JP2018199237A - Injection molding device - Google Patents

Abstract

To provide an injection molding device capable of reliably pressing a nozzle against an inlet of a runner.SOLUTION: There are provided a pair of molding dies 13,14 capable of mold clamping and mold opening, in which an inlet 191 of a runner 19 provided at a predetermined position is opened onto an outer peripheral surface, and an outlet of the runner communicates with a cavity; an injection machine 15 for injecting a molding material from a tip of a cylinder; a nozzle 18 whose one end is connected to the tip of the cylinder and whose another end is brought into pressure contact with the inlet of the runner, by which the molding material is injected to the cavity via the runner; a first chuck 20 fixed to a tip part of the nozzle, and made to be able to be driven to a closed state and an open state by a drive part 21; a facing surface 31 fixed to the molding dies so as to protrude from another outer peripheral surface of the molding die while straddling the inlet of the runner, on which the first chuck in the closed state is possible to pass through; and a second chuck 30 having a first engaging part 32 for engaging by driving the first chuck passing through the facing surface to the open state.SELECTED DRAWING: Figure 3A

Description

  The present invention relates to an injection molding apparatus.

  The nozzle of the injection device arranged at a position offset from the center line of the pair of molds is generated by pulling a protruding portion provided in the mold in the injection molding apparatus formed in an L shape or an arc shape. A device having a chuck device that presses the other end of a nozzle against an inlet of a mold runner by a reaction force is known (Patent Document 1).

Japanese Patent No. 5253078

  However, when the nozzle becomes long, when the nozzle is brought close to the mold, the tip of the nozzle vibrates and misalignment occurs with respect to the inlet of the runner. For this reason, there is a problem that it is difficult to reliably press the nozzle against the inlet of the runner.

  The problem to be solved by the present invention is to provide an injection molding apparatus that can reliably press the nozzle against the inlet of the runner.

  According to the present invention, a first chuck that can be driven in a closed state and an open state by a driving unit is fixed to a tip portion of a nozzle, and a facing surface through which the first chuck in a closed state can pass, and the facing surface pass through The above-mentioned problem is solved by fixing the second chuck having the first engaging portion engaged with the first chuck by driving the first chuck in the open state so as to straddle the inlet of the runner.

  According to the present invention, after the nozzle is brought close to the inlet of the mold runner of the clamped mold, the first chuck is closed and passed through the opposing surface of the second chuck, and then the first chuck is opened. Engage with the first engaging portion. When the first chuck is closed and passed through the opposing surface of the second chuck, the nozzle is aligned. Further, the tip of the nozzle can be pressed against the inlet of the runner by the reaction force generated by the subsequent drive to the open state.

It is a front view (injection machine is an original position) which shows the whole injection molding device concerning one embodiment of the present invention. 1 is a front view (the injection machine is an injection position) showing the entire injection molding apparatus according to an embodiment of the present invention. It is a partial front view of an injection molding device for explaining a subject at the time of attaching a long nozzle to an injection machine. It is a front view which shows the 1st chuck | zipper and 2nd chuck | zipper of the injection molding apparatus which concerns on one embodiment of this invention. It is a side view which shows the state before the 1st chuck | zipper and 2nd chuck | zipper of the injection molding apparatus which concern on one embodiment of this invention engage. It is a front view which shows the state which the 1st chuck | zipper and 2nd chuck | zipper of the injection molding apparatus concerning one embodiment of this invention engaged. It is a side view showing the state where the 1st chuck and the 2nd chuck of the injection molding device concerning one embodiment of the present invention engaged. It is a front view for demonstrating the force which acts on the link of the 1st chuck | zipper of the injection molding apparatus which concerns on one embodiment of this invention. It is a front view (the 1) which shows operation | movement of the 1st chuck | zipper of the injection molding apparatus which concerns on one embodiment of this invention, and a 2nd chuck | zipper. It is a front view (the 2) which shows operation | movement of the 1st chuck | zipper and 2nd chuck | zipper of the injection molding apparatus which concerns on one embodiment of this invention. It is a front view (the 3) which shows operation | movement of the 1st chuck | zipper and 2nd chuck | zipper of the injection molding apparatus which concerns on one embodiment of this invention. It is a front view (the 4) which shows operation | movement of the 1st chuck | zipper and 2nd chuck | zipper of the injection molding apparatus which concerns on one embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1A is a front view showing the entire injection molding apparatus according to an embodiment of the present invention, showing a state where the injection machine is in its original position, and FIG. 1B shows a state where the injection machine is also in the injection position. FIG. The injection molding apparatus 1 according to the present embodiment includes a pair of platens 11 and 12, a pair of molding dies 13 and 14, and an injection machine 15 including a gantry 16, and the pair of platens 11 and 12 and the injection machine 15. Is mounted on the gantry 16.

  The pair of platens 11 and 12 includes a fixed platen (fixed platen) 11, a movable platen (movable platen) 12, and a guide 17 that holds the platens 11 and 12 so as to move forward and backward. 12 can be moved along the guide 17 to the mold opening position shown in FIG. 1A and the mold clamping position shown in FIG. 1B by a mold clamping device (pressurizer using hydraulic pressure or pneumatic pressure, not shown). Yes. The injection machine 15 is disposed on the gantry 16 at a position where the axis of the cylinder is parallel to and offset from the center line of the pair of molds 13 and 14. Then, it can be moved to a standby position shown in FIG. 1A and an injection position shown in FIG. 1B by a driving device (not shown).

  In addition, as shown in the figure, one of the pair of platens 11 and 12 is a fixed platen 11 and the other is a movable platen 12, and both are constituted by a movable platen, and are moved to a mold opening position and a mold clamping position by relative movement. It may be movable. In addition, the injection machine 15 of the present embodiment is applied to a multipoint gate system (a system in which a plurality of gates are provided in a mold and a molten resin is simultaneously injected by a plurality of injection machines). However, in the present invention, the number of injection gates is not limited at all, and a single-point gate system may be used. The injection machine 15 may be disposed on the center line of the pair of molds 13 and 14.

  Of the pair of molds 13 and 14, the fixed mold 13 is fixed to the fixed platen 11, and the movable mold 14 is fixed to the movable platen 12. When the movable platen 12 moves from the mold opening position shown in FIG. 1A to the mold clamping position shown in FIG. 1B, the movable mold 14 approaches the fixed mold 13 and is clamped. While the mold is clamped and the molten resin is being injected, the clamping force acts on the pair of molds 13 and 14 by the pressure applied by the mold clamping device, and the injection pressure prevents leakage of the molten resin from the cavity. The

  Each of the fixed mold 13 and the movable mold 14 has a mating surface as a parting surface, and one parting line is formed by both the parting surfaces. Although detailed illustration is omitted, each of the fixed mold 13 and the movable mold 14 has a concave or flat molding surface, and when the pair of molds 13 and 14 are clamped, A cavity constituted by the molding surface is formed. This cavity corresponds to the outer shape of the product.

  A runner 19 for injecting molten resin into the cavities formed inside the pair of molds 13 and 14 in a clamped state is formed at a predetermined position on the outer peripheral surface of the pair of molds 13 and 14. Yes. FIG. 3A shows a part of the runner 19 including the inlet 191. One end of the runner 19 is an inlet (gate) 191 of the molten resin, and the other end is an outlet of the molten resin into the cavity. In the injection molding apparatus 1 of the present embodiment, for example, one or a plurality of runners 19 are formed at predetermined positions of the parting line, and an injection machine corresponding to the number of runners 19 is used as shown in FIGS. 1A and 1B. It is provided in the injection molding apparatus 1 of the embodiment. In the injection molding apparatus 1 shown in FIG. 1A, since the clamping direction and the axial direction of the runner 19 are not the same direction, the runner 19 is provided at a predetermined position on the parting line for ease of demolding the molded product. However, in the present invention, the setting position of the runner 19 is not limited on the parting line.

  The injection machine 15 is an in-line method (the plasticizing unit and the injection unit are the same unit type, and the molten resin is extruded by a screw) or a plunger method (the plasticizing unit and the injection unit are separate units) The molten resin melted inside the injection machine 15 may be pushed out by a plunger). The injection machine 15 of the present embodiment includes a base portion 151 and a cylinder 152. If the inline system is used, a screw shaft is provided inside the cylinder 152, and if the plunger system is used, a plunger is provided inside the cylinder 152. ing. In any system, an L-shaped or substantially L-shaped nozzle 18 is provided at the tip of the cylinder 152. In the present invention, the shape of the nozzle is not limited at all. In addition to an L shape or a curved shape, a straight line is used as applied when the injection machine 15 is arranged on the center line of the pair of molds 13 and 14. It may be a nozzle.

  Now, the injection molding apparatus 1 for injection molding large molded products such as automobile bumpers and automobile instrument panels has large molding dies 13 and 14 themselves, and many are based on a multipoint gate system. Therefore, when a plurality of injection machines 15 are laid out around the molds 13 and 14, one of them must be offset from the center line of the molds 13 and 14 as shown in FIG. In addition, it is L-shaped and inevitably has a length L of several meters. In such a case, since the nozzle 18 is only cantilevered at the tip of the cylinder 152 of the injector 15, when the injector 15 is moved as shown in FIGS. 1A to 1B, the nozzle 18 approaches the inlet 191 of the runner 19. The tip of the nozzle 18 vibrates in the left-right direction. The longer the length L of the nozzle 18, the greater the amplitude of this vibration.

  If contact is made with the inlet 191 of the runner 19 while the tip is vibrated, the vibration is suppressed by the contact, but the tip of the nozzle 18 and the inlet 191 of the runner 19 are misaligned, or the tip of the nozzle 18 is worn. To do. In addition, as in Patent Document 1 (Patent No. 553078) described in the Background Art section, when a structure (a chuck device 50 of the same document) having a large heat capacity and a large outer shape is attached to the nozzle 18, the structure is mounted. In addition to the loss of the melt energy of the injector 15, the outer shape is a large structure, so that a space for avoiding interference with the structure is required.

  For this reason, in the injection molding apparatus 1 of the present embodiment, the first chuck 20 fixed to the tip of the nozzle 18 and capable of being driven to the closed state and the open state by the drive unit 21 and the inlet 191 of the runner 19 are provided. The opposing surface 31 that is fixed to the forming dies 13 and 14 so as to straddle and protrude from the outer peripheral surfaces of the forming dies 13 and 14 and through which the closed first chuck 20 can pass, and the first that has passed through the opposing surface 31. And a second chuck 30 having a first engaging portion 32 that engages by driving the chuck 20 to an open state.

  As shown in FIGS. 3A and 3B, the first chuck 20 is provided with the nozzle 18 in between, and two pairs of X-shaped links 23 and 24 that simultaneously rotate around a fulcrum shaft 22 fixed to the nozzle 18. , A drive portion 21 provided on the proximal end side of the X-shaped links 23 and 24, and a second portion provided on the distal end side of the X-shaped links 23 and 24 and engaged with the first engagement portion 32 of the second chuck 30. And an engaging portion 25. The fulcrum shaft 22 shown in FIG. 3A is composed of, for example, a pin welded to the side surface of the nozzle 18 and can be rotated by inserting holes of two flat plate linear links constituting the X-shaped link 23 into the fulcrum shaft 22. The X-shaped link 23 is configured by being fixed to. The same applies to the other X-shaped link 24. As shown in FIG. 3B, the base end sides (upper side in the figure) of one X-shaped link 23 are connected by pins 26 and 26, and the distal end sides (lower side in the figure) are second engaged. The parts 25 and 25 are connected by pins constituting the parts. Accordingly, the pair of X-shaped links 23 and 24 are integrally opened and closed. The drive unit 21 can be a contracted and extended fluid pressure cylinder or the like, and is provided in each of the pair of X-shaped links 23 and 24. However, when the operating force to the open state of the X-shaped links 23 and 24 by the drive unit 21 is sufficiently large, it may be provided on either one.

  The second chuck 30 includes a pair of blocks 33, 33 that straddle the inlet 191 of the runner 19 and project from the outer peripheral surfaces of the molds 13, 14. The block 33 includes the facing surface 31 and the molding die for the facing surface 31. And a concave first engaging portion 32 formed on the side. Further, the facing surface 31 is provided outside the block 33 and has a tapered surface 34 that narrows from an inner width larger than the maximum outer width when the closed first chuck 20 passes, and an inner side of the tapered surface 34. And a parallel surface 35 having an inner width larger than the maximum outer width of the first chuck 20 in the closed state.

  As shown in FIG. 3B, the pair of blocks 33 and 33 has a thickness substantially equal to the outer diameter of the nozzle 18 and smaller than the width of the X-shaped links 23 and 24 of the first chuck 20, as shown in FIG. 3A. Further, the runner 19 is fixed to the outer peripheral surfaces of the molds 13 and 14 across the inlet 191. The separation distance between the pair of blocks 33, 33 shown in FIG. 3A is such that the distance between the opposing parallel surfaces 35, 35 is larger than the maximum outer width of the closed first chuck 20, as shown in FIG. 5B. Is set to have an inner width that is about 1 to 10 mm larger.

  As shown in FIG. 3C, when the first chuck 20 and the second chuck 30 are engaged, the leading ends of the X-shaped links 23, 24 are connected to the concave first engaging portions 32, 32 of the blocks 33, 33. The second engaging portions 25, 25 made of connecting pins are engaged. FIG. 4 shows the force acting on the X-shaped links 23 and 24 of the first chuck 20 in this state. As shown in the figure, the driving force F1 in the open state by the drive unit 21 provided on the base end side of the X-shaped links 23 and 24 acts in the horizontal direction of the figure. This driving force F1 becomes a downward force F2 (reaction force from the first engagement portion 32 of the second chuck 30) on the second engagement portions 25, 25 around the fulcrum shaft 22, and the two second engagement portions. The resultant force F3 (= 2F2) of the downward force F2 at the joint portions 25, 25 acts on the fulcrum shaft 22. That is, the nozzle 18 is pressed against the inlet 191 of the runner 19 by the reaction force of the force F3 generated by the driving force F1 of the driving unit 21.

  Here, as shown in FIG. 4, the distance between the operating point of the driving force F1 from the driving unit 21 to the base end side of the X-shaped links 23 and 24 and the fulcrum shaft 22 is L1, and the X-shaped links 23 and 24 The distance between the second engaging portion 25 and the fulcrum shaft 22 is L2, and the angle between the axis of the X-shaped links 23 and 24 in the open state and the axis perpendicular to the axis of the nozzle 18 (vertical direction in the figure). In the case of θ, F1 × L1 × cos (90−θ) = F2 × L2 × cos θ is established from the balance of moments around the fulcrum shaft 22, and when this is organized for F2, F2 = F1 × L1 × tan θ. / L2. Accordingly, the reaction force F3 (= 2F2) on the fulcrum shaft 22, that is, the pressing force required for the nozzle 18, is such that F3 ≦ 2F1 × L1 × tan θ / L2 is satisfied. What is necessary is just to set the position of L1, L2 of the type | mold links 23 and 24, the rated drive force F1 of the drive part 21, and the concave 1st engaging part 32 of the 2nd chuck | zipper 30. FIG.

  Next, the operation of the injection molding apparatus 1 of the present embodiment will be described with reference to FIGS. 5A to 5D. When a mold closing command is issued from the mold open state, the fixed mold 13 and the movable mold 14 are closed, and the inlet 191 of the runner 19 is formed on the outer peripheral side of the parting line. At the same time, a cavity is formed inside the pair of molds 13 and 14, and the outlet of the runner 19 communicates with the cavity. In this state, the tip of the nozzle 18 faces the inlet 191 of the runner 19. When the mold clamping is completed in this way, the injection machine 15 approaches the pair of molds 13 and 14 at a predetermined timing. This approach is shown in FIG. 5A. In this state, the drive unit 21 of the first chuck 20 is contracted and the X-shaped links 23 and 24 are closed.

  As shown in FIG. 5A, when the tip of the nozzle 18 approaches the second chuck 30, the tip of the nozzle 18 vibrates, but as shown in FIG. When approaching 191, the second engagement portion 25 of the first chuck 20 comes into contact with the tapered surface 34 of the blocks 33, 33, thereby stopping the vibration and the second engagement portion 25 of the first chuck 20. However, when passing through the parallel surfaces 35 of the blocks 33, 33, alignment (centering) between the axis of the nozzle 18 and the inlet 191 of the runner 19 is performed.

  Subsequently, when the nozzle 18 is further brought closer to the inlet 191 of the runner 19 as it is, the tip of the nozzle 18 comes into contact with the inlet 191 of the runner 19 as shown in FIG. 5C, so that the movement of the injector 15 is stopped here. In this state, the tip of the nozzle 18 does not have to be pressed against the inlet 191 of the runner 19 and may be in a state of light contact. Then, as shown in FIG. 5D, the drive portion 21 of the first chuck 20 is extended and the X-shaped links 23 and 24 are opened, so that the second engagement portion 25 of the first chuck 20 is recessed in the second chuck 30. The first engagement portion 32 is engaged. At this time, the driving force F2 by the driving unit 21 continues. As described above, the driving force F2 by the driving unit 21 acts on the fulcrum shaft 22 of the X-shaped links 23 and 24 as F3 = 2F1 × L1 × tan θ / L2, and the pressing force as the reaction force acts on the nozzle 18. To do. The nozzle 18 is pressed against the inlet 191 of the runner 19 by this downward force (reaction force of F3).

  When it is detected that the pressing of the nozzle 18 against the inlet 191 of the runner 19 is completed, the screw shaft of the injector 15 moves forward, and the molten resin is injected into the cavity from the inlet 191 of the runner 19 through the nozzle 18. . After the molten resin is injected into the cavity, the nozzle 18 is held in a state of being pressed by the inlet 191 of the runner 19 until a predetermined pressure holding time elapses. Since the product is completed when the molten resin in the cavity is cooled and solidified, the drive unit 21 of the first chuck 20 is contracted at a predetermined timing, and the X-shaped links 23 and 24 are closed. Thereby, the pressing state with respect to the inlet 191 of the runner 19 of the nozzle 18 is cancelled | released. Thereafter, after the injector 15 is separated from the pair of molds 13 and 14, the mold opening is performed. When the mold opening is completed, an ejector pin (not shown) moves forward to push the product out of the cavity and wait for the next mold closing command.

  As described above, according to the injection molding apparatus 1 of the present embodiment, the nozzle 18 is brought close to the inlet 191 of the runner 19 of the molds 13 and 14 that have been clamped, and the first chuck 20 is closed and the second chuck is closed. 30, after passing through the tapered surface 34 and the parallel surface 35 which are opposed surfaces, the first chuck 20 is opened and the second engagement portion 25 is engaged with the first engagement portion 32 of the second chuck 30. . When the first chuck 20 is closed and the taper surface 34 of the second chuck 30 is passed, the vibration of the tip of the nozzle 18 is stopped, and when passing through the parallel surface 35, the adjustment to the inlet 191 of the nozzle 18 is performed. A wick is made. Further, the tip of the nozzle 18 can be pressed against the inlet 191 of the runner 19 by the reaction force generated by the drive to the open state thereafter.

  Further, according to the injection molding apparatus 1 of the present embodiment, the vibration of the tip of the nozzle 18 is restrained by the second engaging portion 25 of the first chuck 20 and the tapered surface 34 of the second chuck 30. Wear of the tip of the is suppressed. Further, since the first chuck 20 has a simple and lightweight structure and is in a closed state, heat extraction due to a large heat capacity is small, loss of melting energy of the injection machine 15 can be suppressed, and interference with surrounding structures. There is no need for space to avoid.

  Further, according to the injection molding apparatus 1 of the present embodiment, the first chuck 20 is configured by a simple structure of the flat plate-like X-shaped links 23 and 24, and therefore, the fulcrum shaft 22 according to the required pressing force. If the position is set, a device such as a fluid pressure cylinder constituting the drive unit 21 can be made smaller. Further, if the position of the fulcrum shaft 22 of the X-shaped links 23 and 24 is changed while using the same drive unit 21, the required pressing force can be adjusted to an appropriate value, and the degree of freedom in design is increased. It gets even higher.

DESCRIPTION OF SYMBOLS 1 ... Injection molding apparatus 11 ... Fixed platen 12 ... Movable platen 13 ... Fixed mold 14 ... Movable mold 15 ... Injection machine 151 ... Base part 152 ... Cylinder 16 ... Mounting stand 17 ... Guide 18 ... Nozzle 19 ... Runner 191 ... Of runner Inlet 20 ... first chuck 21 ... driving unit 22 ... fulcrum shaft 23, 24 ... X-shaped link 25 ... second engaging portion (pin)
26 ... Pin 30 ... Second chuck 31 ... Opposing surface 32 ... First engagement portion 33 ... Block 34 ... Tapered surface 35 ... Parallel surface

Claims (5)

Clamping and mold opening are possible, a runner inlet provided at a predetermined position opens to the outer peripheral surface, and a pair of molding dies in which the runner outlet communicates with the cavity;
An injection machine for injecting molding material from the tip of the cylinder;
In an injection molding apparatus comprising: one end connected to the tip of the cylinder, the other end pressed against the inlet of the runner, and a nozzle that injects the molding material into the cavity through the runner;
A first chuck that is fixed to the tip of the nozzle and can be driven to a closed state and an open state by a driving unit;
A facing surface that is fixed to the mold so as to cross the inlet of the runner and protrude from the outer peripheral surface of the mold, and through which the closed first chuck can pass, and a first chuck that has passed through the facing surface A second chuck having a first engagement portion that engages by driving to open state,
The nozzle is brought close to the inlet of the mold runner of the clamped mold, the first chuck is driven to the closed state and passed through the facing surface, and then the first chuck is driven to the opened state to drive the first chuck. An injection molding apparatus that engages with an engaging portion and presses the tip of the nozzle against the inlet of the runner by a reaction force generated by driving to the open state. The first chuck is
Two pairs of links provided around the nozzle and simultaneously rotating around a fulcrum shaft fixed to the nozzle;
A drive unit provided on the base end side of the link;
A second engagement portion that is provided on a distal end side of the link and engages with the first engagement portion;
The second chuck is
Including a block straddling the runner inlet and projecting from the outer peripheral surface of the mold,
2. The injection molding apparatus according to claim 1, wherein the block includes the facing surface and a concave first engaging portion formed on a molding die side of the facing surface. The facing surface is
A tapered surface provided on the outside of the block, the taper surface being narrowed from the inner width larger than the maximum outer width when the closed first chuck passes;
The injection molding apparatus according to claim 2, further comprising: a parallel surface that is continuous inside the tapered surface and has an inner width that is greater than a maximum outer width of the closed first chuck. The link comprises an X-shaped link;
The driving force in the open state by the driving unit provided on the base end side of the link is F1,
The reaction force at the fulcrum shaft generated by the driving force F1 is F3,
The distance between the operating point of the driving force F1 from the driving unit to the base end side of the link and the fulcrum shaft is L1,
The distance between the second engaging portion of the link and the fulcrum shaft is L2,
When the angle formed by the axis of the link and the axis perpendicular to the axis of the nozzle in the open state is θ,
The first chuck and the second chuck satisfying F3 ≦ 2F1 × L1 × tan θ / L2 with respect to a minimum reaction force F3 required to press the tip of the nozzle against the inlet of the runner. 3. The injection molding apparatus according to 3. The injection machine is disposed at a position where the axis of the cylinder is parallel to and offset from the center line of the mold, and is movable forward and backward in a direction perpendicular to the axis.
The injection molding apparatus according to any one of claims 1 to 4, wherein the nozzle is bent or bent in a direction different from an axial direction of the cylinder, and a tip is directed to an inlet of the runner.

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