JP5855545B2 - Vertical injection molding machine - Google Patents

Description

  The present invention relates to a vertical injection molding machine.

  The vertical injection molding machine includes an injection device that injects molten resin in a heating cylinder from a nozzle and fills the cavity space in the mold apparatus with the molten resin. The mold apparatus includes an upper mold and a lower mold, and a cavity space is formed between the upper mold and the lower mold when the mold is clamped. The molten resin filled in the cavity space is cooled and solidified, and is taken out as a molded product after opening the mold.

  The vertical injection molding machine includes a lower platen to which a lower mold is attached, an upper platen to which an upper mold is attached, a connection mechanism that connects the upper platen and the injection device, and a guide that guides the connection mechanism in the vertical direction. (For example, refer patent document 1). As the upper platen moves up and down, the upper mold comes in contact with and separates from the lower mold, and the mold opening and closing and mold clamping are performed.

Japanese Patent Laid-Open No. 11-333853

  A nozzle hole for inserting the nozzle of the injection device is formed in the center of the upper platen. For this reason, the connection portion of the upper platen with the connection mechanism is provided at the end portion of the upper platen, and the end portion of the upper platen is pushed downward by the weight of the injection device, and the upper platen may be inclined. When the upper platen is tilted, the center line of the upper mold is shifted from the center line of the lower mold.

  The present invention has been made in view of the above problems, and an object thereof is to provide a vertical injection molding machine that can reduce the inclination of the upper platen.

In order to solve the above-described problem, a vertical injection molding machine according to one aspect of the present invention is provided.
A lower platen to which the lower mold is attached and fixed to the frame;
An upper platen to which an upper mold is attached and movable in the vertical direction with respect to the lower platen;
An injection device that is disposed above the upper mold and that fills a cavity space formed between the upper mold and the lower mold when the mold is clamped;
A connection mechanism for connecting the upper platen and the injection device;
A guide that is fixed to the frame and guides the coupling mechanism in a vertical direction;
And n (n is a natural number of 3 or more) tie bars that support the upper platen,
When viewed from above, the center of the connecting portion of the upper platen with the connecting mechanism is located in an n-gon having the center of each tie bar as the apex.

  According to the present invention, a vertical injection molding machine capable of reducing the inclination of the upper platen is provided.

It is a figure which shows the state at the time of mold opening completion of the vertical injection molding machine by one Embodiment of this invention. It is a figure which shows the state at the time of the mold closing completion of the vertical type injection molding machine by one Embodiment of this invention. It is a top view which shows a connection part with the connection mechanism in the upper platen of one Embodiment of this invention. It is a figure which shows the state at the time of nozzle touch cancellation | release of the connection mechanism by one Embodiment of this invention. It is a figure which shows the state at the time of the nozzle touch of the connection mechanism by one Embodiment of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the drawings, the same or corresponding components are denoted by the same or corresponding reference numerals, and description thereof is omitted.

  FIG. 1 is a view showing a state when mold opening is completed in a vertical injection molding machine according to an embodiment of the present invention. FIG. 1 shows a state when the nozzle touch is released when the nozzle 32 (see FIG. 2) of the injection device 30 is pulled upward from the upper mold 12. FIG. 2 is a view showing a state when the mold closing of the vertical injection molding machine according to the embodiment of the present invention is completed. FIG. 2 shows a state at the time of nozzle touch where the nozzle 32 of the injection device 30 is pressed against the upper mold 12.

  The vertical injection molding machine 10 includes a lower platen 13 fixed to the frame Fr, and an upper platen 14 that can move in the vertical direction with respect to the lower platen 13. A lower mold 11 is attached to the lower platen 13, and an upper mold 12 is attached to the upper platen 14. As the upper platen 14 moves up and down, the upper mold 12 comes in contact with and separates from the lower mold 11, and the mold is opened and closed and the mold is clamped. The lower mold 11 and the upper mold 12 constitute a mold apparatus.

  The lower platen 13 rotatably supports the rotary table 15. The lower mold 11 may be attached to the lower platen 13 via a rotary table 15 as shown in FIGS. 1 and 2. A plurality of (for example, two) lower molds 11 are attached around the rotation center of the rotary table 15 at an equal pitch (for example, 180 ° pitch). When the rotary table 15 is rotated 180 ° in the mold open state, the position of the lower mold 11 is switched between the molding position facing the upper mold 12 and the molded product take-out position. The take-out position may also serve as a setup position for setting the insert part in the lower mold 11.

  The lower mold 11 of this embodiment is attached to the lower platen 13 via the rotary table 15, but may be directly attached to the lower platen 13.

  The vertical injection molding machine 10 includes a third platen 16 disposed below the lower platen 13, a plurality of (for example, three) tie bars 17 for connecting the third platen 16 and the upper platen 14, and a third platen 16. A toggle mechanism 20 disposed between the platen 16 and the lower platen 13 and a mold clamping motor 21 for operating the toggle mechanism 20 are further provided. The direction of the toggle mechanism 20 with respect to the lower platen 13 and the frame Fr is not limited to the direction shown in FIGS.

  The rotation of the mold clamping motor 21 is transmitted to the screw shaft 23 via a connecting member 22 such as a belt or a pulley. A nut 24 that moves up and down by rotation of the screw shaft 23 is fixed to a cross head 25 of the toggle mechanism 20. The screw shaft 23, the nut 24, and the like constitute a ball screw mechanism as a motion converting unit that converts the rotational motion of the mold clamping motor 21 into the linear motion of the cross head 25. The cross head 25 is movable in the vertical direction.

  The toggle mechanism 20 includes, for example, a first toggle lever 26 that is swingably attached to the crosshead 25, a second toggle lever 27 that is swingably attached to the third platen 16, and a lower platen. 13 has a toggle arm 28 pivotably attached thereto. The first toggle lever 26 and the second toggle lever 27 are pin-coupled, and the second toggle lever 27 and the toggle arm 28 are respectively pin-coupled. This toggle mechanism 20 is a so-called inner winding 5-node double toggle mechanism.

  In a state where the mold opening is completed (the state shown in FIG. 1), when the mold clamping motor 21 is driven in the forward direction and the toggle mechanism 20 is operated, the third platen 16 is lowered. Along with this, the upper mold 12 and the lower mold 11 facing each other approach each other and the mold is closed. During closing of the mold, the guide post 18 of the upper mold 12 is inserted into the guide hole of the lower mold 11 so that the upper mold 12 and the lower mold 11 are positioned. As shown in FIG. 2, when the upper mold 12 and the lower mold 11 facing each other come into contact with each other, the mold closing is completed.

  The arrangement of the guide post and the guide hole may be reversed, and the upper mold 12 may have a guide hole and the lower mold 11 may have a guide post.

  Subsequently, when the mold clamping motor 21 is further driven in the forward direction, the toggle mechanism 20 generates a mold clamping force obtained by multiplying the propulsive force of the mold clamping motor 21 by the toggle magnification. Clamping is performed by the clamping force. Then, the injection device 30 fills the cavity space formed between the upper mold 12 and the lower mold 11 in the mold-clamped state with the molten resin. The molten resin is cooled and solidified in the cavity space to form a molded product.

Subsequently, when the mold clamping motor 21 is driven in the reverse direction and the toggle mechanism 20 is operated, the third platen 16 is raised. Along with this, the upper platen 14 is raised, and the upper mold 12 and the lower mold 11 facing each other are separated from each other as shown in FIG. During the mold opening, the guide post 18 of the upper mold 12 is pulled out from the guide hole of the lower mold 11. After opening the mold , the rotary table 15 is rotated 180 °, and then the molded product is taken out from the lower mold 11 at the take-out position.

  In the present embodiment, the driving force generated by the mold clamping motor 21 is amplified using the toggle mechanism 20, but the driving force generated by the mold clamping motor 21 can be directly clamped without using the toggle mechanism 20. It may be used as a force. Further, a fluid pressure cylinder (for example, a hydraulic cylinder) may be provided between the third platen 16 and the lower platen 13, and the mold clamping force may be generated by the fluid pressure cylinder.

  As shown in FIGS. 1 and 2, the vertical injection molding machine 10 includes an injection device 30, a connection mechanism 40 that connects the injection device 30 and the upper platen 14, and a guide Gd that guides the connection mechanism 40 in the vertical direction. And further comprising. The guide Gd is fixed to the frame Fr.

  The injection device 30 injects the molten resin in the heating cylinder 31 from the nozzle 32 and fills the cavity space formed between the upper mold 12 and the lower mold 11 in a mold-clamped state with the molten resin. As shown in FIGS. 1 and 2, the injection device 30 is disposed above the upper mold 12, and a nozzle hole 19 (see FIG. 3) for inserting the nozzle 32 of the heating cylinder 31 is provided at the center of the upper platen 14. Is formed. When the molten resin is injected, the nozzle 32 is pressed against the sprue bush of the upper mold 12 as shown in FIG. The molten resin injected from the nozzle 32 is filled into the cavity space via the sprue of the upper mold 12 or the like. When viewed from above, the upper mold 12 may be located in a polygon P (see FIG. 3) having the center of each tie bar 17 as a vertex. If the number of tie bars 17 is n (n is a natural number of 3 or more, n = 3 in FIG. 3), the polygon P is an n-gon.

  As shown in FIG. 2, the connecting mechanism 40 connects the injection device 30 and the upper platen 14. When the upper platen 14 moves up and down during mold opening and closing, the connection mechanism 40 and the injection device 30 can move up and down together with the upper platen 14.

  Since the connection mechanism 40 and the injection device 30 are movable in the vertical direction, the upper platen 14 supports the weight and the like of the injection device 30 (including the weight of the connection mechanism 40) as shown in FIG. The upper platen 14 is supported by n tie bars 17 extending downward from the upper platen 14. The tie bar 17 supports the weight of the upper platen 14 (including the weight of the coupling mechanism 40 and the weight of the injection device 30). At the time of mold clamping, as shown in FIG. 2, the mold apparatus mainly supports the weight of the upper platen 14 and the like.

  FIG. 3 is a top view showing a connecting portion with a connecting mechanism in the upper platen according to the embodiment of the present invention. In FIG. 3, the polygon P having the vertex of the center of each tie bar 17 is indicated by a bold line.

  In the present embodiment, as shown in FIG. 3, when viewed from above, the center 41 </ b> C of the connecting portion 41 of the upper platen 14 with the connecting mechanism 40 is located within a polygon P having the center of each tie bar 17 as the apex. To do. Here, “the center of the connecting portion” means the center of the plurality of connecting portions 41 when there are a plurality of connecting portions 41. Only one connecting portion 41 may be provided.

  When viewed from above, if the centers 41C of the plurality of connecting portions 41 are located within the polygon P, when the connecting portions 41 of the upper platen 14 are pushed downward by the weight of the injection device 30, all tie bars 17 pushes the upper platen 14 upward. Therefore, the upper platen 14 is not easily inclined, and the center line of the upper mold 12 and the center line of the lower mold 11 facing the upper mold 12 are not easily displaced. Therefore, the guide post 18 of the upper mold 12 can be smoothly inserted into the guide hole of the lower mold 11 during mold closing.

  When viewed from above, the centers 41C of the plurality of connecting portions 41 may be located at the center of the polygon P, and may be located at the center of the upper platen 14. That is, when viewed from above, the centers 41 </ b> C of the plurality of connecting portions 41 may be located in the nozzle holes 19 of the upper platen 14. The weight or the like of the upper platen 14 is evenly distributed to the plurality of tie bars 17 so that the upper platen 14 is less inclined.

  In order to further reduce the inclination of the upper platen 14, the center of each connecting portion 41 may be located in the polygon P when viewed from above.

  As shown in FIG. 2 and the like, the connecting mechanism 40 is connected to a connecting portion 41 of the upper platen 14 via a connecting pin 42, and is rotatable about the center line of the connecting pin 42 with respect to the upper platen 14. It is. Each of the connecting portion 41 and the connecting mechanism 40 of the upper platen 14 is formed with a connecting pin hole through which the connecting pin 42 is inserted. When the coupling mechanism 40 is deformed, the deformation is not easily transmitted to the upper platen 14, and the upper platen 14 is not easily tilted.

  In addition, although the connection pin 42 of this embodiment is penetrated by the connection pin hole of the connection mechanism 40, and the connection pin hole of the connection part 41, you may fix to any one of the connection mechanism 40 and the connection part 41. FIG.

  Next, the configuration of the coupling mechanism 40 will be described based on FIGS. 4 and 5. FIG. 4 is a diagram illustrating a state when the nozzle touch is released by the coupling mechanism according to the embodiment of the present invention. FIG. 5 is a diagram illustrating a state of the coupling mechanism according to the embodiment of the present invention when the nozzle is touched.

  The connecting mechanism 40 contacts and separates the nozzle 32 of the injection device 30 from the upper mold 12, so that the bracket 50 connected to the upper platen 14, the base 60 to which the injection device 30 is fixed, and the bracket 50 are connected. And an elevating mechanism 70 for elevating the base 60 relatively. The bracket 50 and the base 60 are independently movable up and down along the guide Gd.

  The bracket 50 includes a slider 51 that can move up and down along the guide Gd, a bracket body 52 that is fixed to the slider 51, and a pair of arms 53 that protrude from the bracket body 52. The distal end portion of each arm 53 is connected to the connecting portion 41 of the upper platen 14.

  The distal end portion of each arm 53 is inserted into the groove of the connecting portion 41 of the upper platen 14 and is connected to the connecting portion 41 via the connecting pin 42. The arm 53 is rotatable about the center line of the connecting pin 42 with respect to the upper platen 14.

  The center line of the connecting pin 42 is horizontal, and is perpendicular to the protruding direction of the arm 53 when viewed from above. Therefore, when the arm 53 is bent, the deformation is hardly transmitted to the upper platen 14, and the upper platen 14 is not easily tilted.

  The base 60 includes a slider 61 that can move up and down along the guide Gd, and a base body 62 that is fixed to the slider 61. The injection device 30 is fixed to the base body 62.

  The lifting mechanism 70 moves the base 60 up and down relatively with respect to the bracket 50. The lifting mechanism 70 includes a nozzle touch motor 71 and a ball screw mechanism 72 as a motion conversion unit that converts the rotational motion of the nozzle touch motor 71 into a linear motion in the vertical direction.

  The housing of the nozzle touch motor 71 is fixed to the motor mounting portion 75, and a plurality of rod holes through which the rods 76 are inserted are formed in the motor mounting portion 75. The rod hole guides the rod 76 in the vertical direction. A stopper 77 larger than the rod hole is provided at the upper end portion of each rod 76, and the lower end portion of each rod 76 is fixed to the base body 62. Between the stopper 77 and the base body 62, the motor mounting portion 75 can move relative to the base body 62 and the like. A coil spring 78 is disposed between the base body 62 and the motor mounting portion 75 so as to surround the outer periphery of the rod 76.

  The ball screw mechanism 72 includes, for example, a nut 73 that is fixed to the bracket 50 (specifically, the bracket body 52), a screw shaft 74 that is screwed into the nut 73, and the like. The screw shaft 74 is coaxially connected to the output shaft of the nozzle touch motor 71 via a coupling.

  When the nozzle touch motor 71 is rotationally driven while the stopper 77 is in contact with the motor mounting portion 75, the screw shaft 74 moves up and down relatively with respect to the nut 73 while rotating, and the nut 73 is fixed. The base 60 moves up and down relative to the bracket 50.

  In addition, the structure of the raising / lowering mechanism 70 is not limited to said structure. For example, in the above embodiment, the nozzle touch motor 71 is disposed on the base 60 side and the nut 73 of the ball screw mechanism 72 is disposed on the bracket 50 side. However, the arrangement of the nozzle touch motor 71 and the nut 73 may be reversed. . That is, the nut 73 is fixed to the base body 62 and the screw shaft rotates, so that the nut moves up and down relative to the screw shaft, and the base 60 moves up and down relative to the bracket 50. . Further, the elevating mechanism 70 of the above embodiment converts the rotational motion of the nozzle touch motor 71 into a linear motion in the vertical direction by the ball screw mechanism 72 and moves the base 60 relative to the bracket 50 relatively. The base 60 may be moved up and down relatively with respect to the bracket 50 by a fluid pressure cylinder such as a hydraulic cylinder.

Next, the operation of the lifting mechanism 70 configured as described above will be described.
When lowering the injection device 30 relative to the upper mold 12 from the state shown in FIG. 5, the nozzle touch motor 71 is driven to rotate in the forward direction, and the screw shaft 74 is rotated to the nut 73. Lower relative to it. The base 60 is lowered relative to the bracket 50 to which the nut 73 is fixed, and the injection device 30 is lowered relative to the upper mold 12. While the injection device 30 descends relative to the upper mold 12, the stopper 77 contacts the motor mounting portion 75, and the positional relationship between the motor mounting portion 75 and the base main body 62 does not change. The nozzle 32 of the injection device 30 is inserted into the nozzle hole 19 of the upper platen 14 and comes into contact with the upper mold 12 to perform nozzle touch. When the injection device 30 comes into contact with the upper mold 12, the lowering of the injection device 30 with respect to the upper mold 12 stops.

With continued rotates the nozzle touch motor 71 in the forward direction, instead of the injection device 30 is lowered relative the upper die 12, the motor mounting portion relative to the base body 62 as shown in FIG. 5 75 Is relatively lowered, and the coil spring 78 interposed between the base main body 62 and the motor mounting portion 75 is contracted. The elastic restoring force of the coil spring 78 is increased, and the nozzle touch force that presses the nozzle 32 against the upper mold 12 is increased. When the nozzle touch force reaches the set value, the drive of the nozzle touch motor 71 is stopped. The nozzle touch motor 71 may be a motor with an electromagnetic brake, and after the drive is stopped, the rotation of the output shaft is stopped by the electromagnetic brake. Thereby, the nozzle touch force is maintained at the set value even after the drive is stopped. The nozzle touch force is measured by a position detector that detects the position of the motor mounting portion 75. Since the nozzle 32 is pressed against the upper mold 12 with a predetermined nozzle touch force, leakage of the molten resin from between the nozzle 32 and the upper mold 12 can be prevented.

On the other hand, when the injection device 30 is raised relative to the upper mold 12 from the state shown in FIG. 5 , the nozzle touch motor 71 is driven to rotate in the reverse direction and the screw shaft 74 is rotated while the nut is rotated. Relative to 73. If it does so, the motor attaching part 75 will raise relatively with respect to the base main body 62, and the coil spring 78 will return to the original state. The injection device 30 does not rise relative to the upper mold 12 until the motor mounting portion 75 contacts the stopper 77. After the motor mounting portion 75 comes into contact with the stopper 77, the nozzle touch motor 71 is continuously driven to rotate in the reverse direction, and when the screw shaft 74 is rotated relative to the nut 73, the nut 73 is rotated. The base 60 rises relative to the bracket 50 to which is fixed. The nozzle 32 of the injection device 30 is pulled upward from the upper mold 12 and pulled out from the nozzle hole 19 of the upper platen 14 to release the nozzle touch.

  By the way, when the nozzle touch force is generated, the connecting portion 41 of the upper platen 14 is pulled upward by a reaction.

  In the present embodiment, as shown in FIG. 3, when viewed from above, the centers 41 </ b> C of the plurality of connecting portions 41 are located in a polygon P having the vertices at the centers of the tie bars 17. Therefore, when the connecting portion 41 of the upper platen 14 is pulled upward, all the tie bars 17 hold the upper platen 14. Therefore, the upper platen 14 is not easily tilted, and the center line of the upper mold 12 and the center line of the lower mold 11 facing the upper mold 12 are not easily displaced.

  The embodiment of the vertical injection molding machine has been described above, but the present invention is not limited to the above embodiment, and various modifications and improvements can be made within the scope described in the claims. .

10 vertical injection molding machine 11 lower mold 12 upper mold 13 lower platen (first platen)
14 Upper platen (second platen)
16 Third platen 17 Tie bar 18 Guide post 19 Nozzle hole 20 Toggle mechanism 21 Mold clamping motor 30 Injection device 31 Heating cylinder 32 Nozzle 40 Connection mechanism 41 Connection portion 41C Connection portion center 42 Connection pin 50 Bracket 51 Slider 52 Bracket body 53 Arm 60 Base 61 Slider 62 Base body 70 Elevating mechanism 71 Nozzle touch motor 72 Ball screw mechanism 73 Nut 74 Screw shaft 75 Motor mounting portion 76 Rod 77 Stopper 78 Coil spring

Claims (5)

A lower platen to which the lower mold is attached and fixed to the frame;
An upper platen to which an upper mold is attached and movable in the vertical direction with respect to the lower platen;
An injection device that is disposed above the upper mold and that fills a cavity space formed between the upper mold and the lower mold when the mold is clamped;
A connection mechanism for connecting the upper platen and the injection device;
A guide that is fixed to the frame and guides the coupling mechanism in a vertical direction;
And n (n is a natural number of 3 or more) tie bars that support the upper platen,
A vertical injection molding machine in which, when viewed from above, the center of the connecting portion of the upper platen with the connecting mechanism is located in an n-gon having the center of each tie bar as a vertex. The coupling mechanism includes a slider that can move up and down along the guide, a bracket body that is fixed to the slider, and an arm that protrudes from the bracket body.
The vertical injection molding machine according to claim 1, wherein a tip portion of the arm is connected to a connecting portion of the upper platen.   The said connection mechanism is connected with the connection part of the said upper platen via the connection pin, and can rotate centering | focusing on the centerline of the said connection pin with respect to the said upper platen. Vertical injection molding machine. The coupling mechanism includes a slider that can move up and down along the guide, a bracket body that is fixed to the slider, and an arm that protrudes from the bracket body.
A tip portion of the arm is connected to a connecting portion of the upper platen via a connecting pin, and is rotatable about a center line of the connecting pin with respect to the upper platen.
2. The vertical injection molding machine according to claim 1, wherein a center line of the connecting pin is horizontal and is perpendicular to a protruding direction of the arm when viewed from above. The coupling mechanism is
A slider that is movable up and down along the guide, a bracket body fixed to the slider, and a bracket including an arm protruding from the bracket body;
A base to which the injection device is fixed;
And a lifting mechanism for relatively lifting the base to the bracket is connected to the upper platen, vertical injection molding machine according to any one of claims 1 to 4.

Images