Injection molding apparatus

Abstract

To provide an injection molding apparatus that can suppress the cooling of high-temperature resin ejected from an injection molding machine into a mold cavity within the mold cavity.SOLUTION: An injection molding apparatus 1 includes a mold 5 in which a resin cavity 72 into which resin is injected is formed. The resin cavity 72 includes: an injection cavity 8 which is formed to extend in a first direction D1; and a component cavity 6 which is connected to the injection cavity 8 and in which a component is formed. The mold 5 includes an injection inner surface 16 which defines the injection cavity 8. The injection inner surface 16 has a first inner surface 20 and a second inner surface 21. The first inner surface 20 includes a supply inner surface 22 and an adjacent inner surface 23. A gap g1 of the supply inner surface 22 in a second direction D2 is narrower than a gap g2 of the adjacent inner surface 23 in the second direction D2, and the gap g1 of the supply inner surface in the second direction D2 is wider than half the gap g2 of the adjacent inner surface in the second direction D2.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to an injection molding apparatus. [Background technology]

[0002] For example, Japanese Patent Application Laid-Open No. 2022-036538 describes an injection molding apparatus for manufacturing insulating materials for batteries. The injection molding apparatus is equipped with a mold having a component space formed in the shape of the component, and is used to manufacture components of a predetermined shape by pouring molten resin into the component space. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-036538 Summary of the Invention [Problem to be solved by the invention]

[0004] In an injection molding device, molten resin ejected from the injection molding machine reaches the part space through passages such as runners. The runner size is determined taking into account the size of the part. Runner sizes installed in molds for molding small, thin parts have narrower and thinner flow paths compared to runner sizes installed in molds for molding large parts. This increases the contact area of ​​the resin passing through the runner with the inner surface that defines the runner, making it easier for the resin to cool and harden. As a result, there is an increased risk of defects such as short shots and flow marks.

[0005] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide an injection molding apparatus that can prevent high-temperature resin ejected from an injection molding machine into a mold from being cooled within the mold. [Means for solving the problem]

[0006] An injection molding apparatus according to a first aspect of the present disclosure includes a mold having a resin space formed therein into which resin is injected, the resin space including an injection space formed to extend in a first direction, and a part space communicating with the injection space and in which a part is formed, the mold including injection inner surfaces that define the injection space, the injection inner surfaces having a first inner surface that defines a first space in which a supply port through which resin is injected in a second direction is located, and a second inner surface that defines a second space located between the first space and the part space, the first inner surfaces including supply inner surfaces that define a supply space in which the supply port is located, and adjacent inner surfaces that define adjacent spaces adjacent to the supply space in the first direction, the spacing between the supply inner surfaces in the second direction being narrower than the spacing between adjacent inner surfaces in the second direction, and the spacing between the supply inner surfaces in the second direction being wider than half the spacing between adjacent inner surfaces in the second direction.

[0007] The second inner surface of the injection molding apparatus according to the first aspect of the present disclosure includes an approach inner surface that defines an approach space adjacent to the adjacent space in the first direction, and an injection inner surface that defines an injection space located between the approach space and the part space, and the spacing between the approach inner surfaces in the third direction is the same as or narrower than the spacing between the adjacent inner surfaces in the third direction, and the spacing between the injection inner surfaces in the second direction narrows as one moves from the approach space toward the part space. [Effects of the Invention]

[0008] According to the injection molding apparatus of the present disclosure, it is possible to prevent high-temperature resin discharged from the injection molding machine into the mold from being cooled within the mold. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a plan view showing a schematic configuration of an injection molding apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic perspective view of a spacer manufactured by the injection molding apparatus according to the present embodiment. [Figure 3] FIG. 2 is an enlarged perspective view of a portion of FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. [Figure 5] FIG. 2 is an enlarged plan view of a part of FIG. [Figure 6] FIG. 2 is a cross-sectional view of an injection molding apparatus that is a comparison target for the injection molding apparatus 1 of the present disclosure. [Figure 7] FIG. 10 is a diagram showing the temperature change of the resin at point A in the injection molding apparatus 1 and the comparative injection molding apparatus 1a. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0011] 1 is a diagram showing the configuration of an injection molding apparatus according to this embodiment. The second direction D2 is an up-down direction that intersects the first direction D1 at a right angle. The third direction D3 is a direction that intersects the plane formed by the first direction D1 and the second direction D2 at a right angle.

[0012] The injection molding apparatus 1 produces, for example, a spacer 2 as shown in Fig. 2. The spacer 2 is one of the components that form a bipolar unit battery.

[0013] The spacer 2 is formed, for example, from polypropylene (PP), polyethylene (PE), polyolefin, or polyester. The spacer 2 is formed, for example, to have a thickness of 330 μm or more and 400 μm or less. The spacer 2 has a plurality of main body portions 3 and a plurality of joint portions 4. In the present disclosure, each spacer 2 is composed of four main body portions 3 and four joint portions 4. The main body portions 3 are arranged in a ring shape on the same plane with gaps between them. The joint portions 4 are arranged so as to fill the gaps between the ring-shaped main body portions 3. The joint portions 4 are formed to have a maximum length of 46 mm in the longitudinal direction.

[0014] The injection molding device 1 manufactures the spacer 2 by injection molding the joint portion 4 of the spacer 2 and joining the main body portion 3 by the joint portion 4.

[0015] 1 again, injection molding apparatus 1 includes an injection molding machine (not shown) and mold 5. Mold 5 has resin space 72 formed therein. Resin space 72 includes component space 6 and injection space 8.

[0016] The part space 6 is an annular space formed within the mold 5. The part space 6 is connected to the injection space 8. The part space 6 includes an accommodation space 70 and a molding space 71. The accommodation space 70 is a space formed along the shape of the main body 3 and is formed so as to be able to accommodate the main body 3. The molding space 71 is a space formed along the shape of the joint 4. The molding space 71 is a space defined by the mold 5 and the main body 3 in the same shape as the joint 4.

[0017] Resin discharged from an injection molding machine flows into the injection space 8. The injection space 8 is formed to extend in the first direction D1. The injection space 8 communicates with the component space 6.

[0018] Figure 3 is an enlarged perspective view of a portion of Figure 1. The injection space 8 includes a first space 10 and a second space 11. The first space 10 and the second space 11 are formed to extend in a first direction D1. The second space 11 communicates with the first space 10 and the component space 6 in the first direction D1.

[0019] The first space 10 includes a supply space 12 and an adjacent space 13. The adjacent space 13 communicates with the supply space 12 and the second space 11 in the first direction D1. The first space 10 may further include a connection space 55. The connection space 55 connects the supply space 12 and the adjacent space 13.

[0020] The second space 11 includes an entrance space 14 and an injection space 15. The entrance space 14 communicates with the adjacent space 13 and the injection space 15 in the first direction D1. The injection space 15 communicates with the entrance space 14 and the component space 6 in the first direction D1.

[0021] The mold 5 includes an injection inner surface 16 that defines the injection space 8. The injection inner surface 16 has an injection upper surface 17, an injection lower surface 18, and an injection side surface 19. The injection upper surface 17 and the injection lower surface 18 are arranged to face each other in the second direction D2. When the injection upper surface 17 and the injection lower surface 18 are viewed in plan from a position away from the injection upper surface 17 and the injection lower surface 18 in the second direction D2, the injection upper surface 17 and the injection lower surface 18 are formed to have the same shape. The injection side surface 19 is formed to connect the outer periphery of the injection upper surface 17 and the outer periphery of the injection lower surface 18. An injection opening 50 is formed in the injection side surface 19 to connect the injection space 8 and the component space 6.

[0022] The injection inner surface 16 has a first inner surface 20 that defines the first space 10 and a second inner surface 21 that defines the second space 11. The first inner surface 20 has a communication opening 51 that allows the first space 10 and the second space 11 to communicate with each other.

[0023] Figure 4 is a cross-sectional view taken along the line IV-IV of Figure 1. The first inner surface 20 has a supply inner surface 22 and an adjacent inner surface 23.

[0024] The feed inner surface 22 forms a part of the first inner surface 20 and defines the feed space 12. The feed inner surface 22 has an upper feed surface 24 and a lower feed surface 25. The upper feed surface 24 and the lower feed surface 25 are arranged opposite each other in the second direction D2. When the upper feed surface 24 and the lower feed surface 25 are viewed in plan from a position away from the upper feed surface 24 and the lower feed surface 25 in the second direction D2, the upper feed surface 24 and the lower feed surface 25 are each formed in the same shape.

[0025] A supply port 27 is arranged on the upper supply surface 24. Through the supply port 27, resin discharged from the injection molding machine is supplied to the supply space 12 in the second direction D2.

[0026] The adjacent inner surface 23 forms a part of the first inner surface 20 and defines the adjacent space 13. The adjacent inner surface 23 has an adjacent upper surface 28 and an adjacent lower surface 29. The adjacent upper surface 28 and the adjacent lower surface 29 are arranged to face each other in the second direction D2. When the adjacent upper surface 28 and the adjacent lower surface 29 are viewed in plan at a position away from the adjacent upper surface 28 and the adjacent lower surface 29 in the second direction D2, the adjacent upper surface 28 and the adjacent lower surface 29 are each formed in the same shape.

[0027] The connecting inner surface 56 forms a part of the first inner surface 20 and defines a connection space 55. The connecting inner surface 56 has an upper connecting surface 57 and a lower connecting surface 58. The upper connecting surface 57 and the lower connecting surface 58 are arranged opposite each other in the second direction D2. In the first direction D1, one end of the upper connecting surface 57 is connected to the upper supply surface 24 and the other end is connected to the adjacent upper surface 28. In the first direction D1, one end of the lower connecting surface 58 is connected to the lower supply surface 25 and the other end is connected to the adjacent lower surface 29.

[0028] The second inner surface 21 has an inlet inner surface 31 and an outlet inner surface 32 . The run-up inner surface 31 forms a part of the second inner surface 21 and defines the run-up space 14. The run-up inner surface 31 has an upper run-up surface 33 and a lower run-up surface 34. The upper run-up surface 33 and the lower run-up surface 34 are arranged to face each other in the second direction D2. When the upper run-up surface 33 and the lower run-up surface 34 are viewed in plan from a position away from the upper run-up surface 33 and the lower run-up surface 34 in the second direction D2, the upper run-up surface 33 and the lower run-up surface 34 are each formed in the same shape.

[0029] The emission inner surface 32 forms a part of the second inner surface 21 and defines the emission space 15. The emission space 15 has an upper emission surface 36 and a lower emission surface 37. The upper emission surface 36 and the lower emission surface 37 are arranged to face each other in the second direction D2. When the upper emission surface 36 and the lower emission surface 37 are viewed in plan from a position away from the upper emission surface 36 and the lower emission surface 37 in the second direction D2, the upper emission surface 36 and the lower emission surface 37 are each formed in the same shape.

[0030] The injection space 8 may be connected to a spool 60 formed to extend in the second direction D2. The injection space 8 and the spool 60 communicate with each other through a supply port 27.

[0031] The lower supply surface 25 and the adjacent lower surface 29 are disposed at the same position in the second direction D2. The upper supply surface 24 and the adjacent upper surface 28 are disposed at positions spaced apart from the lower supply surface 25 and the adjacent lower surface 29, respectively, in the second direction D2. The distance g1 between the upper supply surface 24 and the lower supply surface 25 in the second direction D2 is narrower than the distance g2 between the adjacent upper surface 28 and the adjacent lower surface 29. The distance g1 between the upper supply surface 24 and the lower supply surface 25 is wider than half the distance g2 between the adjacent upper surface 28 and the adjacent lower surface 29. In other words, the distance g1 between the supply inner surfaces 22 in the second direction D2 is narrower than the distance g2 between the adjacent inner surfaces 23 in the second direction D2 and is wider than half the distance g2 between the adjacent inner surfaces 23 in the second direction D2.

[0032] One end of the upper injection surface 36 in the first direction D1 is connected to the upper runway surface 33 that defines the runway space 14, and the other end is connected to the inner component surface 52 of the mold 5 that defines the component space 6. One end of the lower injection surface 37 in the first direction D1 is connected to the lower runway surface 34 that defines the runway space 14, and the other end is connected to the inner component surface 52 of the mold 5 that defines the component space 6. The distance between the upper injection surface 36 and the lower injection surface 37 in the second direction D2 becomes narrower from the runway space 14 toward the component space 6 in the first direction D1. That is, the distance between the inner injection surfaces 32 in the second direction D2 becomes narrower from the runway space 14 toward the component space 6. Preferably, the distance between the upper injection surface 36 and the lower injection surface 37 in the second direction D2 becomes narrower so as to approach the center line O that passes through the center of the upper runway surface 33 and the lower runway surface 34 in the second direction D2.

[0033] FIG. 5 is an enlarged plan view of a part of FIG. The feed inner surface 22 further includes a feed side 26. The feed side 26 forms a portion of the injection side 19. The feed side 26 connects a portion of the outer periphery of the upper feed surface 24 and a portion of the outer periphery of the lower feed surface 25 to extend in the second direction D2.

[0034] The adjacent inner surface 23 further has an adjacent side surface 30. The adjacent side surface 30 forms a part of the injection side surface 19. The adjacent side surface 30 is formed from a pair of adjacent side surfaces 30a, 30b arranged at a distance from each other in the third direction D3. Each of the pair of adjacent side surfaces 30a, 30b connects a part of the outer periphery of the adjacent upper surface 28 and a part of the outer periphery of the adjacent lower surface 29 so as to extend in the second direction D2.

[0035] The inner run-up surface 31 further has run-up sides 35. The run-up sides 35 include a pair of run-up sides 35a, 35b arranged at a distance in the third direction D3. Each of the pair of run-up sides 35a, 35b forms a part of the injection side 19. Each of the pair of run-up sides 35a, 35b connects a part of the outer periphery of the upper run-up surface 33 and a part of the outer periphery of the lower run-up surface 34 so as to extend in the second direction D2.

[0036] The inner injection surface 32 further has an injection side surface 38. The injection side surface 38 includes a pair of injection side surfaces 38a, 38b arranged at a distance from each other in the third direction D3. Each of the pair of injection side surfaces 38a, 38b forms a part of the injection side surface 19. Each of the pair of injection side surfaces 38a, 38b connects a part of the outer periphery of the upper injection surface 36 and a part of the outer periphery of the lower injection surface 37 so as to extend in the second direction D2.

[0037] The connecting inner surface 56 further has a connecting side surface 59. The connecting side surface 59 forms a part of the injection side surface 19. The connecting side surface 59 connects a part of the outer periphery of the upper connecting surface 57 and a part of the outer periphery of the lower connecting surface 58 so as to extend in the second direction D2. In addition, in the first direction D1, one end of the connecting side surface 59 is connected to the supply side surface 26, and the other end is connected to the adjacent side surface 30.

[0038] In the third direction D3, the distance between the pair of approach side surfaces 35a, 35b is equal to or smaller than the distance between the pair of adjacent side surfaces 30a, 30b. That is, the distance between the approach inner surfaces 31 in the third direction D3 is equal to or smaller than the distance between the adjacent inner surfaces 23 in the third direction D3. (Comparative test) 6 is a cross-sectional view of an injection molding apparatus to be compared with injection molding apparatus 1 of the present disclosure. Unless otherwise specified, injection molding apparatus 1a has substantially the same configuration as injection molding apparatus 1.

[0039] The injection molding apparatus 1a includes an injection molding machine (not shown) and a mold 5a having an injection space 8a. The injection space 8a includes a supply space 12a, an adjacent space 13a, an entrance space 14a, and an injection space 15a. The supply space 12a is defined by a supply inner surface 22a. The adjacent space 13a is defined by an adjacent inner surface 23a. The entrance space 14a is defined by an entrance inner surface 31a. The injection space 15a is defined by an injection inner surface 32a.

[0040] A supply port 27a is formed in the supply inner surface 22a. The supply port 27a connects the spool 60 to the injection space 8a. An injection port 50a is formed in the injection inner surface 32a. The injection port 50a connects the injection space 8a to the component space 6.

[0041] In the injection space 8a, the spacing g3 between the supply inner surfaces 22a in the second direction D2 is narrower than half the spacing g4 between the adjacent inner surfaces 23a in the second direction D2.

[0042] The run-up inner surface 31a has an upper run-up surface 33a and a lower run-up surface 34a. The injection inner surface 32a has an upper injection surface 36a and a lower injection surface 37a. The run-up lower surface 34a and the injection lower surface 37a are arranged on the same plane. One end of the injection upper surface 36a in the first direction D1 is connected to the run-up upper surface 33a, and the other end is connected to the component inner surface 52 of the mold 5a, which defines the component space 6. As the injection upper surface 36a moves from the run-up space 14a toward the component space 6, it approaches 37a in the second direction D2.

[0043] In the comparative test, a test was conducted to compare the temperature change over time of the resin filled in the injection space 8 for the injection molding apparatus 1 of the present disclosure and a comparative injection molding apparatus 1a. The tests for the injection molding apparatus 1 and the injection molding apparatus 1a were conducted under the same conditions except for the difference in the shapes of the injection space 8 and the injection space 8a.

[0044] Fig. 7 is a diagram showing the temperature change of the resin at point A in injection molding apparatus 1 and comparative injection molding apparatus 1a. Point A is the point located at the center of injection ports 50, 50a shown in Fig. 5 and Fig. 7, respectively. Fig. 7 is a line graph with the vertical axis representing the temperature [degrees] of the resin discharged from the injection molding machine at point A and the horizontal axis representing time [seconds], with 0 seconds being the time when the front of the resin discharged from the injection molding machine passes through supply ports 27, 27a.

[0045] In the injection molding apparatus 1 and the injection molding apparatus 1a, the leading edge of the resin that passes through the supply port 27, 27a reaches the injection port 50, 50a, where point A is located, approximately 0.23 seconds later. After passing point A, the resin fills the component space 6, stops flowing, and completely hardens. From point A until completely hardened, the heat of the resin is dissipated to the mold 5, 5a. Here, the temperature drop of the resin at point A in the injection molding apparatus 1 is slower than the temperature drop of the resin at point A in the injection molding apparatus 1a. The temperature of the resin at point A in the injection molding apparatus 1 reaches a steady state after approximately 1.75 seconds. The temperature of the resin at point A in the injection molding apparatus 1a reaches a steady state after approximately 1.25 seconds. In other words, the mold 5 with the injection space 8 formed therein is less able to cool the resin than the mold 5a with the injection space 8a formed therein.

[0046] The mold 5 included in the injection molding apparatus 1 of the above embodiment is formed with a first space 10 defined by the first inner surface 20. By adopting such a configuration, the resin injected into the mold 5 can be prevented from cooling inside the mold when the high-temperature resin is discharged into the mold from the injection molding machine, compared to a mold that does not have the first space 10.

[0047] The mold 5 of the above embodiment is formed with a component space 6. The component space 6 includes an accommodation space 70 capable of accommodating the main body 3, and a molding space 71 whose shape is defined by the main body 3 and the component inner surface 52 according to the arrangement of the main body 3 and the shape of the joint 4.

[0048] With this configuration, when the main body portion 3 is placed in the accommodation space 70, the joining portion 4 that joins the main body portion 3 can be molded by filling the molding space 71 with resin.

[0049] Referring again to FIG. 3, the mold 5 included in the injection molding apparatus 1 according to this embodiment may be formed from an outer periphery block 61 and a center block 62. The outer periphery block 61 is formed so as to be separable into an upper mold 63 and a lower mold 64 in the second direction D2, with the resin space 72 as the boundary. The center block 62 has a main portion 65 and a plate-shaped portion 66. The thickness of the plate-shaped portion 66 is formed to be the same length as the length in the second direction D2 of the component space 6 partially formed by the outer periphery block 61. The plate-shaped portion 66 is formed so as to protrude outward from the center of the main portion 65 in the first direction D1 and the third direction D3. The outer periphery of the plate-shaped portion 66 defines a portion of the component space 6.

[0050] In the mold 5 having such a configuration, several center blocks 62 with different widths of the plate-like portion 66 are prepared, with the outer peripheral block 61 being common. In this way, by replacing the center block 62, it is possible to provide a mold 5 in which the longitudinal length of the molding space 71 can be changed as desired.

[0051] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0052] 1, 1a injection molding device, 2 spacer, 3 main body portion, 4 joint portion, 5, 5a mold, 6 part space, 8, 8a injection space, 10 first space, 11 second space, 12, 12a supply space, 13, 13a adjacent space, 14, 14a run-up space, 15, 15a injection space, 16 injection inner surface, 17 injection upper surface, 18 injection lower surface, 19 injection side surface, 20 first inner surface, 21 second inner surface, 22, 22a supply inner surface, 23, 23a adjacent inner surface, 24 supply upper surface, 25 supply lower surface, 26 supply side surface, 27, 27a supply port, 28 adjacent upper surface, 29 adjacent lower surface, 30 adjacent side surface, 30a, 30b adjacent side surface, 31, 31a run-up inner surface, 32, 32a Injection inner surface, 33, 33a upper approach surface, 34, 34a lower approach surface, 35 approach side surface, 35a, 35b approach side surface, 36, 36a upper injection surface, 37, 37a lower injection surface, 38 injection side surface, 38a, 38b injection side surface, 50, 50a injection port, 51 communication port, 52 part inner surface, 55 connection space, 56 connection inner surface, 57 upper connection surface, 58 lower connection surface, 59 connection side surface, 60 spool, 61 outer peripheral block, 62 center block, 63 upper mold, 64 lower mold, 65 main part, 66 plate-shaped portion, 70 accommodation space, 71 molding space, 72 resin space, D1 first direction, D2 second direction, D3 third direction, g1, g2, g3, g4 spacing, O center line.

Claims

1. An injection molding apparatus including a mold having a resin space formed therein into which a resin is injected, The resin space is an injection space formed to extend in a first direction; a part space communicating with the injection space and in which a part is formed; the mold includes an inner injection surface defining the injection space; The injection inner surface is a first inner surface defining a first space in which a supply port through which the resin is injected in a second direction is located; a second inner surface defining a second space located between the first space and the component space; The first inner surface is a feed inner surface defining a feed space in which the feed opening is located; an adjacent inner surface defining an adjacent space adjacent to the supply space in the first direction; the spacing between the feed inner surfaces in the second direction is smaller than the spacing between the adjacent inner surfaces in the second direction; an injection molding apparatus wherein the spacing between the feed interior surfaces in the second direction is greater than half the spacing between the adjacent interior surfaces in the second direction.

2. The second inner surface is an approach inner surface defining an approach space adjacent to the adjacent space in the first direction; an injection inner surface defining an injection space located between the run-up space and the part space; the spacing between the run-up inner surfaces in the third direction is equal to or narrower than the spacing between the adjacent inner surfaces in the third direction; The injection molding apparatus of claim 1 , wherein the spacing between the inner injection surfaces in the second direction decreases from the entrance space toward the part space.

Images