JP3183792B2 - Material measuring device for extruder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the amount of raw materials used in an extruder, which measures the amount of raw materials used by the extruder.

[0002]

2. Description of the Related Art In an extrusion molding machine, a change in weight of raw materials used for a product to be produced is examined, and the result is fed back to production to produce a preset product. Such a technique is disclosed in JP-A-64-24721.

Further, in such an extruder, in the case of producing a single product, for example, an inflation film, the total weight of the raw materials used in the production (hereinafter, referred to as a total use amount) is reduced to one volume. Investigate the weight of raw materials required to produce the product (hereinafter referred to as total weight). Also, the ratio of the product weight (hereinafter, referred to as theoretical weight) expected by setting and the total weight is calculated to determine the raw material efficiency.

Using the total amount of raw materials used and the weight of raw materials required to produce one product, inventory management of raw materials and uniformity of products are checked. Also, the state of the product being manufactured is known from the raw material efficiency of the product, and the product take-up speed is adjusted to improve the raw material efficiency of the product.

[0005]

By the way, in order to check the total weight of a product, the produced product is measured using a weighing device. When checking the total amount of raw materials used, the weights of the measured products are totaled. When examining the raw material efficiency, the theoretical weight is calculated by a computer.

As described above, when examining these values, there is a large part that depends on human labor, and it is difficult to examine the state of the product that changes with time and to respond immediately to this change.

[0007] An object of the present invention is to eliminate the above drawbacks, and to measure the raw material consumption of an extruder capable of automatically calculating the total raw material consumption, total product weight, raw material efficiency, and the like. It is to provide a device.

[0008]

In order to achieve the object, according to the invention of claim 1, a measuring instrument for measuring the weight of the raw material is provided in the extruder during the supply of the raw material to the heating cylinder. An opening / closing mechanism for a material supply path that opens when the measuring device measures the lower limit set value and closes when the measuring device measures the upper limit setting value on the raw material supply side of the measuring device; and In the replenishment suspension period, which is a period from the time when the weight of the raw material measured by the measuring instrument falls below the upper limit set value to the time when the opening / closing mechanism is opened, the amount of reduction in the raw material weight per unit time or the consumption of the constant weight of the raw material. An extrusion amount calculation unit that calculates the extrusion amount from the time required, and calculates the raw material used during the replenishment suspension period from the difference between the upper limit set value and the lower limit set value, and after opening and closing the opening and closing mechanism, the upper limit set value. In the period until The amount of raw materials used in supplementation period, calculated from the product of the extrusion amount calculated in time and the extrusion amount calculating unit of the replenishment period, integrates the raw material usage of both periods that,
A weight integrating unit for calculating the total weight of the used raw materials.

A second aspect of the present invention provides a time detecting unit for detecting a production start time and a production completion time of one product, and, when the production start time is during a replenishment suspension period, a weight of a raw material corresponding to the production start time. Calculate the difference between this and the lower limit set value, calculate the weight during this supply suspension period, and measure the time interval from this production start time to the end time of this supply period when the production start time is during the supply period. The product of this time interval and the amount of extrusion in this replenishment period is the weight in this replenishment period, and when the production completion time is in the replenishment suspension period, the upper limit set value,
The difference between the weight of the raw material corresponding to the production completion time and the weight during the supply suspension period is calculated, and when the production completion time is during the supply period, from the start time of the supply period to the production completion time. And a time-based integrating unit that determines the product of the time interval and the amount of extrusion during the replenishment period as the weight during the replenishment period, and the raw material used between the production start time and the production completion time. Is added to the invention according to claim 1 in which a total weight calculating section for calculating the total weight of the above from the weight calculated by the weight integrating section and the hourly integrating section.

A third aspect of the present invention provides a dimension setting section for setting the dimensions of a product produced by the extruder, a length measuring section for measuring the length of the product produced by the extruder, and a total weight calculating section. Is calculated from the total weight of the raw materials required for the production of one product, the dimensions of the product set in the dimension setting unit, and the product weight calculated from the length of the product measured by the length measuring unit. A raw material efficiency calculation unit for calculating the ratio is added to the invention of claim 2.

[0011]

A measuring device for measuring the weight of the raw material is provided in the raw material supply section of the extruder. There is an opening / closing mechanism for a raw material supply path on the raw material supply side of the measuring device that opens when the lower limit set value is measured and closes when the measuring device measures the upper set value, and controls supply and supply of the raw material.

In the first aspect of the present invention, during the replenishment suspension period, the amount of extrusion is calculated from the amount of reduction in the weight of the raw material per unit time or the time required to consume the raw material of the constant weight in the amount of extrusion unit.

In the weight integrating section, the raw material used during the replenishment stop period is calculated from the difference between the upper limit set value and the lower limit set value, and the amount of the raw material used during the replenishment period is determined by the time of the replenishment period and the extrusion time at that time. Calculate from the product of the amount and the amount of raw materials used in both periods, and calculate the total weight of the used raw materials.

According to the first aspect of the present invention, the total usage fee of the raw material can be automatically calculated. This facilitates stock management of raw materials and the like.

According to the second aspect of the present invention, the time detecting section detects the production start time and the production completion time of one product.

When the production start time is during the replenishment suspension period, the time-based integrating section calculates the difference between the weight of the raw material corresponding to this time and the lower limit set value, and sets the difference as the weight during this period to start production. When the time is during the supply period, the time interval from this time to the end time of this period is measured, and the product of this time interval and the amount of extrusion in this period is defined as weight. Also, when the production completion time is during the supply suspension period, the upper limit set value and
When the difference between the weight of the raw material corresponding to this time and the production completion time is during the replenishment period, the time interval from the start time of this period to this time is measured, and the time interval and the extrusion of this period are measured. The product of the quantity and the weight is defined as the weight.

The total weight calculating section calculates the total weight of the raw materials used between the production start time and the production completion time from the weights calculated by the weight integrating section and the hourly integrating section.

According to the second aspect of the invention, the total weight of the product can be automatically calculated. This eliminates the need for weighing products one by one.

According to the third aspect of the present invention, the dimension setting section sets the dimensions of the product to be produced, and the length measuring section measures the length of the product to be produced.

The raw material efficiency calculating section is calculated from the total weight of the product calculated by the total weight calculating section, the product dimensions set in the dimension setting section, and the product length measured by the length measuring section. Calculate the ratio to the product weight.

According to the third aspect of the present invention, the raw material efficiency can be automatically calculated. This enables quick response when the raw material efficiency is deteriorated.

[0022]

Next, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1 FIG. 1 shows Embodiment 1 of the present invention.
FIG. The raw material consumption measuring device of the extruder is used in a controller 101 of the extruder shown in FIG.

The extruder machine heats and melts the raw materials,
The melted material is extruded. In the raw material supply section of the extruder, a storage hopper 102 and an opening / closing device 10 are provided.
3, the weighing hopper 104 is provided,
By opening and closing 3, the raw material is sent from the storage hopper 102 to the measuring hopper 104. The weighing hopper 104 sends the fed raw material to the heating cylinder 105 and measures the current weight of the raw material. Weighing hopper 1 to measure weight
04 is provided with a pressure sensor like a load cell, for example. The weight 301 measured by this sensor is
Send to 01.

The heating cylinder 105 has a screw (not shown) in a cylindrical cavity. The screw is rotated by the driving device 106 to feed the raw material. During this time, the raw material is heated by a heater (not shown) provided in the heating cylinder 105, and when it reaches the adapter 107, it is in a molten state.

The melted raw material is supplied to the adapter 107 and the die 10
8 to form a blown film.
The blown film is taken up by a pinch roller 109, passes through rollers 110 and 111, and is taken up by the winding device 1.
It is wound around 20 winding shafts 121.

When the winding on the winding shaft 121 is completed, the reversing section 123 of the winding device 120 moves the winding shaft 121.
Is turned to the arrow 201, and the blown film is wound by another winding shaft 122. At the same time, the reversing unit 123
The time detector of (1) sends the inversion signal 302 to the controller 101 during the inversion operation.

Further, as shown in FIG.
A supply control unit 130 is provided between the switch 04 and the opening / closing device 103. In the replenishment control unit 130, an upper limit set value and a lower limit set value of the weighing hopper 104 are set in advance. When the weight 301 measured by the weighing hopper 103 reaches the lower limit set value, the opening / closing device 102 is opened and the storage hopper 1 is opened.
From 01, the raw material is sent to the weighing hopper 103. In addition, weight 3
When 01 reaches the upper limit set value, the opening and closing device 102 is closed to stop the raw material.

The apparatus for measuring the amount of raw material used in the extruder, which is used in the extruder, comprises an extruder calculator 11.
, A weight integrating unit 12, a time detecting unit 14, a time integrating unit 15, and a total weight calculating unit 16.

The extrusion amount calculation unit 11 calculates the extrusion amount by measuring the time for using a fixed amount of raw material. For this purpose, the extrusion amount calculation unit 11 measures the time during which the weight measured by the weighing hopper 104 decreases from the upper limit set value to the lower limit set value, that is, the use time t1. For example, when the resolution of the time measurement is 1/100 [sec] and the measurement of the extrusion amount requires the accuracy of 0.1 [%], the use time is approximately 1/100 [sec] ÷ 0.1. [%] = 100 [sec].

From the upper limit set value, the lower limit set value, and the use time t1, the extrusion amount calculator 11 calculates the extrusion amount Q using the following equation.
Is calculated.

[0032]

(Equation 1) In this equation, the difference between the upper limit value and the lower limit value is set to a value that can measure the use time t1 with sufficient accuracy. When the amount of raw materials used is around 10 [g / sec] on average,
(Upper limit [kg]-lower limit [kg]) is set to approximately 100 [sec] x 10 [g / sec] = 1 [kg]. If the time cannot be accurately measured by the vibration of the extruder, the measurement is repeated several times, and the average value of the calculated extruded amount is used.

As the extrusion amount calculating section 11, there is the following. The extrusion amount calculation unit measures the change in the weight of the raw material at regular time intervals to calculate the extrusion amount. For this purpose, the weight of the raw material measured by the weighing hopper 104 is
Sampling is performed at regular intervals. The sampling time interval is t2. The extrusion amount Q is calculated from the previous value indicating the weight by the previous sampling and the current value indicating the weight by the current sampling using the following equation.

[0034]

(Equation 2) In this equation, for example, when the resolution of the weight measurement is 0.2 [g] and the accuracy of the extrusion amount needs to be 0.1 [%], the difference between the previous value and the current value is calculated as follows. Approximately 0.2 [g] /0.1 [%] = 200 [g]. In addition, the sampling interval time t2 is set to a value that can sufficiently calculate the difference between the previous value and the current value. For example,
When the use amount of the raw material is about 10 [g / sec] on average, the interval time is set to approximately 200 [g] ÷ 10 [g / sec] = 20 [sec]. If the time cannot be accurately measured due to vibration of the extruder or the like, the measurement is repeated several times, and the average value of the calculated extrusion amount is used. Further, a disturbance component is removed using a digital filter or the like.

Upon receiving the weight 301 from the weighing hopper 104 and the pushing amount Q from the pushing amount calculating unit 11, the weight integrating unit 12 integrates the used weight.

When receiving the weight 301 shown in FIG. 4, for example, the weight integrating section 12 sets the supply suspension periods from the upper limit set value MU to the lower limit set value ML in the change of the weight 301 as A1,..., An. , Bn, the supply period from the lower limit set value ML to the next upper limit set value Mu.

In the replenishment suspension period, under the control of the controller 101, the opening / closing device 103 is in the closed state and does not supply the raw material to the weighing hopper 104. At this time, the weight integrating unit 12 calculates the weight of the used raw material,

(Equation 3) It is calculated using the following equation.

During the replenishment period, under the control of the controller 101, the opening / closing device 103 is opened and supplies the raw material to the weighing hopper 104. At this time, since the use and supply of the raw materials are performed at the same time, it is not possible to calculate an accurate weight by the equation (3). At this time, the weight integrating unit 12
Uses the extrusion amount calculated by the extrusion amount calculation unit 11.
The amount of extrusion is a straight line 3131 to 313n in a weight 301.
It becomes the inclination of. The inclination of each straight line, that is, the amount of extrusion is defined as Q1, Q2,..., Qn. Therefore, it is assumed that the weight integrating unit 12 uses the raw material based on the amount of extrusion during the supply period. And the weight accumulator 12

(Equation 4) The weight of the used raw material is calculated using the following equation.

The weight integrating section 12 calculates the weights of the raw materials used in producing the product in this way, and calculates the total weight calculated by the equation (3) and the weight calculated by the equation (4). Calculate the sum of the total weight and the total amount of raw materials used. That is, the weight integrating unit 12

(Equation 5) The total amount of raw materials used is calculated using the equation.

The time detecting unit 14 detects the production start time of one product and the production completion time of this product based on the inversion signal 302 from the inversion unit 123.

The time-based accumulator 15 performs the following calculation based on the time detected by the time detector 14. The production start time or production completion time of one product does not always coincide with the supply stop period or the start time or end time of the supply period.
Therefore, as shown in FIG. 5, when the production start time T1 detected by the time detection unit 14 is within the replenishment suspension period A, as shown in FIG. 5, the weight of the raw material corresponding to the production start time T1 is calculated. The difference S1 between M1 and the lower limit set value ML is calculated. That is,

(Equation 6) Is the weight in the supply stop period A.

Further, as shown in FIG. 6, the time-based integrating section 15 determines that the production start time T1 detected by the time detecting section 14 is
During the supply period B, a time interval t3 from the production start time T1 to the end time of the supply period is measured. Thereafter, the product of the slope (extrusion amount Q) of the straight line 313 indicating the change in weight and the time interval t3 is calculated. That is, the hourly integrating unit 15

(Equation 7) Is the weight during this replenishment period.

As shown in FIG. 7, the time-based integrating section 15
When the production completion time T2 detected by the time detection unit 14 is within A during the supply suspension period, a difference S2 between the upper limit set value MU and the weight M2 of the raw material corresponding to the production completion time T2 is calculated. That is,

(Equation 8) Is the weight in the supply stop period A.

As shown in FIG. 8, when the production completion time T2 is within the supply period B,
A time interval t4 from the start time of the supply period to the production completion time T2 is measured. After this, the hourly accumulator 15
The product of the slope of the straight line 313 (extrusion amount Q) and the time interval t4 is calculated. That is, the hourly integrating unit 15

(Equation 9) Is the weight during this replenishment period.

When the production start time or production completion time of one product coincides with the supply stop period or the start time or end time of the supply period, the total weight calculation unit 16 calculates the total weight calculated by the weight integration unit 12. Is the total weight of one product (total raw material usage).

When the production start time or the production completion time does not coincide with the supply stop period or the start time or the end time of the supply period, the total weight calculation unit 16 calculates the time-based accumulation unit in the period including the inconsistency. The calculation result of No. 15 is defined as weight. In the period that does not include the inconsistency, the weight integrating unit 12
Is calculated as the weight. Then, the total weight calculation unit 16
Defines the sum of these weights as the total raw material usage of one product.

Next, the operation of the first embodiment will be described.

When the production of the product is started and, for example, the weight 301 shown in FIG. 4 is added from the weighing hopper 104 to the extruded amount calculating unit 11, the extruded amount calculating unit 11 calculates the formula (1).
Using the slopes of the straight lines 3131 to 313n of the weight 301,
That is, the extrusion amounts Q1, Q2,..., Qn are calculated. The weight integrating unit 12 calculates the weight of the raw materials used in the supply suspension periods A1, A2,..., An using Expression (3). Further, the weight integrating unit 12 calculates the weight of the raw materials used in the supply periods B1, B2,..., Bn using Equation (4),
Using the equation (5), the total amount of the raw materials used is calculated.

As described above, according to the first embodiment, the total used amount of the raw materials can be automatically calculated using the weight 301 measured by the weighing hopper 104.

When checking the total weight of one product, the time detecting section 14 detects a production start time and a production completion time.

Here, for example, as shown in FIG.
From the production start time T4 of the two products, this production start time T4
Is defined as the production start period D1 and the period from the end time T5 (the start time of the next supply period) to the start time T6 of the last supply period is defined as the intermediate period D2. The period from the start time T6 of the period including the production completion time to the production completion time T7 is defined as a production completion period D3.

In the production start period D1, since the production start time T4 does not coincide with the start time T3 of the supply suspension period, the hourly accumulator 15 calculates the weight of the raw material in the production start period D1 using the equation (6). Is calculated. This calculation result is sent to the total weight calculation unit 16.

In the intermediate period D 2, the calculation result of the weight integrating section 12 is sent to the total weight calculating section 16.

In the production completion period D3, since the production completion time T7 does not coincide with the end time T8 of the replenishment suspension period, the hourly accumulator 15 calculates the weight of the raw material in the production completion period D3 using the equation (9). Is calculated. This calculation result is sent to the total weight calculation unit 16.

The total weight calculating section 16 calculates the weight of the raw material during the production start period D1 and the production completion period D3 calculated by the hourly integrating section 15 and the raw material weight during the intermediate period D2 calculated by the weight integrating section 12. Calculate the sum of the weights.

As described above, according to the first embodiment, the total weight of the product can be automatically calculated.

[Embodiment 2] FIG. 2 shows Embodiment 2 of the present invention.
FIG. The second embodiment is different from the first embodiment described above in that a dimension setting unit 17, a length measuring unit 18, and a raw material efficiency calculating unit 19 are different, and the other is the same. In the following description, the different points will be described, and the overlapping portions will be denoted by the same reference numerals in the drawings, and description thereof will be omitted.

The dimension setting section 17 is for setting the dimensions of a product to be produced. When the product is an inflation film, the dimension to be set includes a folded diameter width, a thickness, and a density of the inflation film. When the film is not a blown film, the cross-sectional area and density of the product are set.

The length measuring section 18 measures the length of a product to be produced. In this measurement, for example, a sensor that outputs p pulses per unit length of the product is used. The pulses from the production start time to the production completion time are integrated to detect the total number q of the pulses. And

(Equation 10) From the formula, calculate the length of the product.

The raw material efficiency calculating section 19 calculates the theoretical weight of the blown film from the value set in the dimension setting section 17 and the actually measured length measured by the length measuring section 18.

[Equation 11] It is calculated from the equation. Here, the coefficient “2” is used
This is because when the film is an inflation film, the film has a tubular shape. Also, when the product is not a blown film,

(Equation 12) It is calculated from the equation.

The raw material efficiency calculating section 19 calculates the raw material efficiency by using the theoretical weight of the product and the total weight (actual weight) calculated by the total weight calculating section 16.

(Equation 13) It is calculated from the equation.

As described above, according to the second embodiment, the raw material efficiency of a product can be automatically calculated. This enables quick response when the raw material efficiency is deteriorated.

In the second embodiment, as shown in FIG.
From the extrusion amount Q calculated by the extrusion amount calculation unit 11 and the product setting value set in the dimension setting unit 17, a speed calculation unit 21 that calculates an appropriate take-up speed, and an output of the speed calculation unit 21, It is possible to add a speed controller 22 for controlling the rotation speed of the pinch roller 109. As a result, the take-up speed can be automatically controlled.

[0064]

As described above, according to the first aspect of the present invention, it is possible to automatically calculate the total amount of raw materials used. This facilitates stock management of raw materials and the like.

According to the second aspect of the present invention, it is possible to automatically calculate the weight of the raw material used in producing one product. This eliminates the need for weighing products one by one.

According to the third aspect of the invention, the raw material efficiency can be automatically calculated. This enables quick response when the raw material efficiency is deteriorated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing Embodiment 2 of the present invention.

FIG. 3 is a block diagram showing an apparatus for controlling a take-up speed.

FIG. 4 is a diagram showing a change in the weight of a product.

FIG. 5 is a diagram showing a change in the weight of a product.

FIG. 6 is a diagram showing a change in the weight of a product.

FIG. 7 is a diagram showing a change in the weight of a product.

FIG. 8 is a diagram showing a change in the weight of a product.

FIG. 9 is a diagram showing a change in the weight of a product.

FIG. 10 is a schematic view showing an extruder.

FIG. 11 is a block diagram showing a device for controlling a switching device.

[Explanation of symbols]

 11 Extrusion amount calculation unit 12 Weight integration unit 13 Usage amount calculation unit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-107426 (JP, A) JP-A-5-329915 (JP, A) JP-A-2-137911 (JP, A) JP-A 64-64 24721 (JP, A) JP-A-5-69471 (JP, A) JP-A-6-162040 (JP, A) JP-A-60-48415 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 47/00-47/96 B29C 31/06

Claims (3)

(57) [Claims] In an extruder, a measuring device for measuring the weight of a raw material is provided on the way of supplying a raw material to a heating cylinder, and when the measuring device measures a lower limit set value on a raw material supply side of the measuring device. An opening and closing mechanism for a material supply path that opens and closes when the measuring device measures the upper limit set value; and after the material opening and closing mechanism closes, the material weight measured by the measuring device falls below the upper limit set value, and then the opening and closing is performed. In a replenishment suspension period, which is a period until the mechanism is opened, an extrusion amount calculation unit that calculates an extrusion amount from a decrease amount of the raw material weight per fixed time or a time required to consume a constant weight of the raw material; The used raw material is calculated from the difference between the upper limit set value and the lower limit set value, and the amount of the raw material used in the replenishment period, which is a period from when the opening and closing mechanism is opened to when the upper limit set value is cut off, is supplied. Period of time and the extrusion An extruder comprising: a weight accumulator for calculating from the product of the extrusion amount calculated by the amount calculator and the amount of raw materials used in both periods, and calculating the total weight of the used raw materials. Raw material consumption measuring device. 2. A time detector for detecting a production start time and a production completion time of one product, and when the production start time is in a replenishment suspension period, setting the weight and lower limit of the raw material corresponding to the production start time. When the production start time is in the replenishment period, the time interval from the production start time to the end time of the replenishment period is measured. The product of the interval and the amount of extrusion during this replenishment period is defined as the weight during this replenishment period, and when the production completion time is during the replenishment suspension period, the difference between the upper limit set value and the weight of the raw material corresponding to this production completion time Is calculated during the replenishment suspension period, and when the production completion time is in the replenishment period, the time interval from the start time of the replenishment period to the production completion time is measured, and the time interval and the replenishment are measured. With the amount of extrusion in the period And the total weight of raw materials used between the production start time and the production completion time is calculated from the weights calculated by the weight integration unit and the hourly integration unit. 2. The apparatus for measuring the amount of raw materials used in an extruder according to claim 1, further comprising: a total weight calculator for performing the calculation. 3. A dimension setting unit for setting dimensions of a product produced by the extruder, a length measuring unit for measuring a length of a product produced by the extruder, and a total weight calculator for calculating The total weight of the raw materials required for the production of one product, the dimensions of the product set in the dimension setting section,
3. The apparatus for measuring a raw material consumption of an extruder according to claim 2, further comprising a raw material efficiency calculating section for calculating a ratio of the product weight calculated from the length of the product measured by the length measuring section.