JPS6266917A - Quality discriminating device for product of injection molding machine - Google Patents

Abstract

PURPOSE:To improve productivity along with reduction of cost by making a space and time for discrimination unnecessary, by providing a storing and discriminating device storing a normal wave form of extrusion pressure and discriminating the quality of a molded article as compared the stored wave form with a pressure wave form of a pressure sensor. CONSTITUTION:A molded article 14 is pushed by an extrusion plate 17 and extruded rightward, by advancing a piston 16 of an extrusion cylinder 15 when the molded article 14 is cured through cooling. Extrusion pressure at this time is measured by a pressure sensor 18 and a variation in pressure to time, that is, a pressure wave form is applied to a storing and discriminating mechanism 19, Hereupon, the extrusion pressure becomes the pressure proportional to extrusion resistance of the molded article 14, and when the molded article is a short shot, the extrusion resistance is small,on the contrary when the same is over-packing the extrusion resistance becomes large. On the one hand, a normal pressure wave form and + - allowable values have been stored in the storing and discriminating mechanism 19 beforehand, the pressure wave form at the time of extrusion applied to the same mechanism 19 is compared with them to discriminate the quality.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a product quality determination device for an injection bottom type machine.

[Prior art]

2. Description of the Related Art Conventionally, there has been a method of measuring the weight of a molded product, that is, a product, as a product quality determination device for an injection molding machine. This method is good if the molded product is small and lightweight, but in the case of large and heavy products such as bumpers, instrument panels, or washing tanks, a large space is required for identification, making the installation area large. The initial cost is high. Furthermore, this method requires time for weight measurement, reducing productivity.

[Purpose of the invention]

The purpose of the present invention is to completely eliminate these drawbacks.
゛It reduces costs by eliminating the need for a space for discrimination, and improves productivity by eliminating the need for time for discrimination.
An object of the present invention is to provide a product quality determination device for an injection molding machine.

[Key points of Shumei]

The product quality determination device for an injection bottom molding machine according to the present invention detects a movable mold, an extrusion plate for a molded product installed in the movable mold, an extrusion cylinder for moving the extrusion plate, and the extrusion pressure of the extrusion cylinder. It is characterized by comprising a pressure sensor and a memory determination device that stores a normal waveform of extrusion pressure and compares the stored waveform with the pressure waveform of the pressure sensor to determine whether the molded product is good or bad75.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be shown and the next explanation will be given. The fixed mold 11 and the movable mold 12 are in close contact with each other, and a cavity 13 is formed on the opposing surfaces thereof, and molten resin is injected from an injection mechanism (not shown) provided with a blade in the figure of the fixed mold 11. The molded product becomes 14. When the molded product 14 is cooled and solidified, the movable mold 12 moves back to the left to open the mold, as shown in the figure.
Then, by moving the piston 16't of the extrusion cylinder 15 forward, the molded product 14 is pushed against the extrusion plate 17 and extruded with a blade. The extrusion pressure at this time is measured by the pressure sensor 18, and the change in pressure over time, that is, the pressure waveform, is input to the memory discrimination mechanism 19.

Here, the extrusion pressure is a pressure proportional to the extrusion resistance of the molded product 14, and if the molded product is a short shot, the extrusion resistance will be small, whereas if the molded product is overback, the extrusion resistance will be large. - The normal pressure waveform and +/- tolerance values are stored in the memory discrimination mechanism 19 in advance, and the pressure waveforms inputted to the mechanism 19 during extrusion are compared here to determine whether it is good or bad. .

Therefore, when the pressure waveform during extrusion is compared with the normal state and exceeds the allowable range, the memory discrimination mechanism 19 outputs an output, thereby issuing an alarm and stopping the bottom injection machine (not shown). Furthermore, or molded product 14? The conveyor (not shown) for transporting the defective products to the next process is switched and the products are transported to a collection point (not shown) for defective products.

〔Effect of the invention〕

As explained above, the device for determining product quality of an injection molding machine according to the present invention compares the extrusion pressure during extrusion of a molded product with the normal state to determine the quality of the product. The installation area of the machine does not become large. Furthermore, since the molded product is discriminated by extruding it, there is no need for time for discrimination, which has the advantage of improving productivity.

[Brief explanation of drawings]

The figure is a sectional view of one embodiment of the present invention.

Claims (1)

[Claims] A movable mold, an extrusion plate for a molded product provided in the movable mold, an extrusion cylinder that moves the extrusion plate, a pressure sensor that detects the extrusion pressure of the extrusion cylinder, and a normal waveform of the extrusion pressure that is memorized. A product quality determination device for an injection molding machine, comprising a memory determination device that compares a stored waveform of the pressure sensor with a pressure waveform of the pressure sensor to determine the quality of the molded product.