JPH04135822A - Automatic measuring method and device for amount of resin used in injection molder - Google Patents

Abstract

PURPOSE:To automatically measure a used amount of resin simultaneously with the finish of lot operation by a method wherein a charging stroke is calculated by subtracting charge starting position from charge completion position so as to calculate the resin consumption per shot. CONSTITUTION:Under the condition that items necessary for lot production are inputted through a keyed input device 6d in a CPU 6a, operation is started. The resin consumption per shot is calculated by actual charge amount (in mm)X the crossection of a screw X the specific gravity of molten resin. A position detector, which is mounted to an injection mechanism 4 detects the resin charge starting position of a resin kneading screw 4c provided in a heating cylinder 4a and, after that, detects its charge completion position. The CPU 6a calculates a charging stroke by subtracting the charge starting position from the charge completion position so as to calculate the resin consumption per shot in order to measure the resin consumption per shot by accumulate every resin consumption per shot in the lot, during which the same product is manufactured.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides an automatic method for measuring the amount of resin used in an injection molding machine, which can automatically calculate the amount of resin consumed at 10 points during operation. Regarding equipment.

(Conventional technology and its problems) A plastic injection molding factory is equipped with one or more molding machines, uses seven molds and materials, and uses a wide variety of molds to meet the demands of various customers. We process and mold molded products. In such molding factories, for factory management purposes, workers measure the total weight of resin shipped and the amount of resin remaining after 10 rounds, calculate the amount of resin used in the lot, and record it in the process control table. I wrote down the amount of ml used above and submitted it.

This type of work is extremely troublesome in mass production sites.
This caused work delays and errors.

(Object of the Invention) The present invention has been made in view of the drawbacks of the conventional example, and its purpose is to automatically measure the amount of resin used in an injection molding machine, which can automatically measure the amount of resin used at the same time as the lot work is completed. The purpose of this invention is to provide a measuring method and device.

(Means for Solving the Problems) In order to achieve the above object, the method for automatically measuring the amount of resin used in the injection molding machine of the present invention is to After detecting the resin charging start position of the screw (4c), the charging completion position is detected, and the charging completion value! Calculate the charge stroke by subtracting the charge start position from the table, then multiply the charge stroke by the cross-sectional area of the screw and the specific gravity of the resin at the time of melting to calculate the resin consumption per shot. The amount of resin used for all shots in the lot is J! The total resin consumption of the lot is measured by multiplying the total amount of resin consumed. The method of automatically measuring the amount of resin used in an injection molding machine according to claim (2) is: ■ Interlocking with the screw (4c) in the heating cylinder (1o) of the injection molding machine (1) A screw arranged to
4C) position detection sensor (9) and the charge start position and charge completion position detected by the position detection sensor (9) as data, and calculate the charge stroke by subtracting the charge start position from the charge completion position. The amount of resin consumed per shot is calculated by multiplying the cross-sectional area of the screw and the specific gravity of the molten resin, which have already been input as data, and then accumulates the amount of resin used for all shots in one lot that produces the same product. CPU (
6g).

(Operation) First, items necessary for lot production are input into the CPU (6m) through the keyboard (6d), and work begins. The resin consumption amount for one shot is calculated by the actual charge amount (unit: -m) x screw cross-sectional area x specific gravity of molten resin.

The amount of resin consumed is, of course, during automatic operation during the production of good products,
It also includes the amount of resin used for a few test shots at the start of work on that lot, the amount of resin used for restarting trial shots after a break in work, and the amount of resin used for cleaning the inside of the heating cylinder after work on the lot is completed. . The resin consumption amount for one shot is accumulated and calculated as 10 resin consumption amounts.

(Example) Hereinafter, the present invention will be described in detail according to illustrated embodiments.

As shown in Fig. 1, the injection molding machine (1) has a mold clamping mechanism (3), an injection mechanism (4), a hydraulic drive unit (5) and It is composed of a control section (6) and the like.

The mold clamping mechanism (3) is fixed! ! ! (3m), movable plate <3b
), and a mold opening/closing cylinder (3c), which is located at the upper left of the molding machine stand (1a) shown in FIG. Fixed plate (3
A) has a fixed mold (3d) and a movable mold! ! A movable mold (3e) is attached to (3b), respectively. The mold opening/closing cylinder (3c) is held by a cylinder plate (3r) fixed to the molding machine stand (1a), and drives a movable platen (3b) to open and close the molds (3d) (3e). There is.

The fixed GL (3a), the movable platen (3b), and the cylinder brake (3f) are connected by a plurality of tie bars (3g) passing through them. In other words, fixed! ! (3
a) and the cylinder dove-1-(3f) are fixed by tie nuts (3h) screwed to both ends of the tie bar (3g), thereby forming a mold clamping machine fA (3).

The movable platen (3b) is slidably supported by the tie bar (3g) and moves forward and backward.

The injection mechanism (4) includes a heating cylinder (4a), an injection cylinder (4b), a screw (4c), and a screw drive section! ! (4d), and is arranged on an injection table (4e) placed on the upper right side of the molding machine table (1&). The heating cylinder (4a) is fixed to the injection table (4e), houses the screw (4c) inside, and has a heater (4c) on the outer periphery.
4F) is wound, and the material is plasticized, melted, and injected, such as thermoplastic resin, which is supplied from the upper hopper (4g). A nozzle (4h) is provided at the tip of the heating cylinder (4a) to form a passage for the molten resin material by touching the sprue bush of the fixed mold (3d). The injection cylinder (4b) is connected to the injection table (4e)
The screw (4c) is moved forward by hydraulic pressure to provide injection pressure and injection speed. The screw drive device (4d) is an electric motor or a hydraulic motor, and applies rotational force to the screw (4c) to transport and mix the molten material in the direction of the nozzle (4h), and prepares it for injection in the next cycle. Be prepared and perform charging work.

The injection mechanism (4) is equipped with a pressure sensor (8) and a position detection sensor (9), which detect the position of the screw (4c) disposed inside the injection cylinder (4b) and detect pressure oil. For example, a potentiometer is used for the 0 position detection sensor (9) which detects the pressure of
c), and inputs the position of the screw (4c) every moment to the control unit (6).

The hydraulic drive section (5) consists of a hydraulic unit and an oil tank, and is arranged at the bottom of the molding machine stand (1a), and is connected to each cylinder such as the mold opening/closing cylinder (3C) and the injection cylinder (4b). Supply hydraulic pressure for mold clamping, injection, charging,
It is designed to perform operations such as ejecting.

The control unit (6) includes a CPU (6a) as shown in FIG.
), memory (6b), RAM <6c), input/output conversion arithmetic unit (6e), input/output interface (6f), and CRT control unit (68), and a keyboard (6d) as an external device. , printer (6h), external storage device fi (6in), etc.CPU (6a)
is a microcomputer-based central processing unit that uses extremely accurate lock pulses as a tact to perform automatic operation sequences according to instructions input to the memory (6b) described later, and also functions as a timing device for automatic operation. The start time of each cycle is recorded in RAM (6c). Furthermore, RAM (
6c).

The memory (6b) is a read-only memory that stores automatic operation sequences, calculation procedures, etc. of the molding machine (1).
The temperature and pressure censuses input via the input interface (6f) described later are calculated by calculating the digital values of the electric signals from the position detection sensor according to a predetermined formula, and the calculation procedure is to calculate the amount of resin used in 10 points. It is already stored in memory.

RAM (6c) is a random access memory that stores operational information of molding 1 (1), data on the progress of molding work, etc., and the actual measured values of specific items measured by the various sensors, memory The calculated value is temporarily stored.

The keyboard (6d) is used to enter the setting values for the lot work conditions. (1), which allows various items to be input digitally by the operator.

A smart keyboard (6d) is used by the molding operator to input various data.

The amount of resin used in 10 points includes the amount of resin used not only during automatic operation during the production of good products, but also from a few test shots at the start of work for that lot, and during restart test shots after a break in work. This includes the amount of resin used for cleaning the inside of the heating cylinder after the completion of the lot work, and is measured as follows.

W=Sx π Coefficients can be entered on the keyboard (6d) before the start of lot work.
is inputted to the control unit (6) in advance.

When producing good products by automatic operation, the screw (4c) is moved back to a predetermined position and the resin is stored at the tip of the heating cylinder (10). A trial shot is performed with a charge, and the defective resin inside is brought out of the heating cylinder (10) as soon as possible, so that the production of good products can be started as quickly as possible.

Even in this case, the actual charge amount r5. Since the value of rWj is about half of that of good product production, the calculated rWj is also about half of that of good product production. The rWj for each shot is calculated and accumulated for both non-defective production and trial shots.
The total amount of resin used in one shot will be calculated. The total amount of resin used in this one shot is displayed in kg.

Figure 2 is a flowchart of the working process of the present invention, in which the charging position is memorized as soon as resin charging starts, the charging stroke is calculated as soon as charging ends, and then the (charging stroke) (cross-sectional area of the screw) is calculated. is multiplied by (resin specific gravity) to calculate (resin consumption per time), and finally, the above (resin consumption per time) is added to (resin consumption up to the previous time) to calculate (total resin consumption). consumption amount) is calculated.

(Effects of the present invention) The method for automatically measuring the amount of resin used in the injection molding machine of the present invention is to detect the resin charging start position of the resin kneading screw installed in the heating cylinder, and then complete the charging. Detect the position and charge Wf!i from the charging completion position
Calculate the charge stroke by subtracting the starting position, then calculate the 1-shot resin consumption by multiplying the charge stroke by the cross-sectional area of the screw and the resin specific gravity,
Since the amount of resin used for each shot between lots that produce the same product is accumulated and the amount of resin consumed for each 10 shots is measured, the resin consumption amount is automatically accumulated for each shot as soon as work starts. This means that, unlike in the past, workers weigh the resin used before starting work, and then measure the resin leakage after work is finished, calculate the difference, and report the total amount of resin used. Not only was it possible to eliminate the work and make the injection work easier, but also it was possible to eliminate measurement errors.9 Also, as shown in claim (2), an injection molding machine A screw position detection sensor arranged to interlock with the screw in the heating cylinder and the charge start position and charge completion position detected by the position detection sensor are captured as data, and the charging start position is changed from the charge completion position to the charge start position. The charge stroke is calculated by subtracting the amount, and the resin consumption per shot is calculated by multiplying the cross-sectional area of the screw and the resin specific gravity that have already been input as data, and the amount of resin consumed per shot between lots producing the same product is calculated. CP that measures resin consumption in 10 points by accumulating resin usage
By equipping U, it is possible to calculate the amount of resin consumed by 10 points, and these values are outputted by a printer and made into a report.

[Brief explanation of the drawing]

Fig. 1: Schematic longitudinal section and block circuit diagram of the molding machine of the present invention

Claims (2)

[Claims] (1) After detecting the resin charging start position of the resin kneading screw installed in the heating cylinder, the charging completion position is detected, and the charging stroke is calculated by subtracting the charging start position from the charging completion position. Then, the one-shot resin consumption is calculated by multiplying the charge stroke by the cross-sectional area of the screw and the specific gravity of the resin at the time of melting, and the resin consumption of all shots in one lot that produces the same product is accumulated. An automatic method for measuring the amount of resin used in an injection molding machine, characterized by measuring the total amount of resin consumed in the lot. (2) a screw position detection sensor arranged to interlock with the screw in the heating cylinder of the injection molding machine;
The charge start position and charge completion position detected by the position detection sensor are taken in as data, and the charge stroke is calculated by subtracting the charge start position from the charge completion position, and the cross-sectional area of the screw and melting that have already been input as data are calculated. Multiply by the resin specific gravity and get 1
An injection molding machine characterized by being equipped with a CPU that calculates shot resin consumption, accumulates the resin consumption of all shots in one lot for producing the same product, and measures the total resin consumption of the lot. Automatic measuring device for the amount of resin used.