JP2019123116A - Mold, and manufacturing method of resin molded article using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold capable of producing a resin molded product having higher strength and less likely to cause burrs, and a method for producing a resin molded product using the mold. A mold 1A is for molding a resin molded product by injection molding, and has a cavity 4A, a first gate 51, and a second gate 52A. The cavity 4A has a shape having a longitudinal direction and a lateral direction, and has a first portion 41 located at one end in the longitudinal direction and a second portion 42A located at one end in the lateral direction and extending in the longitudinal direction. And have. The first gate 51 extends in the longitudinal direction toward the first portion 41. The second gate 52A extends diagonally from one end side to the other end side in the longitudinal direction toward the central portion in the longitudinal direction of the second portion 42A. [Selection diagram] Fig. 2

Description

  The present invention relates to a mold used for injection molding of a resin molded article, and a method of manufacturing a resin molded article using the mold.

  FIG. 9 is a plan view of a conventional power supply device (see Patent Document 1). The power feeding device 301 is a device that is mounted on a vehicle, wires a wire harness from the vehicle floor side to a slide sheet, and feeds power to electrical devices attached to the slide sheet. The slide seat is supported by a slide seat attachment portion 304, and the slide seat attachment portion 304 is slidably attached to a seat rail 305 attached to the vehicle floor.

  As shown in FIG. 9, the power feeding device 301 includes a wire harness, a case 302 for housing the wire harness, and a protector 303 which holds the wire harness and is slidably attached to the seat rail 305.

  The case 302 has a harness excess length absorbing portion 307 extending along the seat rail 305 and a harness guiding portion 308 connected to one end of the excess length absorbing portion 307. The harness excess length absorbing portion 307 accommodates the excess length portion of the wire harness in a U-shape. The harness guiding portion 308 turns the wire harness from the harness excess length absorbing portion 307 by 180 degrees and guides it to one end of the seat rail 305. The case 302 is configured by assembling a synthetic resin base portion and a synthetic resin cover portion 321 in the vertical direction (arrow Z).

  10 and 11 are schematic views of a mold for forming the cover portion 321 described above. As shown in FIGS. 10 and 11, the mold 401 is composed of an upper mold 402 and a lower mold 403, and has a cavity 404 and a gate 405. The molten resin injected from the nozzle of the injection molding machine is injected into the cavity 404 through the gate 405, and the molten resin is cooled and solidified in the mold 401, whereby the cover portion 321 shown in FIG. 9 is formed. Ru.

  Further, as shown in FIG. 11, the molten resin contains glass fibers F for enhancing the strength of the cover portion 321. The gate 405 is provided in communication with one end of the cavity 404 in the longitudinal direction (arrow Y). The molten resin injected from the gate 405 is injected from one end side to the other end of the cavity 404 in the longitudinal direction, whereby the glass fibers F are regularly arrayed, and the strength of the cover portion 321 in the longitudinal direction is further enhanced. .

JP, 2016-136810, A

  However, in the injection molding using the conventional mold 401 described above, there are the following problems. That is, in order to ensure the strength of the cover portion 321 by aligning the arrangement of the glass fibers F in the mold 401, the gate 405 is provided only at one place, and it was necessary to increase the injection pressure of the molten resin. When the injection pressure is high, a minute gap is generated in the parting surface 410 (FIG. 10) of the upper die 402 and the lower die 403, and the resin flows into the gap, resulting in a problem that burrs may occur.

  In order to solve the problem of burrs described above, as shown in FIG. 12, the injection pressure of the molten resin is dispersed using a mold 501 provided with a plurality of gates 551, 552, and 553 for one cavity 504. I can think of a method. However, when the gates 551, 552, and 553 are simply provided at a plurality of locations as described above, the arrangement of the glass fibers F becomes irregular, and a new problem that the strength can not be further increased as shown in FIG. It will occur.

  Therefore, an object of the present invention is to provide a mold which is less likely to generate burrs and which can produce a higher-strength resin molded article, and a method of producing a resin molded article using the mold. .

  The mold of the present invention is a mold having a gate and a cavity into which a molten resin is injected, and cooling and solidifying the molten resin to form a resin molded article, wherein the cavity is in the longitudinal direction and the transverse direction. And has a first portion located at one end in the longitudinal direction and a second portion located at one end in the lateral direction and extending in the longitudinal direction, as the gate A first gate in communication with the first portion and a second gate in communication with the longitudinal middle portion of the second portion are provided, and the first gate is provided in the first portion. Extending in the longitudinal direction, and the second gate extends obliquely from the one end side to the other end side in the longitudinal direction toward the second portion with respect to the longitudinal direction. It features. Further, the “longitudinal middle portion of the second portion” means not only the longitudinally central portion of the second portion but also a portion between one end and the other end in the longitudinal direction.

  According to the present invention, since the injection pressure of the molten resin can be dispersed by providing the first gate and the second gate for one cavity, it is difficult to generate burrs with a small clamping force. Can. Further, since the second gate communicates with the longitudinal middle portion of the second portion and extends obliquely with respect to the longitudinal direction of the cavity, when injecting a molten resin containing fibers into the cavity, The arrangement of fibers can be aligned, and the strength in the longitudinal direction of the resin molded article can be further increased.

It is a perspective view of the resin molded product shape | molded by the metal mold | die concerning the 1st Embodiment of this invention. It is the schematic of the metal mold | die which shape | molds the resin molded product of FIG. It is a perspective view of the resin molded product shape | molded by the metal mold | die concerning the 2nd Embodiment of this invention. It is the schematic of the metal mold | die which shape | molds the resin molded product of FIG. It is an enlarged view of the A section in FIG. It is a perspective view of the resin molded product shape | molded by the metal mold | die concerning the 3rd Embodiment of this invention. It is the schematic of the metal mold | die which shape | molds the resin molded product of FIG. It is an enlarged view of the B section in FIG. It is a top view of the conventional electric power feeder. It is the schematic of the conventional metal mold | die which shape | molds the resin molded product of FIG. It is the schematic which looked at the metal mold | die of FIG. 10 from the top. It is the schematic of the metal mold | die of a reference example.

  The "mold" according to the first embodiment of the present invention and the "method for producing a resin molded product" using the mold will be described with reference to FIGS.

  The mold of this example is for molding the resin molded product 101A shown in FIG. 1 by injection molding. The resin molded product 101A is assembled with the resin molded product 102 shown in FIG. 1 in the vertical direction to constitute a case 103 of the power feeding device. Similar to the power supply device 301 described in the background art section, the power supply device is mounted on an automobile, wires the wire harness from the vehicle floor side to the slide sheet, and supplies electric power to the electrical equipment attached to the slide sheet. It is an apparatus. Also, the case 103 is for housing a wire harness.

  The resin molded product 101A is made of a resin containing glass fiber, and is formed in a shallow box shape having the upper wall 140 and the side walls 141, 142, 146, and 147 that descend from the outer edge of the upper wall 140 There is.

  The upper wall 140 is formed in an elongated plate shape whose longitudinal direction is the arrow Y direction and whose lateral direction is the arrow X. The outer edges located at one end and the other end in the longitudinal direction of the upper wall 140 are formed in an arc shape. Moreover, the outer edge located in the one end and the other end of the transversal direction of the upper wall 140 is formed in linear form. Therefore, the side wall 141 dropped from one end in the longitudinal direction of the upper wall 140 and the side wall 146 dropped from the other end are curved, and the side wall 142 dropped from one end in the lateral direction of the upper wall 140 and the other end The side wall 147 dropped from the side is flat.

  A mold 1A shown in FIG. 2 is for molding the above-described resin molded product 101A, and is configured of an upper mold 2 and a lower mold 3. The mold 1A has a cavity 4A corresponding to the shape of the resin molded product 101A, a first gate 51, a second gate 52A, a runner 6, and a sprue 7.

  The cavity 4A has a longitudinal direction (arrow Y direction) and a lateral direction (arrow X direction), and is located at a first portion 41 located at one end in the longitudinal direction and at one end in the lateral direction. A longitudinally extending second portion 42A and other portions are provided. The first portion 41 is a portion for molding the side wall 141 of the resin molded product 101A. The second portion 42A has a portion 42 for molding the side wall 142 of the resin molded product 101A. The first portion 41, the second portion 42A and the other portions are in communication with one another.

  The first gate 51 communicates with the central portion of the first portion 41 in the lateral direction (the lateral direction of the cavity 4A and in the direction of the arrow X). In addition, the first gate 51 extends in the longitudinal direction of the cavity 4A from the runner 6 toward the first portion 41.

  The second gate 52A communicates with the central portion of the second portion 42A in the longitudinal direction (the longitudinal direction of the cavity 4A, which is the direction of the arrow Y). The second gate 52A extends obliquely from one end side to the other end side in the longitudinal direction of the second portion 42A from the runner 6 toward the second portion 42A with respect to the longitudinal direction. That is, one end side (the first portion 41 side) of the longitudinal direction of the portion 42 for forming the side wall 142 and the second gate 52A form an acute angle.

  The runner 6 is a portion which branches from the sprue 7 to the first gate 51 and the second gate 52A.

  The sprue 7 is a portion into which the molten resin injected from the nozzle of the injection molding machine is injected.

  Then, the manufacturing method of the resin molded product 101A using the metal mold | die 1A mentioned above is demonstrated. The heated and melted resin and the glass fiber are stirred in the injection part of the injection molding machine, and the molten resin containing the glass fiber is injected from the nozzle and injected into the sprue 7. The molten resin in the sprue 7 branches through the runner 6 into the first gate 51 and the second gate 52A, and is injected into the cavity 4A from the first gate 51 and the second gate 52A. At this time, the injection pressure from the second gate 52A is lower than the injection pressure from the first gate 51. The molten resin injected from the gates 51 and 52A into the cavity 4A flows from one end side to the other end side of the cavity 4A, and is filled in the entire area of the cavity 4A. Thereafter, the molten resin is cooled and solidified by passing a predetermined time in the mold 1A, and the upper mold 2 and the lower mold 3 are opened and taken out from the mold 1A. Finally, unnecessary portions solidified in the gates 51 and 52A and the runner 6 are cut, and the resin molded product 101A is completed.

  According to such a manufacturing method, since the injection pressure of the molten resin can be dispersed to the first gate 51 and the second gate 52A, a method for manufacturing a resin molded product using a conventional mold (FIG. Compared with 10 and 11, it is possible to make it difficult to generate burrs (those resulting from the resin flowing into the parting surfaces of the upper mold 2 and the lower mold 3) with a small clamping force.

  In addition, since the second gate 52A communicates with the longitudinal middle portion of the second portion 42A and extends obliquely with respect to the longitudinal direction of the cavity 4A, the melt injected from the first gate 51 Even at the point where the resin and the molten resin injected from the second gate 52A merge, the flow of the molten resin flows from one end side to the other end side of the cavity 4A with little disturbance. By this, the arrangement of glass fibers can be aligned, and the strength in the longitudinal direction of the resin molded product 101A can be further increased.

  Furthermore, in this example, since the injection pressure of the molten resin from the second gate 52A is lower than the injection pressure from the first gate 51, the molten resin injected from the first gate 51 and the first molten resin It is possible to further suppress disturbance of the flow of the molten resin at a point where the molten resin injected from the two gates 52A merges.

  The "mold" according to the second embodiment of the present invention and the "method for producing a resin molded product" using the mold will be described with reference to FIGS. In FIGS. 3 to 5, the same components as those of the first embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted.

  The mold of this example is for molding a resin molded product 101B shown in FIG. 3 by injection molding. The resin molded product 101B constitutes the case of the power feeding device as in the first embodiment. The resin molded product 101B is made of a resin containing glass fiber, and is the first except that a convex portion 144 having a triangular shape in plan view is provided at the central portion of the side wall 142 in the longitudinal direction (arrow Y direction). The configuration is the same as that of the resin molded product 101A of the embodiment.

  A mold 1B shown in FIGS. 4 and 5 is for molding the above-described resin molded product 101B, and is configured of an upper mold 2 and a lower mold 3. The mold 1B has a cavity 4B corresponding to the shape of the resin molded product 101B, a first gate 51, a second gate 52B, a runner 6, and a sprue 7.

  The cavity 4B has a first portion 41, a second portion 42B, and other portions. The second portion 42B includes a portion 44 for molding the convex portion 144 of the resin molded product 101B in addition to the configuration of the second portion 42A of the first embodiment.

  The second gate 52B is in communication with the portion 44 in the longitudinally central portion of the second portion 42B. More specifically, as shown in FIG. 5, the second gate 52B is in communication with a portion 44a of the portion 44 which forms the side surface 144a (FIG. 3) of the convex portion 144. The second gate 52B intersects the portion 44a substantially perpendicularly. Further, as in the first embodiment, the second gate 52B extends from one end side to the other end side in the longitudinal direction of the second portion 42B from the runner 6 toward the second portion 42B in the longitudinal direction. It extends diagonally.

  The method of manufacturing the resin molded product 101B using the mold 1B described above is the same as that of the first embodiment, and thus the description thereof is omitted. Also in this example, as in the first embodiment, it is possible to make burrs less likely to occur with a small mold clamping force. In addition, the arrangement of glass fibers can be aligned, and the strength in the longitudinal direction of the resin molded product 101B can be further increased.

  Furthermore, in the first embodiment described above, the second gate 52A obliquely intersects with the portion 42 that forms the side wall 142, but in this example, the portion where the second gate 52B forms the side surface 144a of the convex portion 144. Since it intersects substantially perpendicularly with 44a, the area of the interface with the portion 44a in the second gate 52B can be made smaller than the interface with the portion 42 in the second gate 52A. By this, the moldability of the resin molded product 101B can be improved.

  The “mold” according to the third embodiment of the present invention and the “method for producing a resin molded product” using the mold will be described with reference to FIGS. 6 to 8, the same components as those of the first and second embodiments described above are denoted by the same reference numerals, and the description thereof will be omitted.

  The mold of this example is for molding a resin molded product 101C shown in FIG. 6 by injection molding. The resin molded product 101C constitutes the case of the power feeding device as in the first embodiment. The resin molded product 101C is made of a resin containing glass fiber, and the first embodiment is implemented except that a concave portion 145 having a triangular shape in plan view is provided at the central portion of the side wall 142 in the longitudinal direction (arrow Y direction). The configuration is the same as that of the resin molded product 101A of the embodiment.

  A mold 1C shown in FIGS. 7 and 8 is for molding the above-described resin molded product 101C, and is configured of an upper mold 2 and a lower mold 3. The mold 1C has a cavity 4C corresponding to the shape of the resin molded product 101C, a first gate 51, a second gate 52C, a runner 6, and a sprue 7.

  The cavity 4C has a first portion 41, a second portion 42C, and other portions. The second portion 42C has a portion 45 for molding the concave portion 145 of the resin molded product 101C, instead of the portion 44 for molding the convex portion 144 of the second embodiment described above. It has the same configuration as the second portion 42B of the second embodiment.

  The second gate 52C is in communication with the portion 45 at the longitudinally central portion of the second portion 42C. More specifically, as shown in FIG. 8, the second gate 52 </ b> C communicates with a portion 45 a of the portion 45 that forms the inner surface 145 a (FIG. 6) of the recess 145. The second gate 52C intersects the portion 45a substantially perpendicularly. Further, as in the first embodiment, the second gate 52C extends from one end side to the other end side of the second portion 42C in the longitudinal direction from the runner 6 toward the second portion 42C in the longitudinal direction. It extends diagonally.

  The method of manufacturing the resin molded product 101C using the mold 1C described above is the same as that of the first embodiment, and thus the description thereof is omitted. Also in this example, as in the first embodiment, it is possible to make burrs less likely to occur with a small mold clamping force. Further, the arrangement of glass fibers can be aligned, and the strength in the longitudinal direction of the resin molded product 101C can be further increased.

  Furthermore, in the first embodiment described above, the second gate 52A obliquely intersects with the portion 42 for forming the side wall 142, but in the present example, the portion 45a for forming the inner surface 145a of the recess 145 in the second gate 52C. The area of the interface of the second gate 52C with the portion 45a can be smaller than the area of the interface with the portion 42 of the second gate 52A. By this, the moldability of the resin molded product 101C can be improved.

  In the first to third embodiments described above, an example was described in which a molten resin containing glass fibers was injected into the mold, but in the present invention, a molten resin containing fibers other than glass is injected into the mold You may In the present invention, it is also possible to use a molten resin which does not contain reinforcing fibers.

  The embodiment described above only shows a typical form of the present invention, and the present invention is not limited to this embodiment. That is, various modifications can be made without departing from the scope of the present invention. Of course, as long as the configuration of the present invention is provided by such a modification, it is of course included in the scope of the present invention.

1A, 1B, 1C mold 4A, 4B, 4C cavity 41 first portion 42A, 42B, 42C second portion 51 first gate 52A, 52B, 52C second gate 101A, 101B, 101C resin molded article

Claims (3)

A mold having a gate and a cavity into which a molten resin is injected, and cooling and solidifying the molten resin to form a resin molded article,
The cavity has a shape having a longitudinal direction and a lateral direction, and the first portion located at one end in the longitudinal direction and the second portion located at one end in the lateral direction and extending in the longitudinal direction And
As the gate, a first gate in communication with the first portion and a second gate in communication with a longitudinal middle portion of the second portion are provided.
The first gate extends in the longitudinal direction towards the first portion;
A mold characterized in that the second gate extends obliquely to the longitudinal direction from one end side to the other end side in the longitudinal direction toward the second portion. A method for producing a resin molded product, comprising molding a resin molded product using the mold according to claim 1. A molten resin containing fibers is injected into the cavity from the first gate and the second gate, and the injection pressure from the second gate is lower than the injection pressure from the first gate The manufacturing method of the resin molded product of Claim 2 characterized by the above-mentioned.

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