JP5306412B2 - Method and apparatus for measuring parison length - Google Patents

Description

  The present invention relates to a parison length measurement method and apparatus, and more particularly to a novel method for measuring a parison by using a change amount related to the parison from the linear sensor by linearly moving in parallel with the parison flow direction. Regarding improvement.

Examples of this type of parison length measuring method and apparatus conventionally used include the methods disclosed in Patent Document 1 and Patent Document 2.
That is, in the method of Patent Document 1 shown in FIG. 4, a plurality of parison sensors 60 a to 60 n are arranged in a vertical direction at a predetermined position below the die 10, and the lower end portion of the parison 22 ejected from the die 10 is detected. Then, the detection signal is input to the quadratic regression curve calculator 64 of the parison correction unit 62, and a quadratic regression curve is calculated from the position of the parison sensors 60 a to 60 n and the detection time of the parison 22 by the quadratic regression curve calculation unit 64. Calculate. Thereafter, the acceleration calculator 66 calculates the drawdown acceleration of the parison 22 from the quadratic regression curve, compares it with the optimum drawdown acceleration by the comparison unit 70, and inputs the deviation between them to the correction value calculator 72. The correction value calculator 72 calculates a correction value of a signal for controlling the die gap 20 output from the program signal generator 40 based on a signal from the comparison unit 70.

  Further, in the method of Patent Document 2 shown in FIG. 5, in FIG. 5, 1 is an extruder, 2 is a die of the extruder, 3 is a molten parison that is descending, and 4 is a photograph of the descending state of the molten parison. The camera 5 includes a black backboard for preventing harmful light that becomes noise from entering the camera 4, an image processing apparatus 6, a monitor TV 7, and a printer 8. First, the molten parison is extruded from the extruder, and when the molten parison is in a state of being constantly extruded, the molten parison is cut off at the position of the die outlet. The extrusion is continued, the camera is operated from the time when the tip of the molten parison passes the measurement start point, the molten parison is photographed, and the photographing time is recorded. Shooting continues until the end of the melt parison passes the end of measurement. Note that, as described above, usually, the imaging starts from a position where the molten parison descends from the die exit by a certain distance, but the measurement may be started when the molten parison appears at the die exit. The image obtained by the camera is processed by the image processing device 7 to obtain the length or tip position of the molten parison at each photographing time point. Based on the data of the time of this shooting and the length or tip position of the melt parison, the descent speed and descent acceleration at each time point of the melt parison are calculated. It is possible to know exactly how it will proceed.

JP-A-4-338510 Japanese Patent Laid-Open No. 9-234783 JP-A-6-293062 JP 2008-238727 A

Since the conventional parison length measuring method and apparatus are configured as described above, the following problems exist.
That is, in the method shown in the above-mentioned Patent Document 1, a plurality of parison sensors are vertically arranged and ejected at a predetermined position on the side portion of the parison, below the crosshead that ejects the parison. Since the lower end of the parison is detected and the length of the parison is measured, the situation of the parison swell could not be detected at all.

  Moreover, in the method of the above-mentioned patent document 2, the descent state of the parison discharged from the crosshead is photographed over time with a single camera, and the obtained image data is processed with an image processing apparatus, and each photographing time point is captured. In this configuration, the total length of the parison and the status of the parison swell can be measured. For example, when wall thickness control as disclosed in Patent Documents 3 and 4 is added, the parison The shape of the parison swell changes depending on the part of the parison, but since only one plane of the parison can be photographed with one camera, it is necessary to cope with various parison swell changes that vary depending on the part on the outer periphery of the parison to which wall thickness control has been added. Was impossible.

  The present invention has been made to solve the above-described problems, and in particular, a plurality of linear sensors are arranged on the side portion of the parison so as to be movable up and down, and any of the parison length, the drawdown amount, and the parison swell is provided. Another object of the present invention is to provide a parison length measuring method and apparatus which can measure all or all of them and further measure a temporal temperature change from a parison temperature distribution by adding a temperature sensor.

  The parison length measurement method according to the present invention is a parison length measurement method in which any or all of the parison length, drawdown amount and parison swell of the parison discharged downward from the die gap of the die core of the crosshead are measured by a sensor. A plurality of linear sensors arranged at positions corresponding to the side surfaces of the parison as the sensors, the linear sensors are linearly moved in parallel to the flow direction of the parison via an operating mechanism, It is a method for measuring any or all of the parison length, drawdown amount, and parison swell of the parison by calculating a change amount of the parison obtained by a linear sensor into a distance by a control unit. The sensor is provided with a temperature sensor, and a temperature output signal from the temperature sensor Further, the parison length measuring apparatus according to the present invention includes a parison length, a drawdown amount, and a parison swell discharged downward from a die gap of a die core of a crosshead. In a parison length measuring device that measures any or all of the above using a sensor, a plurality of linear sensors arranged at positions corresponding to the side surfaces of the parison are used as the sensors, and each linear sensor is connected via an operating mechanism. By moving the parison linearly in parallel with the direction of flow of the parison and calculating the amount of change of the parison obtained by each linear sensor into a distance by a control unit, so that the parison length, drawdown amount, and parison of the parison are calculated. It is configured to measure any or all of the swells, and the linear sensor The provided temperature sensors, is configured to measure the temperature distribution in the parison length by temperature output signal from the temperature sensor.

Since the parison length measuring method and apparatus according to the present invention are configured as described above, the following effects can be obtained.
That is, in the parison length measurement method and apparatus in which any or all of the parison length, the drawdown amount, and the parison swell of the parison discharged downward from the die gap of the die core of the crosshead are measured by the sensor, Using a plurality of linear sensors arranged at positions corresponding to the side surfaces of the parison, each linear sensor is linearly moved in parallel to the flow direction of the parison via an operating mechanism, and is obtained by each linear sensor. Further, by calculating the parison change amount into a distance by the control unit, by measuring any or all of the parison length, drawdown amount and parison swell of the parison, an output signal from the linear sensor is used, Parison length, parison descent acceleration, drawdown amount, parison Measurements Le, of course, similarly by utilizing the temperature sensor can also be performed observation of association of the temperature distribution and temporal change.
Conventional parison swell cuts out the discharged parison at the time of inspection, and humans measure it, but in this case, the cut parison shrinks when exposed to normal temperature for a long time, and the accuracy of swell measurement Although there is a slight error in the current situation, by using the method and apparatus according to the present invention, various states of the parison during discharge can be observed in real time, so data collection necessary for molding can be performed. It becomes easy.
The linear sensor is provided with a temperature sensor, and the temperature distribution at the parison length can be measured by a temperature output signal from the temperature sensor. Hollow molding can be performed.

It is a whole lineblock diagram showing the parison length measuring method and device by the present invention. It is a characteristic view which shows the measurement state of the parison length measuring method in this invention. It is a parison length change curve in the parison length measuring method in the present invention. It is a schematic block diagram which shows the conventional parison length measuring method. It is a schematic block diagram which shows the other conventional parison length measuring method.

  It is an object of the present invention to provide a parison length measuring method and apparatus for measuring a parison by using a change amount related to the parison from the linear sensor by linearly moving in parallel to the parison flow direction. Objective.

Hereinafter, preferred embodiments of a parison length measuring method and apparatus according to the present invention will be described with reference to the drawings.
In addition, the same code | symbol is attached | subjected and demonstrated to the same or equivalent part as a prior art example (FIG. 4).
In FIG. 1, reference numeral 15 denotes a cross head, and the die gap 20 formed in the die core 16 below the cross head 15 hangs downward in a state where a cylindrical parison 22 is discharged. It is configured as follows.
The parison 22 is configured to flow in a vertical direction along a parison flow direction A indicated by an arrow.

  At a position corresponding to the side surface 23 of the parison 22, an operation mechanism 65 arranged in a vertical direction so as to perform an up and down movement operation is provided. The linear sensor 60a to be formed is mounted so as to be linearly movable along the vertical direction as shown in the vertical direction B according to the position indicated by the solid line and the dotted line as shown.

  In the configuration shown in FIG. 1, the number of the operation mechanisms 65 indicates a case where a pair of the movement mechanisms 65 are disposed at positions corresponding to the side surfaces 23 of the parison 22 so as to face each other by 180 degrees. In view of the above, it is possible to use not only the above-described pair configuration but also every 90 degrees, 45 degrees, 30 degrees, etc. corresponding to the periphery of the parison 22.

Although the detailed structure of the operating mechanism 65 is not shown, for example, a motor may be connected to a well-known rack and pinion (not shown), and the linear sensor 60a is attached to the rack. The operation along the vertical direction B described above can be performed.
The position of the linear sensor 60a in the vertical direction B can be freely controlled by performing the known servo control using the aforementioned motor as a known servo motor or step motor.

  The linear sensor 60a is configured to measure the distance from the side surface 23 of the parison 22 to the linear sensor 60a via a known medium such as infrared, laser, ultrasonic wave, or light. By detecting the physical change amount 23 and converting the change amount into a distance, the distance displacement of the parison 22 from the linear sensor 60a can be measured.

  The change amount 70, which is an output signal of each linear sensor 60a, is input to the calculation unit 71 constituting the control unit 64 and is calculated. By this calculation, the change amount 70 is converted into the distance 73. 73 is input to the processing unit 72 so that the parison length of the parison 22, the drawdown amount of the parison 22, and the parison swell of the parison 22 can be measured.

Next, the operation of the parison length measuring method according to the present invention in the above-described configuration will be described.
First, as shown in FIG. 1, a plurality of linear sensors 60 a are arranged around the side surface 23 of the parison 22 via an operation mechanism 65.
In the above-described state, by moving each linear sensor 60a along the vertical direction B with the die gap 20 as a base point, as shown in FIG. And the state of the parison swell b immediately after discharge from the die gap 20 can be detected.
Further, when the parison 22 is discharged and time elapses, the change of the parison swell b can be grasped as shown in FIG.

  Further, by repeating the vertical movement of each linear sensor 60a, the temporal change of the parison 22 can be continuously measured, and the data obtained from the linear sensors 60a thus obtained can be used. By processing the data of the parison bottom 22a at a certain change amount 70 by the controller 64 by a known method, the acceleration and drawdown amount of the parison 22 can be obtained.

Further, by providing a temperature sensor 80 in each linear sensor 60a and taking in the temperature output signal 70a of each part of the parison 22, the relationship between the acceleration of the parison 22 and the drawdown amount can be easily observed.
Therefore, as described above, by backing up and accumulating various data relating to the amount of change 70 output from each linear sensor 60a, it is possible to easily determine the molding conditions for the subsequent parison 22 and to produce a new die core. It can be important data.

  That is, in the parison length measuring method and apparatus according to the present invention, any or all of the parison length, the drawdown amount, and the parison swell of the parison 22 discharged downward from the die gap 20 of the die core 16 of the crosshead 15 are measured by a sensor. In the parison length measurement method and apparatus configured to measure, a plurality of linear sensors 60a disposed at positions corresponding to the side surfaces 23 of the parison 22 are used as the sensors, and each linear sensor 60a is connected via an operation mechanism 56. By moving the parison 22 linearly in parallel with the flow direction A of the parison 22 and calculating the amount of change of the parison 22 obtained by the linear sensors 60a into the distance by the control unit 64, the parison length of the parison 22 Any or all of the drawdown amount and parison swell Characterized by a constant, the temperature sensor 80 is provided in the linear sensor 60a, it can be characterized by measuring the temperature distribution in the parison length by a temperature output signal 70a from the temperature sensor 80.

  The parison length measuring method and apparatus according to the present invention can measure any or all of the parison length, the drawdown amount, and the parison swell by taking data with a plurality of linear sensors moving along the parison flow. .

A Parison flow direction B Vertical direction 15 Cross head 16 Die core 20 Die gap 22 Parison 22a Lower part of parison 23 Side 60a Linear sensor 64 Control unit 65 Operating mechanism 70 Change 70a Temperature output signal 71 Calculation unit 72 Processing unit 73 Distance 80 Temperature Sensor

Claims (4)

A parison in which the parison length, drawdown amount, and parison swell of the parison (22) discharged downward from the die gap (20) of the die core (16) of the crosshead (15) are measured by a sensor. In the length measurement method,
As the sensor, a plurality of linear sensors (60a) disposed at positions corresponding to the side surface (23) of the parison (22) are used, and each linear sensor (60a) is connected to the parison (65) via an operating mechanism (65). 22) is linearly moved in parallel with the flow direction (A), and the amount of change (70) of the parison (22) obtained by each linear sensor (60a) is calculated as a distance by the control unit (64). Thus, any or all of the parison length, the drawdown amount, and the parison swell of the parison (22) are measured.   The temperature sensor (80) is provided in the linear sensor (60a), and the temperature distribution at the parison length is measured by a temperature output signal (70a) from the temperature sensor (80). The parison length measuring method as described. A parison in which the parison length, drawdown amount, and parison swell of the parison (22) discharged downward from the die gap (20) of the die core (16) of the crosshead (15) are measured by a sensor. In the length measuring device,
As the sensor, a plurality of linear sensors (60a) disposed at positions corresponding to the side surface (23) of the parison (22) are used, and each linear sensor (60a) is connected to the parison (65) via an operating mechanism (65). 22) is linearly moved in parallel with the flow direction (A), and the amount of change (70) of the parison (22) obtained by each linear sensor (60a) is calculated as a distance by the control unit (64). Thus, any one or all of the parison length, drawdown amount, and parison swell of the parison (22) are measured.   The temperature sensor (80) is provided in the linear sensor (60a), and the temperature distribution at the parison length is measured by a temperature output signal (70a) from the temperature sensor (80). The parison length measuring device described.

Images