JP2018001619A - Molding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid deterioration in strength by suppressing generation of weld.SOLUTION: Provided is a molding device which includes: a core cylinder 60; a supply part 35 which is disposed on an outer periphery of the core cylinder 60 and forms, with the core cylinder 60, a first supply passage 16b extended in an axial direction and a second supply passage 16a extended in the axial direction and in an outer diameter direction; a first die 22 which is disposed on the outer periphery of the core cylinder 60 and forms a gate 18 with the core cylinder 60; a sleeve body 30 which is inserted/separated to/from the gate 18; and a second die 70 which forms, with the first die 22, a cavity 12 as an annular space. In the molding device, a third supply passage 16d is connected on an upstream side of the first supply passage 16b, the first die and the second die are brought in contact, and a molten resin is flown to the cavity 12 in order of the third supply passage 16d, the first supply passage 16b, the second supply passage 16a, and the gate 18 to mold a resin product. An annular throttle part 16f with a passage area reduced over a whole circumference is provided to the first supply passage 16b.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a mold apparatus for injection molding having an annular gate.

  When an annular resin product is injection-molded by a mold device for injection molding, the gate for supplying the molten resin to the cavity forming the resin product is at one point on the circumference of the cavity formed in the annular shape. In some cases, there is a problem that a resin confluence point called a weld is formed by injection molding, and a part that is extremely weaker than other parts is formed in the product.

  In the ring valve gate mold of Patent Document 1, a cylindrical core cylinder, a cylindrical valve probe, a cylindrical sleeve body, and a first mold are arranged in order from the inner diameter side to the outer diameter side. A gate that forms a first supply passage extending in the axial direction between the probe and a second supply passage extending in the axial direction and in the outer diameter direction, and is a cylindrical space extending in the axial direction between the core cylinder and the first mold. The sleeve is inserted into and removed from the gate, and a cavity that is an annular space with the first mold is formed in the second mold that approaches and separates from the first mold in the axial direction. Two molds are brought into contact with each other, and a molten resin is caused to flow into the cavity in the order of the first supply passage, the second supply passage, and the gate, thereby forming an annular resin product in the cavity and preventing welds from occurring.

Japanese Patent Laid-Open No. 2015-112728

  The third supply passage connected on the upstream side of the first supply passage is disposed on the outer diameter side of the first supply passage. Since the third supply passage is connected to the first supply passage at one place on the circumference, the place connected to the third supply passage flows to the first supply passage earliest, and the place where the phase is shifted 180 degrees from the connected place is the most. It flows with a delay to the first supply passage. This flow is not canceled even if it passes through the second supply passage and the gate, and a phenomenon occurs in which the molten resin that has flowed into the cavity first circulates in the circumferential direction to the place where the molten resin enters with a delay.

  As a result, the temperature of the molten resin is lower in the cavity than in the first supply passage, and a weld that contacts the molten resin and the molten resin is generated in the cavity, resulting in a decrease in strength.

  An object of the present invention is to prevent welds from occurring and to eliminate a decrease in strength.

  The invention according to claim 1 is a core cylinder, a first supply passage which is disposed on an outer periphery of the core cylinder and extends in the axial direction with the core cylinder, and a second supply passage which extends in the axial direction and in the outer diameter direction. A first part that forms a gate that is a cylindrical space that is disposed on the outer periphery of the core cylinder and extends in the axial direction with the core cylinder, and the shaft to be inserted into and removed from the gate. A sleeve body that moves in a direction, and a second mold that is close to and away from the first mold in the axial direction and forms a cavity that is an annular space with the first mold. The third supply passage is connected upstream of the first mold, the first mold and the second mold are brought into contact with each other, and the third supply path, the first supply path, the second supply path, and the gate are sequentially melted into the cavity. Pour resin And a, a mold apparatus so as to mold the resin product in the cavity, is provided with a stop ring having a small passage area over the entire circumference in the first supply passage.

  According to the configuration of claim 1, even if the molten resin flows through the first supply passage first when it is connected from the third supply passage to the first supply passage, the molten resin that has flowed first is circumferential before the throttling. After wrapping in the direction and passing through the throttle, the molten resin flows through the first supply passage almost simultaneously over the circumference. As a result, welds that contact the molten resin with the molten resin do not occur in the cavity, and strength reduction can be eliminated.

  According to a second aspect of the present invention, a plurality of the annular throttles are provided in the flow direction of the molten resin in the first supply passage.

  According to the configuration of claim 2, even if the molten resin flows to the first supply passage first when it is connected from the third supply passage to the first supply passage, the molten resin that has flowed first is circumferential before the throttling. After wrapping in the direction and passing through the throttle, the molten resin flows through the first supply passage almost simultaneously over the circumference. The phenomenon in which the molten resin that has flowed first circulates in the circumferential direction before the throttling is repeated by the plurality of throttlings, and after passing through the plurality of throttlings, the molten resin passes through the first supply passage at the same time along the circumference. Flowing. As a result, welds that contact the molten resin with the molten resin are less generated in the cavity, and the strength reduction can be further eliminated.

  According to the configuration of the present invention, even if the molten resin first flows through the first supply passage when it is connected from the third supply passage to the first supply passage, the molten resin that has flowed first is in the circumferential direction before squeezing. After going around and passing through the throttle, the molten resin flows through the first supply passage almost simultaneously over the circumference. As a result, welds that contact the molten resin with the molten resin do not occur in the cavity, and strength reduction can be eliminated.

It is sectional drawing which shows the state after the injection | emission of the metal mold apparatus which concerns on the 1st Embodiment of this invention. It is the sectional view on the AA line of FIG. 1 which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the mold open state of the metal mold apparatus which concerns on the 1st Embodiment of this invention. FIG. 3 is a cross-sectional view showing a state during injection of the mold apparatus according to the first embodiment of the present invention. FIG. 2 is a state diagram illustrating a flow of molten resin at a first throttle according to the first embodiment of the present invention, and is a cross-sectional view taken along line BB in FIG. 1. It is a state figure showing the flow of the molten resin in the 1st 2nd diaphragm concerning the 1st embodiment of the present invention. It is a state figure showing the flow of the molten resin in the 3rd 2nd restriction concerning the 1st embodiment of the present invention. It is principal part sectional drawing of the metal mold | die apparatus which concerns on the 2nd Embodiment of this invention. It is CC sectional view taken on the line of FIG. 8 which concerns on the 2nd Embodiment of this invention.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

  The first embodiment of the present invention is a ring valve gate mold apparatus 10 (hereinafter referred to as a mold apparatus 10) that molds a relatively large-diameter annular (ring-shaped) resin product. As a resin product in which a cylindrical metal part is inserted on the inner peripheral side, for example, there is a worm wheel 90. The worm wheel 90 has a resin part 92 integrally formed on the outer peripheral side to reduce the meshing noise with the worm, and a cylindrical part on the inner peripheral side of the resin part 92 to transmit the rotational force to the rotary shaft on the inner peripheral side. A metal part 93 is inserted. A gear 91 is formed on the outer periphery of the resin component 92 by injection molding.

  FIG. 1 is a cross-sectional view showing the main part of the mold apparatus 10. The mold apparatus 10 is roughly composed of a fixed mold 20 which is one mold and a movable mold 40 which is the other mold. In the first embodiment, the fixed mold 20 is disposed on the upper side, and the movable mold 40 is disposed on the lower side, and the movable mold 40 approaches and separates from the fixed mold 20 in the vertical direction.

  The fixed mold 20 and the movable mold 40 have mating surfaces 20a and 40a that are in close contact with each other. Due to the approach and separation of the movable mold 40, both the mating surfaces 20a and 40a take a position in which they are joined and separated. The movement of the movable mold 40 in the approaching and separating direction is performed by a known hydraulic drive device (not shown).

  A cavity 12 that is an annular (ring-shaped) space is formed on the mating surface 40 a of the movable mold 40, and an insertion recess 81 that is a cylindrical space is formed at the center side position of the cavity 12. Has been. The other end of the gate 18, which is a cylindrical space, is opened on the mating surface 20 a of the fixed mold 20, and the gate 18 is positioned on the inner diameter side from the middle in the radial direction of the cavity 12. Further, on the mating surface 20 a of the fixed mold 20, the small-diameter shaft portion 64 protrudes toward the movable mold 40 at the center side position of the gate 18, and the small-diameter shaft portion 64 is fitted into the fitting recess 81 of the movable mold 40.

  The movable mold 40 is roughly divided into a second main body mold 42 in which a storage recess 41 that is a cylindrical space is formed, a cylindrical insert mold 70 that is inserted and disposed in the storage recess 41, and screwed to the insert mold 70. The holding member 80 and a pin 85 that pushes out the worm wheel 90 from the cavity 12.

  The cylindrical portion 82 of the holding member 80 is fitted into the fitting hole of the nested mold 70 and positioned in the radial direction, and the female screw 83 of the holding member 80 is screwed into the female screw 73 of the nested mold 70, so that the nested mold A holding member 80 is fixed to 70. A cavity 12 that is an annular space is formed in the nested mold 70, and convex portions 71 that form the gear 91 are formed at equal intervals in the circumferential direction on the inner periphery of the nested mold 70. A part of the holding member 80 protrudes into the cavity 12. The metal part 93 is fitted into the cylindrical part 82 that is a protruding part of the holding member 80 to position and hold the metal part 93 in the radial direction, and the metal part 93 is held in the axial direction by the core cylinder 60 and the insert mold 70. Thus, the metal part 93 is positioned and held in the axial direction. A fitting recess 81 that is a cylindrical space is formed on the end surface of the holding component 80 on the fixed mold 20 side.

  The fixed mold 20 is broadly divided into a first body mold 22, a valve probe 35 disposed on the inner periphery of the first body mold 22, and a sleeve body 30 as a valve body disposed on the inner periphery of the first body 22. A core cylinder 60 disposed on the inner periphery of the valve probe 35, a hot runner manifold 57 and a base mold 50 disposed on the opposite side of the movable body 40 with respect to the first body mold 22, and a first heater 55 And the second heater 56. These components are arranged in the order of the core cylinder 60, the valve probe 35, the sleeve body 30, and the first main body mold 22 in order from the center to the outer diameter direction when viewed from the position of the mating surface 20 a of the fixed mold 20. Has been placed. Similarly, at the position of the hot runner manifold 57, the core cylinder 60 and the hot runner manifold 57 are arranged in this order from the center. The first heater 55 has a columnar shape and is fitted in the cylindrical hole 65 of the core cylinder 60. The second heater 56 has a cylindrical shape and is embedded in the valve probe 35.

  The core cylinder 60 includes a first half member 60a and a second half member 60b, and the first half member 60a and the second half member 60b are screwed together. A recess is perforated on the end surface of the first half member 60a on the second half member 60b side, and a female screw 60c is formed in the recess. A convex portion is formed on the end surface of the second half member 60b on the first half member 60a side, and a screw 60d is formed on the convex portion. The first half member 60a and the second half member 60b are threadedly engaged with the female screw 60c until the end surfaces thereof are in close contact with each other.

  The core cylinder 60 is formed in a substantially cylindrical shape, and the above-described first heater 55 is fitted in the central cylindrical hole 65, and a step portion formed in the middle of the cylindrical hole 65 in the axial direction and the cylindrical hole 65. The first heater 55 is clamped in the axial direction by a circlip 66 attached to the other end of the first heater 55.

  The core cylinder 60 includes a flange portion 61 projecting in the outer diameter direction, a cylindrical large-diameter shaft portion 62, a tapered taper portion 63, and a cylindrical small-diameter shaft portion 64, which are movable from the base mold 50. It has in order toward 40. The core cylinder 60 is positioned in the axial direction by sandwiching the flange portion 61 of the core cylinder 60 between the base mold 50 and the hot runner manifold 57. By fitting the fitting portion 62 a of the large diameter shaft portion 62 into the first cylindrical hole 58 of the hot runner manifold 57, the core cylinder 60 is positioned in the radial direction with respect to the hot runner manifold 57. The tapered portion 63 has a shape that gradually increases in diameter toward the movable mold 40, and the small-diameter shaft portion 64 is a cylindrical shape that extends in the axial direction and has a diameter that is smaller than the large-diameter shaft portion 62. The small-diameter shaft portion 64 is loosely fitted in the fitting recess 81 of the holding member 80.

  On the outer periphery of the large diameter shaft portion 62 of the core cylinder 60, there are a fitting portion 62a, a first groove 62b, a first land portion 62c, a second groove 62d, a second land portion 62e, and a cylindrical portion 62f. They are formed in order in the axial direction. The second groove 62d and the second land portion 62e are repeatedly formed three times in the axial direction. The fitting portion 62a is fitted into the first cylindrical hole 58 of the hot runner manifold 57 and has a larger diameter than the cylindrical portion 62f. The first groove 62b is a groove having a semicircular cross section, and has a deeper depth than the second groove 62d. The second groove 62d is a trapezoidal groove in cross section, and the cylindrical portion 62f is in the shape of a trapezoidal cross section that is long in the axial direction. The first land portion 62c protrudes toward the outer diameter side as compared with the second land portion 62e.

  A first diaphragm 16 f is formed between the first land portion 62 c and the first cylindrical hole 58 of the hot runner manifold 57. An expansion portion 16 h is formed between the second groove 62 d and the first cylindrical hole 58 of the hot runner manifold 57 and between the second groove 62 d and the third cylindrical hole 37 of the valve probe 35. A second throttle 16g is formed between the second land 62e and the first cylindrical hole 58 of the hot runner manifold 57 and between the second land 62e and the third cylindrical hole 37 of the valve probe 35. The opening area of the first diaphragm 16f is smaller than the opening area of the second diaphragm 16g. A first supply passage 16 b is formed between the first groove 62 b, the first land portion 62 c, the second groove 62 d and the second land portion 62 e, and the first cylindrical hole 58 of the hot runner manifold 57. A first supply passage 16c is formed between the second groove 62d, the second land portion 62e, the cylindrical portion 62f, and the third cylindrical hole 37 of the valve probe 35. That is, a first diaphragm 16f, three expansion portions 16h, and three second diaphragms 16g are provided in a part of the first supply passages 16b and 16c. In order from the first groove 62b side, the first expansion part 16h, the first second diaphragm 16g, the first second groove 62d, the second expansion part 16h, the second second diaphragm 16g, and the second second The second groove 62d, the third expansion portion 16h, the third second diaphragm 16g, and the third second groove 62d are referred to.

  The core cylinder 60 has a step portion extending in the radial direction between the taper portion 63 and the small diameter shaft portion 64. The stepped portion is an end surface that is a part of the mating surface 20 a of the fixed mold 20. An attachment recess that is an annular space is formed in the stepped portion, and an annular and sheet-like heat insulating material 68 is fixed to the attachment recess via an adhesive.

  The valve probe 35 is formed in a substantially cylindrical shape, and a flange portion 36 that is enlarged in the outer diameter direction is formed at one end of the valve probe 35 on the base 50 side. By positioning the flange portion 36 of the valve probe 35 in the axial direction between the step portion of the first main body mold 22 and the hot runner manifold 57, the valve probe 35 is positioned in the axial direction with respect to the first main body mold 22. Is done. By fitting the flange portion 36 of the valve probe 35 into the fitting hole of the first main body mold 22, the valve probe 35 is positioned in the radial direction with respect to the first main body mold 22.

  The valve probe 35 has a third cylindrical hole 37 penetrating in the axial direction at a central position, and a tapered hole 38 that expands in the radial direction toward the movable mold 40 at the other end. A predetermined gap is provided between the third cylindrical hole 37 and the large-diameter shaft portion 62 to constitute the first supply passage 16b. A predetermined gap is provided between the taper hole 38 and the taper portion 63 to constitute the second supply passage 16a. The first supply passage 16b is a cylindrical space extending in the axial direction. The second supply passage 16a is a tapered space extending in the axial direction and in the outer diameter direction. One end of the second supply passage 16a is connected to the first supply passage 16b, and the other end of the second supply passage 16a is connected to the gate 18.

  A predetermined gap is provided between the tapered portion 63 and the inner periphery of the first main body mold 22 to constitute the gate 18. The gate 18 is a cylindrical space extending in the axial direction, and is disposed between the second supply passage 16 a and the cavity 12 in the axial direction. A sleeve body 30 is removably inserted into the gate 18.

  The sleeve body 30 as a valve body is disposed between the valve probe 35 and the first main body mold 22 so as to be movable in the axial direction. The sleeve body 30 has a flange portion 31 extending in the outer diameter direction at one end, an operating rod 33 is connected to the flange portion 31, and a cylinder device (not shown) is connected to the operating rod 33. As the sleeve 26 advances and retreats in the axial direction via the cylinder device and the operating rod 33, the gate 18 is opened and closed. The sleeve body 30 is formed in a substantially cylindrical shape, and the insertion portion 32 at the other end is formed as a thin-walled cylindrical shape. The insertion part 32 is detachably inserted into the gate 18 to open and close the gate 18.

  A first cylindrical hole 58 is formed through the hot runner manifold 57. The hot runner manifold 57 is disposed in a state in which the large-diameter shaft portion 62 of the core cylinder 60 is fitted into the first cylindrical hole 58, and the end surface on the first body die 22 side is the flange portion 36 of the valve probe 35. It is in a joined state with the end face. In the hot runner manifold 57, a third supply passage 16d of molten resin is formed as shown by a broken line in FIG. The third supply passage 16 d is formed as a single passage as shown in FIG. 2 and is connected to a first supply passage 16 c formed between the hot runner manifold 57 and the core cylinder 60. The first supply passage 16c is formed as a cylindrical passage similarly to the first supply passage 16b described above, and one end of the first supply passage 16b is connected to the first supply passage 16c.

  In the first embodiment, the second supply passage 16a, the first supply passage 16b, and the first supply passage 16c have a circular cross section and communicate in the axial direction. In the first embodiment, the sleeve body 30 as the valve body is disposed at the outer peripheral side position of the second supply passage 16a, the first supply passage 16b, and the first supply passage 16c formed in a circular cross section. ing. Even if the sleeve body 30 is configured to move in the axial direction to open and close the gate 18, there is no particular problem in forming the sleeve body 30 with a large diameter. Accordingly, the gate 18 having a circular cross section can have a large diameter, and the product-shaped cavity 12 to which the molten resin is supplied from the gate 18 can also have a large diameter. It becomes possible to mold a resin product.

  The first heater 55 is disposed in the cylindrical hole 65 of the core cylinder 60 as described above. The other end of the first heater 55 extends to the small diameter shaft portion 64, and the first heater 55 positively heats not only the large diameter shaft portion 62 but also the tapered portion 63 and the small diameter shaft portion 64. The second heater 56 is disposed so as to be embedded in the valve probe 35, and is disposed in a cylindrical shape at the outer peripheral portion of the first supply passage 16b. The other end of the second heater 56 extends to the vicinity of the tapered hole 38 and actively heats not only the first supply passage 16b but also the second supply passage 16a. The molten resin in the first supply passage 16b and the second supply passage 16a is heated by the first heater 55 and the second heater 56 so that the molten state of the molten resin supplied to the cavity 12 is appropriately maintained. In the first embodiment, in particular, since the molten resin in the first supply passage 16b is heated from both the inner diameter side and the outer diameter side of the first supply passage 16b close to the cavity 12, the heating is efficiently performed. Can be performed.

  In the first embodiment, the first heater 55 and the second heater 56 are arranged at positions that are in a positional relationship from the center to the annular outer peripheral position of the annular cavity 12 as seen in FIG. It is installed. This makes it possible to configure the mold apparatus 10 without relatively increasing the size, although it is a molding apparatus for a product having a relatively large diameter.

  Next, the flow of the molten resin in the mold apparatus 10 described above will be described with reference to FIGS. 1, 2, and 5 to 7.

  When the molten resin p is supplied from the third supply passage 16d to the first supply passage 16c, the third supply passage 16d is connected to the first supply passage 16c at one circumferential position and in the tangential direction, and the first restriction 16f Since the first supply passage 16c is narrowed, the molten resin p flows along the first groove 62b in the clockwise direction in FIG. 2 from the position where the first supply passage 16c is connected to the third supply passage 16d. Although the amount is small compared to the surroundings, the molten resin p also flows in the counterclockwise direction of FIG. 2 along the first groove 62b. When the molten resin p flows into the first groove 62b, the molten resin p flows into the first throttle 16f. The portion where the first supply passage 16c is connected to the third supply passage 16d flows the molten resin p into the first throttle 16f earliest, the portion farthest from the connected portion is the latest, and the molten resin p enters the first throttle 16f latest. As shown by the two-dot chain line in FIG. 5, the difference in position of the molten resin p appears on the first land portion 62c.

  When the molten resin p flows from the first restrictor 16f to the first expansion portion 16h, it flows more easily along the first second groove 62d than when it flows to the first second restrictor 16g. It flows along the first second groove 62d while flowing through the second second diaphragm 16g. The portion where the first supply passage 16c is connected to the third supply passage 16d flows the molten resin p into the second throttle 16g earliest, the portion farthest from the connected portion is the latest and the molten resin p enters the second throttle 16g latest. As shown by the two-dot chain line in FIG. 6, the difference in the position of the molten resin p appears on the first second land portion 62d. The two-dot chain line in FIG. 6 has a smaller inclination than the two-dot chain line in FIG. 5, and the difference in the position of the molten resin p between the earliest and the latest parts is smaller than in FIG. Become.

  When the molten resin p flows from the first second restrictor 16g to the second expansion portion 16h, the molten resin p flows more easily along the second second groove 62d than when it flows to the second second restrictor 16g. Flows along the second second groove 62d while flowing through the second second diaphragm 16g. The portion where the first supply passage 16c is connected to the third supply passage 16d flows the molten resin p into the second throttle 16g earliest, the portion farthest from the connected portion is the latest and the molten resin p enters the second throttle 16g latest. Flows in. The difference in the position of the molten resin p between the earliest part and the slowest part is improved by the second second diaphragm 16g.

  When the molten resin p flows from the second second restrictor 16g to the third expansion portion 16h, the molten resin p flows more easily along the third second groove 62d than when it flows to the third second restrictor 16g. Flows along the third second groove 62d while flowing through the third second diaphragm 16g. The portion where the first supply passage 16c is connected to the third supply passage 16d flows the molten resin p into the second throttle 16g earliest, the portion farthest from the connected portion is the latest and the molten resin p enters the second throttle 16g latest. As shown by the two-dot chain line in FIG. 6, the difference in the position of the molten resin p appears on the third second land portion 62d. The two-dot chain line in FIG. 7 has a smaller inclination than the two-dot chain line in FIG. 6, and the difference in the position of the molten resin p between the earliest part and the slowest part is smaller than in FIG. Become.

  Next, the injection molding operation of the mold apparatus 10 will be described with reference to FIGS.

  FIG. 4 shows the mold closed state. The metal part 93 is fitted into the holding member 80 until it comes into contact with the nested mold 70, the movable mold 40 approaches the fixed mold 20, and the sleeve 30 is moved to the base mold 50 side. An injection molding state is shown in which the gate 18 is opened by being moved. In this state, the gate 18 is in an open state, and the molten resin in the second supply passage 16 a is supplied to the cavity 12 through the gate 18. At this time, since the gate 18 is connected to the entire circumferential surface of the annular cavity 12, the molten resin is supplied to the cavity 12 from the entire circumference of the annular cavity. For this reason, it is possible to prevent welds from occurring in the resin molded product.

  FIG. 1 shows a state in which the gate 18 is closed by moving the sleeve body 30 toward the movable mold 40 after the injection molding of the molten resin into the cavity 12 shown in FIG. 4 is completed. In this state, the annular cavity 12 is filled with the molten resin, and the supply of the molten resin from the gate 18 to the cavity 12 is stopped, and is molded according to the shape of the cavity 12 by naturally cooling it. The worm wheel 90 becomes.

  3 shows a state where the worm wheel 90 is formed in the cavity 12 through the natural cooling state shown in FIG. In this state, the mating surfaces 20a and 40a of the mold 20 and the movable mold 40 are opened, the pin 85 is moved to the fixed mold 20 side, and the worm wheel 90 is taken out from the position where the cavity 12 of the movable mold 40 is formed.

  By repeating the operations shown in FIGS. 1 and 3 to 7, a relatively large-diameter annular worm wheel 90 can be produced in large quantities by injection molding.

  According to the first embodiment described above, the arrangement position of the sleeve body 30 as the valve body is set such that the second supply passage 16a and the first supply passage having a circular cross section for supplying the molten resin to the cavity 12 through the gate 18 are provided. By setting the outer peripheral side positions of 16b and the first supply passage 16c, the cylindrical sleeve body 30 that opens and closes the gate 18 can be formed in a large diameter. As a result, the annular cavity 12 to which the circular gate 18 is connected to the entire circumference can also have a large diameter, and the large diameter worm wheel 90 can be injection molded.

  The present invention is not limited to these embodiments, and can of course be implemented in various modes without departing from the gist of the present invention.

  In the first embodiment described above, the second main body mold 42, the nesting mold 70, and the holding member 80 are configured as separate members. As another embodiment, the second main body mold 42, the nesting mold 70, and the holding member 80 may be configured as an integral member.

  In the first embodiment described above, the supply part is composed of two members, the hot runner manifold 57 and the valve probe 35, the third supply passage 16d is formed in the hot runner manifold 57, and the third supply passage 16d is supplied as the first supply. An example in which the passage 16c is connected at one circumferential point and in the tangential direction has been described. As a second embodiment, as shown in FIGS. 8 and 9, the supply part 135 is composed of one member, a supply passage 116 d is formed in the core cylinder 160 in the axial direction, and a third supply passage 116 k is formed in the radial direction. And the third supply passage 116k may be connected to the first supply passage 116c at one place in the circumference and in the radial direction.

The second embodiment will be described in detail with reference to FIGS. 8 and 9.
The mold apparatus includes a fixed mold and a movable mold that approaches and separates from the fixed mold. Since the movable type is the same as that of the first embodiment, description thereof is omitted. The fixed mold will be described in detail with a focus on differences from the first embodiment.

  The fixed type is roughly divided into a first main body type, a supply part 135 disposed on the inner periphery of the first main body mold, a sleeve body serving as a valve body disposed on the inner periphery of the first main body 22, and a supply part. A core cylinder 160 disposed on the inner periphery of 135, a base mold 150, a first heater 155, and a second heater 156 are configured. Since the first main body mold and the sleeve body are the same as those in the first embodiment, description thereof is omitted. The first heater 155 has a columnar shape and is fitted in the cylindrical hole 165 of the core cylinder 60. The second heater 156 has a cylindrical shape and is embedded in the supply part 135.

  The core cylinder 160 includes a first half member 160a and a second half member 160b. The first half member 160a and the second half member 160b are integrated by screwing the male screw 160d of the second half member 160b to the female screw 160c of the first half member 160a until the end surfaces thereof are in close contact with each other. ing. The second half member 160b is formed in a substantially cylindrical shape, and the first heater 155 described above is fitted in the cylindrical hole 165 on the center side.

  The core cylinder 160 includes a rod-shaped supply shaft portion 161a, a flange portion 161 protruding in the outer diameter direction, a cylindrical large-diameter shaft portion 162, a tapered taper portion, and a cylindrical small-diameter shaft portion. It has in order in the axial direction. Since the taper portion and the small diameter shaft portion are the same as those in the first embodiment, description thereof is omitted. The flange portion 161 of the core cylinder 160 is sandwiched in the axial direction between the base mold 150 and the supply part 135, and the fitting portion 162 a of the large diameter shaft portion 162 is fitted in the third cylindrical hole 137 of the supply part 135. .

  A receiving surface 116j with which an injection nozzle of the injection molding machine comes into contact is formed on the end surface of the supply shaft portion 161a, and one end of the supply passage 116d is opened on the concave receiving surface 116j. A third supply passage 116k is connected to the other end of the supply passage 116d, and the third supply passage 116k opens in a first groove 162b described later. The supply passage 116 is formed in the core cylinder 160 in the axial direction, and the third supply passage 116k is formed in the radial direction. Providing the core cylinder 160 with the receiving surface 116j and the supply passage 116d shortens the distance from the injection nozzle to the cavity. The third supply passage 116k is connected to the first groove 162b in the radial direction of the core cylinder 160, so that the molten resin flows almost evenly in both directions in the circumferential direction as compared to the case where the third supply passage 116k is connected in the tangential direction of the first embodiment. Cheap. In the case of the first embodiment, it tends to flow clockwise in FIG. 2, and a difference is likely to appear between both circumferential directions.

  On the outer periphery of the large-diameter shaft portion 162 of the core cylinder 160, there are a fitting portion 162a, a first groove 162b, a first land portion 162c, a second groove 162d, a second land portion 162e, and a cylindrical portion 162f. They are formed in order in the axial direction. The second groove 162d and the second land portion 162e are repeatedly formed three times in the axial direction. The fitting portion 162a is fitted into the third cylindrical hole 37 of the supply part 135 and has a larger diameter than the cylindrical portion 162f. The first groove 162b is a groove having a semicircular cross section, and the groove depth is deeper than that of the second groove 162d. The second groove 162d is a trapezoidal groove in cross section, and the cylindrical portion 162f is in the shape of a trapezoidal cross section that is long in the axial direction. The first land portion 162c protrudes toward the outer diameter side as compared with the second land portion 162e.

  A first aperture 116 f is formed between the first land portion 162 c and the third cylindrical hole 137 of the supply part 135, and an expansion portion 16 h is formed between the second groove 162 d and the third cylindrical hole 137 of the supply part 135. A second aperture 116g is formed between the second land 162e and the third cylindrical hole 137 of the supply part 135. The opening area of the first diaphragm 116f is smaller than the opening area of the second diaphragm 116g. A first supply passage 116c is formed between the first groove 162b, the first land portion 162c, the second groove 162d, the second land portion 162e, and the cylindrical portion 162f, and the third cylindrical hole 137 of the supply part 135. Yes. That is, a first throttle 116f, three expansion portions 116h, and three second throttles 116g are provided in a part of the first supply passage 116c.

  The supply part 135 comprises two members, the hot runner manifold 57 and the valve probe 35 of the first embodiment, as a single member. The supply part 135 similarly has the tapered hole 38 of the valve probe 35 of the first embodiment. Of course, the second embodiment has a gate and a second supply passage in the same manner as the first embodiment.

  Next, the flow of the molten resin in the mold apparatus according to the second embodiment will be described with reference to FIGS.

  When molten resin is supplied from the third supply passage 116k to the first supply passage 116c, the third supply passage 116k is connected to the first supply passage 116c at one place in the circumference and in the radial direction. Since the first supply passage 116c is narrowed, the molten resin flows along the first groove 162b counterclockwise in FIG. 9 from the position where the first supply passage 116c is connected to the third supply passage 116k. Although the amount is slightly smaller than the surroundings, the molten resin also flows in the clockwise direction in FIG. 2 along the first groove 162b. When the molten resin flows into the first groove 162b, the molten resin flows into the first throttle 116f. The location where the first supply passage 116c is connected to the third supply passage 116k flows the molten resin into the first restrictor 116f earliest, the portion farthest from the connected portion flows into the first restrictor 116f the latest, The difference in position of the molten resin appears on the first land portion 162c.

  When the molten resin flows from the first restrictor 116f to the first expansion portion 116h, the molten resin flows more easily along the first second groove 162d than to the first second restrictor 116g. It flows along the first second groove 162d while flowing through the second diaphragm 116g. The portion where the first supply passage 116c is connected to the third supply passage 116k flows the molten resin into the second throttle 116g earliest, the portion farthest from the connected portion flows into the second throttle 116g the latest, The difference in position of the molten resin appears on the first second land portion 162d. The difference in the position of the molten resin between the earliest part and the slowest part is smaller than that of the first land part 162c.

  When the molten resin flows from the first second throttle 116g to the second expansion portion 116h, the molten resin flows more easily along the second second groove 162d than when it flows to the second second throttle 116g. It flows along the second second groove 162d while flowing through the second second diaphragm 116g. The portion where the first supply passage 116c is connected to the third supply passage 116k flows the molten resin into the second throttle 116g earliest, and the portion farthest from the connected portion flows into the second throttle 116g the latest. The difference in the position of the molten resin between the earliest part and the slowest part is improved by the second second diaphragm 116g.

  When the molten resin flows from the second second throttle 116g to the third expansion part 116h, the molten resin flows more easily along the third second groove 162d than when flowing to the third second throttle 116g. It flows along the third second groove 162d while flowing through the third second diaphragm 116g. The location where the first supply passage 116c is connected to the third supply passage 116k flows the molten resin into the second throttle 116g earliest, the portion farthest from the connected portion flows into the second throttle 116g the latest, The difference in position of the molten resin appears on the third second land portion 162d. The difference in the position of the molten resin between the earliest part and the slowest part is smaller than that of the second second land portion 162d.

  10: ring valve gate type mold apparatus, 12: cavity, 16a: second supply passage, 16b: first supply passage, 16d: third supply passage, 16f: first restriction, 16h: expansion portion, 16g: second Aperture, 18: gate, 20: fixed mold, 20a: mating surface, 22: first body mold (first mold), 30: sleeve body, 35: valve probe (supply parts), 37: third cylindrical hole, 38 : Taper hole, 40: movable type, 40a: mating surface, 42: second body type (second type), 55: first heater, 56: second heater, 57: hot runner manifold (supply parts), 58: First cylindrical hole, 60: core cylinder, 62: large diameter shaft portion, 62b: first groove, 62c: first land portion, 62d: second groove, 62e: second land portion, 62f: cylindrical portion, 63: Tapered portion, 64: small diameter shaft portion, 7 : Nested type (second type), 80: Holding member, 82: Cylindrical part, 90: Worm wheel (resin product), 91: Gear, 92: Resin part, 93: Metal part, 116a: Second supply passage, 116b : First supply passage, 116d: third supply passage, 116f: first restriction, 116h: expansion part, 116g: second restriction, 135: supply parts, 137: third cylindrical hole, 160: core cylinder, 162: large Diameter shaft portion, 162b: first groove, 162c: first land portion, 162d: second groove, 162e: second land portion, 162f: cylindrical portion

Claims (2)

A supply part that forms a core cylinder, a first supply passage that is disposed on an outer periphery of the core cylinder and extends in the axial direction with the core cylinder, and a second supply passage that extends in the axial direction and in the outer diameter direction;
A first mold that is disposed on an outer periphery of the core cylinder and forms a gate that is a cylindrical space extending in the axial direction with the core cylinder;
A sleeve body that moves in the axial direction to be inserted into and removed from the gate;
A second mold that is close to and away from the first mold in the axial direction and forms a cavity that is an annular space with the first mold;
A third supply passage is connected upstream of the first supply passage, the first mold and the second mold are brought into contact, and the third supply passage, the first supply passage, the second supply passage, and the gate A mold apparatus in which a resin product is molded in the cavity by flowing molten resin into the cavity in order,
A mold apparatus characterized in that the first supply passage is provided with an annular throttle having a small passage area over the entire circumference. The mold apparatus according to claim 1, wherein a plurality of the annular throttles are provided in the flow direction of the molten resin in the first supply passage.

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