JPH025937Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to an eject device for an electric injection machine.

(b) Conventional technology As a conventional electric injection machine, for example, JP-A-58-
Some of these are disclosed in Japanese Patent Application Laid-open No. 62030, Japanese Patent Application Laid-open No. 112417/1984, and the like. The electric injection machines shown above use an electric motor as a drive source and are configured to perform injection operations and mold opening/closing operations.

(c) Problems that the invention aims to solve However, in the conventional electric injection machine as described above, when each process is performed sequentially using one electric motor, two operations are performed simultaneously. However, if a dedicated electric motor is used for each operation, simultaneous operation is possible, but the number of electric motors increases and the cost increases. It feels hot.

(d) Means for solving the problem The present invention solves the above problem by enabling the electric motor for opening and closing the mold to also be used for ejecting the molded product so that the mold opening process and the molded product ejection process can be performed simultaneously. Solve the points. That is, the ejecting device of the electric injection machine according to the present invention connects the mold opening/closing motor and the ejecting ball screw mechanism provided on the movable platen with an electromagnetic clutch, a variable shaft length rotational force transmission mechanism, and a rotation between parallel shafts. They are connected by a power transmission line having a force transmission mechanism.

(E) Action After completion of injection molding of the molded product, the mold is opened after a necessary cooling time. The mold is opened by operating a mold opening/closing electric motor. By turning on the electromagnetic clutch during mold opening, the driving force of the mold opening/closing motor is transmitted to the ejecting ball screw mechanism provided on the movable platen through the power transmission line.
By doing so, the mold opening process and the molded product ejection process can be performed simultaneously using one electric motor, thereby shortening the cycle time and reducing the number of required electric motors. Note that the variable axial length rotational force transmission mechanism, which is configured by a ball spline, for example, is provided to absorb changes in the axial length due to movement of the movable platen during mold opening. Furthermore, if the electromagnetic clutch is of a variable transmission torque type, it becomes possible to control the ejection force, ejection speed, etc.

(F) Embodiments Hereinafter, embodiments of the present invention will be described based on FIG. 1 of the accompanying drawings.

The toggle type mold clamping device includes a fixed platen 10, a housing 12, four tie bars 14 connecting the fixed platen 10 and the housing 12, a movable platen 16 guided by the tie bars 14, a short link 18, a long link 20, and a cross link. 22, crosshead 24, short link 18
a pin 26 that connects the long link 20 to the movable platen 16, a pin 30 that connects the short link 18 and the long link 20, and a pin 3 that connects the short link 18 and the cross link 22.
2. It has a pin 34 that connects the cross link 22 and cross head 24. crosshead 24
is connected to a ball screw 36, and this ball screw 36 meshes with a ball nut 40 that rotates together with a driven gear 38. The ball screw 36 and the ball nut 40 constitute a ball screw mechanism for opening and closing the mold. The driven gear 38 is rotatable with respect to the housing 12, but is restricted in the axial direction. Driven gear 3
8 is a key 4 so as to rotate together with the gear shaft 42.
It meshes with a drive gear 46 connected by 4. One end of the gear shaft 42 is connected to a mold opening/closing electric motor 50 via a coupling ring 48. A mold opening/closing electric motor 50 is fixed to the housing 12. The other end of the gear shaft 42 is connected to a ball spline mechanism 54 (variable shaft length rotational force transmission mechanism) via an electromagnetic clutch 52. The ball spline mechanism 54 includes a spline shaft 56, a ball spline 58, and a hollow shaft 60 integrated with the ball spline 58. The hollow shaft 60 is integral with a pulley shaft 62, and a key 6 is attached to this pulley shaft 62.
A drive pulley 66 is attached by 4. The driving pulley 66 is connected to a driven pulley 70 via a belt 68 so as to be able to transmit rotational force. The driving pulley 66, the belt 68, and the driven pulley 70 constitute a rotational force transmission mechanism 71 between parallel shafts. The driven pulley 70 is provided to rotate together with the ball nut 72. The ball nut 72 is rotatable relative to the movable platen 16, but is axially restricted. ball nut 7
2 is engaged with a ball screw 74. The ball nut 72 and the ball screw 74 constitute an ejecting ball screw mechanism 75. A fixed die 76 is attached to the fixed platen 10, and a movable die 78 is attached to the movable platen 16.

Next, the operation of this embodiment will be explained.

FIG. 1 shows the mold in an open state. From this state, the mold opening/closing electric motor 50 is operated, and the coupling 4
8. Gear shaft 42, driving gear 46 and driven gear 38
When the ball nut 40 is rotated through the ball screw 36 and the crosshead 24 integrated therewith, the ball screw 36 and the crosshead 24 integrated therewith move forward, the movable platen 16 moves in a direction approaching the fixed platen 10, and the movable mold 78 comes into contact with the fixed mold 76. The mold is closed, and then a predetermined mold clamping force is applied to the fixed mold 76 and the movable mold 78 by further rotating the mold opening/closing electric motor 50. During this time, the electromagnetic clutch 52 is kept in the "disengaged" state. After mold clamping, injection process,
A pressure holding process and a cooling process are performed, and then a mold opening process is performed. That is, the mold opening/closing electric motor 50 is rotated in the opposite direction to that for mold closing, and the movable platen 16 and the movable mold 78 are moved backward. When the electromagnetic clutch 52 is turned on at a predetermined time after the mold opening starts,
The rotational force of the mold opening/closing electric motor 50 is transmitted to the ball nut 72 via the ball spline mechanism 54, pulley shaft 62, drive pulley 66, belt 68, and driven pulley 70, and this rotates the ball screw 74 in the direction of the movable mold 78. The eject plate (not shown) inside the movable mold 78 is advanced.
As a result, the molded product attached to the movable mold 78 is ejected. After the molded product has been ejected,
The mold opening process is completed. In addition, if the electromagnetic clutch 52 is turned on in the next mold closing process, the ball nut 7
2 rotates in the opposite direction to that in the above case, and the ball screw 74 retreats. Retraction of the ball screw 74 ends before the movable mold 78 contacts the fixed mold 76.

As a result, the above operation allows the molded product to be ejected using the rotational force of the mold opening/closing electric motor 50 during the mold opening process. Therefore, a dedicated electric motor is not required for ejecting the molded product, and since simultaneous operations are performed, the cycle time does not become long.

In the above embodiment, the electromagnetic clutch 52 is of a type that can be switched between "on" and "off", but the transmission torque can be changed by remote control, such as an electromagnetic powder clutch, for example. This makes it possible to control the ejection speed and ejection force of the ball screw 74. Further, by configuring a power transmission line including an electromagnetic clutch between the driving gear 48 and the driven gear 38, the mold opening/closing ball screw mechanism and the ejecting ball screw mechanism can be independently controlled. You can also do it.
Further, although this embodiment shows a mold clamping device using a toggle mechanism, it is clear that the present invention is also applicable to a direct pressure type mold clamping device.

Further, in this embodiment, the ball spline mechanism 54 is used as the variable shaft length rotational force transmission mechanism, but this may be other mechanisms such as a mechanism using a sliding key. Further, although a mechanism using pulleys and a belt has been shown as a rotational force transmission mechanism between parallel axes, other types of mechanisms such as a mechanism using gears or a mechanism using a chain can also be used.

(g) Effect of the invention As explained above, according to the invention, the ejecting ball screw mechanism is operated using the rotational force of the mold opening/closing motor, so the mold can be opened/closed by one electric motor. It becomes possible to perform the process and the molded product ejection process at the same time, which shortens the cycle time and reduces the cost of the equipment.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an ejecting device of an electric injection machine according to the present invention. 10...Fixed plate, 12...Housing, 14...Tie bar, 16...Movable plate, 36...Ball screw, 40...
Ball nut, 50... Electric motor for mold opening/closing, 52... Electromagnetic clutch, 54... Ball brine mechanism (variable shaft length rotational force transmission mechanism), 66... Drive pulley, 68
...belt, 70...driven pulley, 71...parallel shaft inter-rotational force transmission mechanism, 72...ball nut, 74...ball screw, 75...eject ball screw mechanism.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In an ejecting device for an electric injection machine that performs mold opening/closing operations using a mold opening/closing motor, there is An ejecting device for an electric injection machine, characterized in that the ejecting device is connected by a power transmission line having an electromagnetic clutch, a variable shaft length rotational force transmission mechanism, and a parallel shaft-to-parallel shaft rotational force transmission mechanism. 2. The ejecting device for an electric injection machine according to claim 1, wherein the electromagnetic clutch is a remotely controllable transmission torque variable electromagnetic clutch.