JP2008132627A - Injection molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an injection molding machine which can reduce the occurrence of defective molding by preventing the dripping of a molten resin from an injection nozzle part. <P>SOLUTION: The injection molding machine includes an injection nozzle part 4 which injects the molten resin into a mold, a resin extrusion part 3 which extrudes a prescribed amount of the molten resin to the injection nozzle part 4 for injection, and a resin supply part 2 which delivers the molten resin to the resin extrusion part 3. Between the resin supply part 2, the resin extrusion part 3, and the injection nozzle part 4, change-over valves 5 are arranged which intercept the communication between the resin extrusion part 3 and the injection nozzle part 4 when the resin supply part 2 and the resin extrusion part 3 are made to communicate with each other and intercept the communication between the resin supply part 2 and the resin extrusion part 3 when the resin extrusion part 3 and the injection part 4 are made to communicate with each other. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an injection molding apparatus.

  Conventionally, an injection molding apparatus 1 as shown in FIG. 5 is known (see, for example, Patent Document 1). The injection molding apparatus 1 includes a resin supply unit 2 that sends a molten resin of a molding material to a resin extrusion unit 3 and a resin that extrudes a predetermined amount of molten resin toward an injection nozzle unit 4 that faces a molding die 6 for injection. The resin extrusion unit 3 and the injection nozzle unit 4 are provided between the resin supply unit 2 and the resin extrusion unit 3 when the resin supply unit 2 and the resin extrusion unit 3 are communicated with each other. And a switching valve 5 for disabling the resin supply part 2 and the resin extrusion part 3 when the resin extrusion part 3 and the injection nozzle part 4 are communicated with each other. . Here, the switching valve 5 is configured such that a rod-like movable valve body 20 that is long in the vertical direction is slidably arranged in the valve chamber 19 so that the movable valve body 20 is positioned above the valve chamber 19. The resin supply unit 2 and the resin extrusion unit 3 are in communication with each other via a groove channel 30 provided in the periphery of the movable valve body 20, and the movable valve body 20 is movable when the movable valve body 20 is positioned below the valve chamber 19. The base end of the through-hole flow path 31 penetrating the inside of the valve body 20 communicates with the resin extrusion part 3, and the injection nozzle part 4 constituted by the front end of the through-hole flow path 31 faces the molding die 6, and the resin extrusion part The molten resin from 3 can be injected into the molding die 6.

In this injection molding apparatus 1, by providing the switching valve 5, the molten resin extruded from the resin extrusion unit 3 does not flow backward to the resin supply unit 2, and a predetermined amount of molten resin is molded into the mold. The molding defects are reduced in that they can be reliably injected into the inside 6. However, the injection nozzle portion 4 is provided at the lower end portion of the movable valve body 20 that slides up and down, and when the injection nozzle portion 4 is moved above the valve chamber 19 in order to manufacture a molded product continuously. However, there is a high possibility that uncured molten resin will drop from the injection nozzle portion 4 into the molding die 6 due to the impact of movement and cause molding defects. That is, in the injection molding apparatus 1, it is difficult to say that the molding defects are sufficiently reduced.
JP-A-56-93528

  The present invention has been made in view of the above points, and an object of the present invention is to provide an injection molding apparatus that can prevent dripping of molten resin from the injection nozzle portion and improve reduction in molding defects. It is an object to do.

  In order to solve the above-mentioned problem, in the injection molding apparatus according to claim 1, the injection nozzle unit 4 for injecting the molten resin for injection into the molding die, and the injection nozzle for injecting a predetermined amount of the molten resin for injection A resin extruding part 3 for extruding to the part 4 and a resin supplying part 2 for sending the molten resin of the molding material to the resin extruding part 3, and the resin is provided between the resin supplying part 2, the resin extruding part 3 and the injection nozzle part 4. When the supply unit 2 and the resin extrusion unit 3 are communicated with each other, the resin extrusion unit 3 and the injection nozzle unit 4 are brought into a non-communication state, and when the resin extrusion unit 3 and the injection nozzle unit 4 are communicated with each other, the resin is obtained. A switching valve 5 for disabling the supply unit 2 and the resin extrusion unit 3 is provided. According to this, by providing the switching valve 5, the molten resin pushed out from the resin extruding unit 3 does not flow back to the resin supplying unit 2, and a predetermined amount of molten resin can be reliably injected into the molding die. Further, the injection nozzle portion 4 is not provided in the movable valve body 20 of the switching valve 5 as in the prior art, and can be positioned separately from the switching valve 5 so as to always face the molding die. Therefore, dripping of the uncured molten resin from the injection nozzle portion 4 can be prevented, and the occurrence of molding defects can be effectively prevented.

  The injection molding apparatus according to claim 2 is characterized in that, in claim 1, the resin extruding part 3 and the injection nozzle part 4 are communicated in a straight line via the switching valve 5. According to this, the extrusion pressure of the molten resin for injection at the resin extrusion part 3 can be used as the injection pressure to the molding die at the injection nozzle part 4 with almost no loss, and the efficiency of the injection molding apparatus 1 is improved. it can.

  In this invention, it has the advantage that the dripping of the molten resin from an injection nozzle part can be prevented, and reduction of a molding defect can be improved.

  Hereinafter, the present invention will be described based on embodiments shown in the accompanying drawings.

  As shown in FIG. 1, the injection molding apparatus 1 of this example includes a resin supply unit 2 that sends a molten resin of a molding material to a resin extrusion unit 3 through a supply path 7, and a predetermined amount of molten resin for injection. The resin supply unit 2 includes a resin extruding unit 3 that is pushed out to the injection nozzle unit 4 through 8 and an injection nozzle unit 4 that is provided at the tip of the injection path 8 and injects a molten resin for injection into a molding die. In the middle of the supply path 7 and the injection path 8, which are parts between the resin extrusion part 3 and the injection nozzle part 4, the supply path 7 is closed when the supply path 7 is opened, and the supply path A switching valve 5 is provided for opening the injection path 8 when 7 is closed.

  Here, the injection molding apparatus 1 of the present example includes an injection block 10 and a supply block 11. The supply block 11 is provided with a resin supply unit 2, and the injection block 10 includes a resin extrusion unit 3 from the base end side. A switching valve 5 and an injection nozzle portion 4 are arranged in this order. Specifically, the switching valve 5 is disposed at the distal end portion of the injection block 10, and the injection nozzle portion 4 is disposed at the distal end of the injection block 10 that is the distal end of the distal end portion. The injection block 10 is a part that is installed substantially horizontally on the installation surface of the injection molding apparatus 1, and the supply block 11 is pivotally connected to an upper position of the injection block 10. Each of the supply block 11 and the injection block 10 is provided. The tip can be contacted and separated. When the injection molding apparatus 1 is in use, the supply block 11 is in a state of being lowered first, and the leading ends of the supply block 11 and the injection block 10 are connected by a fixture 12 such as a bolt. In addition, a molding die (not shown) is detachably attached to the tip of the injection block 10 of the injection molding apparatus 1. At this time, the injection nozzle portion 4 is positioned so as to face a cavity in the molding die.

  As shown in FIG. 2, the resin supply unit 2 includes a screw 15 coaxial with a cylinder axis inside a cylinder cylinder 14 to which the material supply port 13 and the inlet of the supply path 7 are connected, and the screw 15 is rotated by a motor. By driving, the molten resin in the cylinder 14 can be conveyed to the supply path 7 by an amount corresponding to the number of rotations of the screw 15. The supply path 7 is formed across the respective front end portions of the supply block 11 and the injection block 10. The supply path 7 on the supply block 11 side and the supply path 7 on the injection block 10 side are the same as those of the supply block 11 and the injection block 10. Connection is possible when the tips are connected.

  In the resin extruding unit 3, a plunger 17 is slidably disposed inside a cylinder cylinder 16 to which a resin passage 9 serving as an outlet of the supply passage 7 and an inlet of the injection passage 8 is connected. The molten resin filled in the pot space 18 in the cylinder cylinder 16 can be pushed out into the resin passage 9 by being slid toward the side. The resin passage 9 extends from the pot space 18 toward the distal end side of the injection block 10. The resin extrusion unit 3 and the resin supply unit 2 may be provided with a heating unit to heat the resin as a molding material to a molten state or to maintain a molten state.

  The switching valve 5 is configured by disposing a movable valve body 20 in a valve chamber 19. In the valve chamber 19, the outlet port 7 b of the supply path 7 leading to the resin extrusion part 3 and the port 9 a of the resin passage 9 constituting the inlet side port 8 a of the injection path 8 leading from the resin extrusion part 3, and the resin supply part 2 An inlet-side port 7a of the supply path 7 extending from the outlet and an outlet-side port 8b of the injection path 8 reaching the injection nozzle portion 4 are formed. The port 9 a of the resin passage 9 and the outlet side port 8 b of the injection passage 8 are arranged substantially horizontally in a straight line at both sides of the valve chamber 19, and the inlet side port 7 a of the supply passage 7 is a port of the resin passage 9. It is arranged at a position above the valve chamber 19, which is a direction orthogonal to the line connecting 9 a and the outlet side port 8 b of the injection path 8. The ports 7a, 8b, 9a (7b, 8a) are formed at the same position in the axial direction of the valve chamber 19 and the movable valve body 20. As appropriate, the movable valve body 20 communicates with the port 9a of the resin passage 9 and the outlet side port 8b of the injection passage 8, or communicates the inlet side port 7a of the supply passage 7 with the port 9a of the resin passage 9. A through-hole-shaped valve passage 21 is formed.

  In this example, the valve chamber 19 is a space having a circular cross section, and the movable valve body 20 having a circular cross section makes its outer peripheral surface slidable on the inner peripheral surface of the valve chamber 19, and the position (in the axial direction). Does not move). The movable valve body 20 has a through-passage portion 22 whose both ends are open ends to the outer peripheral surface, and one end communicates with the through-passage portion 22 so as to be orthogonal to each other, and the other end is an open end to the outer peripheral surface. One T-shaped valve passage 21 composed of the semi-through passage portion 23 is formed.

  As shown in FIG. 2A, one open end of the through-passage portion 22 is connected to the inlet-side port 7a of the supply passage 7 and the other open end is closed by the inner surface of the valve chamber 19. Is connected to the port 9 a of the resin passage 9, the valve passage 21 and the resin passage 9 constitute a part of the supply path 7, that is, the supply path 7 connects the resin supply portion 2 and the resin extrusion portion 3. Then, the molten resin is supplied from the resin supply unit 2 to the pot space 18 of the resin extrusion unit 3 via the supply channel 7 in the open state. The molten resin supplied to the resin extruding unit 3 pushes and moves the plunger 17 so as to expand the pot space 18, and the pot space 18 is filled with the molten resin (arrow A). The supply of a predetermined amount of molten resin to the pot space 18 controls the amount of rotation of the screw 15 in the resin extruding unit 3 or controls the open state time of the valve passage 21 by controlling the operation of the movable valve body 20. Or by setting the maximum capacity of the pot space 18. Since the resin supply unit 2 is located above the resin extrusion unit 3, the molten resin is smoothly supplied to the resin extrusion unit 3 with the help of the gravitational action.

  The movable valve body 20 is rotated from the above state, and as shown in FIG. 2B, one opening end of the through-passage portion 22 is connected to the outlet side port 8b of the injection passage 8 and the other opening end is connected to the resin passage. 9 is connected to the port 9a and the open end of the semi-through passage portion 23 is closed by the inner surface of the valve chamber 19, the through passage portion 22 of the valve passage 21 and the resin passage 9 constitute a part of the injection passage 8. That is, the injection path 8 is in a state in which the injection nozzle portion 4 and the resin extrusion portion 3 are connected (the injection path 8 is in an open state), and the injection path in the open state by the pushing operation by the plunger 17 in the resin extrusion portion 3 at this time. 8, the molten resin is injected from the resin extrusion part 3 into the injection nozzle part 4 and eventually into the molding die (arrow B). The injection path 8 in the open state allows the resin extrusion part 3 and the injection nozzle part 4 to communicate with each other in a straight line, and the injection nozzle part has almost no loss of the extrusion pressure of the molten resin for injection at the resin extrusion part 3. 4 can be used as an injection pressure to the molding die, and the efficiency of the injection molding apparatus 1 is improved.

  By repeating the above operation, a predetermined amount of molten resin is supplied from the resin supply unit 2 to the resin extrusion unit 3, and a predetermined amount of molten resin is extruded from the resin extrusion unit 3 to the injection nozzle unit 4 for injection. The resin molded product is continuously manufactured by injecting a predetermined amount of the molten resin from the injection nozzle portion 4 into the molding die and molding the resin molded product.

  In the injection molding apparatus 1 configured as described above, when the resin supply unit 2 and the resin extrusion unit 3 are communicated with each other between the resin supply unit 2, the resin extrusion unit 3, and the injection nozzle unit 4 as described above. In addition, the resin extrusion unit 3 and the injection nozzle unit 4 are brought into a non-communication state, and the resin supply unit 2 and the resin extrusion unit 3 are brought into a non-communication state when the resin extrusion unit 3 and the injection nozzle unit 4 are communicated with each other. By providing the switching valve 5 to be operated, the molten resin extruded from the resin extruding unit 3 does not flow back to the resin supplying unit 2, and a predetermined amount of the molten resin can be reliably injected into the molding die. In other words, the injection nozzle portion 4 is not provided on the movable valve body 20 of the switching valve 5 as in the prior art, and can be positioned separately from the switching valve 5 so as to always face the molding die. Therefore, dripping of uncured molten resin from the injection nozzle part 4 can also be prevented, In which it was possible to effectively prevent occurrence of molding failure by Les.

  Hereinafter, other examples of the embodiment of the present invention will be listed. In any case, the switching valve 5 is different, and the other parts follow the precedent. The same parts as those in the previous example are denoted by the same reference numerals, description thereof is omitted, and different parts will be described.

  The switching valve 5 in the example of FIG. 3 has a so-called spool valve structure in which the supply valve 7 and the injection path 8 can be opened and closed by sliding the movable valve body 20 in the valve chamber 19 in the axial direction. Yes. Specifically, the movable valve body 20 includes an L-shaped supply passage valve passage 21a whose both ends are open ends to the outer peripheral surface, and a straight injection passage valve passage whose both ends are open ends to the outer peripheral surface. 21b is formed by shifting the position in the axial direction. When one open end of the supply passage valve passage 21a is connected to the inlet side port 7a of the supply passage 7 and the other open end is connected to the port 9a of the resin passage 9 as shown in FIG. The passage valve passage 21a and the resin passage 9 constitute a part of the supply passage 7, that is, the supply passage 7 is in a state in which the resin supply portion 2 and the resin extrusion portion 3 are connected (open state of the supply passage 7). The molten resin can be supplied from the resin supply part 2 to the pot space 18 of the resin extrusion part 3 through the supply path 7 in the open state. At this time, both open ends of the injection passage valve passage 21 b are closed by the inner surface of the valve chamber 19. Further, the movable valve body 20 is slid in the axial direction from this state, and one open end of the injection passage valve passage 21b is connected to the outlet side port 8b of the injection passage 8 as shown in FIG. Is connected to the port 9 a of the resin passage 9, the injection passage valve passage 21 b and the resin passage 9 constitute a part of the injection passage 8, that is, the injection passage 8 includes the injection nozzle portion 4 and the resin extrusion portion 3. Are connected (the injection path 8 is in the open state), and the molten resin is injected from the resin extrusion section 3 through the open injection path 8 by the pushing operation of the plunger 17 in the resin extrusion section 3 at this time. 4. As a result, it can be injected into the molding die. At this time, both open ends of the supply passage valve passage 21 a are closed by the inner surface of the valve chamber 19.

  The switching valve 5 in the example of FIG. 4 can open and close the supply path 7 and the injection path 8 by sliding the movable valve body 20 in the valve chamber 19 while rotating in the axial direction. Specifically, a screw portion 24 is provided between the inner peripheral surface of the valve chamber 19 and the outer peripheral surface of the movable valve body 20, and when the movable valve body 20 is rotated by a predetermined amount by the screw portion 24, the movable valve body 20. Is slidable by a predetermined amount in the axial direction, and accurate positioning control is enabled. This switching valve 5 also enables the molten resin to be supplied from the resin supply part 2 to the resin extrusion part 3 via the supply path valve passage 21a as shown in FIG. 4 (a), and as shown in FIG. 4 (b). In addition, the molten resin can be injected from the resin extrusion portion 3 into the injection nozzle portion 4 and thus into the molding die via the injection passage valve passage 21b.

  In other examples of the above-described embodiment, it goes without saying that the effect of effectively preventing the occurrence of molding defects can be obtained as in the previous examples (FIGS. 1 and 2).

It is the side view which saw through a part of injection molding apparatus of the example of an embodiment of the invention. It is explanatory drawing explaining operation | movement of a switching valve same as the above, (a) is a schematic block diagram of the principal part of the state which made the injection path closed, and made the supply path open, (b) is a supply path. It is a schematic block diagram of the principal part of the state which made the injection path open by making it a closed state. It is the perspective view which saw through the circumference | surroundings of the movable valve body in the other example of embodiment of this invention, (a) is a perspective view of the state which made the injection path closed and made the supply path open, (b ) Is a perspective view of a state where the supply path is closed and the injection path is opened. It is the perspective view which saw through the circumference | surroundings of the movable valve body in the further another example of embodiment of this invention, (a) is a perspective view of the state which made the injection path closed and made the supply path open. b) is a perspective view of a state where the supply path is closed and the injection path is opened. It is an injection molding device of an example of a prior art, (a) is a sectional side view in the state of supplying molten resin from a resin supply part to a resin extrusion part, (b) is an injection nozzle part from molten resin from a resin extrusion part It is a sectional side view of the state inject | poured into a shaping die via, (c) is a perspective view of a movable valve body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Injection molding apparatus 2 Resin supply part 3 Resin extrusion part 4 Injection nozzle part 5 Switching valve

Claims (2)

  Injection nozzle part for injecting molten resin for injection into the mold, resin extrusion part for extruding a predetermined amount of molten resin to the injection nozzle part for injection, and resin supply for sending molten resin of molding material to the resin extrusion part And when the resin supply unit and the resin extrusion unit are communicated with each other between the resin supply unit, the resin extrusion unit, and the injection nozzle unit, the resin extrusion unit and the injection nozzle unit are brought into a non-communication state. An injection molding apparatus comprising: a switching valve for disabling the resin supply unit and the resin extrusion unit when the resin extrusion unit and the injection nozzle unit are communicated with each other.   The injection molding apparatus according to claim 1, wherein the resin extruding part and the injection nozzle part are communicated in a straight line through a switching valve.

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