JP2010012700A - Method of drawing screw of electric injection molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of backwardly drawing a screw of an electric injection molding machine in which movement of the screw when injection is performed by spinning two ball screws prepared behind both sides of the screw. <P>SOLUTION: In the method of drawing the screw of an electric injection molding machine in which movement of the screw 21 when injection is performed by spinning of two ball screws 33 prepared behind both sides of the screw, a transmission shaft 28 in which an aft end of the screw is inserted and which transfers spinning of a metering motor to the screw is prepared and a hole which can pass the screw is prepared on an extension line of a screw rear end of a rear plate in which nuts fixed in the axial direction which are fixed to two ball screws and revolved by a motor for injection to make two ball screws advance/retreat in the axial direction, and thereby the screw is backwardly drawn when drawing the screw. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a screw drawing method for an electric injection molding machine.

    An injection unit of an injection molding machine of a conventional electric injection molding machine will be described with reference to FIGS. 7 and 8. The injection unit 1 includes heat from a heating device in which a material resin 3 charged from a hopper 2 is provided in a heating barrel 4. After the heat is melted by shearing heat generated by the rotation of the screw 6 mounted in the heating barrel 4 by the measuring motor 5 and measured as the molten resin at the tip of the screw 6, the sliding base 7 on which the injection unit 1 is mounted is nozzle-touched. The ball screw 9 is rotated forward by the ball motor 9 (leftward in the figure), the nozzle at the tip of the heating barrel 4 is touched to the mold 10 in the mold clamping device, and the ball screw 12 is rotated by the injection motor 11. Then, the screw 6 screwed into this is moved forward, the above-mentioned measured molten resin is injected, cooled and cured, and then taken out as a molded product.

The screw 6 inserted into the heating barrel 4 so as to be freely rotatable and retreatable is used as a material resin used in the previous molding remaining in the heating barrel 4 when changing the color or changing the material corresponding to the molded product. In order to remove this effectively, the screw 6 is pulled out of the heating barrel 4 and cleaned.
The drawing of the screw 6 from the heating barrel 4 has a mold clamping device on the drawing side of the screw 6 and a drawing space cannot be secured. Therefore, as shown in FIG. 8, the injection unit 1 is swung as shown by a chain line 1a. Avoiding fastening devices is being done.
Japanese Patent Laid-Open No. 2003-340867 JP 2003-39482 A

  However, the conventional method for pulling out the screw needs to swivel the sliding base on which the injection unit is mounted, and the swivel device has a complicated configuration and is expensive to manufacture. In addition, the injection unit is heavy, and the swiveling work and subsequent screw pulling work are troublesome and take time.

  For that purpose, the method of turning the injection unit that avoids the mold clamping device is not adopted, and if the screw is pulled backward, the conclusion is reached that the complicated turning device is not used and the work is easy and does not take time. .

  In order to achieve the above-mentioned object, the present invention provides a screw pulling method for an electric injection molding machine in which the screw advances at the time of injection by the rotation of two ball screws provided at both rear sides of the screw. Insertion and transmission shaft that transmits the rotation of the metering motor to the screw, and a nut fixed in the axial direction that is screwed into two ball screws and rotated by the injection motor to advance and retract the two ball screws in the axial direction The screw pulling method is characterized in that a hole through which the screw can pass is provided on the extension line of the screw rear end of the rear plate provided with the screw, and the screw is pulled out backward when pulling out the screw.

  In addition, a screw hole is provided in the screw rear end face, a rod provided with a bolt at the tip end is inserted from a hole through which the screw of the rear plate can pass, and the screw at the rod end is screwed into the screw hole on the screw rear end face. If the screw is pulled out rearward, a more preferable screw pulling method is obtained.

  Furthermore, it is more preferable if a guide rail parallel to the floor surface is selectively attached to the frame of the molding machine main body, the rod provided with a bolt at the tip is retracted along the guide rail, and the screw is pulled out rearward. It becomes a simple screw pull-out method.

  According to the present invention, it is not necessary to swivel the heavy injection unit, and it is possible to easily pull out the screw without installing a swiveling device having a complicated mechanism, and the disadvantages of the conventional screw pulling work are eliminated. .

Next, an embodiment of the present invention will be described with reference to FIGS.
The injection unit 20 is provided with a fixed plate 23 to which a heating barrel 22 inserted so that the screw 21 is rotatable and movable by a predetermined distance is fixed, and a hole 24 through which the screw can pass on an extension line of the rear end of the screw 21. The rear plate 25 is connected by a tie bar 26, and a movable plate 27 is provided between the plates 23 and 25. The movable plate 27 is guided by the tie bar 26 at the time of injection and weighing, and moves forward and backward by a predetermined distance. It is like that.

The movable plate 27 is provided with a through hole through which the screw 21 can pass in the shaft center part, and a transmission shaft 28 that is rotatable but does not move in the axial direction is attached. The rear end of the screw 21 is inserted into the through hole of the transmission shaft 28. The rotation of a measuring motor (not shown) is transmitted to the screw 21 via a timing belt (not shown) and a pulley 30 by a key 29.
As shown in FIGS. 3 and 4, a split collar 31 and a presser plate 32 are attached to the front end face and rear end face of the transmission shaft 28 with screws 36 and 37, respectively, to prevent the screw 21 from coming off.

  Two ball screws 33 are fixed to symmetrical positions deviating from the extension line of the screw rear end of the surface A facing the rear plate 25 of the movable plate 27, respectively, from the injection motor not shown on the rear plate 25. The rotation is performed only by a timing belt (not shown) and a pulley 34 and is screwed into a nut 35 fixed in the axial direction. When the nut 35 rotates during injection and measurement, the movable plate 25 moves back and forth (left and right in the figure). The screw 21 that moves and is fixed to the movable plate 25 via the nut 35 moves forward and backward within the heating barrel 22 by a predetermined distance L.

Since it is configured as described above, when the screw is pulled out, the movable plate 25 is moved to the retreat limit as shown in FIG. 2, then the split collar 31 and the presser plate 32 indicated by the chain line are removed, and the key 29 is removed. After removing these two members, it can be pulled out backward by the human hand behind the injection unit 20 (in the direction of arrow C) like the chain screw 21a.
Here, as shown in FIG. 5, a screw hole 40 is provided in the rear end surface of the screw 21 and a screw 42 provided at the tip of the rod 41 is screwed into the screw hole 40, so that the screw can be easily pulled out.

  Further, as shown in FIGS. 6 (a) and 6 (b), a guide rail 43 parallel to the floor surface is attached to a frame or the like of a molding machine (not shown), and the bolt 42 and the screw 21 at the tip of the rod 41 attached to the drawer tool 44 are attached. If the screw hole 40 is screwed into the rear end face and the pulling tool 44 is pulled rearward (to the right in the figure) along the guide rail 43, the screw can be pulled out more efficiently.

  Since it is configured in this manner, it is not necessary to manufacture a swiveling device having a complicated mechanism, and therefore it is not necessary to swivel the injection unit. Furthermore, it is possible to easily pull out the screw without performing a troublesome and time-consuming screw pulling operation.

It is explanatory drawing which shows one Embodiment with which this invention is applied, and shows the advance limit of a screw. It is explanatory drawing which shows one Embodiment with which this invention is applied, and shows the backward limit of a screw. FIG. 2 shows an embodiment to which the present invention is applied, and is an enlarged cross-sectional view taken along the line BB in FIG. 1. FIG. 2 shows an embodiment to which the present invention is applied, and is an enlarged Z arrow view of FIG. 1. FIG. 5 is a view illustrating an embodiment to which the present invention is applied, and illustrating a connection state between a screw rear end surface and a rod of a drawer. The other embodiment to which this invention is applied is shown, and it is explanatory drawing at the time of pulling out the drawing tool which attached the rod back along a guide rail, (a) is the front view, (b) is the Y arrow view FIG. It is the front view explaining the outline | summary of the conventional electric injection molding machine. It is explanatory drawing which shows a part of top view explaining the outline | summary of the conventional electric injection molding machine.

Explanation of symbols

20 Injection unit 21 Screw 22 Heating barrel 23 Fixed plate 24 Hole 25 Rear plate 26 Tie bar 27 Movable plate 28 Transmission shaft 29 Key 30, 34 Pulley 31 Split collar 32 Holding plate 33 Ball screw 35 Nut
36, 37 Screw 40 Screw hole 41 Rod 42 Bolt 43 Guide rail 44 Drawer

Claims (3)

  In the screw pull-out method of an electric injection molding machine in which the progress of the screw during injection is performed by the rotation of two ball screws provided at the rear of both sides of the screw, the rear end of the screw is inserted, and the rotation of the metering motor is turned into the screw. Screws are engaged with the transmission shaft and the two ball screws, rotated by an injection motor, and provided with nuts fixed in the axial direction to advance and retract the two ball screws in the axial direction. A screw pulling method characterized in that a hole through which a screw can pass is provided on an extension line, and the screw is pulled backward when pulling out the screw.   A screw hole is provided in the screw rear end face, a rod with a bolt provided at the tip end is inserted through a hole through which the screw of the rear plate can pass, and the screw at the rod end is screwed into the screw hole on the screw rear end face. The screw pulling method according to claim 1, wherein the screw is pulled backward. 3. A screw according to claim 2, wherein a guide rail parallel to the floor surface is selectively attached to a frame or the like of the molding machine main body, the rod provided with the bolt at the tip is retracted along the guide rail, and the screw is pulled out rearward. Drawer method.

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