JPH0349733B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a raw material supply device for an injection molding machine.

[Prior art]

In many injection molding machines, a feed screw is provided as a feeder between a hopper that stores raw materials and a barrel. Conventionally, a motor with a constant rotation speed has been used to drive the feed screw. Therefore, as the metering progresses, the L/D of the feed section of the screw in the molding machine becomes smaller and it is necessary to reduce the raw material supply, but since the feed screw supplies a constant amount of raw material, If the resin is not preheated from the outside of the barrel, it will not be sufficiently melted, and the friction heat in the compression section will increase, which will cause the resin to decompose, burnt, and cause defects such as burnt dirt. We were becoming one.

In this way, as weighing approaches completion, the metering speed, that is, the screw rotation speed, decreases and the transfer capacity of the screw decreases, so it is necessary to lower the feed screw rotation speed and reduce the amount of raw material fed into the barrel. In spite of this, as mentioned above, since the feed screw rotates at a constant speed, more material was supplied into the barrel than the feed screw could transport, and the screw could not respond. In addition, when the screw rotation speed was changed in addition to the above, it was also necessary to change the feed screw rotation speed, but this was also impossible to handle, and good molded products could not be obtained.

[Purpose of the invention]

The present invention has been made to eliminate such drawbacks, and its purpose is to provide a raw material supply device for an injection molding machine that can change the rotational speed of the feed screw according to the measuring time when measuring the screw. It's about doing.

[Key points of the invention]

The raw material supply device for an injection molding machine in the present invention includes:
In a raw material supply device for an injection molding machine that supplies raw materials into the barrel of an injection molding machine by a feed screw, the measuring process time is divided into a plurality of periods, and the rotation speed of the feed screw is changed for each of the divided times. It is characterized by

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG.

A nozzle 12 is attached to the tip of the barrel 11, and a screw 13 is inserted into the nozzle 12 so that it can rotate and move forward and backward. The screw 13 is rotated by having its rear end fitted to the output shaft of a driving motor 15 fixed to the mounting plate 14. Cylinder 1 formed integrally or separately from barrel 11
The piston 17 of No. 6 is attached to a mounting plate 14 via a piston rod 18, and the mounting plate 14 is moved from side to side in the figure by the piston 17, and as a result, the screw 13 is moved forward and backward.

Raw material supply port 1 is located slightly behind the center of barrel 1.
9 is provided, and the raw material supply port 19 is connected to a feeder 20.
It is connected to the. The feeder 20 includes a feed screw 21, a driving motor 23 connected to this via a coupling ring 22, and a hopper 24.
etc. are the main constituent requirements.

Next, the rotation speed control portion of the motor 23 will be explained.

The feeder rotation speed switching time setting section 51 is provided with, for example, one or more timers (not shown), and this switching signal causes the control section 52 to adjust the rotation speed for the feed screw 21 set in advance. The signals from the number setting section 53 are sequentially sent to the motor 23. Therefore, the motor 23 that drives the feed screw 21 is rotated at a set rotational speed according to the elapsed time at the time of measurement.

〔Effect of the invention〕

As explained above, the raw material supply device for an injection molding machine according to the present invention is configured to change the rotational speed of the motor that drives the feed screw corresponding to the measuring time divided into a plurality of parts during the measuring process of the injection molding machine. As a result, it has become possible to finely adjust the amount of raw resin supplied to the screw in accordance with the passage of time in the metering process. This has the advantage that defective phenomena such as resin decomposition and discoloration are suppressed, molding conditions can be determined easily, and operability and quality of molded products are improved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 11... Barrel, 13... Screw, 21... Feed screw, 23... Motor, 51... Time setting part for rotation speed switching, 52... Control part.

Claims (1)

[Scope of Claims] 1. A raw material supply device for an injection molding machine that supplies raw materials into the barrel of an injection molding machine using a feed screw, which includes a time setting section that divides the measuring process time into a plurality of parts and sets the same divided time for each part. , a rotation speed setting section for setting the rotation speed of the feed screw so that the feed screw rotates at a predetermined rotation speed at the time set in the time setting section; A raw material supply device for an injection molding machine comprising a control section that receives an output signal from a time setting section and drives a drive motor at a rotation speed set in a rotation speed setting section corresponding to the same time. 2. The raw material supply device for an injection molding machine according to claim 1, wherein a timer is used in the time setting section.