JP2013193396A - Injection molding die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the time for cooling a molded product while avoiding complication of a die structure.SOLUTION: An injection molding die includes: an injection side mounting part 1 having a primary sprue 5 into which molten resin flows first from a nozzle; an injection side cavity plate 2 having a runner 7 communicating with the primary sprue 5 and guiding the molten resin to cavity parts 8 through secondary sprues 9; and a movable side cavity plate 3 separating from and approaching the injection side cavity plate 2 to form a resin molded product by the solidification of the molten resin that flows into the cavity parts 8, in cooperation with the injection side cavity plate 2. The injection side cavity plate 2 is configured to be capable of separating a resin solid 10 including a primary sprue resin solid part 5a, a runner resin solid part 7a' and a secondary sprue resin solid part 9a by separating from the injection side mounting part 1. The runner 7 is formed with a lightening protrusion 7b projected toward the primary sprue.

Description

  The present invention includes a primary sprue resin solid portion formed by solidification of a molten resin that has flowed into a primary sprue with respect to a molded product at the time of mold opening, and a runner resin solid portion that is formed by solidification of a molten resin that has flowed into a runner. The present invention relates to an improvement of a three-plate type injection molding die for producing a molded product by separating a resin solid material including a secondary sprue resin solid portion formed by solidification of a molten resin flowing into a secondary sprue.

  Conventionally, the primary sprue resin solid part formed by solidification of the molten resin flowing into the primary sprue with respect to the molded product when the mold is opened and the runner resin solid part formed by solidification of the molten resin flowing into the runner There is known a three-plate injection mold for producing a molded product by separating a resin solid material including a secondary sprue resin solid portion formed by solidification of molten resin flowing into the next sprue (for example, , See Patent Document 1).

  The thing disclosed by this patent document 1 is providing the unevenness | corrugation in a nozzle gate, a runner, a 1st sprue, and a 2nd sprue, the area of each heat-transfer wall is enlarged, and the cooling efficiency is improved. In addition, an air flow path is provided around the nozzle gate and the sprue, and cooling efficiency is enhanced by providing an air flow path along the bottom of the runner.

  In addition, in order to take a large number of molded products, the injection mold has a spout of the injection mold that communicates with the nozzle of the injection molding apparatus and has a convex injection molding core toward the injection molding apparatus. There is also known one (see Patent Document 2).

  By the way, in general, in the mold for injection molding which manufactures a molded product by separating resin solids from the molded product at the time of mold opening, the molten resin in the cavity can be cooled and solidified and taken out. Even so, the molten resin staying in the molten resin flow path between the sprue and the runner is not sufficiently cooled and solidified.

  Therefore, in order to forcibly shorten the molding cycle, if the resin solid material made of resin staying in the molten resin flow path between the sprue and the runner is removed from the injection mold, the resin solid material Since it is not cooled and solidified, the primary sprue resin solid part of the resin solid is divided and remains in the injection mold, or the unsolidified runner resin solid part of the resin solid is displaced due to deformation. Thus, there is a disadvantage that it cannot be removed using the automatic take-out mechanism.

  Thus, even if the solidification time of the molded product in the cavity is shortened, there is a disadvantage that the molding cycle of the molded product is restricted by the solidification time of the resin solid material and the molding cycle cannot be shortened.

  In view of such circumstances, in the three-plate injection mold disclosed in Patent Document 1, the nozzle gate, the runner, the first sprue and the second sprue are provided with irregularities so that each heat transfer wall Although the cooling efficiency is improved by increasing the area and increasing the cooling efficiency, and providing the air flow path around the nozzle gate and sprue, and providing the air flow path along the bottom of the runner, the mold structure It cannot be denied that it becomes complicated and the cost increases.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an injection mold that can shorten the cooling time of a molded product while avoiding the complexity of the mold structure. And

  An injection mold according to the present invention includes an injection-side mounting portion having a primary sprue into which molten resin first flows from a nozzle of an injection molding apparatus, and molten resin that is communicated with the primary sprue and flows into the primary sprue. An injection-side cavity plate having a runner that guides to the cavity part via the resin, and a resin molded product by solidification of the molten resin that is separated from and approaches the injection-side cavity plate and flows into the cavity part in cooperation with the injection-side cavity plate And a movable cavity plate for forming the.

  The injection side cavity plate is configured to be separated from the injection side mounting portion so as to be able to separate the resin solid matter including the primary sprue resin solid portion, the runner resin solid portion, and the secondary sprue resin solid portion. The movable side cavity plate is configured such that the resin molded product can be released.

  The runner has a lightening convex portion that protrudes toward the primary sprue to lighten the solid portion of the primary sprue resin at the communication location where the molten resin that has flowed into the primary sprue first strikes and changes the flow direction. Is formed.

  According to the present invention, the first sprue resin is formed at the communication portion between the runner and the primary sprue so that the first sprue resin protrudes toward the primary sprue and performs the lightening of the primary sprue resin solid portion. The connection part between the solid part and the runner resin solid part can be prevented from becoming thick, and the molten resin can be solidified faster than before. As a result, the cycle time of the resin molded product can be shortened.

FIG. 1 is a sectional view showing a mold opening state of an injection mold according to the present invention. FIG. 2 is a cross-sectional view showing a state in the middle of mold clamping of the injection mold according to the present invention, and is a cross-sectional view showing a state where the movable side cavity plate is in contact with the injection side cavity plate. FIG. 3 is a cross-sectional view showing a state in the middle of clamping of the injection mold according to the present invention, and is a cross-sectional view showing a state where the injection-side cavity plate is in contact with the stripper plate. FIG. 4 is a cross-sectional view showing the clamping state of the injection mold according to the present invention, and is a cross-sectional view showing a state in which the cavity portion of the injection mold is filled with molten resin. FIG. 5 is a cross-sectional view showing a state immediately before taking out the resin molded product by separating the movable side cavity plate shown in FIG. 4 from the injection side cavity plate. FIG. 6 is a cross-sectional view showing a state where the injection side cavity plate shown in FIG. 5 is separated from the stripper plate and the resin solid material is separated from the injection side cavity plate. FIG. 7 is a cross-sectional view showing a state in which the stripper plate shown in FIG. 6 is separated from the injection side mounting portion and the resin solid material is separated from the primary sprue. 8 (a) and 8 (b) are perspective views showing an example of a solid resin, (a) is a perspective view of the solid resin as seen from the side of the injection side mounting portion, and (b). FIG. 3 is a perspective view of the resin solid body shown in FIG. FIG. 9 is a partial perspective view showing a runner portion of the injection side cavity plate for forming the resin solid shown in FIG. FIG. 10 is a partial perspective view showing the shape of the stripper plate forming the resin solid shown in FIG. 11 (a) and 11 (b) are perspective views showing another example of the solid resin material, and (a) is a perspective view of the solid resin material as seen from the side of the injection side mounting portion. (b) is the perspective view which looked at the resin solid substance shown to (a) from the injection side cavity plate side. FIG. 12 is a partial perspective view showing a runner portion of the injection side cavity plate for forming the resin solid shown in FIG.

(General configuration of a three-plate injection mold)
First, after describing the general configuration of a three-plate injection mold, the detailed configuration of the injection mold according to the present invention will be described.

  The three-plate type injection mold includes an injection side mounting portion 1 as a fixed side mounting plate fixed to an injection molding apparatus (not shown), and an injection side cavity plate (on the side close to the injection side mounting portion 1). A fixed-side cavity plate) 2, a movable-side cavity plate 3 that is separated from and close to the injection-side cavity plate 2, and a stripper plate 4 that is interposed between the injection-side cavity plate 2 and the injection-side mounting portion 1. ing.

  The injection side mounting portion 1 has a primary sprue 5 into which molten resin first flows from a nozzle (not shown) of an injection molding apparatus. The injection side cavity plate 2 and the injection side mounting portion 1 are connected by support pins 6 and 6.

  The injection side cavity plate 2 is guided by the support pins 6 and 6 and is moved away from and close to the injection side mounting portion 1. The injection side cavity plate 2 has runners 7 formed on the side of the surface facing the injection side mounting portion 1. A cavity portion 8 is formed in the emission side cavity plate 2 on the side of the surface facing the movable side cavity plate 3.

A secondary sprue 9 is formed between the runner 7 and the cavity portion 8 as a gate for guiding the molten resin to the cavity portion 8. The runner 7 is formed with a chucking projection forming recess 7a for forming a chucking projection in a runner resin solid portion described later, and for forming a hollow hole in a primary sprue resin solid portion described later. A lightening convex portion 7b is formed.
Detailed configurations of the runner 7 and the secondary sprue 9 will be described with reference to the shape of the resin solid 10 described later.

  The stripper plate 4 has a through-hole 12 through which a primary sprue constituting bush 11 constituting the primary sprue 5 penetrates at the center thereof. The injection side cavity plate 2 and the stripper plate 4 are connected by a blur bolt 13. The blur bolt 13 has a stop bolt head 13a.

  In the injection side mounting portion 1, the resin solid material 10 (see FIGS. 6 to 8, 11) is locked to the stripper plate 4 when the injection side cavity plate 2 is separated from the injection side mounting portion 1. A lock pin 14 is provided. The tip of the lock pin 14 passes through the through hole 4 a of the stripper plate 4 and protrudes toward the runner 7.

  The stripper plate 4 is moved away from and close to the injection side mounting portion 1 in conjunction with the separation and approach of the injection side cavity plate 2, and when separated from the injection side mounting portion 1, a primary sprue resin solid portion (described later). To separate). The stripper plate 4 has a recess 4b for forming a later-described collapse-preventing protrusion on the resin solid material 10, and a lightening protrusion for forming a lightening hole in the secondary sprue resin solid portion described later. 4c is formed.

  In this embodiment, the movable side cavity plate 3 is moved away from the horizontal direction with respect to the emission side cavity plate 2 by a drive mechanism (not shown). The movable side cavity plate 3 is roughly composed of a movable side mounting plate 15, a first ejector plate 16, a second ejector plate 17, a return pin 18, a return spring 19, a receiving plate 20, and a core plate 21. It is configured. It should be noted that at least one of the recesses 4b for forming the protrusions for preventing the fall on the resin solid 10 is located on the upper side in the vertical direction with respect to the primary sprue 5.

  The core plate 21 is provided with a nesting 22 as a cavity portion, and the nesting 22 is opposed to the cavity portion 8. An ejector pin 23 is provided between the first ejector plate 16 and the core plate 21, and the tip of the ejector pin 23 passes through the insert 22 and faces the cavity portion 8.

  The movable side cavity plate 3 and the injection molding side cavity plate 2 are connected by a tensile link member 24. The tension link member 24 has a long hole (not shown) in the longitudinal direction. When the mold is clamped, the movable side cavity plate 3 is brought close to the injection side mounting part 1 while the connecting part 3a is guided by the elongated hole, and comes into contact with the injection molding side cavity plate 2 as shown in FIG. Is done.

  Further, when the movable side cavity plate 3 is approached toward the injection side mounting portion 1, the injection side mounting cavity plate 2 is pressed by the movable side cavity plate 3 and guided to the support pins 6, 6 while being mounted on the injection side. Approached toward part 1.

  Next, as shown in FIG. 3, when the injection side cavity plate 2 comes into contact with the stripper plate 4, the stripper plate 4 is brought close to the injection side mounting portion 1 together with the injection side cavity plate 2 and is injected as shown in FIG. The primary sprue constituting bush 11 comes into contact with the side mounting portion 1 and enters the through hole 12, and the tip thereof faces the runner 7. The blur bolt 13 is also moved in the same direction as the stripper plate 4 is moved toward the injection side mounting portion 1.

  This completes the clamping of the injection mold, and in this state, the molten resin flows from the nozzle (not shown) of the injection molding apparatus into the primary sprue 5 as shown by the arrow F as shown in FIG. The molten resin that has flowed into the primary sprue 5 is guided to the secondary sprue 9 via the runner 7 and filled into the cavity portion 8 from the secondary sprue 9.

  The molten resin filled in the cavity portion 8 is cooled and solidified to form a resin molded product 25 shown in FIG. The molten resin present in the molten resin flow paths of the primary sprue 5, the runner 7 and the secondary sprue 9 is cooled and solidified, and the primary sprue resin solid portion 5a and the runner resin solid portion 7a shown in FIGS. It becomes the resin solid substance 10 containing the next sprue resin solid part 9a.

  After the molten resin is solidified, the movable side cavity plate 3 is separated from the injection side cavity plate 2 and opened as shown in FIG. As a result, the resin molded product 25 is separated from the injection-side cavity plate 2, and then the second ejector plate 17 is driven by an ejector plate driving rod (not shown), whereby the ejector pins 23 protrude toward the resin molded product 25. Then, the resin molded product 25 is released from the movable cavity plate 3.

  The second ejector plate 17 and the ejector pin 23 integrated with the second ejector plate 17 are returned to their original positions by the return spring 19 after the resin molded product 25 is released. When the movable side cavity plate 3 is further moved in the direction away from the injection side cavity plate 2 as shown in FIG. 6, the emission side cavity plate 2 is moved in the direction away from the stripper plate 4 by the pull link member 24. Is done.

  Thereby, the resin solid material 10 is separated from the injection-side cavity plate 2. Further, as shown in FIG. 7, when the injection side cavity plate 2 is moved in the direction away from the injection side mounting portion 1, the stripper plate 4 is moved in the direction away from the injection side mounting portion 1 by the blur bolt 13. The The amount of separation is regulated by the stop bolt head 13a.

The primary sprue resin solid portion 5 a is separated from the primary sprue 5 by the separation of the stripper plate 4 from the injection side mounting portion 1. The resin solid 10 is held on the stripper plate 4. The resin solid 10 is formed with a chucking protrusion 26 for chucking and removing the resin solid 10. The chucking protrusion 26 is chucked by the chuck claw 28 of the resin solid automatic removal mechanism and removed from the stripper plate 4.
In addition, the resin solid material 10 is provided with a protrusion 27 for preventing falling by the recess 4b.

(Example of resin solid 10)
In FIG. 1 to FIG. 7, it is connected to an injection molding device and communicates with a primary sprue 5 into which molten resin first flows from a nozzle of the injection molding device and flows toward a cavity portion 8 via a secondary sprue 9. The shape of the runner 7 which is the flow path of the molten resin and the shape of the resin solid material 10 are simplified, and only the portion related to the main part of the present invention is described characteristically.
An example of the detailed configuration of the resin solid material 10 is shown in FIG. 8, and the shapes of the injection-side cavity plate 2 and the stripper plate 4 that form the resin solid material 10 shown in FIG. 8 are shown in FIGS. ing.

  In FIG. 8 (a), reference numeral 9a 'indicates a thinning hole formed by the thinning hole forming projection 4c, and reference numeral 14' is formed by a locking recess formed by the lock pin 14 and the through hole 4a. The locking convex portion is shown. The resin solid material 10 includes a first branch runner resin solid portion 71a and a second branch runner resin solid portion 72a that are branched in two directions as a straight runner resin solid portion. In FIG. 8B, reference numeral 7b 'indicates a lightening hole formed by the lightening protrusion 7b.

The first branch runner resin solid part 71a, the second branch runner resin solid part 72a, and the primary sprue resin solid part 5a are connected so as to intersect in directions orthogonal to each other as shown in FIG.
The first branched runner resin solid portion 71a, the second branched runner resin solid portion 72a, and the primary sprue resin solid portion 5a are connected to each other, and the molten resin flowing into the primary sprue 5 first hits the runner 7. In the connecting portion that changes the direction of flow, the hole 7b 'is located.

  Conventionally, at the start of injection molding, in order to prevent the resin in a semi-solid state at the tip of a nozzle (not shown) from flowing into the cavity 8, for example, in the resin solid material disclosed in Patent Document 1, a primary sprue is used. A cold slag (not shown) was formed on the opposite side of the primary sprue resin solid part 5a, which is a connection part between the resin solid part 5a and the runner resin solid part.

For this reason, heat accumulates in the connection part which consists of the 1st branch runner resin solid part 71a, the 2nd branch runner resin solid part 72a, the primary sprue resin solid part 5a, and cold slug (illustration omitted), and a connection part cannot cool easily. There was a trend.
Thus, if a cold slag is provided at the connection portion that becomes the center of the branch point of the resin solid material, the volume of the connection portion increases, and this connection portion tends to be difficult to cool. A hollow hole 7b 'is formed in the inner wall, the volume of the connecting portion is reduced as compared with the conventional case, and the cold slug is formed at another location.

In addition, since the molten resin that has flowed in at the end of the molding cycle remains in the primary sprue 5, if the number of resin solid parts branching around this connection part is increased, the increased amount of the connection part is increased. The volume increases, and the time for cooling and solidifying the connection portion becomes longer.
For example, in the resin solid material disclosed in Patent Document 1, the number of branches centering on the connection portion of the resin solid portion is 4 for the primary sprue resin solid portion, the runner resin solid portion branched in two directions, and the cold slug well. In this embodiment, the number of branches of the resin solid portion is 3 or less, and the volume of the connection portion is reduced as much as possible.

That is, in this embodiment, the cold slag is formed at a location different from the communication location where the molten resin that has flowed into the primary sprue 5 hits the runner 7 and changes the flow direction, as will be described later. The number of resin solid parts centering on the connection part is reduced, and the first branch runner resin solid part 71a, the second branch runner resin solid part 72a, and the primary sprue resin solid part 5a are centered on the connection part. Since the number of connecting portions of the solid resin portion is three, the volume of the connecting portion can be further reduced as compared with the conventional case, and the cooling and solidifying time of the solid resin material can be shortened.
The solid resin portion referred to here includes a protrusion 27 for preventing falling, a protrusion 26 for chucking, and a convex portion 14 'for locking, and these also focus on the connecting portion with the runner resin solid portion 7a'. The number of branches is three.

  A cold slug 71a 'is formed at the end of the first branch runner resin solid portion 71a. The first branched runner resin solid portion 71a is formed with an intermediate runner resin solid portion 71b having a bent portion. The tip of the intermediate runner resin solid part 71b is branched only in two directions to form a bifurcated intermediate branch runner resin solid part 71c. The tip of the bifurcated intermediate branch runner resin solid portion 71c is bent to form a terminal runner resin solid portion 71d.

  The chucking protrusion 26 is located in the intermediate runner resin solid portion 71b. The chucking protrusion 26 may be formed in an appropriate shape and at an appropriate position. The fall prevention protrusions 27 are located in the intermediate branch runner resin solid portion 71c and the terminal runner resin solid portion 71d. The secondary sprue resin solid portion 9a is located at the end of the end runner resin solid portion 71d.

  The second branch runner resin solid part 72a is connected to an intermediate branch runner resin solid part 72b as a straight runner resin solid part that branches only in two directions. The second branch runner resin solid portion 72a and the intermediate branch runner resin solid portion 72b branch in three directions with the connection portion as the center.

  The intermediate branch runner resin solid portions 72b and 72b have cold slugs 71a 'at their ends. The intermediate branch runner resin solid portions 72b and 72b are connected to the terminal runner resin solid portion 72c. One of the intermediate branch runner resin solid portions 72b, 72b has a fall prevention protrusion 27. Due to the presence of the fall-preventing protrusions 27, the injection-side cavity plate 2 can be separated from the stripper 4 in a state closer to complete solidification than semi-solidification even if the resin solid 10 is not completely solidified. Thus, the molding cycle can be further shortened than before. Note that the fall-preventing protrusions 27 may be formed in an appropriate shape.

  The one end runner resin solid portion 72c has locking convex portions 14 'on both sides of the secondary sprue resin solid portion 9a. At the end of the other end runner resin solid portion 72c, there is a locking convex portion 14 'adjacent to the secondary sprue resin solid portion 9a.

(Structure of the injection side cavity plate 2 having the runner 7 corresponding to the resin solid 10 shown in FIG. 8)
FIG. 9 shows the shape of the surface of the exit side cavity plate 2 facing the stripper plate 4. A runner 7 corresponding to the solid resin 10 shown in FIG. 8 is formed on the injection side cavity plate 2.

The runner 7 includes a first branch runner portion 71a "and a second branch runner resin solid portion corresponding to the first branch runner resin solid portion 71a that is branched only in two directions around the communication point with the first sprue 5. And a second branch runner portion 72a "corresponding to.
The communication location is a location where the molten resin that has flowed into the primary sprue 5 first hits and changes the direction of the flow. The communication portion protrudes toward the primary sprue 5 and the primary sprue resin solid portion 5a is thinned. The thinning convex portion 7b is located.

The first branch runner portion 71a "and the second branch runner portion 72a" are straight runner portions, and the first branch runner portion 71a "and the second branch runner portion 72a" are orthogonal to each other.
In the first branch runner portion 71a ″, the side where the molten resin flows into the primary sprue 5 is the upstream side, and the side where the molten resin flows into the secondary sprue 9 is the downstream side. A resin reservoir portion is formed to guide and form a cold slag 71a′.For the convenience of explanation, the resin reservoir portion has the same reference numeral 71a ′ as the reference numeral 71a ′ used for the cold slug. Is attached.

  The first branch runner portion 71a "is communicated with an intermediate runner portion 71b" corresponding to the intermediate runner resin solid portion 71b. The chucking projection forming recess 7a is located in the intermediate runner portion 71b ". The intermediate runner portion 71b" is an intermediate branch runner portion corresponding to the bifurcated intermediate branch runner resin solid portion 71c branched in only two directions. The intermediate branch runner portions 71c "and 71c" are communicated with the end runner portions 71d "and 71d" corresponding to the end runner resin solid portion 71d.

  One secondary sprue 9 is positioned at the end of one end runner portion 71d ″. The other secondary sprue 9 is positioned midway in the other end runner portion 71d ″. The second branch runner portion 72a ″ communicates with an intermediate branch runner portion 72b ″ corresponding to the intermediate branch runner resin solid portion 72b that branches only in two directions.

  The intermediate branch runner portion 72b ″ is also a straight runner portion, and the intermediate branch runner portion 72b ″ has a side where the molten resin flows into the primary sprue 5 as an upstream side and a side where the molten resin flows into the secondary sprue 9 as a downstream side. As shown, a resin reservoir 71a ′ for forming the cold slug 71a ′ is formed at the downstream end thereof. The intermediate branch runner portion 72b ″ communicates with a terminal runner portion 72c ″ intersecting in a direction orthogonal to the intermediate branch runner portion 72b ″. One secondary sprue 9 is in the middle of one terminal runner portion 72c ″. Is located. The other secondary sprue 9 is located at the end of the other end runner portion 72c ″.

(Structure of the stripper plate 4 corresponding to the solid resin material 10 shown in FIG. 8)
FIG. 10 shows the surface shape of the stripper plate 4 on the side facing the injection side cavity plate 2.
Through holes 12 and 4a shown in FIG. 1, recesses 4b for forming protrusions for preventing collapse shown in FIG. 1, and through holes corresponding to the protrusions 4c for forming a hollow hole in the secondary sprue resin solid portion 9a, Recesses and protrusions are shown with the same reference numerals as those shown in FIG.

(Other examples of resin solid 10)
FIG. 11 is a perspective view showing another example of the resin solid material 10, and the shape of the injection-side cavity plate 2 forming the resin solid material 10 shown in FIG. 11 is shown in FIG.
In FIG. 11 (a), reference numeral 9a 'indicates a lightening hole formed by the thinning hole forming projection 4c, and reference numeral 14' is formed by a locking recess made of the lock pin 14 and the through hole 4a. The locking convex portion is shown. The resin solid part 10 has a straight runner resin solid part 71e. The straight runner resin solid portion 71e is provided on the downstream side that guides the molten resin straightly from the communication point with the side where the molten resin flows into the primary sprue 5 being the upstream side and the side where the molten resin flows into the secondary sprue 9 is the downstream side. A cold slug 71a ′ is formed at a location corresponding to the end.

  The straight runner resin solid portion 71e is connected to an intermediate runner resin solid portion 71f having a bent portion. The front end of the intermediate runner resin solid portion 71f is intermediate branch runner resin solid portions 71g and 71g that are bifurcated. The intermediate branch runner resin solid portions 71g, 71g and the intermediate runner resin solid portion 71f are orthogonal to each other.

  A cold slug 71a 'is formed at one end of the intermediate branch runner resin solid portion 71g. One intermediate branch runner resin solid part 71g is connected to one branch runner resin solid part 71h. The secondary sprue resin solid portion 9a is located at the end of the branched runner resin solid portion 71h.

  The end runner resin solid part 71i is connected to the middle of the branched runner resin solid part 71h. A cold slug 71a 'is also formed at the end of the terminal runner resin solid portion 71i. The terminal runner resin solid part 71j in the final stage is connected to the terminal runner resin solid part 71i.

The other intermediate branch runner resin solid part 71g is connected to the other branch runner resin solid part 71h. The secondary sprue resin solid portion 9a is also located at the end of the other branch runner resin solid portion 71h.
The end runner resin solid part 71i is connected to the middle of the branched runner resin solid part 71h. A cold slug 71a ′ is also formed at the end of the terminal runner resin solid portion 71i. The terminal runner resin solid part 71j in the final stage is connected to the terminal runner resin solid part 71i. The secondary sprue resin solid part 9a is formed in the middle of the terminal runner resin solid part 71j in the final stage. The resin solid 10 is asymmetrical, but may be formed symmetrically.

(Structure of injection side cavity plate 2 corresponding to another example of resin solid material 10)
FIG. 12 is a partial perspective view showing the shape of the exit side cavity plate 2. Since the shape of the resin flow path of the runner 7 of the injection side cavity plate 2 shown in FIG. 12 corresponds to the shape of the solid resin 10 shown in FIG. 11, the resin corresponding to each resin solid portion shown in FIG. A detailed description of the flow path will be omitted by attaching “′” to the reference numerals assigned to the resin solid portions in the flow path.
In the runner 7 shown in FIG. 12, the number of the straight runner portions communicating with the primary sprue 5 is one, and therefore, the runner 7 branches around the connection portion formed by the communication portion between the primary sprue 5 and the straight runner. The number of resin solid portions is two, that is, the straight runner resin solid portion 71e and the primary sprue resin solid portion 5a. The number of remaining resin solid portions is a maximum of three with the connection portion as the center.

DESCRIPTION OF SYMBOLS 1 ... Injection side attaching part 2 ... Injection side cavity plate 3 ... Movable side cavity plate 5 ... Primary sprue 7 ... Runner 8 ... Cavity part 9 ... Secondary sprue 25 ... Resin molded product 5a ... Primary sprue resin solid part 7a ... Runner resin Solid part 7b ... Meat removal convex part 9a ... Secondary sprue resin solid part 10 ... Resin solid matter

JP-A-11-333898 Japanese Patent Laid-Open No. 10-235691

Claims (18)

An injection side attachment having a primary sprue connected to the injection molding apparatus and into which molten resin first flows from the nozzle of the injection molding apparatus;
An injection-side cavity plate having a runner formed on the side facing the injection-side mounting portion and communicating with the primary sprue and guiding molten resin flowing into the primary sprue to the cavity portion through the secondary sprue; ,
A resin molded product is formed by solidifying the molten resin flowing into the cavity portion, having a cavity portion facing the cavity portion, being separated from and approaching the injection side cavity plate and cooperating with the injection side cavity plate Movable side cavity plate
The injection-side cavity plate is separated from the injection-side mounting portion, and is formed by solidifying the primary sprue resin solid portion formed by solidification of the molten resin flowing into the primary sprue and the molten resin flowing into the runner. It is configured to be able to separate a resin solid matter including a runner resin solid portion to be formed and a secondary sprue resin solid portion formed by solidification of the molten resin flowing into the secondary sprue,
The movable side cavity plate is configured to release the resin molded product,
In the runner, the melted resin that has flowed into the primary sprue first hits the communicating portion that changes the flow direction and projects toward the primary sprue so as to lighten the primary sprue resin solid part. A three-plate type injection mold characterized in that a convex portion is formed.   The runner guides the molten resin straight from the communicating portion toward the downstream side, with the side on which the molten resin flows into the primary sprue as the upstream side and the side on which the molten resin flows into the secondary sprue as the downstream side. A straight runner portion in which a molten resin reservoir portion that forms cold slug is formed, and an intermediate runner portion that communicates with the straight runner portion and guides the molten resin toward the secondary sprue. The injection mold according to claim 1.   3. The intermediate runner portion has a branch runner portion that is branched only in two directions, and a molten resin reservoir portion that forms a cold slug is provided in at least one of the branch runner portions. The mold for injection molding as described in 2.   The said branch runner part has the end runner part in which the secondary sprue was each formed, The metal mold | die for injection molding of Claim 3 characterized by the above-mentioned.   2. The injection mold according to claim 1, wherein the runner includes a first branch runner portion and a second branch runner portion that are branched only in two directions around the communication portion.   The first branch runner portion is configured such that the side where the molten resin flows into the primary sprue is the upstream side and the side where the molten resin flows into the secondary sprue is the downstream side, and the molten resin is linearly moved downstream from the communication location. A straight runner portion formed with a molten resin reservoir portion that guides toward the cold slug, an intermediate runner portion that communicates with the straight runner portion and has a bent portion, and communicates with the intermediate runner portion and the intermediate runner portion 6. The injection mold according to claim 5, further comprising a terminal runner portion that branches only in two directions with respect to the runner portion and guides the molten resin toward the secondary sprue.   The second branch runner portion is configured such that the side where the molten resin flows into the primary sprue is the upstream side and the side where the molten resin flows into the secondary sprue is the downstream side, and the molten resin is linearly moved downstream from the communication location. A second straight runner portion that guides the vehicle, an intermediate branch runner portion that communicates with the second straight runner portion and branches in only two directions with respect to the second straight runner portion to form a cold slug, and the intermediate The mold for injection molding according to claim 6, further comprising a terminal runner portion that communicates with the branch runner portion and communicates with the secondary sprue.   8. A chucking protrusion forming recess for forming a chucking protrusion on the resin solid to chuck and remove the resin solid is formed in the runner. The injection mold according to any one of the above.   9. The injection mold according to claim 8, wherein the chucking projection forming recess is formed adjacent to the lightening projection. The injection mold according to claim 9, wherein the chucking projection forming recesses are disposed on both sides of the lightening projection. A runner stripper plate for separating the primary sprue solid part from the primary sprue is provided between the injection side mounting part and the injection side cavity plate,
The runner stripper plate is formed with a locking recess for locking the resin solid material to the runner stripper plate when the injection side cavity plate is separated from the injection side mounting portion. The injection mold according to any one of claims 1 to 10.   The mold for injection molding according to claim 11, wherein a protrusion for forming a lightening hole for forming a lightening hole in the solid portion of the secondary sprue resin is formed on the runner stripper plate.   The injection mold according to claim 12, wherein the locking recess is provided adjacent to the protrusion. 13. The injection mold according to claim 12, wherein the locking recess is disposed on both sides of the protrusion.   15. The injection mold according to claim 14, wherein one of the locking recesses is provided at an abutting position of a terminal runner portion at a final stage for guiding the molten resin to the second sprue.   The movable-side cavity plate is moved away from the horizontal direction with respect to the injection-side cavity plate, and the stripper plate has a recess for forming a fall-preventing protrusion that prevents the resin solid material from falling down more vertically than the primary sprue. The injection mold according to any one of claims 11 to 15, wherein at least one is formed on an upper side in the direction.   The runner is formed on the injection-side cavity plate such that the resin solid is formed by the runner so that the number of resin solid portions branched about the connecting portion of the resin solid is 3 or less. The mold for injection molding according to any one of claims 1 to 16, wherein the mold is for injection molding.   The resin reservoir portion forming the cold slag is formed not at a position directly below the communication location where the molten resin that first flows into the primary sprue changes the flow direction but at another location. Item 18. The mold for injection molding according to any one of Items 17.