JPH0741635B2 - Material supply equipment for injection molding - Google Patents

Description

TECHNICAL FIELD The present invention relates to a molding material supply apparatus used for unmanned molding of a specified number of products, and is applicable to an injection molding system for high-mix low-volume production. Used.

(Prior Art) When performing color change or material change of a molded product in injection molding, it is necessary to remove excess material in the molding machine, clean the inside of the cylinder with a cleaning material, supply different color materials, etc. In the past, all these tasks were done manually.

On the other hand, Japanese Patent Application Laid-Open No. 57-178734 proposes a method for automatically converting and supplying a coloring material in which a cleaning material hopper and a plurality of molding material hoppers are sequentially and selectively moved in order to improve workability during color change. ing.

(Problems to be Solved by the Invention) However, in this coloring material automatic conversion and supply method, since the supply of the material is stopped at the time when a predetermined number of products of the material of a certain color are manufactured, the next material is Prior to the supply, the old material remaining in the cylinder is removed by performing blank injection or the like, and further the cleaning material is used for injection. That is,
This method has a problem of poor productivity because the old material remaining in the cylinder and the blank injection are performed every time the color is changed or the material is changed.

(Means for Solving Problems) A material supply device in injection molding according to the present invention includes a valve section provided in a pipe section between a hopper and a molding machine cylinder section, a command section for instructing the number of products to be molded, A predetermined value is obtained by subtracting the number of moldable products from the specified number of molded products and a calculation unit that calculates the number of moldable products with the material remaining when the valve section is closed. And a valve unit control unit for controlling the valve unit to be closed.

(Function) Close the valve section with a margin of the number of products to be molded from the number of products that can be molded by the material remaining in the piping section and the molding machine cylinder section. After closing the valve, injection is performed with the remaining material.

(Example) Hereinafter, the Example of this invention is described with reference to drawings.

The drawings are schematic views showing the configuration of a material supply apparatus in injection molding according to the present invention.

This example exemplifies a material supply device in the case of having two kinds of hoppers, and each hopper stores a molding material of a different color or material.

Molding materials 1 and 2 of different or different colors are used in molding material hoppers 3 and 4.
It is stored in. On the material supply port side (lower side in the drawing) of the hoppers 3 and 4, pipe portions 6 and 7 that connect the hoppers 3 and 4 and the molding machine cylinder portion 5 are formed, and the lower portions of these pipe portions 6 and 7 are formed. Are connected to communicate with the molding machine cylinder section 5. Shutters 8 and 9 for opening and closing the pipes are provided above the pipes 6 and 7. Opening and closing of these shutters 8 and 9 are controlled by the operation of the cylinders 10 and 11, and the supply of the molding materials 1 and 2 to the molding machine cylinder portion 5 is controlled. The controller 12 commands the driving and stopping timing of the cylinders 10 and 11, and is connected to the product counting device 13 and the main control device 14. The product counting device 13 is a device for counting the current product output based on the shot number signal and the non-defective / defective product discrimination signal sent from the injection molding machine (not shown). Main controller 14
Is a device for storing a production plan, molding conditions, setup conditions, etc. instructed by a host computer (not shown),
These conditions are set from a keyboard (not shown). The hoppers 3 and 4 may of course be composed of three or more units, and a hopper for supplying the cleaning material may be provided therein.

Next, a control procedure of material exchange in the material supply device having the above-described configuration will be described.

First, molding is performed using the molding material 1 (first molding material) in the hopper 3 with the shutter 8 opened and the shutter 9 closed. At this time, from the storage device (not shown) of the main controller 14, the hopper number used, the material specific gravity, the standard product weight,
Data such as cylinder volume is taken out. Main controller 14
Using these data, calculate how many more materials are currently being molded and can be molded with the material supplied in the molding machine cylinder section 5 and the molding material remaining in the piping section 6 below the shutter 8. Then send it to the controller 12. The controller 12 compares the current production volume sent from the product counting device 13 with the number of products to be molded (target production volume) transmitted from the main control device 14, and calculates the value of (target production volume-current production volume). When the value of the number of products that can be molded with the remaining molding material sent from the main controller 14 matches, the cylinder 10 is operated and the shutter 8 is closed. Molding after closing the shutter 8
Only the material remaining in the pipe section 6 and the molding machine cylinder section 5 is used, and when the target production quantity is reached, the remaining material in the piping section 6 and the molding machine cylinder section 5 is almost gone. At this time, in order to supply the second molding material 2, the controller 12 operates the cylinder 11 and opens the shutter 9, so that the second molding material 2 from the hopper 4 to the molding machine cylinder portion 5 through the pipe portion 7. It is thrown in. Then, this second
Molding is sequentially performed by using the molding material 2 of No. 2, and when the target production number is reached, the operation reverse to the material changing operation from the first molding material 1 to the second molding material 2 as described above is performed. Is controlled and the shutter 8 is controlled to be opened this time. Then, after the remaining molding is performed with the material remaining in the pipe section 7 and the molding machine cylinder section 5, the shutter 8 is opened, and then the first molding material 1 is used for molding.

In the above-described embodiment, the material supply device composed of two hoppers has been illustrated, but of course, when there is no need to change the material, there is one hopper. Further, the timing of closing the shutters 8 and 9 may be automatically set using the cylinders 10 and 11 as described above, and may be set by manual setting, for example.

(Effect of the Invention) As described above, according to the present invention, the timing of stopping the supply of the molding material can be arbitrarily adjusted according to the calculation result, so that the molding material can be used sufficiently effectively and the material loss can be extremely reduced. can do. As a result, the blank injection can be almost eliminated, and the amount of the cleaning material used can be reduced, so that the productivity is improved and it is very suitable for the production of a wide variety of products in small quantities.

[Brief description of drawings]

The drawings are schematic views showing the configuration of a material supply device in injection molding according to the present invention. 1,2 …… Molding material, 3,4 …… Hopper 5 …… Molding machine cylinder section, 6,7 …… Piping section 8,9 …… Shutter (valve section), 12 …… Controller 14 …… Main controller

Claims (1)

[Claims] 1. A valve section provided in a pipe section between a hopper and a molding machine cylinder section, a command section for instructing the number of products to be molded, and a valve section which is supplied into the molding machine cylinder section when the valve section is closed. And the calculation part that calculates the number of products that can be molded with the material remaining in the piping below the valve part, and the value obtained by subtracting the number of moldable products from the specified number of molded products will be the specified value. And a valve unit control unit for controlling the valve unit to be closed when the material supply device in injection molding.