depending on the properties of the resin”. "Control. Therefore, in the injection mold according to the present invention, even when a molded body having a predetermined shape is molded by a molding material having any characteristic, a weld line is visually recognized according to the characteristics of the molding material. This can be suppressed. That is, the injection mold of the present invention is a molding in which the weld line is suppressed from being visually recognized by a single mold even if the properties of the molding material are changed as long as the shape of the molded body is the same. The body can be manufactured.

As one aspect of the injection mold of the present invention,
The resin flow control means includes
When the resin flowing in the flow path begins to associate, “the front end surface of the outer peripheral portion in the vicinity of the wall surface defining the cavity among the head portions of the resin flowing in the one flow path” and “the other The front end surface of the outer peripheral portion in the vicinity of the wall surface that defines the cavity among the head portion of the resin flowing in the flow path, and other portions adjacent to the meeting portion sequentially meet from one portion. As described above, the outer peripheral portion may have a distal end surface that is not parallel to each other.

  Hereinafter, the injection mold according to this aspect will be described with reference to the drawings. Fig.1 (a) is a schematic diagram for demonstrating the form of resin which flows through the inside of a flow path. In FIG. 1A, the resin flow R flows through a flow path (cavity) 100 having a cylindrical shape in a direction indicated by a white arrow in the drawing. At this time, generally, the leading portion FF of the resin flow R has a convex shape that protrudes in the flow direction (that is, the direction indicated by the white arrow in the figure) as it is away from the wall surface W that defines the flow path (cavity) 100. It is considered to have Further, generally, the direction of the flow of the resin constituting the resin flow R is curved along the front end surface FFS in the vicinity of the front end surface FFS of the head portion FF, as shown by the broken arrow in the figure. It is thought to go to W. Thus, the resin injected into the flow path is generally considered to flow through the flow path in the form of a fountain.

  In the above-mentioned “site where the resin meets”, the leading portions of the resin flow having such a convex shape come into contact with each other. Therefore, in the top portion FF of the resin flow, “the resin flowing in the position corresponding to the vicinity of the surface of the molded body (that is, the vicinity of the wall surface W defining the cavity)” is visible from the outside of the molded body. This is thought to have a particular impact on Therefore, in the following, the head portion FF of the resin flow will be examined in more detail.

  FIG. 1B is an enlarged view of the leading portion FF of the resin flow R shown in FIG. In FIG. 1B, the hatched area in the figure represents the “outer peripheral portion OPP” that is a portion in the vicinity of the wall surface W in the head portion FF of the resin flow R. The resin flow control means in the injection mold according to the present aspect is such that the outer peripheral portion OPP properly meets the front end surface of the front portion FF of the resin flow R from the viewpoint of suppressing the weld line from being visually recognized. Control the shape of the FFS.

  FIG. 2A to FIG. 2D are schematic views for explaining how the leading portions of the two resin flows are associated with each other in this embodiment. As shown in FIG. 2 (a), the resin flow control means of the injection mold according to this aspect is provided in the vicinity of the wall surface W that defines a cavity in the leading portion FF1 of the resin F1 that flows in one flow path 201. The distal end surface of the outer peripheral portion OPP1 and the distal end surface of the outer peripheral portion OPP2 in the vicinity of the wall surface W defining the cavity in the leading portion FF2 of the resin F2 flowing in the other flow path 202 are not parallel to each other. Let me.

  Thereby, as shown in FIG. 2B, when the tip surface of the outer peripheral portion OPP1 of the resin flow F1 and the tip surface of the outer peripheral portion OPP2 of the resin flow F2 meet, Meeting begins from a part of them (see the meeting point CP1 in FIG. 2B). Next, as shown in FIG. 2 (c) and FIG. 2 (d), other parts adjacent to the meeting part successively meet (the meeting point CP2 in FIG. 2 (c) and the meeting in FIG. 2 (d)). (See point CP3.)

  As described above, when the outer peripheral portion OPP1 and the outer peripheral portion OPP2 sequentially meet, the outer peripheral portions OPP1, OPP2 are arranged in the same direction as the direction in which the meeting points (that is, the meeting points CP1 to CP3) move. It is thought that the resin inside flows. As a result, it is considered that “the resin flows along the wall surface W that defines the flow path in the vicinity of the portion where the resin is associated” (for example, see at least the broken line arrow in the region ACP in FIG. 2D). As a result, it is possible to prevent the “bias of the resin characteristics” from occurring, and thus it is possible to suppress the weld line from being visually recognized.

  Here, the above-mentioned “outer peripheral portion” is at least one portion of the top portion of the resin flowing through the flow path and a portion (region) to the extent that the object of the present invention is achieved as described above. To express. That is, the “outer peripheral portion” may be a part of the top portion of the resin flowing through the flow path or the entire top portion of the resin flowing through the flow path.

  Furthermore, the above-mentioned “the distal end surface of the outer peripheral portion OPP1 and the distal end surface of the outer peripheral portion OPP2 are not parallel to each other” means that the plane including the downstream end surface of the outer peripheral portion OPP1 and the outer peripheral portion OPP2 This means that the plane including the downstream end face is not at least parallel to the plane. It should be noted that the plane including the portion other than the downstream end face of the outer peripheral portion OPP1 and the plane including the portion other than the downstream end face of the outer peripheral portion OPP2 may or may not be parallel. .

  In addition, when there is no end face on the downstream side of the outer peripheral portions OPP1 and OPP2 (that is, as shown in FIG. 3A, for example, the outer peripheral portions OPP1 and OPP2 converge to one end point on the downstream side thereof. ) “The front end surface of the outer peripheral portion OPP1 and the front end surface of the outer peripheral portion OPP2 are not parallel to each other” means that the tangential plane at the downstream end point of the outer peripheral portion OPP1 and the downstream side of the outer peripheral portion OPP2 The tangent plane at the end point of is not at least parallel. Similarly to the above, the tangent plane at a point other than the downstream end point of the outer peripheral portion OPP1 and the tangent plane at a point other than the downstream end point of the outer peripheral portion OPP2 may be parallel or not parallel. Good.

Furthermore, as another aspect of the injection mold of the present invention,
The resin flow control means includes
The front end surface of the outer peripheral portion of the front portion of the resin flowing in the flow path “before” the front end surfaces “other than” the front end surface of the outer peripheral portion of the front portion of the resin flowing in the flow path contact each other Can be configured to associate with each other.

  FIG. 3A to FIG. 3D are schematic views for explaining how the leading portions of the two resin flows are associated with each other in this embodiment. As shown in FIG. 3A, the resin flow control means of the injection mold according to this aspect is provided in the vicinity of the wall surface W that defines a cavity in the leading portion FF1 of the resin F1 that flows in one flow path 301. The distal end surface of the outer peripheral portion OPP1 is formed into a shape in which the resin constituting the resin F1 does not exist on the downstream side of the distal end surface. Furthermore, the resin constituting the resin F2 on the downstream side of the front end surface of the outer peripheral portion OPP2 in the vicinity of the wall surface W defining the cavity in the front portion FF2 of the resin F2 flowing in the other flow path 302. The shape does not exist.

  Thereby, as shown in FIG. 3B, the front end surface of the outer peripheral portion OPP1 of the resin flow F1 and the front end surface of the outer peripheral portion OPP2 of the resin flow F2 are the same as the outer peripheral portions OPP1 and OPP2. The tip surfaces “other than” the tip surfaces meet “in front” where they contact each other. Further, similarly to the above “one aspect”, the distal end surface of the outer peripheral portion OPP1 and the distal end surface of the outer peripheral portion OPP2 start to meet from a part thereof (see the meeting point CP1 in FIG. 3B). Other parts adjacent to the meeting part successively meet (see the meeting point CP2 in FIG. 3C and the meeting point CP3 in FIG. 3D).

  At this time, as the outer peripheral portions OPP1 and OPP2 are sequentially associated with each other, the resin inside the outer peripheral portions OPP1 and OPP2 is arranged in a direction substantially the same as the direction in which the meeting points (that is, the meeting points CP1 to CP3) move. Flows. In this embodiment, there is substantially no substance that hinders the movement of the association points (that is, the association points CP1 to CP3) in the direction of movement. Therefore, the meeting points CP1 to CP3 of the outer peripheral portions OPP1 and OPP2 can move more smoothly than the “one aspect”. As a result, it is considered that “the resin flows more smoothly along the wall surface W defining the flow path in the vicinity of the portion where the resin meets” (for example, see at least the broken line arrow in the region ACP in FIG. 3D) .) As a result, the occurrence of “unevenness in resin characteristics” is further prevented, and thus the visual recognition of the weld line is further suppressed.

In the mold for injection molding of each aspect described above,
The resin flow control means includes
When the resin flowing in the flow path starts to associate, at least one of “the flow speed of the resin flowing in the one flow path” and “the flow speed of the resin flowing in the other flow path” is determined by these flow rates. It can be configured to “control” depending on the nature of the resin flowing in the path.

As one aspect of the injection mold,
The resin flow control means includes
When the resin flowing in the flow path begins to associate, the “flow velocity of the leading portion of the resin flowing in the one flow passage” is set to be more than the “flow velocity of the leading portion of the resin flowing in the other flow passage”. It can be configured to be large.

  The flow rate of the resin when the resin flowing in the flow path begins to associate affects the amount of resin that can flow in the outer peripheral portion from the time when the resin begins to associate until the resin solidifies. . Therefore, in addition to “the shape of the front end surface of the resin flowing in the flow path”, “the flow velocity of the resin leading part flowing in the flow path” is controlled according to the properties of the resin. Is further suppressed from being visually recognized.

  For example, depending on the nature of the resin, as in the above embodiment, the “flow velocity of the leading portion of the resin flowing in the one flow path” when the resin flowing in the flow path begins to associate is “the flow of the other flow”. By making it larger than the “flow velocity of the leading portion of the resin flowing in the road”, it is further suppressed that the weld line is visually recognized.

As a specific aspect of the injection mold of the present invention,
The resin flow control means includes
When the resin injecting means is a “first resin injecting means”, it is a “second resin injecting means” different from the first resin injecting means, and injects resin into the one channel. A second resin injection means;
"Resin discharging means" for discharging the resin flowing in the other channel from the other channel;
Can be configured.

The resin flow control means configured in this way is
(A) “After the resin flowing in the one flow path passes through the portion where the second resin injection means injects the resin into the one flow path, the resin flowing in the one flow path is Until the second resin injecting means injects the resin into the one channel until it begins to associate with the resin flowing in the other channel,
and,
(B) “After the resin flowing in the other flow path passes through the portion where the resin discharging means discharges the resin flowing in the other flow path from the other flow path, `` Until the resin flowing through the one flow path begins to associate with the resin flowing through the one flow path '', causing the resin discharge means to discharge the resin flowing through the other flow path from the other flow path,
By at least one of
At least one of “the shape of the leading end surface of the resin flowing in the one flow path” and “the shape of the leading end surface of the resin flowing in the other flow path” flows in these flow paths. It can be configured to control depending on the properties of the resin.

  In the injection mold having the above configuration, when the resin flow control means injects resin into one flow path as shown in (A) above, the “second resin injection means injects resin into the flow path. The amount of resin that flows through the “position close to the injection site” in the flow channel downstream of the site to be performed (hereinafter referred to as “injection site” for convenience) flows through the “position away from the injection site”. More than the amount of resin. That is, the closer to the injection site, the more resin flows in the flow path. As a result, the leading portion of the resin flowing in the one flow path has a shape that protrudes in the flow direction as it approaches the injection site (see, for example, the shape of the leading portion FF1 in FIG. 3A). Thus, by injecting resin from the injection site, the shape of the front end surface of the leading portion of the resin flowing in the flow path can be changed.

  On the other hand, when the resin flow control means discharges the resin from the other flow path as shown in (B) above, “the resin discharge means discharges the resin from the flow path (hereinafter referred to as“ discharge part ”for convenience. The amount of resin flowing through the “position close to the discharge site” on the downstream side of “)” is smaller than the amount of resin flowing through the “position away from the discharge site”. In other words, as the distance from the discharge site increases, the amount of resin flowing in the flow path increases. As a result, the leading portion of the resin flowing in the other flow path has a shape that protrudes in the flow direction as the distance from the discharge portion increases (see, for example, the shape of the leading portion FF2 in FIG. 3A). Thus, by discharging the resin from the discharge site, the shape of the tip surface of the leading portion of the resin flowing in the flow path can be changed.

  Thus, the shape of the leading portion of the resin flowing in the flow path can be changed by either (A) or (B). Therefore, the resin discharging means of this aspect controls the shape of the front end surface of the leading portion of the resin flowing in the flow path according to the property of the resin by at least one of the above (A) and (B).

  Here, the resin flow control means includes, for example, the position where the injection site is provided, the amount of resin injected from the injection site, the timing when the resin is injected from the injection site, the position where the discharge site is provided, and the discharge site. The shape of the leading portion of the resin flowing in the flow path can be controlled to a desired shape by changing the amount of the resin discharged from the outlet and the timing for discharging the resin from the discharge portion.

As a more specific aspect of the injection mold of the present invention,
The first resin injection means includes
A first resin inlet opening toward the cavity; the resin can pass through the first resin inlet when the valve is opened; and the resin passes through the first resin inlet when the valve is closed. A first control valve that is disabled,
The second resin injection means includes
A second resin inlet opening toward the one flow path; and when the valve is opened, the resin can pass through the second resin inlet and when the valve is closed, the second resin inlet is A second control valve through which resin cannot pass,
The resin discharging means is
A resin outlet opening toward the other flow path, and when the valve is opened, the resin can pass through the resin outlet, and when the valve is closed, the resin cannot pass through the resin outlet. And a third control valve.

In the above-described more specific embodiment of the injection mold,
The resin flow control means includes
Opening the first control valve at a first time point;
After the resin flowing in the one flow path passes through the portion where the second resin inlet is open, the resin flowing in the one flow path starts to associate with the resin flowing in the other flow path. The second control valve is opened at a second time point until
And,
From the time when the resin flowing in the other flow path passes through the portion where the resin outlet is open until the resin flowing in the other flow path begins to associate with the resin flowing in the one flow path Opening the third control valve at a third time point,
By
Control the shape of the leading end surface of the resin flowing in the one flow path and the shape of the leading end surface of the resin flowing in the other flow path according to the properties of the resin flowing in these flow paths. To be configured.

In each of the injection molds of the specific embodiment described above,
The injection mold may be configured to have a plurality of the second resin injection means.

  As described above, the injection mold of the above aspect controls the shape of the front end surface of the leading portion of the resin flowing in one flow path by the resin injected into the flow path by the second resin injection means. Yes. Therefore, in the case where the shape of the front end surface of the leading portion of the resin flowing through one flow path cannot be sufficiently controlled by the single second resin injection means, for example, the injection mold of the above aspect is used. A plurality of the second resin injection means may be provided. Thereby, the shape of the front end surface of the leading portion of the resin flowing in one flow path can be controlled with higher accuracy.

Furthermore, in the mold for injection molding of the present invention including the above-described aspects,
The resin may be configured to contain a glitter.

  As described above, when a bright body is contained in the resin, there is a possibility that “bias of the orientation direction of the bright body” may occur in the vicinity of the portion where the resin is associated. However, as described above, if the shape of the front end surface of the flow of the resin is controlled, the portion where the resin meets after the resin flowing in the flow path starts to associate until the resin solidifies In the vicinity, the resin can flow along the wall surface defining the flow path (see, for example, the broken line arrow in the region ACP in FIG. 2D). Thereby, the orientation of the luminous body in the vicinity of the portion where the resin is associated and the orientation of the luminous body in the portion other than the vicinity of the portion where the resin is associated are substantially the same at least in the region near the wall surface defining the flow path. Become. That is, it is possible to prevent the occurrence of “bias in the orientation direction of the luminous body”. Therefore, even when the resin containing the glitter is applied to the above-described injection mold, the weld line is suppressed from being visually recognized.

Next, an “injection molding method” according to the present invention for achieving the above-described problems will be described.
The injection molding method of the present invention comprises:
An injection molding method in which a molded body having a predetermined shape is injection molded with a resin, and includes a resin injection step and a resin flow control step.

More specifically, the resin injection step is
A portion where the flow paths are connected to each other in a cavity having a shape corresponding to the predetermined shape and having at least two flow paths connected to each other at an end portion of the resin constituting the molded body In the step, the resin flowing in these flow paths is injected so as to meet.

  Here, in this resin injection step, a member involved in injecting resin into the flow path can be used. Specifically, as a member involved in injecting resin into the flow path, for example, a resin injection port through which resin injected into the flow path passes, an opening / closing member for opening and closing the resin injection port, and this Examples include an adjusting member that adjusts the amount of resin that passes through the resin inlet per unit time. Further, the member involved in injecting the resin into the flow path may include a resin injection apparatus that melts and pressurizes the resin and injects the resin into the flow path, and includes the resin injection apparatus. You don't have to.

Furthermore, the resin flow control step includes
“The resin can flow along the wall surface defining the flow path in the vicinity of the site where the resin meets after the resin flowing in the flow path starts to solidify until the resin solidifies. "When the resin flowing in the flow path begins to associate," the shape of the leading end surface of the resin flowing in one flow path "and" the tip of the leading portion of the resin flowing in the other flow path " This is a process of “controlling” at least one of “the shape of the surface” according to the property of the resin flowing in these flow paths.

  As described above, the resin flows in the flow direction of the resin in the vicinity of the portion where the resin associates between the time when the resin flowing in the flow channel starts to associate and the time when the resin solidifies (that is, the flow channel is defined). If it can flow (along the wall surface), the flow rate of the resin can be prevented from abruptly decreasing, so that “unevenness of resin characteristics” is prevented from occurring in the vicinity of the site where the resin meets. As a result, the weld line is suppressed from being visually recognized.

  Further, in the resin flow control step, the shape of the tip surface of the leading portion of the resin flowing in the flow path is controlled “depending on the properties of the resin”. Here, “resin properties” are properties that affect the visibility of the weld line among the properties of the resin itself, such as the viscosity and elastic modulus of the resin, when the molding material is only the resin. including. On the other hand, “resin properties” means that when the molding material is a mixture of a resin and another substance (such as a luminous body), for example, the properties of the resin itself, the shape and size of the other substance, and the light It includes properties that affect the visual recognition of the weld line among the properties of other materials such as reflectance and the mixing ratio of the resin and other materials.

  Thus, in the injection molding method of the present invention, the shape of the tip surface of the leading portion of the resin flowing in the flow path is “in accordance with the properties of the resin” so as to prevent the weld line from being visually recognized. Controlled ". Therefore, in the injection molding method of the present invention, even when a molded body having a predetermined shape is injection-molded with a molding material having any characteristics, a weld line is visually recognized according to the characteristics of the molding material. It is suppressed. That is, according to the injection molding method of the present invention, as long as the shape of the molded body is the same, even if the characteristics of the molding material are changed, the molding in which the weld line is suppressed from being visually recognized by a single mold. The body can be manufactured.

As one aspect of the injection molding method of the present invention,
The injection molding method is:
In the resin flow control step, when the resin flowing in the flow path starts to associate, “the front end surface of the outer peripheral portion in the vicinity of the wall surface defining the cavity among the head portions of the resin flowing in the one flow path. ”And“ the front end surface of the outer peripheral portion in the vicinity of the wall surface defining the cavity among the head portion of the resin flowing in the other flow path ”, and a part of the part It may be configured such that the shape of the front end surface of the outer peripheral portion is not parallel to each other so that other adjacent portions sequentially meet.

  Hereinafter, the injection mold according to this aspect will be described with reference to the drawings. Fig.1 (a) is a schematic diagram for demonstrating the form of resin which flows through the inside of a flow path. In FIG. 1A, the resin flow R flows in a flow path (cavity) 100 having a cylindrical shape in a direction indicated by a white arrow in the drawing. At this time, generally, the leading portion FF of the resin flow R has a convex shape that protrudes in the flow direction (that is, the direction indicated by the white arrow in the figure) as it is away from the wall surface W that defines the flow path (cavity) 100. It is considered to have Further, generally, the direction of the flow of the resin constituting the resin flow R is curved along the front end surface FFS in the vicinity of the front end surface FFS of the head portion FF, as shown by the broken arrow in the figure. It is thought to go to W. Thus, the resin injected into the flow path is generally considered to flow through the flow path in the form of a fountain.

  In the above-mentioned “site where the resin meets”, the leading portions of the resin flow having such a convex shape come into contact with each other. Therefore, in the top portion FF of the resin flow, “the resin flowing in the position corresponding to the vicinity of the surface of the molded body (that is, the vicinity of the wall surface W defining the cavity)” is visible from the outside of the molded body. This is thought to have a particular impact on Therefore, in the following, the head portion FF of the resin flow will be examined in more detail.

  FIG. 1B is an enlarged view of the leading portion FF of the resin flow R shown in FIG. In FIG. 1B, the hatched area in the figure represents the “outer peripheral portion OPP” that is a portion in the vicinity of the wall surface W in the head portion FF of the resin flow R. In the resin flow control step of the injection molding method according to this aspect, the front end surface FFS of the leading portion FF of the resin flow R is set so that the outer peripheral portion OPP properly meets from the viewpoint of suppressing the weld line from being visually recognized. The shape is controlled.

  FIG. 2A to FIG. 2D are schematic views for explaining how the leading portions of the two resin flows are associated with each other in this embodiment. In the resin flow control step of the injection molding method of this aspect, as shown in FIG. 2A, the outside of the vicinity of the wall surface W that defines the cavity in the leading portion FF1 of the resin F1 that flows in the one flow path 201. The distal end surface of the peripheral portion OPP1 and the distal end surface of the outer peripheral portion OPP2 in the vicinity of the wall surface W defining the cavity among the leading portion FF2 of the resin F2 flowing in the other flow path 202 are not parallel to each other. Is done.

  Thereby, as shown in FIG. 2B, when the tip surface of the outer peripheral portion OPP1 of the resin flow F1 and the tip surface of the outer peripheral portion OPP2 of the resin flow F2 meet, Meeting begins from a part of them (see the meeting point CP1 in FIG. 2B). Next, as shown in FIG. 2 (c) and FIG. 2 (d), other parts adjacent to the meeting part successively meet (the meeting point CP2 in FIG. 2 (c) and the meeting in FIG. 2 (d)). (See point CP3.)

  As described above, when the outer peripheral portion OPP1 and the outer peripheral portion OPP2 sequentially meet, the outer peripheral portions OPP1 and OPP2 are arranged in the same direction as the direction in which the meeting points (that is, the meeting points CP1 to CP3) move. It is thought that the resin inside flows. As a result, it is considered that “the resin flows along the wall surface W that defines the flow path in the vicinity of the portion where the resin is associated” (for example, see at least the broken line arrow in the region ACP in FIG. 2D). As a result, it is possible to prevent the “bias of the resin characteristics” from occurring, and thus it is possible to suppress the weld line from being visually recognized.

  Here, the above-mentioned “outer peripheral portion” is at least one portion of the top portion of the resin flowing through the flow path and a portion (region) to the extent that the object of the present invention is achieved as described above. To express. That is, the “outer peripheral portion” may be a part of the top portion of the resin flowing through the flow path or the entire top portion of the resin flowing through the flow path.

  Furthermore, the above-mentioned “the distal end surface of the outer peripheral portion OPP1 and the distal end surface of the outer peripheral portion OPP2 are not parallel to each other” means that the plane including the downstream end surface of the outer peripheral portion OPP1 and the outer peripheral portion OPP2 This means that the plane including the downstream end face is not at least parallel to the plane. It should be noted that the plane including the portion other than the downstream end face of the outer peripheral portion OPP1 and the plane including the portion other than the downstream end face of the outer peripheral portion OPP2 may or may not be parallel. .

  In addition, when there is no end face on the downstream side of the outer peripheral portions OPP1 and OPP2 (that is, as shown in FIG. 3A, for example, the outer peripheral portions OPP1 and OPP2 converge to one end point on the downstream side thereof. ) “The front end surface of the outer peripheral portion OPP1 and the front end surface of the outer peripheral portion OPP2 are not parallel to each other” means that the tangential plane at the downstream end point of the outer peripheral portion OPP1 and the downstream side of the outer peripheral portion OPP2 The tangent plane at the end point of is not at least parallel. Similarly to the above, the tangent plane at a point other than the downstream end point of the outer peripheral portion OPP1 and the tangent plane at a point other than the downstream end point of the outer peripheral portion OPP2 may be parallel or not parallel. Good.

Furthermore, as another aspect of the injection molding method of the present invention,
The injection molding method is:
In the resin flow control step, the leading portion of the resin flowing in the flow path is “before” the leading end surfaces “other than” the leading end surfaces of the outer peripheral portion of the leading portion of the resin flowing in the flow path are in contact with each other. The front peripheral surfaces of the outer peripheral portions may be configured to be associated with each other.

  FIG. 3A to FIG. 3D are schematic views for explaining how the leading portions of the two resin flows are associated with each other in this embodiment. In the resin flow control step of the injection molding method of this aspect, as shown in FIG. 3A, the outside of the vicinity of the wall surface W that defines the cavity in the leading portion FF1 of the resin F1 that flows in one flow path 301. The distal end surface of the peripheral portion OPP1 has a shape in which the resin constituting the resin F1 does not exist on the downstream side of the distal end surface. Furthermore, the front end surface of the outer peripheral portion OPP2 in the vicinity of the wall surface W that defines the cavity in the front portion FF2 of the resin F2 that flows in the other flow path 302 forms the resin F2 on the downstream side of the front end surface. The shape does not exist.

  Thereby, as shown in FIG. 3B, the front end surface of the outer peripheral portion OPP1 of the resin flow F1 and the front end surface of the outer peripheral portion OPP2 of the resin flow F2 are the same as the outer peripheral portions OPP1 and OPP2. The tip surfaces “other than” the tip surfaces meet “in front” where they contact each other. Further, similarly to the above “one aspect”, the distal end surface of the outer peripheral portion OPP1 and the distal end surface of the outer peripheral portion OPP2 start to meet from a part thereof (see the meeting point CP1 in FIG. 3B). Other parts adjacent to the meeting part successively meet (see the meeting point CP2 in FIG. 3C and the meeting point CP3 in FIG. 3D).

  At this time, as the outer peripheral portions OPP1 and OPP2 are sequentially associated with each other, the resin inside the outer peripheral portions OPP1 and OPP2 is arranged in a direction substantially the same as the direction in which the meeting points (that is, the meeting points CP1 to CP3) move. Is thought to flow. In this embodiment, there is substantially no substance that hinders the movement of the meeting point (that is, the meeting point CP1 to the meeting point CP3) in the moving direction. Therefore, the meeting points CP1 to CP3 of the outer peripheral portions OPP1 and OPP2 can move more smoothly than the “one aspect”. As a result, it is considered that “the resin flows more smoothly along the wall surface W defining the flow path in the vicinity of the portion where the resin meets” (for example, see at least the broken line arrow in the region ACP in FIG. 3D) .) As a result, the occurrence of “unevenness in resin characteristics” is further prevented, and thus the visual recognition of the weld line is further suppressed.

In the injection molding method of each aspect described above,
The injection molding method is:
In the resin flow control step, when the resin flowing in the flow path begins to associate, “the flow velocity of the head portion of the resin flowing in the one flow path” and “the flow speed of the resin flowing in the other flow path” At least one of “part flow velocity” may be configured to be “controlled” depending on the nature of the resin flowing in these flow paths.

Furthermore, as one aspect of the injection molding method,
The injection molding method is:
In the resin flow control step, when the resin flowing in the flow path begins to associate, “the flow velocity of the head portion of the resin flowing in the one flow path” is “the flow speed of the resin flowing in the other flow path”. It can be configured to be greater than the “partial flow rate”.

  The flow rate of the resin when the resin flowing in the flow path begins to associate affects the amount of resin that can flow in the outer peripheral portion from the time when the resin begins to associate until the resin solidifies. . Therefore, in addition to “the shape of the front end surface of the resin flowing in the flow path”, “the flow velocity of the resin leading part flowing in the flow path” is controlled according to the properties of the resin. Is further suppressed from being visually recognized.

  For example, depending on the nature of the resin, as in the above embodiment, the “flow velocity of the leading portion of the resin flowing in the one flow path” when the resin flowing in the flow path begins to associate is “the flow of the other flow”. By making it larger than the “flow velocity of the leading portion of the resin flowing in the road”, it is further suppressed that the weld line is visually recognized.

As a specific aspect of the injection molding method of the present invention,
The injection molding method is:
In the resin flow control step,
(C) “The resin flowing in the one flow path after the resin flowing in the one flow path passes through a predetermined position of the one flow path is associated with the resin flowing in the other flow path. The resin is injected into a predetermined position of the one flow path by “to begin”,
and,
(D) “The resin flowing in the other flow path after the resin flowing in the other flow path passes through a predetermined position of the other flow path is associated with the resin flowing in the one flow path. The resin is discharged from a predetermined position of the other flow path by
By at least one of
Resin in which at least one of “the shape of the tip surface of the leading portion of the resin flowing in the one channel” and “the shape of the tip surface of the leading portion of the resin flowing in the other channel” flows in these channels It can be configured to be controlled according to the nature of the.

  In the resin flow control step of the injection molding method having the above configuration, when the resin is injected into one flow path as shown in (C) above, “the predetermined position that is the position where the resin is injected into one flow path” The amount of resin that flows through the “position close to the injection position” in the flow channel downstream of the position (hereinafter referred to as “injection position” for convenience) flows through the “position away from the injection position”. More than the amount of resin. That is, the closer to the injection position, the more resin flows in the flow path. As a result, the leading portion of the resin flowing in the one flow path has a shape that protrudes in the flow direction as it approaches the injection position (see, for example, the shape of the leading portion FF1 in FIG. 3A). Thus, the shape of the front end surface of the leading portion of the resin flowing in the flow path can be changed by injecting the resin from the injection position.

  In contrast, in the resin flow control step of the injection molding method having the above configuration, when the resin is discharged from the other flow path as shown in (D) above, “the resin is discharged from the other flow path. The amount of resin flowing through the “position close to the discharge position” downstream from the predetermined position (hereinafter referred to as “discharge position” for convenience) ”flows through the“ position away from the discharge position ”. Less than the amount of resin. In other words, as the distance from the discharge position increases, the amount of resin flowing in the flow path increases. As a result, the leading portion of the resin flowing in the other flow path has a shape that protrudes in the flow direction as the distance from the discharge position increases (see, for example, the shape of the leading portion FF2 in FIG. 3A). Thus, by discharging the resin from the discharge position, the shape of the front end surface of the leading portion of the resin flowing in the flow path can be changed.

  Thus, the shape of the leading portion of the resin flowing in the flow path can be changed by either (C) or (D). Therefore, in the resin flow control step of this aspect, the shape of the front end surface of the leading portion of the resin flowing in the flow path is controlled according to the properties of the resin by at least one of the above (C) and (D). .

  Here, in this resin flow control step, the injection position, the amount of resin injected from the injection position, the time when the resin is injected from the injection position, and the discharge position, the amount of resin discharged from the discharge position, Further, by changing the timing of discharging the resin from the discharge position, the shape of the leading portion of the resin flowing in the flow path can be controlled to a desired shape.

In the injection molding method of the specific embodiment,
In the resin flow control step, when the predetermined position of the one flow path is defined as a “first predetermined position”, the resin flowing in the one flow path is different from the first predetermined position. The resin is injected from the second predetermined position after passing through the second predetermined position until the resin flowing in the one passage begins to associate with the resin flowing in the other flow path. Can be configured as follows.

  As described above, in the injection molding method of the above aspect, the tip surface of the leading portion of the resin flowing in one flow path is obtained by injecting the resin from the first predetermined position into the resin flowing in one flow path. The shape is controlled. Therefore, in the injection molding method of the above aspect, the shape of the front end surface of the leading portion of the resin flowing in one flow path cannot be controlled sufficiently, for example, by injecting the resin from the first predetermined position. In some cases, the resin may be injected into one flow path from a second predetermined position different from the first predetermined position. That is, the injection molding method of the above aspect may be configured such that the resin is injected into one flow path from a plurality of locations (first predetermined location and second predetermined location). Thereby, the shape of the front end surface of the leading portion of the resin flowing in one flow path can be controlled with higher accuracy.

Furthermore, in the injection molding method of the present invention including each aspect described above,
The resin may be configured to contain a glitter.

  As described above, when a bright body is contained in the resin, there is a possibility that “bias of the orientation direction of the bright body” may occur in the vicinity of the portion where the resin is associated. However, as described above, if the shape of the front end surface of the flow of the resin is controlled, the portion where the resin meets after the resin flowing in the flow path starts to associate until the resin solidifies In the vicinity, the resin can flow along the wall surface defining the flow path (see, for example, the broken line arrow in the region ACP in FIG. 2D). Thereby, the orientation of the luminous body in the vicinity of the portion where the resin is associated and the orientation of the luminous body in the portion other than the vicinity of the portion where the resin is associated are substantially the same at least in the region near the wall surface defining the flow path. Become. That is, it is possible to prevent the occurrence of “bias in the orientation direction of the luminous body”. Therefore, even when the resin containing the glitter is applied to the above-described injection molding method, the weld line is suppressed from being visually recognized.

It is a schematic diagram which shows the form of the molding material which flows through the inside of a flow path. It is a schematic diagram which shows one form of this to-be-molded material when the to-be-molded material which flows through the inside of a flow path meets. It is a schematic diagram which shows the other form of this to-be-molded material when the to-be-molded material which flows through the inside of a flow path meets. It is a schematic diagram which shows one Embodiment of the metal mold | die for injection molding of this invention. It is a schematic diagram which shows a mode that a to-be-molded material is inject | poured into the injection die shown in FIG. It is a schematic diagram which shows a mode that a to-be-molded material is inject | poured into the injection die shown in FIG. It is a schematic diagram which shows a mode that a to-be-molded material is inject | poured into the injection die shown in FIG. It is a schematic diagram which shows a mode that a to-be-molded material is inject | poured into the injection die shown in FIG.

  Hereinafter, embodiments of an injection mold according to the present invention and embodiments of an injection molding method will be described with reference to the drawings.

(Injection mold)
First, an embodiment of an “injection mold” according to the present invention will be described.
As shown in FIG. 4, the injection mold 10 of the present embodiment includes a mold body 11, a cavity 21, a first injection port 31, a second injection port 32, a discharge port 33, a discharge material reservoir 41, 1 control valve 51, 2nd control valve 52, and 3rd control valve 53 are provided. By injection-injecting a predetermined molding material into the injection mold 10, a molded body having a predetermined shape (annular shape in the present embodiment) is obtained (injection-molded). It has become.

  The mold body 11 has a plurality of members (not shown) made of a material (for example, metal) having a melting point higher than the melting point of the molding material injected into the injection mold 10. Each of the plurality of members has a recess corresponding to a part of the wall surface defining the cavity 21. And the cavity 21 is comprised in the inside of the metal mold | die main body 11 by combining these several members.

  The cavity 21 is configured inside the mold body 11 as described above. The cavity 21 has an annular shape corresponding to the shape of the molded body. When the molded body is injection-molded, a molding material is injected into the cavity 21. When the molding material is injected into the cavity 21, the cavity 21 has an annular shape. Therefore, the flow of the molding material injected into the cavity 21 is the first flow (for example, the counterclockwise in FIG. 5A). The flow is branched into two flows, a flow F1) in the rotating direction and a second flow (for example, a flow F2 in the clockwise direction in FIG. 5A). Each of the first flow and the second flow travels in the cavity 21 (see, for example, FIG. 6A). The first flow and the second flow meet at a predetermined location in the cavity 21 (see, for example, FIG. 7A). Thus, the cavity 21 has two flow paths connected to each other at the end.

  The first injection port 31 has one end connected to the first position of the cavity 21 and the other end connected to a molding material injection device (not shown) provided outside the mold body 11. It is a passage for passing material. That is, the first inlet 31 opens toward the cavity 21. When the molded body is injection-molded, the material to be molded is injected into the cavity 21 through the first injection port 31 at a predetermined timing as shown by the white arrow in FIG.

  The second injection port 32 has one end connected to a second position different from the first position of the cavity 21 and the other end provided outside the mold body 11 (not shown). ) Is a passage for allowing the material to be molded connected thereto to pass through. More specifically, the second position is a predetermined position on the flow path through which the first flow flows. In other words, the second inlet 32 opens toward the flow path through which the first flow flows. When the molded body is injection-molded, the material to be molded is injected into the cavity 21 through the second injection port 32 at a predetermined timing as shown by the white arrow in FIG. The molding material injection device to which the second injection port 32 is connected may be the same as or different from the molding material injection device to which the first injection port 31 is connected.

  The discharge port 33 is connected to a molding material having one end connected to a third position different from both the first position and the second position of the cavity 21 and the other end connected to a discharge material reservoir 41. It is a passage for making it. More specifically, the third position is a predetermined position on the flow path through which the second flow flows. That is, the discharge port 33 opens toward the flow path through which the second flow flows. When the molded body is injection-molded, the material to be molded is discharged from the cavity 21 to the discharge material reservoir 41 through the discharge port 33 as shown by the white arrow in FIG. 4 at a predetermined timing.

  The discharge material reservoir 41 is a cavity having a substantially rectangular parallelepiped shape. When the molded body is injection-molded, as shown by the white arrow in FIG. 4 at a predetermined timing, the molding material injected into the cavity 21 and unnecessary for the molded body (that is, the cavity) The difference between the amount of the molding material injected into 21 and the amount of the molding material necessary for constituting the molded body) is discharged from the cavity 21 to the discharge material reservoir 41 through the discharge port 33. ing.

  The first control valve 51 is a control valve that switches between conduction and blocking of the first inlet 31. More specifically, the first control valve 51 allows the molding material to pass through the first inlet 31 when the first control valve 51 is opened, and the first control valve 51 is closed. The molding material is configured so that it cannot pass through the first injection port 31 when being formed.

  The second control valve 52 is a control valve that switches between conduction and blocking of the second inlet 32. More specifically, the second injection port 32 allows the molding material to pass through the second injection port 32 when the second control valve 52 is opened, and the second control valve 52 is closed. The molding material is configured so that it cannot pass through the second injection port 32 when being formed.

  The third control valve 53 is a control valve that switches between conduction and interruption of the discharge port 33. More specifically, the third control valve 53 is configured such that when the third control valve 53 is opened, the molding material can pass through the discharge port 33, and the third control valve 53 is closed. The material to be molded is configured so that it cannot pass through the discharge port 33 when it is in operation. The above is the embodiment of the injection mold according to the present invention.

(Injection molding method)
Next, an embodiment of the “injection molding method” of the present invention will be described.
In the injection molding method of the present embodiment, the above-described injection mold 10 is employed. By injecting a predetermined molding material into the injection mold 10, the molded body can be obtained (injection molding).

  In the injection molding method of the present embodiment, a mixture of a resin and a luminous body (hereinafter simply referred to as “mixture” for convenience) is used as a material to be molded. As this resin, an appropriate resin considering the strength and durability required for the molded body is employed. Further, as this glittering body, an appropriate glittering body taking into consideration the aesthetics required for the molded body is employed. In addition, the content of the luminous body relative to the resin in the mixture is set to an appropriate value in consideration of the strength and durability required for the molded body, the aesthetics required for the molded body, and the like. The luminous body has a prolate ellipsoidal shape, and is a material in which the reflectance of light in the axial direction is different from the reflectance of light in the direction perpendicular to the axial direction.

  First, the mold body 11 has a mold temperature control provided outside the mold body 11 in a state where the plurality of members are combined before the mixture is injected into the injection mold 10. The apparatus (not shown) is heated until the temperature reaches a predetermined temperature. When the temperature of the mold body 11 reaches the predetermined temperature, the temperature of the mold body 11 is maintained at the predetermined temperature by the mold temperature control device. This predetermined temperature is set to an appropriate temperature from the viewpoint of obtaining a good molded article when the mixture is injection molded using the injection mold 10. This predetermined temperature depends on the properties of the mixture (resin properties such as viscosity and elastic modulus of the resin, properties of the luminous body such as the shape, size and light reflectance of the luminous body, and the content of the luminous body relative to the resin, etc. ).

  When the temperature of the mold body 11 is maintained at the predetermined temperature, the mixture is injected and injected into the injection mold 10. More specifically, first, the mixture melted and pressurized by a molding material injection device (not shown) is passed through the first injection port 31 and injected into the cavity 21. That is, the first control valve 51 is opened at a predetermined timing.

  FIG. 5A is a schematic view when the state of the mixture flowing in the cavity 21 at this time (that is, the flow of the mixture) is viewed from one direction (above the mold body 11). b) is a schematic view when the flow of the mixture at this time is viewed from another direction (side of the mold body 11) orthogonal to the one direction. The mixture injected into the cavity 21 through the first inlet 31 branches into a first flow F1 and a second flow F2, as shown in FIGS. Progress (flow) inside. At this time, the leading portion of the first flow F1 is upstream of the portion where the second inlet 32 is provided, and the leading portion of the second flow F2 is upstream of the portion where the discharge port 33 is provided. It is in.

  At this time, the front end surface of the outer peripheral portion OPP1 of the first flow F1 and the front end surface of the outer peripheral portion OPP2 of the second flow F2 are substantially parallel as shown in FIG. Further, at this time, both the second control valve 52 and the third control valve 53 are closed.

  Next, after the leading portion of the first flow F1 passes through the portion where the second inlet 32 is provided, the leading portion of the first flow F1 starts to meet the leading portion of the second flow F2. The mixture melted and pressurized by a molding material injection device (not shown) is passed through the second injection port 32 and injected into the cavity 21 (the channel through which the first flow F1 flows). That is, the period from when the leading portion of the first flow F1 passes through the portion where the second inlet 32 is provided until the leading portion of the first flow F1 begins to meet the leading portion of the second flow F2. The second control valve 52 is opened at the predetermined timing. This predetermined timing is set to an appropriate time according to the properties of the mixture.

  Furthermore, after the leading portion of the second flow F2 passes through the portion where the discharge port 33 is provided, the mixture does not start until the leading portion of the second flow F2 begins to associate with the leading portion of the first flow F1. The discharge port 33 is passed through the cavity 21 (the flow path through which the second flow F2 flows) and discharged to the discharge material reservoir 41. That is, a predetermined timing from when the leading portion of the second flow F2 passes through the portion where the discharge port 33 is provided until the leading portion of the second flow F2 starts to associate with the leading portion of the first flow F1. Thus, the third control valve 53 is opened. This predetermined timing is set to an appropriate time according to the properties of the mixture.

  FIG. 6A is a schematic view when the flow of the mixture at this time is viewed from the one direction, and FIG. 6B is a schematic view when the flow of the mixture at this time is viewed from the other direction. FIG.

  At this time, since the mixture is passed through the second inlet 32 and injected into the flow path through which the first flow F1 flows, the second inlet on the downstream side of the portion where the second inlet 32 is provided. The amount of the mixture flowing near the position 32 is larger than the amount of the mixture flowing away from the second inlet 32. That is, the closer to the second inlet 32, the greater the amount of the mixture flowing in this flow path. Therefore, at this time, the leading end surface of the leading portion of the first flow F1 has a shape that protrudes in the flow direction as it approaches the second inlet 32, as shown in FIG. 6B. Furthermore, if the amount of the mixture injected into the flow path is equal to or greater than a predetermined amount, the leading end surface of the first flow F1 is downstream of the leading end surface of the outer peripheral portion OPP1 of the first flow F1. On the side, there is a shape in which no tip surface other than the tip surface of the outer peripheral portion OPP1 exists. This predetermined amount is determined according to the nature of the mixture, the flow rate of the first flow F1, the frictional force between the wall surface defining the cavity 21 and the mixture, and the like.

  On the other hand, at this time, since the mixture is passed through the discharge port 33 and discharged from the flow path through which the second flow F2 flows, the position closer to the discharge port 33 on the downstream side than the portion where the discharge port 33 is provided. The amount of the mixture flowing through is less than the amount of the mixture flowing through the position away from the discharge port 33. That is, as the distance from the discharge port 33 increases, the amount of the mixture flowing in the flow path increases. Therefore, at this time, the leading end surface of the leading portion of the second flow F2 has a shape that protrudes in the flow direction as the distance from the discharge port 33 increases, as shown in FIG. Furthermore, if the amount of the mixture discharged from the flow path is equal to or greater than a predetermined amount, the leading end surface of the second flow F2 is further downstream than the leading end surface of the outer peripheral portion OPP2 of the second flow F2. On the side, there is a shape in which no tip surface other than the tip surface of the outer peripheral portion OPP2 exists. This predetermined amount is determined according to the nature of the mixture, the flow rate of the second flow F2, the frictional force between the wall defining the cavity 21 and the mixture, and the like.

  Further, at this time, as shown in FIG. 6B, the front end surface of the outer peripheral portion OPP1 of the first flow F1 and the front end surface of the outer peripheral portion OPP2 of the second flow F2 are not parallel. In addition, since the flow velocity of the mixture is considered to be proportional to the amount of the mixture present in the flow path, the flow velocity of the first portion of the first flow F1 is higher than the flow velocity of the first portion of the second flow F2. large.

  Next, the leading portion of the first flow F1 and the leading portion of the second flow F2 having the shape described above meet. FIG. 7A is a schematic view when the flow of the mixture at this time is viewed from the one direction, and FIG. 7B is a schematic view when the flow of the mixture at this time is viewed from the other direction. FIG. As shown in FIG. 7A, the leading portion of the first flow F1 and the leading portion of the second flow F2 meet at a predetermined meeting position CP. Thus, by the first inlet 31 and the first control valve 51 (depending on the nature of the mixture, the first inlet 31, the second inlet 32, the outlet 33, the first control valve 51, the second control valve 52). And the third control valve 53) so that the mixture flowing in these flow paths is associated with each other at the portion where the two flow paths are connected to each other (in this embodiment, the meeting position CP). The mixture is injected into the.

  At this time, as described above, the front end surface of the outer peripheral portion OPP1 of the first flow F1 and the front end surface of the outer peripheral portion OPP2 of the second flow F2 are not parallel (see FIG. 6B). As shown in FIG. 7B, the front end surface of the outer peripheral portion OPP1 of the first flow F1 and the front end surface of the outer peripheral portion OPP2 of the second flow F2 start to meet from a part of them and The other parts adjacent to the selected part meet sequentially. That is, the meeting point CPE shown in FIG. 7B moves downward in FIG. 7B.

  Further, as described above, the flow velocity at the leading portion of the first flow F1 is larger than the flow velocity at the leading portion of the second flow F2, and therefore the front end surface of the outer peripheral portion OPP1 of the first flow F1 and the second The meeting surface CF, which is a surface in contact with the tip surface of the outer peripheral portion OPP2 of the flow F2, is not orthogonal to the flow direction of the first flow F1 and the flow direction of the second flow F2. That is, the meeting surface CF and the wall surface defining the cavity 21 (the surface of the molded body) intersect so as to form a predetermined angle that is not perpendicular.

  In addition, at this time, it is considered that the mixture inside the outer peripheral portion OPP1 and the outer peripheral portion OPP2 flows in a direction substantially the same as the direction in which the meeting point CPE moves. If the mixture flows in this manner, the first flow F1 is near the position where the tip surface of the outer peripheral portion OPP1 of the first flow F1 and the tip surface of the outer peripheral portion OPP2 of the second flow F2 meet. The mixture that forms the outer peripheral portion OPP1 and the mixture that forms the outer peripheral portion OPP2 of the second flow F2 flow along the wall surface W that defines the cavity 21 (see the broken-line arrows shown in FIG. 7B). reference.). That is, the mixture flows along the wall surface defining the flow path in the vicinity of the site where the mixture meets.

  The cavity 21 is then completely filled with the first flow F1 and the second flow F2. FIG. 8A is a schematic diagram when the flow of the mixture at this time is viewed from the one direction, and FIG. 8B is a schematic diagram when the flow of the mixture at this time is viewed from the other direction. FIG. Until the cavity 21 is completely filled with the mixture in this way, as shown in FIG. 8B, the front end surface of the outer peripheral portion OPP1 of the first flow F1 and the outer peripheral portion of the second flow F2 In the vicinity of the position where the front end surface of OPP2 meets, the mixture constituting the outer peripheral portion OPP1 of the first flow F1 and the mixture constituting the outer peripheral portion OPP2 of the second flow F2 are wall surfaces that define the cavity 21. It flows along W (see the broken line arrow shown in FIG. 8B).

  Further, when the cavity 21 is completely filled with the mixture, as shown in FIG. 8B, the meeting surface CF and the wall surface (the surface of the molded body) defining the cavity 21 are not perpendicular to each other. It intersects to make. At this time, the discharged material reservoir 41 is filled with the discharged mixture that has been passed through the discharge port 33.

  Thereafter, the temperature of the mold main body 11 is lowered by a mold temperature control device (not shown) until reaching a predetermined temperature at which the resin constituting the mixture is solidified. After a predetermined time has elapsed since the temperature of the mold body 11 reaches the predetermined temperature, the mold body 11 is separated into the plurality of members. And a molded object is taken out from the inside of the isolate | separated metal mold body 11.

  Further, when the molded body is taken out from the mold main body 11, the solidified product obtained by solidifying the mixture discharged into the discharge material reservoir 41 is also taken out from the mold main body 11. When the solidified product and the molded body are connected, the solidified product is cut from the molded body. The above is the embodiment of the injection molding method according to the present invention.

  In FIGS. 7A and 8A, a linear boundary line is shown at the position where the leading portion of the first flow F1 and the leading portion of the second flow F2 meet. . This boundary line is an ideal boundary line for explaining the state in which the resins are associated in the present embodiment, and does not indicate a weld line.

(Summary of embodiment)
Thus, in the embodiment of the injection mold and the injection molding method of the present invention, the timing at which the mixture is injected into the flow path in which the first flow F1 flows (that is, the first flow F1) according to the properties of the mixture (that is, the first 2 timing when the second control valve 52 provided at the inlet 32 is opened), and timing when the mixture is discharged from the flow path through which the second flow F2 flows (that is, provided at the outlet 33). The timing at which the third control valve 53 is opened) is controlled.

  As a result, the mixture flowing in the flow path (the first flow F1 and the second flow F2) starts to associate until the mixture solidifies (at least the first portion of the first flow F1 and the second flow (From the beginning of the flow F2 to the beginning of the flow F2 until the cavity 21 is completely filled), in the vicinity of the site where the mixture meets, the mixture along the wall W defining the flow path (cavity) 21 Can flow (see dashed arrows shown in FIGS. 7 (b) and 8 (b)). Therefore, the deviation of the characteristics of the mixture and the deviation of the orientation direction of the luminous body in the vicinity of the site where the mixture is associated are suppressed. As a result, according to the present embodiment, a molded body in which the weld line is suppressed from being visually recognized is obtained.

  Furthermore, as described above, generally, the material to be molded is not sufficiently mixed in the portion where the weld line is visually recognized. In other words, the molding material is not sufficiently bonded at this portion. Therefore, in general, the mechanical strength (for example, tensile strength) of the molded body at the site where the weld line is visually recognized is inferior to the mechanical strength of the molded body at the site where the weld line is not visually recognized.

  On the other hand, in the embodiment of the injection mold and the injection molding method of the present invention, the meeting surface CF of the mixture and the wall surface W (the surface of the molded body) defining the cavity 21 are not at a predetermined angle. (Refer to FIG. 8B). The area of the meeting surface CF is larger than the area of the meeting surface CF when the meeting surface CF and the wall surface W defining the cavity 21 intersect perpendicularly (see, for example, FIG. 3D). That is, in the molded body obtained in the above embodiment, the area where the mixture constituting the first flow F1 and the mixture constituting the second flow F2 can be joined is expanded. As a result, the mechanical strength in the vicinity of the meeting position CP of the molded body obtained in the above-described embodiment (generally the site where the weld line is visually recognized) It is superior to the mechanical strength. In other words, according to the present embodiment, a molded body having improved mechanical strength in the vicinity of the meeting position can be obtained.

As described above, the injection mold 10 of the present invention is
A mold 10 for injection-molding a molded body having a predetermined shape with a resin (mixture; hereinafter omitted),
A cavity 21 having a shape corresponding to the predetermined shape, and at least two flow paths connected to each other at the end (in this embodiment, a flow path in which the first flow F1 flows and a second flow A cavity 21 having two flow paths) and a flow path through which F2 flows;
Resin injection means (first injection port 31 and first control valve 51) for injecting resin constituting the molded body into the flow path (cavity 21), where the flow path 21 is connected to each other. Resin injection means 31, 51 for injecting resin into the flow path 21 so that the resin flowing in the flow paths 21 meet;
The resin flows along the wall surface W defining the flow path 21 in the vicinity of the portion CP where the resin meets after the resin flowing in the flow path 21 starts to be solidified until the resin is solidified. (See FIGS. 7B and 8B), the leading portion of the resin F1 flowing in one flow path when the resin flowing in the flow path 21 starts to associate (specifically Specifically, at least one of the shape of the front end surface of the outer peripheral portion OPP1) and the shape of the front end portion of the resin F2 flowing in the other flow path (specifically, the outer peripheral portion OPP2) (this embodiment) In the form, both F1 and F2) are controlled according to the properties of the resin flowing in the flow passages 21 (characteristics of the mixture itself, characteristics of the luminous body, and content of the luminous body relative to the mixture). Control means (second injection 32, the second control valve 52, the outlet 33, the third control valve 53 and, provided with a resin reservoir 41), the.

In the injection mold 10 of the present invention,
The resin flow control means includes
When the resin flowing in the flow channel 21 begins to associate, the front end surface of the outer peripheral portion OPP1 in the vicinity of the wall surface W defining the cavity 21 among the leading portion of the resin F1 flowing in the one flow channel, Other than the front end portion of the outer peripheral portion OPP2 in the vicinity of the wall surface W defining the cavity 21 among the head portion of the resin F2 flowing in the other flow path, the first end portion of the resin F2 starts to meet from one portion and is adjacent to the meeting portion. So that the outer peripheral portions OPP1 and OPP2 are not parallel to each other (see FIG. 6 (b). ))).

Furthermore, in the injection mold 10 of the present invention,
The resin flow control means includes
The leading portions of the resins F1, F2 flowing in the flow channel 21 before the leading end surfaces other than the leading end surfaces of the outer peripheral portions OPP1, OPP2 of the leading portions of the resins F1, F2 flowing in the flow channel 21 contact each other. The front end surfaces of the outer peripheral portions OPP1 and OPP2 are configured to associate with each other (see FIG. 7B).

In addition, in the injection mold 10 of the present invention,
The resin flow control means includes
When the resins F1 and F2 flowing in the flow path 21 start to associate, at least one of the flow speed of the resin F1 flowing in the one flow path and the flow speed of the resin F2 flowing in the other flow path is Control is made in accordance with the properties of the resin flowing in the flow paths 21.

Specifically, in the injection mold 10 of the present invention,
The resin flow control means includes
When the resins F1 and F2 flowing in the flow path 21 start to associate, the flow rate of the leading portion OPP1 of the resin F1 flowing in the one flow path is set to the flow rate of the leading portion OPP2 of the resin F2 flowing in the other flow path. It is comprised so that it may become larger than a flow rate.

More specifically, in the injection mold 10 of the present invention,
The resin flow control means includes
When the resin injection means is the first resin injection means (the first injection port 31 and the first control valve 51), the second resin injection means (the first resin injection means 31, 51) is different from the first resin injection means (51). 2 injection ports 32 and a second control valve 52), second resin injection means 32, 52 for injecting resin into the one flow path (flow path through which the resin F1 flows),
Resin discharge means (discharge port 33 and third control valve 53) for discharging resin F2 flowing in the other flow path from the other flow path;
Have
The resin F1 flowing in the one flow path passes through a part where the second resin injection means 32, 52 injects resin into the one flow path (part where the second injection port 32 is provided). Until the resin F1 flowing in the one flow path starts to associate with the resin F2 flowing in the other flow path, the second resin injection means 32, 52 causes the resin to be injected into the one flow path. (Refer to FIGS. 6A and 6B), and the resin F2 flowing in the other flow path causes the resin discharging means 33 and 53 to change the resin F2 flowing in the other flow path. The resin F2 flowing through the other flow path after passing through the portion discharged from the other flow path (the portion where the discharge port 33 is provided) begins to associate with the resin F1 flowing through the one flow path. By the time, the resin discharge means 33, 53 flows through the other flow path. By discharging at least one of the resin F2 from the other channel (see FIGS. 6A and 6B) (both in the present embodiment), the inside of the one channel is made. At least one of the shape of the leading end surface of the leading portion OPP1 of the flowing resin F1 and the shape of the leading end surface of the leading portion OPP2 of the resin F2 flowing in the other flow path (both in the present embodiment) is within these flow paths. It is configured to control in accordance with the property of the resin flowing through.

More specifically, in the injection mold 10 of the present invention,
The first resin injection means includes a first resin injection port 31 that opens toward the cavity 21, and when the resin can pass through the first resin injection port 31 when the valve is opened and the valve is closed. And a first control valve 51 through which the resin cannot pass through the first resin inlet 31,
The second resin injection means includes a second resin injection port 32 that opens toward the one channel (a channel through which the first flow F1 flows), and the second resin injection port when the valve is opened. A second control valve 52 through which the resin can pass through 32 and the resin cannot pass through the second resin inlet 32 when closed.
The resin discharge means includes a resin discharge port 33 that opens toward the other flow channel (flow channel through which the second flow F2 flows), and the resin can pass through the resin discharge port 33 when the valve is opened. And a third control valve 53 through which the resin cannot pass through the resin outlet 33 when the valve is closed,
The resin flow control means includes
The first control valve 51 is opened at the first time point, and the resin F1 flowing in the one flow path passes through the portion where the second resin injection port 32 is open, and then the one flow path The second control valve 52 is opened at a second point in time until the resin F1 flowing inside begins to associate with the resin F2 flowing in the other channel, and the resin F2 flowing in the other channel At a third time point from when the resin F2 flowing through the other flow path starts to associate with the resin F1 flowing through the one flow path after passing through the portion where the resin discharge port 33 is open By opening the third control valve 53, the shape of the leading end portion of the leading portion OPP1 of the resin F1 flowing in the one flow path and the leading end surface of the leading portion OPP2 of the resin F2 flowing in the other flow path. The shape of the resin flowing through these channels Controlled according to, and is configured to.

Furthermore, in the injection mold 10 of the present invention,
The resin is configured to contain a bright body.

On the other hand, the injection molding method of the present invention is
An injection molding method for injection molding a molded body having a predetermined shape with a resin,
The resin constituting the molded body is a cavity 21 having a shape corresponding to the predetermined shape, and is connected to at least two flow paths (a flow path through which F1 flows and a flow path through which F2 flows). A resin injecting step (FIGS. 5A and 5) for injecting into the cavity 21 having two flow paths) so that the resin flowing in the flow paths 21 meets at a portion where the flow paths are connected to each other. (See (b).)
The resin flows along the wall surface W defining the flow path 21 in the vicinity of the portion CP where the resin meets after the resin flowing in the flow path 21 starts to be solidified until the resin is solidified. The shape of the front end surface of the leading portion OPP1 of the resin F1 flowing in one flow path when the resin flowing in the flow path 21 begins to associate and the top of the resin F2 flowing in the other flow path A resin flow control step for controlling at least one (both in the present embodiment) of the tip surface of the portion OPP2 in accordance with the property of the resin flowing in the flow path 21 (FIG. 6 (a) and FIG. 6 (b)).

In the resin flow control step of the injection molding method of the present invention,
When the resins F1 and F2 flowing in the flow channel 21 start to meet, the front end surface of the outer peripheral portion OPP1 in the vicinity of the wall surface W defining the cavity 21 among the leading portions of the resin F1 flowing in the one flow channel And the front end surface of the outer peripheral portion OPP2 in the vicinity of the wall surface W that defines the cavity 21 among the head portion of the resin F2 flowing in the other flow path begins to meet from a part thereof and the meeting portion The outer peripheral portions OPP1 and OPP2 are not parallel to each other so that other portions adjacent to each other sequentially meet (see FIGS. 7B and 8B). (See FIG. 6B).

Furthermore, in the resin flow control step of the injection molding method of the present invention,
The leading portions of the resins F1, F2 flowing in the flow channel 21 before the leading end surfaces other than the leading end surfaces of the outer peripheral portions OPP1, OPP2 of the leading portions of the resins F1, F2 flowing in the flow channel 21 contact each other. The front end surfaces of the outer peripheral portions OPP1 and OPP2 are configured to be associated with each other (see FIG. 7B).

In addition, in the resin flow control step of the injection molding method of the present invention,
When the resins F1 and F2 flowing in the flow path 21 start to associate, the flow rate of the leading portion OPP1 of the resin F1 flowing in the one flow path and the leading portion OPP2 of the resin F2 flowing in the other flow path At least one of the flow rate is configured to be controlled in accordance with the property of the resin flowing in the flow channel 21.

Specifically, in the resin flow control step of the injection molding method of the present invention,
When the resins F1 and F2 flowing in the flow path 21 start to associate, the flow velocity of the leading portion OPP1 of the resin F1 flowing in the one flow path is equal to that of the leading portion OPP2 of the resin F2 flowing in the other flow path. It is configured to be larger than the flow rate.

More specifically, in the resin flow control step of the injection molding method of the present invention,
After the resin F1 flowing in the one flow path passes through a predetermined position of the one flow path (a position where the second injection port 32 is provided in the present embodiment), the inside of the one flow path The resin is injected from a predetermined position (position where the second injection port 32 is provided) of the one flow path until the resin F1 flowing through the second flow path begins to associate with the resin F2 flowing through the other flow path. (See FIGS. 6 (a) and 6 (b).), And the resin F2 flowing in the other channel is in a predetermined position in the other channel (in this embodiment, the discharge port 33 is A predetermined position (discharge port) of the other flow path from when the resin F2 flowing through the other flow path starts to associate with the resin F1 flowing through the one flow path The resin is discharged from the position where 33 is provided (FIG. 6A). 6B)), and the shape of the front end surface of the leading portion OPP1 of the resin F1 flowing in the one flow path and the other flow path in the other flow path. At least one (in this embodiment, both) of the shape of the front end surface of the leading portion OPP2 of the resin F2 flowing through the resin F2 is controlled in accordance with the properties of the resin flowing through these flow paths.

Furthermore, in the injection molding method of the present invention,
The resin is configured to contain a bright body.

  The present invention is not limited to the above embodiments, and various modifications can be adopted within the scope of the present invention.

  For example, in the above-described embodiment, a mixture of a resin and a luminous body is used as the molding material. However, in the present invention, only a resin may be employed as the molding material. Furthermore, in the present invention, a mixture of a resin, a luminous body, and one or a plurality of other substances may be employed as the molding material.

  Further, in the above embodiment, both the injection of the mixture into the flow path in which the first flow F1 flows and the discharge of the mixture from the flow path in which the second flow F2 flows are performed. Yes. However, in the present invention, one of these may be performed.

  In addition, in the said embodiment, the 2nd injection port 32 is provided only in one place. However, in the present invention, the second inlet 32 may be provided at a plurality of locations. That is, the injection mold 10 may be configured to have a plurality of second injection ports 32. If the injection mold 10 has a plurality of second injection ports 32, the shape of the tip surface of the leading portion of the first flow F1 can be controlled more accurately. When the injection mold 10 has a plurality of second injection ports 32, the first flow F1 passes after the leading portion of the first flow F1 passes through the position where each of the plurality of second injection ports 32 is provided. Until the leading portion of the second flow F2 begins to associate with the leading portion of the second flow F2, the mixture is passed through each of the plurality of second inlets 32 and injected into the flow path through which the first flow F1 flows. That's fine.

  That is, when the second inlet 32 is provided at a plurality of locations, in the above-described resin flow control step of the injection molding method of the present invention, a predetermined flow path of the one flow path (flow path through which the first flow F1 flows) is determined. When the position (position where one of the plurality of second inlets 32 is provided) is the first predetermined position, the resin F1 flowing in the one flow path is the first Passing through a second predetermined position different from the predetermined position (a position where another second inlet 32 different from the one second inlet 32 among the plurality of second inlets 32 is provided). The resin (mixture) may be injected from the second predetermined position until the resin F1 flowing in the one passage starts to associate with the resin F2 flowing in the other flow path.

  Furthermore, in the present invention, each control valve (the first control valve 51, the second control valve 52, and the third control valve 53) is a mixture that passes through a portion where each control valve is provided according to the opening degree. It may be configured to be able to adjust the amount. In addition, in the present invention, the opening degree of each control valve may be adjusted according to the property of the mixture.

DESCRIPTION OF SYMBOLS 10 ... Mold for injection molding, 11 ... Mold body, 21 ... Cavity, 31 ... 1st resin injection port, 32 ... 2nd resin injection port, 33 ... Resin discharge Outlet, 41 ... resin reservoir, 51 ... first control valve, 52 ... second control valve, 53 ... third control valve, F1 ... first flow, F2 ... first 2 flow, OPP1, OPP2 ... outer peripheral part

Claims (17)

An injection mold for injection molding a molded body having a predetermined shape with a resin,
A cavity having a shape corresponding to the predetermined shape, the cavity having at least two flow paths connected to each other at an end portion;
Resin injecting means for injecting the resin constituting the molded body into the flow path, wherein the resin flows into the flow path so that the resin flowing in the flow paths meet at a portion where the flow paths are connected to each other. Resin injecting means for injecting;
The resin can flow along the wall surface defining the flow path in the vicinity of the portion where the resin meets after the resin flowing in the flow path starts to be solidified until the resin is solidified. The shape of the tip surface of the leading portion of the resin flowing in one channel when the resin flowing in the channel begins to associate with the shape of the tip surface of the leading portion of the resin flowing in the other channel. Resin flow control means for controlling at least one according to the properties of the resin flowing in these flow paths;
Mold for injection molding. In the injection mold according to claim 1,
The resin flow control means includes
When the resin flowing in the flow path begins to associate, the front end surface of the outer peripheral portion in the vicinity of the wall surface defining the cavity among the head portion of the resin flowing in the one flow path, and in the other flow path The leading end surface of the outer peripheral portion in the vicinity of the wall surface defining the cavity of the leading portion of the resin flowing through the resin, and the other portions adjacent to the meeting portion are sequentially associated with each other. An injection mold for making the shape of the front end surface of the outer peripheral portion not parallel to each other. The injection mold according to claim 1 or 2,
The resin flow control means includes
The leading end surfaces of the outer peripheral portion of the leading portion of the resin flowing in the flow path are associated with each other before the leading end surfaces other than the leading end surfaces of the outer peripheral portion of the leading portion of the resin flowing in the flow channel contact each other. , Mold for injection molding. In the injection mold according to any one of claims 2 and 3,
The resin flow control means includes
When the resin flowing in the flow path begins to associate, at least one of the flow speed of the resin flowing in the one flow path and the flow speed of the resin flowing in the other flow path flows in these flow paths. Injection mold that is controlled according to the properties of the resin. In the injection mold according to claim 4,
The resin flow control means includes
When the resin flowing in the flow path begins to associate, the flow rate of the head portion of the resin flowing in the one flow path is made larger than the flow speed of the head portion of the resin flowing in the other flow path. Mold for molding. An injection mold according to any one of claims 1 to 5,
The resin flow control means includes
When the resin injecting means is the first resin injecting means, the second resin injecting means is different from the first resin injecting means, and injects the resin into the one flow path. Injection means;
Resin discharging means for discharging the resin flowing in the other channel from the other channel;
Have
The resin flowing in the one flow path after the resin flowing in the one flow path passes through the portion where the second resin injection means injects the resin into the one flow path, Until the second resin injecting means injects the resin into the one flow path, and the resin flowing out in the other flow path is The resin discharge from the passage through which the resin flowing in the flow path is discharged from the other flow path until the resin flowing in the other flow path starts to associate with the resin flowing in the one flow path The shape of the front end surface of the leading portion of the resin flowing in the one flow path and the other flow path by at least one of causing the means to discharge the resin flowing in the other flow path from the other flow path Little difference from the shape of the tip of the top part of the resin flowing inside Kutomo while the controls depending on the nature of the resin flowing in these passages,
Injection mold. The injection mold according to claim 6, wherein
The first resin injection means includes: a first resin injection port that opens toward the cavity; and the first resin injection means that allows the resin to pass through the first resin injection port when the valve is opened and closes the first resin injection port. A first control valve through which the resin cannot pass through one resin inlet,
The second resin injection means includes a second resin injection port that opens toward the one flow path, and when the resin can pass through the second resin injection port when the valve is opened and the valve is closed. A second control valve through which the resin cannot pass through the second resin inlet,
The resin discharge means includes a resin discharge opening that opens toward the other flow path, and the resin discharge opening that allows the resin to pass through the resin discharge opening when the valve is opened and closes the resin discharge opening. A third control valve through which resin cannot pass,
The resin flow control means includes
The first control valve is opened at a first time point, and the resin flowing in the one flow path flows through the one flow path after passing through a portion where the second resin inlet is open. The second control valve is opened at a second time point until the resin starts to associate with the resin flowing in the other flow path, and the resin discharge port is opened by the resin flowing in the other flow path. The third control valve is opened at a third time from when the resin flowing in the other flow path passes through a portion that is in contact with the resin flowing in the one flow path. Accordingly, the shape of the leading end surface of the resin flowing in the one channel and the shape of the leading end surface of the resin flowing in the other channel according to the properties of the resin flowing in these channels Control
Injection mold. In the injection mold according to claim 6 or 7,
An injection mold having a plurality of the second resin injection means. In the injection mold according to any one of claims 1 to 8,
The resin is a mold for injection molding containing a luminous body. An injection molding method for injection molding a molded body having a predetermined shape with a resin,
A portion where the flow paths are connected to each other in a cavity having a shape corresponding to the predetermined shape and having at least two flow paths connected to each other at an end portion of the resin constituting the molded body A resin injection step of injecting the resin flowing in these flow paths so as to meet,
The resin can flow along the wall surface defining the flow path in the vicinity of the portion where the resin meets after the resin flowing in the flow path starts to be solidified until the resin is solidified. The shape of the tip surface of the leading portion of the resin flowing in one channel when the resin flowing in the channel begins to associate with the shape of the tip surface of the leading portion of the resin flowing in the other channel. A resin flow control step for controlling at least one of them in accordance with the properties of the resin flowing in these flow paths;
An injection molding method. The injection molding method according to claim 10,
In the resin flow control step, when the resin flowing in the flow path begins to associate, the front end surface of the outer peripheral portion in the vicinity of the wall surface defining the cavity among the head portion of the resin flowing in the one flow path And the front end surface of the outer peripheral portion in the vicinity of the wall surface defining the cavity among the leading portion of the resin flowing in the other flow path, and the other end portion adjacent to the associated portion The injection molding method, wherein the shapes of the front end surfaces of the outer peripheral portions are not parallel to each other so that the portions meet sequentially. In the injection molding method according to claim 10 or 11,
In the resin flow control step, the outer peripheral portion of the leading portion of the resin flowing in the flow path before the tip surfaces other than the leading end surfaces of the outer peripheral portion of the leading portion of the resin flowing in the flow channel contact each other An injection molding method in which the front end surfaces of each other are associated with each other. In the injection molding method according to any one of claims 10 to 12,
In the resin flow control step, when the resin flowing in the flow path begins to associate, the flow velocity of the leading portion of the resin flowing in the one flow passage and the flow of the leading portion of the resin flowing in the other flow passage An injection molding method in which at least one of the speed is controlled according to the property of the resin flowing in these flow paths. The injection molding method according to claim 13,
In the resin flow control step, when the resin flowing in the flow path starts to associate, the flow velocity of the front portion of the resin flowing in the one flow path is the flow rate of the front portion of the resin flowing in the other flow path. An injection molding method that is greater than the speed. In the injection molding method according to any one of claims 10 to 14,
In the resin flow control step, the resin flowing in the one flow path after the resin flowing in the one flow path passes through a predetermined position of the one flow path, and the resin flowing in the other flow path The resin is injected into a predetermined position of the one flow path before it starts to associate with the liquid flow path, and the resin flowing in the other flow path passes through the predetermined position of the other flow path. The resin is discharged from a predetermined position of the other flow path before the resin flowing in the other flow path starts to associate with the resin flowing in the one flow path. At least one of the shape of the leading end surface of the resin flowing in the path and the shape of the leading end surface of the resin flowing in the other flow path is controlled according to the properties of the resin flowing in the flow path , Injection molding method. The injection molding method according to claim 15,
In the resin flow control step, when the predetermined position of the one flow path is the first predetermined position, the resin flowing in the one flow path is different from the first predetermined position. An injection molding method in which a resin is injected from the second predetermined position after passing through a predetermined position and before the resin flowing in the one passage begins to associate with the resin flowing in the other flow path. In the injection molding method according to any one of claims 10 to 16,
An injection molding method in which the resin contains a luminous body.

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