JP2001347545A - Method and apparatus for controlling measurement and supply of material in injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for controlling measurement and supply of material in an injection molding machine which makes a material density in a cylinder uniform in view of time and position to stabilize the operation and enables injection-molding to give an injection-molded item showing a stable quality, and to provide a method for controlling measurement and supply of material therein. SOLUTION: An apparatus for controlling measurement and supply of a material to measure the material and supply it to an inner side of a cylinder 1 is mounted in an injection molding machine in which the material is sent to the forward side of the cylinder 1 by a screw 2 to be stored in a storing portion 1b and is provided with a measurement and supply portion 7 to measure the material and a supply controller 8 to control the amount of the supplied material. While the screw 2 rotates, the back pressure of the cylinder 1 are sampled several times for a predetermined period and the controller 8 conducts a predetermined computing treatment based on the measured back pressures to determine the next supply amount of the material. In the next injection-molding process the time for the measurement and supply portion 7 to supply the material to the cylinder 1 is the time computed by the supply controller 8 whereby the supply amount of the material is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material metering and feeding control device for an injection molding machine for obtaining a molded product by injecting a material such as a mixture of a resin or a powder of a metal, an alloy or a ceramic and a binder into a mold. Regarding the material metering and supply control method, in particular, in order to stabilize the operation by increasing the accuracy of the injection amount and to obtain a high quality molded product stably, an injection molding machine for accurately controlling the material supply amount is required. The present invention relates to a material metering and supply control device and a material metering and supply control method.

[0002]

2. Description of the Related Art The material to be supplied to an injection molding machine should be essentially constant. However, the amount used every time is slightly changed due to a change in a compression force of a mold, a burr generated on a molded product, and the like. Further, there is a certain degree of variation (approximately ± 5%) in the chip fixed amount supply device, and the amount of material supplied from the hopper cannot be said to be stable. Due to these factors, it is difficult to maintain the amount of staying material or material density in the cylinder in a constant state both temporally and temporally. For this reason, stable measurement is difficult. Due to the non-uniformity of the material density in the cylinder, the proper amount of material that should originally be present in the cylinder is likely to be excessive or deficient, which adversely affects the quality of the molded product and the operation rate of the injection molding machine.

[0003] Therefore, techniques for preventing the excess or deficiency of the material have been conventionally proposed. FIG. 7 is a schematic view showing a conventional in-line screw type injection molding machine. A screw 101 is provided inside the cylinder 100, and the screw 101 is driven to rotate by a motor 103. The screw 101 and the motor 103 are driven forward and backward in the cylinder 100 by a forward and backward motor 104. A material is supplied into the cylinder 100 from a hopper 102, and the material in the cylinder 100 is plasticized by the rotation of the screw 101. Then, the back pressure sensor 105 measures the retreating force of the screw 101 or the back pressure such as the pressure of the molten resin near the nozzle, which is generated as the plasticized molten resin is accumulated in the cylinder 100. The back pressure measurement signal of the back pressure sensor 105 is transmitted to the controller 1
06, the control device 106 controls the screw forward / reverse motor 104 and the screw rotation motor 103 based on the back pressure measurement signal.

In this conventional injection molding machine, after rotating the screw 101 by a fixed amount, a back pressure is measured by a back pressure sensor 105, and the back pressure measurement signal is compared with a set value to obtain a back pressure measurement signal. If the value is below the set value, screw 10
The process of rotating 1 by a fixed amount is repeated. On the other hand, when the back pressure measurement signal exceeds the set value, the position of the screw 101 is moved backward by a small fixed amount by the forward / reverse motor 104. Such a process is performed until the position of the screw 101 reaches the target weighing position. After reaching this position, the rotation of the screw 101 is stopped, and the weighing is completed. In this way, the detected value of the back pressure is fed back to the control of the motors 103 and 104 so that the back pressure is controlled to be a constant value. Injection is performed and the molded product is taken out of the mold to complete one injection molding.

[0005]

However, in the above-described conventional injection molding machine, changing the rotation speed of the screw 101 causes the material density in the cylinder 100 to vary with time and position. Cause
This affects the density of the material stored at the tip of the screw 101. Therefore, there is a problem that it is difficult to form the material stably.

In addition, in the injection molding of a metal or alloy harder than a resin material, if the material is excessively supplied, the material in the supply portion (the hopper 102 side) of the screw 101 or the heating / compressing portion (substantially in the center of the cylinder 100) is formed. The density becomes high, which becomes a hindrance to the rotation of the screw 101, and often causes a problem that the screw 101 does not rotate properly. As a result, the integrity of the material transport due to the rotation of the screw 101 is lost, and the weighing process becomes unstable. That is, the act of storing the material at the tip of the screw 101 is as follows.
When the screw 101 stops rotating, the supply of the material forward from the heating and compressing section is stopped. Therefore, the material accumulated at the tip bites air. This has an adverse effect on the molded product. When the material density in the cylinder 100 increases, the maximum output (full power) of the molding machine increases.
In some cases, the screw 101 may not be able to retreat. In this case, there is a problem that the operating rate of the molding machine is reduced because the temperature of the supply unit and the heating / compression unit must be once increased, and the material in the cylinder 100 must be purged and driven out.

On the other hand, even if the rotational speed of the screw 101 is set to be low to solve the above-mentioned problem, and the material density of the supply unit or the heating unit is not increased, the material stored at the tip of the screw 101 is still required. However, air is bitten, and a good product cannot be formed stably.

The present invention has been made in view of the above problems, and stabilizes the measuring process to make the material density in the cylinder uniform over time and position, thereby stabilizing the molding operation. It is another object of the present invention to provide a material metering / feeding control device and a material metering / feeding control method for an injection molding machine capable of performing injection molding with a stable quality of a molded product.

[0009]

According to the present invention, there is provided a material metering and supply control device for an injection molding machine which rotates a screw to transfer and accumulate material in a storage portion in front of a cylinder. In the control device, a fixed-quantity supply unit that measures the amount of the material to be charged into the cylinder outside the cylinder and supplies it quantitatively, and detects a physical amount that changes according to the material retention amount or the positional density distribution in the cylinder. It is characterized by comprising a detecting means, and a control means for changing the amount of material supplied in the cylinder by the fixed-quantity supplying means in the cylinder based on the detection result of the detecting means. Here, the physical quantity is, for example, an injection oil pressure for injecting a material into a mold, a cylinder back pressure, a screw rotation torque, a screw rotation pressure, a screw rotation time, a screw retreat speed or a screw retreat speed. The force or pressure required to make it work.

[0010] A material metering and supply control method for an injection molding machine according to the present invention is directed to a material metering and supply control method for an injection molding machine for rotating a screw to transfer and accumulate material in a storage section in front of a cylinder. A detection step of detecting a physical quantity that varies in accordance with a material retention amount or a positional density distribution in the cylinder, and measuring and quantifying an amount of the material to be charged into the cylinder based on the detection result outside the cylinder. A supply amount setting step of setting the amount of the next and subsequent materials to be supplied into the cylinder by the constant supply means, and a material to supply the material into the cylinder based on the set supply amount of the material. And a supply step.

[0011] In the present invention, the amount of material retained in the cylinder or the physical quantity that changes in accordance with the positional density distribution of the material is measured, and based on the obtained detection results, the amount necessary for the next and subsequent injection molding steps is determined. An appropriate material supply amount is calculated, and material supply is performed based on the calculated amount. As a result, the material retention amount or the density distribution in the cylinder is kept constant, and a high-quality molded product can be obtained stably.

In the present invention, injection molding means not only general injection molding using a pellet-shaped material as a raw material, but also injection molding.
Tixomoldin made from cut pieces
g) The law is also included.

[0013]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing a configuration of an injection molding machine including a material metering control device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view illustrating a metering section of the material metering control device of the present embodiment.

In the injection molding machine of the present embodiment, a screw 2 is disposed in a cylinder 1 and an accumulation portion 1b for accumulating a semi-molten material is formed at the tip of the cylinder 1. The injection nozzle 1a is formed continuously. The injection nozzle 1a communicates with a cavity of a mold 11 having a predetermined product shape. A driving unit 3 for driving the screw 2 is provided at the rear end of the cylinder 1. The driving unit 3 includes a forward / backward moving mechanism for moving the screw 2 forward and backward by a hydraulic cylinder, and a rotating mechanism for rotating the screw 2 by a hydraulic motor. It can move forward and backward, and can further rotate about the central axis as a rotation axis.

A driving unit 3 has a back pressure sensor 4 for measuring the back pressure of the material acting on the screw 2 from the material in the cylinder 1.
Is provided. A stocker (material storage unit) 9 for storing injection material is connected to the cylinder 1 via a pipe 14, and the material is supplied into the cylinder 1 via the pipe 14. In the middle of the pipe 14, there is provided a material measuring and supplying device 6 for measuring the injection material in the stocker 9 and supplying it to the cylinder 1. The material measuring and supplying device 6 is provided with a measuring and supplying section 7 for measuring an amount of the material to be supplied to the cylinder 1 and a supply controller 8 for adjusting the amount of the material supplied from the measuring and supplying section 7.

The supply controller 8 is connected to the cylinder 2
A measurement system control unit 8a that calculates a material supply time based on the back pressure in the inside, a material supply system control unit 8b that controls a material supply amount from the metering supply unit 7 to the cylinder 1 based on the material supply time, Operation unit 8 for instructing setting of parameters, activation or stop of measurement system control unit 8a and material supply system control unit 8b
c. The material supply system control unit 8b receives a start signal from the main body control controller 10, whereby the metering supply unit 7 and the supply controller 8 are activated. Also, when there is a start instruction of the operation unit 8c, the measurement system control unit 8a
And the material supply system controller 8b operate independently. The value of the material supply time calculated by the measurement system control unit 8a is input to the material supply system control unit 8b.

The main body controller 10 controls the rotation of the screw 2, the forward and backward operations, and the opening and closing of the mold 11.
, A signal g for instructing the screw 2 to move forward and backward, and a signal F for instructing the mold 11 to open and close the mold 2.

As shown in FIG. 2, in the metering / supplying section 7, the supply amount of the material 13 stored in the stocker 9 to the cylinder 1 is controlled. In the metering unit 7, an impeller 12 having a plurality of blades 20 is provided so that the rotation range of the blades 20 and the pipe 14 overlap, and a motor 21 is connected to the impeller 12. ing. An inverter 22 is connected to the motor 21, and a drive signal E is input to the inverter 22 from the material supply system control unit 8 b. While the drive signal E is being input, the motor 2
1 causes the impeller 12 to rotate at a constant speed. That is, the rotation time of the impeller 12 is specified by the drive signal E from the supply controller 8.

As described above, the speed at which the material flowing through the pipe 14 is supplied to the cylinder 1 is controlled to be constant by rotating the impeller 12 at a constant speed.
When the impeller 12 stops, the supply of the material also stops. Therefore, by controlling the rotation time of the impeller 12, the amount of material supplied from the stocker 9 to the cylinder 1 can be adjusted.

Next, the operation of this embodiment will be described.
FIG. 3 is a timing chart of each signal of the material metering control device of the present embodiment, and FIG. 4 is a flowchart illustrating a control method of the material metering device of the present embodiment.

First, an operator inputs a start instruction signal to the main body controller 10, a start signal is input to the operation unit 8c, the operation unit 8c is activated, and the measurement system control unit 8a and the material supply system control unit 8b are operated. to start. The operator inputs the type of the molded article to be molded into the main body controller 10 and the material measuring and supplying apparatus 6 determines whether or not the molded article is registered in the material measuring and supplying apparatus 6 (see FIG. 4). Step S1). That is, the operation unit 8c compares the type of the input molded product with the list of the molded products stored in the memory to check whether or not there is one that matches the type of the input molded product. if,
If the molded article has been registered, the operation unit 8c reads out the parameters corresponding to the molded article and sets them in the material measuring and supplying device 6 (step S3).

If the molded article has not been registered, the operator registers values such as the standard material supply time in the memory of the operation unit 8c (step S2). Then, the operation unit 8c reads out the parameters corresponding to the molded product and sets them in the material measuring and supplying device 6 (step S3).

Next, the operator instructs whether or not to execute the material supply time correction control, and the material metering / supplying device 6 determines based on the instruction (step S4). That is, the operation unit 8c compares the molding condition data stored in the memory with the read data. If no correction is made in step S4, the setting is made so that the metering unit 7 supplies the material to the cylinder 1 at the standard material supply time (step S5). Then, when the signal G is output from the main body controller 10 to the drive unit 3, the screw 2 rotates and the screw rotation signal A is turned on.
When the supply system control unit 8b receives the material supply instruction signal C (fixed length signal) from the main body controller 10, the supply system control unit 8b initially supplies the supply time (standard time) based on the read parameters. At a time (material supply time) T ₁ , the drive signal E is output to the metering unit 7, and the metering unit 7 supplies the material for the time to the cylinder 1. Then, step S4
Return to

If correction is to be performed in step S4, the operation unit 8c instructs the measurement system control unit 8a and the material supply system control unit 8b to operate (step S4).
6).

Next, the operation of the measurement system controller 8a will be described. FIG. 5 is a flowchart illustrating a control method of the measurement system control unit according to the present embodiment. First, as shown in FIG.
When a screw rotation signal A of "1" (on) is input to the supply controller 8 (step S10 in FIG. 5), the supply controller 8 detects that the screw 2 has started to rotate, and the back pressure sensor at this time. 4 to back pressure detection signal B
Is sampled at a predetermined sampling cycle (for example, 0.1 second), and the measurement system controller 8a of the supply controller 8
Is output to The supply controller 8 sequentially takes in the back pressure detection signal B into a register (not shown) during the whole or a part of the time during one material supply time (step S).
11 to S13). That is, after the screw 2 starts rotating, the measurement system controller 8a determines whether or not 0.1 second has elapsed from the previous measurement of the back pressure (step S11), and 0.1 second has elapsed since the previous measurement of the back pressure. If it has elapsed, the back pressure is measured (step S12), and the measurement result of the back pressure is written into a register (step S13).

In this way, the measurement system controller 8a takes in the back pressure measurement result into the register at 0.1 second intervals and stores it. This is executed until the screw 2 stops rotating (step S14). That is, when the screw 2 is rotating, the back pressure, which is a physical quantity, is continuously detected. Thereafter, after the screw 2 is stopped, in parallel with the step of injecting and molding using the supplied material, the supply controller 8 performs the following operations based on the values of the plurality of back pressure detection signals B taken into the register. determine the pressure effective value P ₁ of the back pressure. Supply controller 8 based on the effective pressure value P ₁
Calculates the amount of material to be supplied from the metering / supplying unit 7 to the cylinder 1, and calculates the next material supply time (rotation time of the impeller 12) corresponding to the effective value, that is, the material supply time at the time of the second material supply. setting the T ₂ (step S15). Since the supply of the material is performed at substantially the same timing as the back pressure measurement by the rotation of the screw 2, the material supply time corrected based on the measurement result is used as the material supply time in the next cycle.

There are various methods for obtaining the execution value of the back pressure from the plurality of measured values, for example, the following method. How to take the maximum value. A method of taking the average of all measured back pressure values. A method of performing pattern matching on a plurality of back pressure progresses and setting an effective value corresponding to a predetermined progress pattern.

In the method of setting the effective value of the back pressure by this pattern matching, a part or all of the register value is matched with the pattern of the pressure change pattern stored in another storage means so that the back pressure P Can be determined. At this time, the effective value of the back pressure P can be set differently depending on whether the pressure value has changed rapidly or gradually. Thus, for example, it is possible to determine and control whether the material is in a state of being clogged between the screw 2 and the flange, or whether the material itself is excessively supplied.

Next, the supply controller 8 stores the material supply time obtained in step S15 in a memory (step S16). The material next using feed time T ₂ output time of the drive signal E of the material supply time (second time) is controlled. As described above, the period when the drive signal output from the supply controller 8 to the metering supply unit 7 is in the ON state, that is,
The metering unit 7 supplies the material from the stocker 9 to the cylinder 1 with the material supply time calculated based on the back pressure in the previous material supply time. Thus, the material supply time is set as T _k. Here, k is the number of times the material is supplied. Then, it returns to the start and waits for the next instruction.

Next, the operation of the supply system controller 8b will be described. FIG. 6 is a flowchart illustrating a control method of the supply system control unit according to the present embodiment. First, as shown in FIG. 3, the supply signal C is input from the main body controller 10 to the material supply system controller 8b, and the supply controller 8 determines whether or not there is a material supply instruction (step S2 in FIG. 6).
0) If there is a supply instruction, the supply controller 8
Starts measuring the material supply time (step S21).
Next, the supply controller 8 sends a drive signal E to the metering supply unit 7.
And the supply of the material from the stocker 9 to the cylinder 1 is started (step S22). Then, the supply controller 8 determines whether supply time T ₁ from the start of the supply of the material has passed (step S23), after reaching the feed time T _1,
The supply of the material is stopped by stopping the output of the drive signal E (step S24). Then, the process returns to the start and waits for the next supply start instruction. Thereby, the predetermined supply time T
_The material is supplied from the stocker 9 to the cylinder 1 by one. The supply time of the second and subsequent material supply may be the material supply time calculated from the back pressure shown in the flowchart of FIG. Then, after the measurement system control unit 8a and the material supply system control unit 8b end the operation and return to the start,
It returns to step S4.

After the above-described metering process, the main body controller 10 turns off the signal G, stops the screw 2 and, as shown in FIG.
Falls from on to off, the rotation of the screw 2 or the opening and closing of the mold 11 and the like are controlled by a control system different from the control of the material metering control device according to the flowcharts shown in FIGS. That is, the main body controller 10 causes the screw 2 to advance in the direction toward the nozzle 1a by the driving device 3 in accordance with the signal g to discharge and fill the mold 11 with the material. Next, the material is solidified in the mold 11, the main body controller 10 opens the mold 11 according to the signal F, takes out the product, and the molded product is formed. Thus, the injection molding is completed. As described above, the injection molding operation is performed by repeating the material supply time calculation, the material supply, the material injection, and the removal of the molded product.

Next, when performing the second injection molding, as described above, the material metering / feeding device 6 determines whether or not the material supply time T ₁ or T ₂ needs to be corrected (step S in FIG. 4).
4). If no correction is required, the material is supplied into the cylinder 1 and injection-molded at the material supply time T ₁ (step S5), as in the _first time. If the correction is necessary in step S4, the material supply time due to the back pressure is corrected as described above, and then the material supply time is controlled (step S4).
6). In this case, the screw rotation signal A is turned on,
When a pulse of the material supply instruction signal C is supplied controller 8 receives the drive signal E is output to the metering unit 7 in the material supply time T ₂ obtained by calculating from the pressure actual value P ₁ of the last time (in FIG. 6 Steps S20 to S24). At the same time
The back pressure is measured in the same manner as the first time, the material supply time is calculated based on the back pressure, and the calculation result is stored in the memory (steps S10 to S16 in FIG. 5). That is, when the material used for the second injection molding is being supplied into the cylinder 1, the back pressure is sampled and the effective value P ₂ is measured.
It computes the next material supply time T _3. As described above, the supply controller 8 instructs the metering / supply unit 7 to supply the currently obtained material in the next material supply process after the injection and molding operations based on the material supply time obtained from the previous back pressure. The drive signal E is output.

At the time of the (k-1) th injection molding, k
The metering / supplying unit 7 supplies the material at a material supply time _Tk-1 calculated based on the effective pressure value _Pk-2 at the time of the _second material supply. Thereafter, injection molding is performed, and the k-th material supply time T _k is obtained from the effective pressure value P _k−1 of the back pressure at the k−1-th material supply. This operation is repeated to perform injection molding.

In this embodiment, the back pressure in the cylinder is measured while the screw is rotating, the measurement signal of this back pressure is sampled for a predetermined period, and a plurality of measured values are processed to calculate the next order. Since the material supply amount is determined by calculating the material supply time in the injection molding process, the state of the material in the cylinder can be accurately grasped. That is, if the detection result of the back pressure is immediately reflected in the material supply amount as in the related art, the material supply amount is increased more than necessary based on, for example, the back pressure value detected in the transition state of melting. Alternatively, the amount of reduction may be controlled. In this embodiment, the state of the material in the cylinder can be accurately grasped as the effective value of the back pressure without being affected by such noise. In particular,
In injection molding, in which high melting point material is melted in a cylinder,
Since the output form of the back pressure is different depending on the state of the material in the cylinder, the material is clogged between the flights of the screw, and if a processing failure occurs, according to the present embodiment, this can be easily detected. It is possible to take immediate action to improve work efficiency.

As described above, according to the present embodiment, the operating state of the injection molding machine can be stabilized. Also,
According to this embodiment, since the measurement in the cylinder can be performed accurately, the quality of the molded product can be stabilized.

When the effective value of the back pressure is obtained by pattern matching of the back pressure, the effective value of the pattern matching is obtained based on the change due to the state in the cylinder.
The state in the cylinder can be more accurately estimated. For this reason, the measurement accuracy of the material can be further improved, and the quality of the product can be further improved. Further, since the internal state can be accurately estimated, the working efficiency is further improved.

In addition to the back pressure value in each cycle, the trend of the effective value of the pressure for several or several tens of times is grasped from the effective value of the pressure measured up to that time and the like, and the material supply read in advance is obtained. By performing the control, more stable material supply can be performed.

In the present embodiment, the back pressure is measured as a physical quantity that varies according to the amount of material retained in the cylinder or the positional density distribution of the material. However, the present invention is not limited to this. , The screw rotation time, the screw retreat speed, or the force or pressure required to retreat the screw. These may be measured by appropriately selecting an appropriate physical quantity by a mechanism of the molding machine. Alternatively, the method of supplying the material may be adjusted by determining whether the material is clogged between the screw and the flight, or whether the material itself is in an excessive supply state. At this time, in the calculation processing of the material supply time in the embodiment, a determination based on another physical quantity different from the measured back pressure, for example, a rotational torque may be performed, and the calculation processing may be performed in accordance with the determination.

Although the material metering and feeding device of the present embodiment has a metering and feeding unit, the present invention is not limited to this. In the case where there is a metering / supplying unit that supplies an amount of material into the cylinder, only the feeding controller may be a material metering / controlling device.

[0040] Further, in this embodiment, for calculating the T _k, but using pressure effective value P _k-1 of the previous, in some circumstances in the cylinder, T _k using P _k-2 May be calculated. Although _Tk is calculated using only one effective pressure value, it may be calculated from a plurality of effective pressure values. For example, to calculate T _k , P _k−1
And the average of P _k-2 and P _{k-1 to} P _k-3 may be used. The number of effective pressure values in this case is not particularly limited.

[0041]

As described above in detail, according to the present invention, the amount of material retained in the cylinder or the physical quantity that changes according to the positional density distribution of the material is measured by the detecting means, and based on the measurement result, A signal for controlling the amount of material supplied to the cylinder is output from the supply controller to the metering unit, and by adjusting the amount of material supplied to the cylinder, the state of the cylinder can be maintained constant, and the material in the cylinder can be maintained. The amount can be constant. Therefore, by injecting the material into the mold in this state, a product of stable quality can be formed every time.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of an injection molding machine including a material metering control device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a metering unit of the material metering control device of the present embodiment.

FIG. 3 is a timing chart of each signal of the material metering control device of the present embodiment.

FIG. 4 is a flowchart illustrating a control method of the material measuring and supplying apparatus according to the present embodiment.

FIG. 5 is a flowchart illustrating a control method of a measurement system control unit according to the present embodiment.

FIG. 6 is a flowchart illustrating a control method of a supply system control unit according to the present embodiment.

FIG. 7 is a schematic view showing a conventional in-line screw type injection molding machine.

[Explanation of symbols]

1, 100; Cylinder, 1a; Injection nozzle, 1b; Reservoir, 2, 101; Screw, 3, 103; Drive, 4, 105; Back pressure sensor, 6; Material metering device, 7; 8; supply controller,
8a: measurement system control unit, 8b: material supply system control unit, 8
c; operation unit, 9; stocker, 10; main body controller, 11; mold, 12; impeller, 13; material, 14; pipe, 20; impeller, 104; motor, 106;

Claims (2)

[Claims] 1. A material metering and supply control device for an injection molding machine for rotating a screw to transfer and accumulate a material in a storage portion in front of a cylinder, wherein an amount of the material to be charged into the cylinder is measured outside the cylinder. Quantitative supply means for quantitatively supplying, detection means for detecting a physical quantity that varies in accordance with a material retention amount in a cylinder or a positional density distribution, and the quantitative supply means based on a detection result of the detection means. Control means for changing the amount of material to be supplied to the cylinder in the next or subsequent order. 2. A material metering and supply control method for an injection molding machine for rotating a screw to transfer and accumulate a material in a storage portion in front of a cylinder according to a material accumulation amount or a positional density distribution in the cylinder. A step of detecting a physical quantity that changes in the cylinder, based on the detection result, and supplying the amount of the material to be introduced into the cylinder to the cylinder by quantitative supply means that measures the quantity outside the cylinder and supplies the quantity quantitatively. A material for an injection molding machine, comprising: a supply amount setting step of setting an amount of a material in a subsequent order; and a material supply step of supplying a material into the cylinder based on the set material supply amount. Metering control method.