JP6624478B2 - Cooling block and runnerless injection molding equipment - Google Patents

Description

  The present invention relates to a cooling block and a runnerless injection molding device.

  Conventionally, in a runnerless injection molding apparatus for injection-molding a thermosetting resin, a heating means for heating the cavity is provided near a cavity formed on a parting surface and communicates with the cavity. In some cases, cooling means (cooling block) for cooling the resin passage is provided near the resin passage. In such a runnerless injection molding apparatus, there is known an apparatus in which a heat insulating means is interposed between a cavity portion heated by a heating means and a resin passage cooled by a cooling means (for example, Patent Document 1). reference).

  In this runnerless injection molding apparatus, the resin is not cured because the resin passage is cooled by the cooling action of the cooling means during molding. On the other hand, the resin filled in the cavity is cured by the heating action of the heating means. In this case, the hardened portion in the cavity is up to the position where the heat insulating means exists. Therefore, when the mold is opened after molding, only the molded product on the cavity side is taken out from the position of the heat insulating means, and runnerless molding can be performed.

JP-A-62-16114

  By the way, in the conventional open gate type runnerless injection molding apparatus, there is a problem that the position where the gate is cut is not always constant and the position varies. Due to such variation, waste of the resin member is increased, or a molded product is chipped. For this reason, in recent years, in order to stabilize the position of the gate cut, a technique of interposing a gate block that is not temperature-controlled between the cavity and the resin passage has been studied. However, even if a gate block is simply interposed between the cavity and the resin passage, the gate block thermally expands due to heat from the cavity. When the gate block thermally expands, the state of contact between the gate block and the resin passage portion fluctuates, and the state of heat transfer between the two also greatly fluctuates. As a result, the resin may be hardened in the resin passage portion, and this has been one of the causes of dispersion of the resin filling in the cavity portion.

  Therefore, the present invention provides a cooling block and a runnerless injection molding device that not only suppresses the curing of the resin in the flow path portion, but also stabilizes the fluidity of the resin and suppresses variations in resin filling. The purpose is to:

  In order to achieve the above object, a cooling block according to one embodiment of the present invention includes a resin flow path which is a flow path of a thermosetting resin, and a cooling flow through which a coolant is disposed around the resin flow path. A cooling block formed with a path, wherein the cooling flow path includes a plurality of unit winding portions wound around the resin flow path, and among the plurality of unit winding portions, at least one set of adjacent unit winding portions. The distance between the pitches of the portions is 1.5 mm or more and 8.0 mm or less, and the shortest distance between the plurality of unit winding portions and the resin flow path is 1.0 mm or more and 5.0 mm or less.

  Further, a runnerless injection molding apparatus according to one aspect of the present invention includes the cooling block described above and a heating block having a heat source for curing a thermosetting resin.

  According to the present invention, it is possible to provide a cooling block and a runnerless injection molding device that can stabilize the fluidity of a resin by suppressing curing of the resin in a flow path portion and suppress variations in resin filling. Can be.

FIG. 1 is a cross-sectional view schematically illustrating a main configuration of a runnerless injection molding apparatus according to an embodiment. FIG. 2 is a cross-sectional view illustrating the cooling block according to the embodiment. FIG. 3 is a top view schematically showing the overall shape of the cooling channel according to the embodiment. FIG. 4 is an explanatory diagram showing a temperature distribution when the distance between pitches is 9 mm in the cooling block according to the embodiment. FIG. 5 is an explanatory diagram illustrating a temperature distribution when the pitch distance is 8 mm in the cooling block according to the embodiment. FIG. 6 is an explanatory diagram showing a temperature distribution when the pitch distance is 7 mm in the cooling block according to the embodiment. FIG. 7 is an explanatory diagram showing a temperature distribution when the distance between pitches is 6 mm in the cooling block according to the embodiment. FIG. 8 is an explanatory diagram illustrating a temperature distribution when the distance between pitches is 2 mm in the cooling block according to the embodiment. FIG. 9 is an explanatory diagram showing a temperature distribution when the shortest distance between the plurality of unit winding portions and the second sprue is 10 mm in the cooling block according to the embodiment. FIG. 10 is an explanatory diagram showing a temperature distribution when the shortest distance between the plurality of unit winding portions and the second sprue is 8 mm in the cooling block according to the embodiment. FIG. 11 is an explanatory diagram showing a temperature distribution when the shortest distance between the plurality of unit winding portions and the second sprue is 7 mm in the cooling block according to the embodiment. FIG. 12 is an explanatory diagram illustrating a temperature distribution when the shortest distance between the plurality of unit winding portions and the second sprue is 6 mm in the cooling block according to the embodiment. FIG. 13 is an explanatory diagram showing a temperature distribution when the shortest distance between the plurality of unit winding portions and the second sprue is 5 mm in the cooling block according to the embodiment. FIG. 14 is an explanatory diagram showing a temperature distribution when the shortest distance between the plurality of unit winding portions and the second sprue is 1 mm in the cooling block according to the embodiment. FIG. 15 is a perspective view schematically showing one step of the method of manufacturing the cooling block according to the embodiment. FIG. 16 is a perspective view schematically showing one step of the method of manufacturing the cooling block according to the embodiment. FIG. 17 is a perspective view schematically showing one step of the method of manufacturing the cooling block according to the embodiment. FIG. 18 is an explanatory diagram illustrating an example of a cross-sectional shape of the cooling channel according to the embodiment. FIG. 19 is a cross-sectional view of a runnerless injection molding apparatus showing each step of the method for manufacturing a resin molded product according to the embodiment. FIG. 20 is a cross-sectional view of a runnerless injection molding apparatus showing each step of the method for manufacturing a resin molded product according to the embodiment. FIG. 21 is a cross-sectional view illustrating a cooling block according to the first modification. FIG. 22 is a perspective view illustrating a schematic configuration of a cooling channel according to a second modification. FIG. 23 is a front view illustrating a schematic configuration of a cooling channel according to a second modification. FIG. 24 is a side view illustrating a schematic configuration of the cooling flow channel according to the second modification.

  Hereinafter, a runnerless injection molding apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings. Each of the embodiments described below shows a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, constituent elements, arrangement and connection forms of constituent elements, steps, order of steps, and the like shown in the following embodiments are merely examples, and do not limit the present invention. Therefore, among the components in the following embodiments, components that are not described in independent claims that represent the highest concept of the present invention are described as arbitrary components.

  In addition, each drawing is a schematic diagram and is not necessarily strictly illustrated. In each of the drawings, the same components are denoted by the same reference numerals.

(Embodiment)
[Runnerless injection molding equipment]
FIG. 1 is a cross-sectional view schematically showing a main configuration of a runnerless injection molding apparatus 10 according to an embodiment. The runnerless injection molding apparatus 10 is an apparatus for injection molding a thermosetting resin. Here, the thermosetting resin is a resin that is cured by heating, for example, phenol resin, urea resin, melamine resin, epoxy resin, silicon resin, unsaturated polyester resin (BMC: Bulk Molding Compound, SMC: Seat) Molding Compound). The thermosetting resin also includes a thermosetting elastomer. In addition, vulcanization and cross-linking are also included in the thermosetting here.

  The runnerless injection molding apparatus 10 includes a mold 20 for molding a thermosetting resin (hereinafter, referred to as a resin 11; see FIG. 19), and a mold for communicating with the mold 20 and a resin communication passage to supply the resin. A resin injection section (not shown) for injecting resin from a manifold (not shown) for a point gate and a first sprue (not shown), and a molded product removal device 80 (FIG. 20) for removing a resin molded product from the mold 20 And a control unit (computer: not shown) for controlling these operations. The control unit includes, for example, a non-volatile memory in which a program is stored, a volatile memory that is a temporary storage area for executing the program, an input / output port, and a processor that executes the program.

[Mold]
The mold 20 includes a cooling block 30, a gate block 40, a fixed-side heating block 50, and a movable-side heating block 60. The resin 11 having high fluidity is supplied to the mold 20 by a resin injection unit (not shown). For example, when the resin 11 is BMC, the resin injection unit injects the BMC into the mold 20 in a state where the temperature of the BMC is adjusted to 70 ° C. or more and 80 ° C. or less, where the viscosity becomes the lowest. In the mold 20, a cooling block 30, a gate block 40, a fixed-side heating block 50, and a movable-side heating block 60 are arranged in this order from the upstream in the flow direction of the resin 11. In the present embodiment, the upstream side in the flow direction of the resin 11 is defined as “up”, and the downstream side is defined as “down”.

[Cooling block]
FIG. 2 is a cross-sectional view illustrating the cooling block 30 according to the embodiment. As shown in FIG. 2, the cooling block 30 includes a second sprue 31 which forms a part of a sprue which is a flow path of the resin 11, and a cooling flow path 32 for cooling the resin 11 in the second sprue 31. Is formed. The cooling block 30 is formed of, for example, a metal material such as stainless steel.

  The second sprue 31 is a resin flow path that guides the resin 11 injected from the resin injection unit to the gate block 40. The direction in which the second sprue 31 extends is the same as the direction in which the resin 11 flows, and in the present embodiment, is the vertical direction. Specifically, the second sprue 31 includes a first flow path 311 that is a cylindrical space, a tapered section 312 that is continuous with the lower end of the first flow path 311 and that is a tapered space, and a tapered section 312. And a second flow path 313 which is a columnar space continuous with the lower end of the second flow path. That is, the second channel 313 is thinner than the first channel 311.

  The cooling channel 32 is arranged around the second sprue 31 and is a channel through which the coolant 33 flows. Examples of the coolant 33 include a coolant such as water and oil. A cooling source (not shown) is connected to the cooling channel 32, and the cooling source circulates the coolant 33 in the cooling channel 32. The cooling source adjusts the temperature of the coolant 33 to a predetermined temperature. Thereby, the coolant 33 controls the temperature of the resin 11 in the second sprue 31 via the cooling channel 32. Here, the predetermined temperature is a temperature at which the fluidity of the resin 11 can be stabilized in a high state (a state with a low viscosity). For example, when the resin 11 is BMC, a temperature of 70 ° C. or more and 80 ° C. or less is set as a predetermined temperature.

  FIG. 3 is a top view schematically showing the overall shape of the cooling channel 32 according to the embodiment. FIG. 2 is a cross-sectional view of the section taken along the line II-II in FIG.

  As shown in FIGS. 2 and 3, the cooling channel 32 is a single channel in the cooling block 30. The cooling channel 32 includes a supply section 321 to which the coolant 33 is supplied from a cooling source, a discharge section 322 for discharging the coolant 33 to the cooling source, and an intermediate section 323 between the supply section 321 and the discharge section 322. It has. The supply section 321 is disposed above the cooling block 30 and above the intermediate section 323. The discharge part 322 is located below the cooling block 30 and below the intermediate part 323. Note that the positional relationship between the supply unit 321 and the discharge unit 322 may be reversed. Then, the cooling channel 32 forms a closed space inside the cooling block 30 except for the supply unit 321 and the discharge unit 322. This prevents the coolant 33 from leaking from the cooling block 30.

  The intermediate portion 323 of the cooling channel 32 is a portion that contributes to temperature control of the resin 11 in the second sprue 31. The intermediate portion 323 is formed in a spiral shape as a whole, and allows the coolant 33 to flow from upstream to downstream in the flow direction of the resin 11.

  In FIGS. 2 and 3, in the intermediate portion 323, a portion on the near side of the cut surface including the line II-II is illustrated by a black line, and a portion on the back side is illustrated by a gray line. . Further, the cross-sectional shape of the cooling channel 32 is illustrated as a circle, but may be an elliptical shape, a long hole shape, or a droplet shape. Note that the inner diameter of the cooling channel 32 is not less than 3.0 mm and not more than 10.0 mm. When the inner diameter of the cooling channel 32 is not less than 3.0 mm and not more than 10.0 mm, the speed can be increased within a range where the coolant 33 flows smoothly in the cooling channel 32, and the cooling efficiency can be increased. When the cross-sectional shape is a cooling flow path other than a circular shape, the width of the shortest portion is defined as the inner diameter.

  The intermediate portion 323 has a plurality of unit winding portions 323a wound around the second sprue 31. The unit winding portion 323a is a portion wound around the second sprue 31 once. And all the unit winding parts 323a have the shape wound by the same winding diameter.

  Next, an appropriate pitch distance A of the intermediate portion 323 of the cooling channel 32 will be described.

  Here, the pitch-to-pitch distance A is an interval between at least one set of adjacent unit winding portions 323a. Specifically, the pitch distance A is the vertical distance between at least one pair of adjacent unit winding portions 323a. The temperature distribution of the cooling block 30 at each pitch distance A was obtained by performing a simulation with the pitch distances A different.

  4 to 8 are explanatory diagrams illustrating temperature distributions at the respective pitch distances A in the cooling block 30 according to the embodiment. Specifically, FIG. 4 shows a temperature distribution when the pitch distance A is 9 mm. FIG. 5 shows the temperature distribution when the pitch distance A is 8 mm. FIG. 6 shows the temperature distribution when the pitch distance A is 7 mm. FIG. 7 shows a temperature distribution when the pitch distance A is 6 mm. FIG. 8 shows the temperature distribution when the pitch distance A is 2 mm.

  In FIG. 4, it can be seen that in the flow direction of the resin 11 in the second sprue 31, the temperature distribution in the low temperature zone (around 70 ° C.) is divided. However, in FIGS. 5 to 8, it can be seen that the temperature distribution in the low temperature zone is not divided in the flow direction of the resin 11, and that the second sprue 31 is cooled substantially uniformly. Further, it can be seen that the range of the temperature distribution in the low temperature zone becomes wider as the distance A between the pitches becomes smaller. As described above, when the distance A between the pitches is small, the unit winding portions are densely arranged in the cooling block 30, and the resin 11 in the second sprue 31 can be efficiently cooled. In particular, if the distance A between the pitches is 8 mm or less, the resin 11 in the second sprue 31 can be uniformly cooled, and the resin 11 is reliably prevented from being hardened in the second sprue 31. Can be.

  If the pitch A is smaller than 1.5 mm, the wall between the adjacent unit winding portions 323a may not be stably formed. Therefore, the pitch A is 1.5 mm or more. That is, the appropriate distance A between the pitches is 1.5 mm or more and 8.0 mm or less. If the distance A between the pitches of all adjacent unit winding portions 323a is 1.5 mm or more and 8.0 mm or less, the resin 11 in the second sprue 31 can be cooled more efficiently.

  Next, an appropriate shortest distance B between the plurality of unit winding portions 323a and the second sprue 31 will be described.

  Here, the shortest distance B is the shortest distance between the plurality of unit winding portions 323a and the second sprue 31, as shown in FIG. Specifically, the shortest distance B is a horizontal distance between the plurality of unit winding portions 323a and the second sprue 31. The temperature distribution of the cooling block 30 at each of the shortest distances B was obtained by performing a simulation while varying the shortest distances B.

  9 to 14 are explanatory diagrams illustrating temperature distributions at the shortest distances B in the cooling block 30 according to the embodiment. Specifically, FIG. 9 shows a temperature distribution when the shortest distance B is 10 mm. FIG. 10 shows a temperature distribution when the shortest distance B is 8 mm. FIG. 11 shows a temperature distribution when the shortest distance B is 7 mm. FIG. 12 shows a temperature distribution when the shortest distance B is 6 mm. FIG. 13 shows a temperature distribution when the shortest distance B is 5 mm. FIG. 14 shows a temperature distribution when the shortest distance B is 1 mm. 9 to 14, the cooling block 30 is shown in an enlarged manner.

  9 to 12, it can be seen that a high-temperature zone (around 75 ° C.) occurs in the tapered portion 312 of the second sprue 31. However, in FIGS. 13 and 14, it can be seen that the temperature in the tapered portion 312 is lower than in other cases. As described above, when the shortest distance B is 5 mm or less, it is possible to suppress the resin 11 from being cured in the tapered portion 312.

  If the shortest distance B is smaller than 1.0 mm, the wall between the unit winding portion 323a and the second sprue 31 may not be stably formed. I do. That is, the appropriate shortest distance B is 1.0 mm or more and 5.0 mm or less.

  The whole of the plurality of unit winding portions 323a may be arranged at a position that satisfies the shortest distance B to the second sprue 31. Thereby, the resin 11 in the second sprue 31 can be cooled evenly.

  Further, as shown in FIG. 2, the shortest distance C between the cooling flow path 32 and the second flow path 313 of the second sprue 31 may be 1.5 mm or more and 4.0 mm or less. Thereby, it is possible to optimize the temperature distribution in the second flow path 313.

  Note that the shortest distance C is a distance at a position where the cooling flow path 32 and the second flow path 313 of the second sprue 31 are closest. For this reason, the shortest distance C may not be the distance in the vertical or horizontal direction.

[Gate block]
As shown in FIG. 1, the gate block 40 is disposed between the cooling block 30 and the fixed-side heating block 50. The gate block 40 is formed of a metal material such as stainless steel or a material having a low thermal conductivity (for example, ceramics) so that the temperature is not adjusted. The gate block 40 has a gate block-side gate 42 that forms a part of a sprue that is a flow path of the resin 11.

  As shown in FIG. 1, the gate block side gate 42 is a flow path that guides the resin 11 supplied from the second sprue 31 of the cooling block 30 to the fixed side heating block 50. The gate block side gate 42 extends vertically as a whole. The upper end of the gate 42 on the gate block side is a throttle 41 having a smaller inner diameter than the second sprue 31. The diaphragm 41 is a cylindrical space. Further, on the downstream side of the throttle portion 41 in the gate 42 on the gate block side, there is an enlarged portion 43 having an inner diameter larger than that of the throttle portion 41. The enlarged diameter portion 43 is a tapered space having the smallest inner diameter at the upper end and the largest inner diameter at the lower end.

[Fixed heating block]
The fixed-side heating block 50 is disposed between the gate block 40 and the movable-side heating block 60. The fixed side heating block 50 is formed of a metal material such as stainless steel, for example. In the fixed-side heating block 50, a heating block-side gate 53 forming a part of a sprue, which is a flow path of the resin 11, and a cavity 54 are formed.

  The heating block side gate 53 is a flow path for guiding the resin 11 supplied from the gate block side gate 42 of the gate block 40 to the cavity 54. The heating block-side gate 53 extends vertically as a whole, and is a tapered space having the smallest inner diameter at the upper end and the largest inner diameter at the lower end.

  The cavity 54 is a concave portion for forming a resin molded product, and its lower part is open. The cavity 54 is a closed space when the movable heating block 60 overlaps when the mold is closed. The resin 11 is filled into the closed space when the mold is closed and hardened, thereby forming a resin molded product. This space is formed in a shape corresponding to the shape of the resin molded product.

  The fixed-side heating block 50 has a heating block 51 and a heat source 51 for curing the resin 11 in the cavity 54. Specifically, the heat source 51 is, for example, a heating wire, and is disposed around the heating block-side gate 53 and the cavity 54 in the fixed-side heating block 50. When heat from the heat source 51 is transmitted to the heating block side gate 53 and the resin 11 in the cavity 54, the resin 11 is cured to form a resin molded product. In the resin molded product, a portion corresponding to the cavity 54 is a product portion, and a portion corresponding to the heating block side gate 53 is a non-product portion.

  The heat source 51 adjusts the temperature to a temperature at which the resin 11 in the heating block side gate 53 and the cavity 54 is cured. For example, when the resin 11 is BMC, it is heated to 140 ° C. or higher.

[Movable heating block]
The movable-side heating block 60 is a mold that moves up and down to move toward and away from the fixed-side heating block 50. The movable-side heating block 60 is formed of, for example, a metal material such as stainless steel. The upper surface of the movable-side heating block 60 has a shape portion 61 having a shape corresponding to a part of the cavity 54. When the movable-side heating block 60 overlaps the fixed-side heating block 50 and the mold is closed. The cavity 54 is closed.

  The movable heating block 60 has a heat source 62 for curing the resin 11 in the cavity 54. Specifically, the heat source 62 is, for example, a heating wire, and is disposed around the shape portion 61. When the heat from the heat source 62 is transmitted to the resin 11 in the cavity 54, the resin 11 is cured to form a resin molded product.

[Cooling block manufacturing method]
Next, a method for manufacturing the cooling block 30 according to the embodiment will be described.

  15 to 17 are perspective views schematically showing one process of a method of manufacturing the cooling block 30 according to the embodiment.

  As shown in FIGS. 15 to 17, the cooling block 30 is manufactured by an optical three-dimensionally shaped object manufacturing apparatus (hereinafter, simply referred to as a manufacturing apparatus 200). The manufacturing apparatus 200 includes a modeling unit 210 and a transfer unit 230.

  The modeling unit 210 has a tank shape, and a modeling table 211 is provided on a bottom surface thereof. Sintered layers formed by sintering the powder material 240 are sequentially stacked on the modeling table 211 to form the cooling block 30. Powder made of stainless steel or the like is used as the powder material 240.

  The transfer unit 230 is for transferring the powder material 240 to the modeling unit 210 and forming a powder layer having a predetermined thickness on the modeling unit 210. The transfer unit 230 is supported by the modeling unit 210 so as to reciprocate with respect to the modeling unit 210. When the transfer unit 230 reciprocates above the modeling unit 210, the lower portion of the transfer unit 230 can move in parallel while maintaining a constant distance from the modeling table 211. As a result, a powder layer having a uniform thickness can be formed on the modeling table 211 or the sintered layer formed thereon while the powder material 240 is transported onto the modeling table 211 by the transport unit 230. I have.

  Above the modeling unit 210, a light beam irradiation device 250 that irradiates a light beam L such as a laser beam is arranged. The light beam irradiation device 250 irradiates the light beam L by changing the irradiation position, the focal position, and the like of the light beam L.

  When the cooling block 30 is manufactured, the transfer unit 230 reciprocates to transfer the powder material 240 to the modeling unit 210 and form a powder layer on the modeling table 211. FIG. 15 shows a state in which a powder layer is formed on the modeling table 211.

  Thereafter, as shown in FIG. 16, a predetermined portion of the powder layer is irradiated with a light beam L from a light beam irradiation device 250, and the powder material 240 at the irradiated portion is melted and sintered to form a sintered layer. I do. Next, as shown in FIG. 17, the transfer section 230 reciprocates again to transfer the powder material 240 to the powder layer of the modeling section 210 and form a new powder layer on the powder layer. Then, by irradiating the light beam L to a predetermined portion of the newly formed powder layer, the powder material 240 at the irradiated portion is melted and sintered. By repeating this, the cooling block 30 which is a metal stereolithography is manufactured.

  When the cooling block 30 is a stereolithographic object, the cross-sectional shape of the cooling channel 32 is desirably a droplet. FIG. 18 is an explanatory diagram illustrating an example of a cross-sectional shape of the cooling channel 32 according to the embodiment. As shown in FIG. 18, the cooling channel 32 is formed in a cross-sectional droplet shape in which the laminating direction of the powder layer is sharp. Thereby, the cooling channel 32 can be easily formed by stereolithography.

  Note that the gate block 40, the fixed-side heating block 50, and the movable-side heating block 60 may be optically formed objects.

[Production method of resin molded product]
Next, a method for manufacturing a resin molded product according to the embodiment will be described with reference to FIGS. 19 and 20 are cross-sectional views of the runnerless injection molding apparatus 10 showing respective steps of the method for manufacturing a resin molded product according to the embodiment.

  First, as shown in FIG. 1, when the movable-side heating block 60 overlaps the fixed-side heating block 50 and enters a mold-closed state, the resin 11 is injected from the resin injection unit. Thereby, as shown in FIG. 19, the resin 11 is supplied and filled into the cavity 54 via the second sprue 31, the gate block side gate 42, and the heating block side gate 53.

  When the resin 11 is supplied, a coolant 33 is circulating in the cooling channel 32 of the cooling block 30, and the temperature of the resin 11 in the second sprue 31 is adjusted. On the other hand, in the fixed-side heating block 50 and the movable-side heating block 60, the heat sources 51 and 62 generate heat, respectively, and the inside of the heating block-side gate 53 and the cavity 54 is adjusted to a temperature at which the resin 11 cures. Thereby, the resin 11 can be hardened stably in the fixed-side heating block 50. The resin 11 in the gate block 40 is also cured because heat is transmitted from the resin 11 in the fixed-side heating block 50.

  After the curing of the resin 11 in the fixed-side heating block 50, as shown in FIG. 20, the movable-side heating block 60 descends and separates from the fixed-side heating block 50, so that the mold is opened. After that, the resin molded product 100 is taken out from the shaped part 61 of the movable side heating block 60 by the molded product take-out device 80. At the time of this removal, a gate cut is performed near the boundary between the gate block 40 and the cooling block 30 where the resin 11 has low fluidity. At this time, since the narrowed portion 41 having an inner diameter smaller than the inner diameter portion 43 of the gate block side gate 42 is arranged near the boundary, the stress at the time of removal can be concentrated on the narrowed portion 41. Therefore, the reliability of the gate cut performed near the boundary can be improved.

[Effects, etc.]
As described above, the cooling block according to the present embodiment is arranged around the second sprue 31 (resin flow path), which is a flow path for the resin 11 (thermosetting resin), and around the second sprue 31. The cooling block 30 is formed with a cooling channel 32 through which a coolant 33 flows. The cooling passage 32 includes a plurality of unit winding portions 323a wound around the second sprue 31. The pitch distance A between at least one pair of adjacent unit winding portions 323a among the plurality of unit winding portions 323a is 1.5 mm or more and 8.0 mm or less. The shortest distance B between the plurality of unit winding portions 323a and the second sprue 31 is 1.0 mm or more and 5.0 mm or less.

  Further, the runnerless injection molding apparatus 10 according to the present embodiment includes the cooling block 30 and a fixed-side heating block 50 (heating block) having a heat source for curing the resin 11.

  According to this configuration, the pitch distance A between at least one pair of adjacent unit winding portions 323a is 1.5 mm or more and 8.0 mm or less, and the shortest distance B between the plurality of unit winding portions 323a and the second sprue 31 is set. Is not less than 1.0 mm and not more than 5.0 mm, the resin 11 in the second sprue 31 can be efficiently cooled. Therefore, the hardening of the resin 11 in the second sprue 31 can be suppressed, the fluidity of the resin 11 can be stabilized, and variations in resin filling can be suppressed.

  In particular, in the case where the resin is injected into the plurality of molds 20 simultaneously from the resin injection unit, since the fluidity of the resin 11 is stabilized, variations in the resin filling in the plurality of molds 20 are suppressed. It is possible.

  The inner diameter of the cooling channel 32 is not less than 3.0 mm and not more than 10.0 mm.

  According to this configuration, since the inner diameter of the cooling channel 32 is not less than 3.0 mm and not more than 10.0 mm, the speed can be increased within a range in which the coolant 33 flows smoothly in the cooling channel 32, and the cooling efficiency is improved. Can be enhanced.

  Further, the cooling block 30 is an optically formed object made of metal.

  According to this configuration, since the cooling block 30 is a stereolithographic object made of metal, manufacturing restrictions are reduced, and the degree of freedom in designing the cooling channel 32 can be increased.

  In addition, the second sprue 31 includes a first flow path 311 and a second flow path 313 that communicates with the first flow path 311 and is smaller than the first flow path 311. The shortest distance C between the cooling channel 32 and the second channel 313 is 1.5 mm or more and 4.0 mm or less.

  According to this configuration, since the shortest distance C between the cooling channel 32 and the second channel 313 is 1.5 mm or more and 4.0 mm or less, it is possible to optimize the temperature distribution in the second channel 313. It is possible.

(Modification 1)
Next, Modified Example 1 according to the present embodiment will be described.

  In the above embodiment, the cooling block 30 in which the discharge unit 322 is provided in the lower part has been described as an example, but the layout of the discharge unit may be any. In the following description, the same portions as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof may be omitted.

  FIG. 21 is a cross-sectional view illustrating a cooling block 30B according to the first modification. As shown in FIG. 21, the discharge portion 322b of the cooling channel 32B provided in the cooling block 30B horizontally extends outward from the lower end of the intermediate portion 323, and then bends and extends upward. Further, the discharge portion 322b is bent at the same height position as the supply portion 321, and then horizontally extends outward. Note that the positional relationship between the supply unit 321 and the discharge unit 322b may be reversed.

(Modification 2)
Next, Modification 2 according to the present embodiment will be described.

  In the above embodiment, the cooling channel 32 having the spiral intermediate portion 323 has been described as an example, but the channel shape of the cooling channel 32 is arranged around the second sprue 31 and Any shape may be used as long as the two sprues 31 are partially or spirally wound.

  In the second modification, an example of another shape of the cooling channel will be described with reference to FIGS. FIG. 22 is a perspective view illustrating a schematic configuration of a cooling channel 32A according to Modification 2. FIG. 23 is a front view illustrating a schematic configuration of the cooling flow channel 32A according to the second modification. FIG. 24 is a side view showing a schematic configuration of the cooling flow path 32A according to the second modification.

  As shown in FIGS. 20 to 23, an intermediate portion 323 a of the cooling channel 32 </ b> A according to the second modification is formed so as to entirely surround the second sprue 31. Specifically, the intermediate portion 323a includes a plurality of arc portions 3231 and a plurality of connecting portions 3232.

  The plurality of arc portions 3231 are flow channels arranged so as to be wound around the second sprue 31 at different positions in the vertical direction. That is, one circular arc portion 3231 is a unit winding portion. Specifically, six arc portions 3231 are provided. Hereinafter, these are referred to as a first arc portion 3231a, a second arc portion 3231b, a third arc portion 3231c, a fourth arc portion 3231d, a fifth arc portion 3231e, and a sixth arc portion 3231f in order from the top. The first arc portion 3231a, the third arc portion 3231c, the fourth arc portion 3231d, the fifth arc portion 3231e, and the sixth arc portion 3231f are formed in a C shape in a top view. The second arc portion 3231b is formed by two divided arcs 3231b1 and 3231b2.

  The plurality of connecting portions 3232 are flow paths extending in the up-down direction, and are portions connecting the arc portions 3231.

  Hereinafter, the connection relationship between the respective arc portions 3231 and the respective connection portions 3232 will be specifically described. Here, in each of the arc portions 3231, the upstream side in the flow direction of the coolant 33 is referred to as “one end”, and the downstream side is referred to as “other end”.

  The supply part 321a is connected and communicates with one end of the first circular part 3231a. 22 to 24 show only a part of the supply unit 321a. In addition, the other end of the first arc portion 3231a and one end of the arc 3231b1 of the second arc portion 3231b are connected via a connection portion 3232 and communicate with each other. The other end of the arc 3231b1 of the second arc portion 3231b and one end of the third arc portion 3231c are connected via a connecting portion 3232 and communicate with each other. The other end of the third arc portion 3231c and one end of the arc 3231b2 of the second arc portion 3231b are connected and connected via a connection portion 3232. The other end of the arc 3231b2 of the second arc portion 3231b and one end of the fourth arc portion 3231d are connected via a connecting portion 3232 and are in communication. The other end of the fourth arc portion 3231d and one end of the fifth arc portion 3231e are connected via a connecting portion 3232 and communicate with each other. The other end of the fifth circular arc portion 3231e and one end of the sixth circular arc portion 3231f are connected via a connecting portion 3232 and communicate with each other. The discharge portion 322a is connected to and communicates with the other end of the sixth circular arc portion 3231f.

  Also in such an intermediate portion 323a of the cooling channel 32A, the distance A between the pitches of at least one pair of adjacent arc portions 3231 is set to 1.5 mm or more and 8.0 mm or less, and the plurality of arc portions 3231 and the second sprue 31 May be set to be 1.0 mm or more and 5.0 mm or less. Thereby, the same effect as in the above embodiment can be obtained.

(Other)
As described above, the cooling block 30 and the runnerless injection molding apparatus 10 according to the present invention have been described based on the embodiments, but the present invention is not limited to the above embodiments.

  In addition, a form obtained by applying various modifications conceived by those skilled in the art to the above-described embodiments and modifications, and components and functions of the above-described embodiments and modifications arbitrarily without departing from the spirit of the present invention. A form realized by combining them is also included in the present invention.

10 Runnerless injection molding device 11 Resin (thermosetting resin)
30 cooling block 31 second sprue (resin flow path)
32, 32A Cooling channel 33 Coolant 50 Fixed side heating block (heating block)
51, 62 Heat source 311 First flow path 313 Second flow path 323a Unit winding part 3231 Arc part (unit winding part)
A Distance between pitches B, C Shortest distance

Claims (4)

A cooling block in which a resin flow path that is a flow path of a thermosetting resin and a cooling flow path that is disposed around the resin flow path and through which a coolant flows are formed,
The cooling channel includes a plurality of unit winding portions wound around the resin channel,
The plurality of unit wound portion, the pitch distance between each set of unit wound portion adjacent to meet the 1.5mm or 8.0mm or less, Ri Contact wound on the entire of the resin flow path,
A cooling block, wherein a shortest distance between all of the plurality of unit winding portions and the resin flow path is 1.0 mm or more and 5.0 mm or less. It said cooling block, the cooling block according to claim 1, wherein the metal stereolithography material. The resin flow path includes a first flow path and a second flow path that is smaller than the first flow path and communicates with the first flow path.
The shortest distance between cooling channel and said second flow path, the cooling block according to claim 1 or 2 is 1.5mm or more 4.0mm or less. A cooling block according to any one of claims 1 to 3 ,
A heating block having a heat source for curing the thermosetting resin.

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