JPH0371007B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a defective product processing device for changing types of injection molding equipment.

(Prior Art) Conventionally, as a method for distinguishing between good and defective products molded in an injection molding system, for example, in Japanese Patent Publication No. 60-39535, the mold temperature and molten resin temperature are detected, and based on these values, A device has been proposed that is configured to determine whether a product is good or bad and to store products determined to be defective into a special box using a rack method. Furthermore, for example, in JP-A-60-247538 and JP-A-57-159632, the molding state is monitored,
A defective product processing device has been proposed that determines a product to be defective if the product exceeds a predetermined tolerance.

(Problem to be solved by the invention) However, in recent years, there has been a demand for unmanned operation of injection molding equipment and for high-mix, low-volume production. There is a need to do.

In view of this point, it is an object of the present invention to provide a defective product processing device necessary for simplifying and automating the start operation when changing product types.

(Means for Solving the Problems) The defective product processing device in the injection molding system of the present invention includes a means for determining whether a product is good or defective;
In an injection molding system equipped with a product unloading means that changes the unloading position of the product based on the determination result, at least the number of products that can be molded with the resin remaining in the cylinder of the molding machine when switching types is used. are treated as defective products. The number of products that can be molded is, for example, a value calculated based on the attributes of the molding machine and the product.

(Function) When changing the product type, only the number of products required to completely replace the resin in the cylinder are treated as defective products unconditionally. Moreover, this number of products depends on, for example, the attributes of the molding machine and products (cylinder volume,
The number of products to be treated as defective is automatically set each time the product type is changed.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a defective product processing apparatus in an injection molding system according to the present invention.

The control device 1 controls the operation of the injection molding machine 2 and other peripheral equipment 3 to 9 that constitute the injection molding equipment. is connected to by a communication line 10. Furthermore, the injection molding machine 2 is linked by communication with a mold changing device 3, a product unloading device 4, a material conveying device 6, and a mold temperature control device 7, and these devices are 3, 4, 6, and 7 operate in conjunction with the operation of the injection molding machine 2. The product take-out device 4 is communicatively linked to a good product conveyance line 8 and a defective product conveyance line 9 via a product conveyance facility 5, and these devices 5, 8, and 9 are connected to the operation of the injection molding machine 2 and the product take-out device 4. Work together. The injection molding machine 2 is provided with means for determining the number of shots of a molded product and whether it is a good product or a defective product, and the number of shots, a good product signal, and a defective product signal are sent to the control device 1. In addition, the control device 1 sends a molding stop signal to the injection molding machine 2 when production is stopped, a signal instructing the product take-out device 4 to change the position of product delivery of good and defective products, and a signal to stop the production when production is stopped. Output a signal. The product conveyance equipment 5
The conveyor line is changed in response to a signal indicating good or defective products sent from the control device 1. Good products are sent to the good product transport line 8, and defective products are sent to the defective product transport line 9. Furthermore, the control device 1 stores molding conditions for dozens of types, and when a type change is commanded, each molding condition is instructed to the injection molding machine 2, product take-out device 4, and product conveyance equipment 5. Ru.

Next, the operation of handling defective products when the molding resin material is changed will be explained.

When the resin is changed, the control device 1 calculates the predetermined number A by calculating the following formula (1) based on the attributes of the molding machine and the product stored in advance.

Predetermined number A = (cylinder volume - screw volume) x α / (molded product weight) + β ... (1) However, α: Color change coefficient β: Weight outside the product This predetermined number A must be at least as long as the parts already remaining inside the cylinder. This indicates the number of molded products that can be molded until the existing resin is completely replaced with new resin. In particular, the color change coefficient α in equation (1) is a constant set based on experience, and is set to a relatively small value when changing from a light color to a dark color; If changed, it is set to a relatively large value. Therefore, at the time of type switching 11, information indicating the predetermined number A (see FIG. 2a) calculated by the above equation (1) is sent to the product take-out device 4. Even if good product signals are sent from the control device 1 for the predetermined number A, these are regarded as defective product signals and are output to the product conveyance equipment 5. Therefore, a predetermined number A of the products will be transported to the defective product transport line 9 even if they are good products.

Furthermore, after molding of at least a predetermined number A is performed, a large number of defective products (the hatched area in FIG. 2b) 12 are shot. Thereafter, when a predetermined number B of non-defective products are continuously produced, counting is started from the subsequent products as non-defective products, and transport to the non-defective product transport line 8 is started. This predetermined number B is also stored in advance in the storage device of the control device 1 for each product type. by the way,
If a predetermined number C is exceeded after a predetermined number A has been molded, but the predetermined number B of non-defective products still cannot be produced [see Figure 2 c], it is assumed that an equipment abnormality has occurred, and production is stopped. . This predetermined number C is also stored in advance in the storage device of the control device 1 for each product type.

In addition, in the control device 1, the data necessary for the calculation of the above formula (1) is stored for each product type, and the data required for the calculation of the above formula (1) is stored for each product type, and the order of product changeover set by the controller of the injection molding machine 2 (not shown) and the data set by the control device 1 are stored. The order of product switching is synchronized.

In addition, in the above embodiment, the predetermined number A was calculated based on the attributes of the molding machine and the product, but it is not limited to this. It is also possible to set a certain constant for the number of products that can be molded based on past results.

(Effects of the Invention) As described above, according to the present invention, it is possible to simplify the starting operation when switching types, and therefore it is extremely suitable for high-mix low-volume production.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a defective product processing apparatus in an injection molding system according to the present invention, and FIGS. 2a, b, and c are timing charts showing the flow of defective product processing. 1...Control device, 2...Injection molding machine, 4...Product take-out device, 5...Product conveyance equipment, 8...Good product conveyance line, 9...Defective product conveyance line.

Claims (1)

[Scope of Claims] 1. In an injection molding system equipped with a means for determining whether a product is good or defective, and a product unloading means for changing the unloading position of the product according to the determination result, at least the molding A defective product processing device for an injection molding system, characterized in that products as many as the number of products that can be molded using the resin remaining in the cylinder of the machine are treated as defective products.