Measuring device provided in extruder and measuring method

Abstract

To provide a measuring device and a measuring method capable of easily acquiring various information about an extruder in use.SOLUTION: An extruder 1 having a measuring device 2 includes: a drive unit 11 that is rotatably driven; a shaft 13 that is connected to the drive unit 11; and a screw 14 that rotates in cooperation with the shaft 13. The measuring device 2 includes: a sensor part 21 including an optical fiber; and a control unit 22 that controls the sensor part. The sensor part 21 is disposed in contact with the shaft 13.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a measuring device that is provided in an extruder and can estimate the state of a fluid flowing inside the extruder. [Background technology]

[0002] An extruder is a device that puts fluids such as food ingredients and thermoplastic resins into the internal pipes, melts them, and pushes them out to the discharge port with a screw. Extruders adjust the heating level and drive speed parameters and select the shape of the screw according to the properties of the material and the product being manufactured. However, it is difficult to accurately grasp the state of the extruder while it is running and the behavior of the resin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Publication No. 48-046678 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 describes a device that uses a strain gauge to measure the internal pressure of a cylinder device. Although this device is useful, there is a problem in that the information that can be obtained from the strain gauge is limited.

[0005] In view of the above problems, an object of the present invention is to provide a measuring device and a measuring method that can easily obtain various information about an extruder in use. [Means for solving the problem]

[0006] The present invention, which solves the above problems, is a measuring device provided in an extruder that has a rotationally driven drive unit, a shaft connected to the drive unit, and a screw that rotates in cooperation with the shaft, the measuring device having a sensor unit including an optical fiber, and an information processing unit that processes information obtained from the sensor unit, the sensor unit being positioned in contact with the shaft. With this configuration, various information can be easily obtained by installing an optical fiber in the extruder while it is in use.

[0007] In a preferred embodiment of the present invention, the sensor unit and the control unit are connected via a rotary joint. With this configuration, even if the shaft rotates with the control unit fixed, it is possible to prevent accumulation of the sensor unit.

[0008] In a preferred embodiment of the present invention, the shaft has a shaft groove on a circumferential surface thereof that is parallel to the axial direction, and the sensor portion is provided along the shaft groove. With this configuration, the mounting position of the sensor unit can be easily determined.

[0009] In a preferred embodiment of the present invention, the shaft groove is engaged with a fitting protrusion provided on the inner peripheral surface of the screw, and the sensor unit is disposed between the shaft groove and the fitting protrusion. With this configuration, the optical fiber can be reliably and practically fixed by utilizing the structures of the shaft and the screw.

[0010] In a preferred embodiment of the present invention, the sensor portion is folded back at the end of the shaft, thereby making it possible to further increase the amount of data that can be obtained from a single optical fiber.

[0011] In a preferred embodiment of the present invention, the shaft includes a plurality of shafts arranged in parallel, and the sensor unit is provided on at least one of the shafts, thereby enabling simple sensing to be performed even with a plurality of shafts.

[0012] The present invention is a measurement method for measuring an extruder having a rotationally driven drive unit, a shaft connected to the drive unit, and a screw that rotates in cooperation with the shaft while covering it, the measurement method including a placement step of placing a sensor unit including an optical fiber in contact with the shaft, and a measurement step of measuring the condition of the shaft by an information processing unit that processes information obtained from the sensor unit. This allows various information about the extruder in use to be easily obtained.

[0013] In a preferred form of the present invention, the measurement step includes a torque calculation step in which the information processing unit calculates a torque applied to the entire shaft, and the torque calculation step is a measurement method including a torsion angle calculation step in which a torsion angle is calculated from an amount of strain in the optical fiber, and a torque distribution calculation step in which a torque is calculated from the torsion angle. By using optical fiber in this way, it is possible to calculate the torque of the extruder shaft, which can easily affect the molded product, leading to improved molding quality.

[0014] In a preferred embodiment of the present invention, the sensor unit measures a temperature of the shaft, and the torque calculation step includes a thermal strain correction step of correcting thermal elongation of the shaft based on the temperature obtained by the sensor unit. This reduces errors caused by heating the resin, and allows correction to be made to calculate the torque even when a resin with a high melting point is used.

[0015] In a preferred embodiment of the present invention, the sensor unit has a pressure gauge that measures the internal pressure of the extruder, and the torque calculation process includes a twist angle calculation process that calculates a twist angle from the amount of strain of the optical fiber, and an axial strain correction process that corrects the amount of strain in the axial direction of the shaft, and the axial strain correction process is a measurement method that corrects the amount of strain based on the pressure obtained from the pressure gauge. By correcting the axial distortion in this manner, the torque can be calculated with correction even when pressure is applied to the shaft during actual use. Effect of the Invention

[0016] The present invention, which solves the above problems, can provide a measuring device and a measuring method that can easily obtain various information about an extruder in use. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic diagram of an extruder and a measuring device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic perspective view of a shaft portion according to the first embodiment of the present invention. [Diagram 3] FIG. 2 is an explanatory diagram of a shaft and an element according to the first embodiment of the present invention. [Figure 4] FIG. 2 is an explanatory diagram of a shaft and an element according to the first embodiment of the present invention. [Diagram 5] FIG. 2 is a schematic diagram of a joint according to the first embodiment of the present invention. [Figure 6] FIG. 4 is a schematic diagram of an extruder and a meter according to a second embodiment of the present invention. [Figure 7] FIG. 11 is an explanatory diagram of a shaft and an element according to a third embodiment of the present invention. [Figure 8] FIG. 11 is a cross-sectional view of a shaft and an element according to a third embodiment of the present invention. [Figure 9] 13 is a flowchart illustrating details of a measurement process according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, a measurement device according to each embodiment of the present invention will be described with reference to the drawings. The description will be made in detail in the order of the configuration of the embodiment, the method of implementation, and other examples. The following embodiments are merely examples of the present invention, and the present invention is not limited to the following embodiments. In addition, the word "substantially" in the application documents is a concept that includes shapes that follow with chamfering or rounding, and elements that make up the shape that have been deformed or changed in length within a range that does not impede the purpose of the configuration.

[0019] First Embodiment The extruder 1 is cylindrical and rotates an internal screw to squeeze out the fluid L. The fluid L can be any of a variety of materials, including plastic, rubber, ceramic, aluminum, and food. In addition, various molding methods, including extrusion molding, injection molding, and blow molding, can be used.

[0020] As shown in the schematic diagram of FIG. 1, the extruder 1 has a drive unit 11 that rotates, a speed reducer unit 12 that adjusts the rotational speed of the drive unit 11, a shaft 13 that rotates in response to the rotation of the drive unit 11, a screw 14 for moving fluid L that rotates in cooperation with the shaft 13, and a cylinder 15 that holds the fluid L at a predetermined position inside the extruder 1.

[0021] The measuring device 2 is a device for measuring the extruder 1 and estimating the state of the fluid L inside. In the embodiment, the measurement device 2 includes an optical fiber measurement instrument 2A that measures the state of the shaft 13 by an optical fiber, and a pressure measurement instrument 2B that penetrates into the cylinder 15 to measure the internal pressure. The optical fiber measuring instrument 2A has a sensor unit 21, which is an optical fiber installed in the extruder 1, and a control unit 22 for controlling the sensor unit 21. The sensor unit 21 is connected to an end of the extruder 1 via a joint unit 23. The measuring device 2 also has an information processing unit C that processes information obtained from the control unit 22 and the pressure measuring instrument 2B.

[0022] The driving unit 11 has a driving body 110 that is driven to rotate, and a driving shaft 111 that is an axis that rotates in cooperation with the driving body 110. The driving body 110 is assumed to be, for example, an engine or an electric motor, and it is preferable that the rotation speed can be adjusted by an information processing unit C.

[0023] The speed reducer 12 is a part for adjusting the rotational power received from the drive unit 11 to an appropriate rotational speed and torque, and specifically, is a reducer. The speed reducer 12 has a speed reducer housing 120 that houses a speed reducer mechanism therein, a speed reducer gear 121 that reduces the speed of the drive shaft 111, and an insertion part 122 through which the shaft 13 is rotatably inserted.

[0024] The reduction gear 121 is a gear that meshes with a part of the drive shaft 111 and has a diameter larger than that of the drive shaft 111, and is connected to the shaft 13 at the center of rotation so as to be rotatable together with the shaft 111. Note that a plurality of reduction gears 121 may be provided and connected together.

[0025] The insertion part 122 is a hole portion that is inserted from one end face to the other end face of the reduction housing 120, the sensor part 21 passes through the entirety, and a bearing is provided at a predetermined position to rotatably support the shaft 13. In addition, the reduction gear 121 is provided in the middle of the insertion part 122, and the insertion part 122 passes through the center of the reduction gear 121.

[0026] The shaft 13 is a member having one end penetrating into the reduction housing 120, and rotates together with the rotation of the reduction gear 121. As shown in Fig. 2, the shaft 13 has an axial shaft body 130, an expanded portion 131 connected to the end of the shaft body 130, a covering portion 132 that covers the shaft body 130 inside the reduction unit 12, and a shaft end portion 133 at the end of the shaft body 130 opposite to the covering portion 132.

[0027] 2, the screw 14 is provided so as to be separable into a plurality of elements 140. Each element 140 has a fitting cylinder 141 that fits the shaft 13 on its inner circumferential surface, and blades 142 that are provided on the outer circumferential surface of the fitting cylinder 141 and that transport the fluid L by rotation. In addition, a cap 144 is provided on the end of the screw 14.

[0028] The cylinder 15 has a cylindrical cylinder body 150 in which the screw 14 is provided, a hopper 151 for feeding the raw material of the fluid L into the cylinder body 150, and a discharge port 152 provided at the end of the cylinder body 150 for discharging the fluid L. In addition, a plurality of heaters 153 for melting the material of the fluid L and reducing the viscosity are arranged on the outer circumferential surface of the cylinder 15.

[0029] The shaft body 130 is a long and thin columnar member that is inserted into the screw 14, the widened portion 131, and the covered portion 132. The shaft body 130 is solid in the area covered by the screw 14, and is hollow in the area covered by the widened portion 131 or the covered portion 132.

[0030] A plurality of shaft grooves 134 of equal depth and at equal intervals extend in the axial direction on the outer peripheral surface of the shaft body 130. A plurality of mating projections 143 of equal height and at equal intervals are provided on the inner peripheral surface of the mating tube 141 in correspondence with the shaft grooves 134. The shaft grooves 134 and the mating projections 143 fit together, causing the screw 14 to rotate in cooperation with the shaft body 130.

[0031] 3(a), the sensor unit 21 is disposed between the shaft groove 134 and the fitting protrusion 143. That is, the concave surface of the shaft groove 134 and the convex surface of the fitting protrusion 143 have a recessed portion D that is at least spaced apart from each other by a distance greater than the diameter of the sensor unit 21. The concave surface refers to the surface that corresponds to the bottom of the groove, and the convex surface refers to the surface that corresponds to the top end of the protrusion.

[0032] The recessed portion D may have any configuration as long as it can accommodate the sensor portion 21. For example, as shown in Fig. 3(b), it may be provided by cutting a part of the fitting protrusion 143 over the entire axial direction, or as shown in Fig. 3(c), it may be provided by further cutting the concave surface of the shaft groove 134 over the entire axial direction. By providing the recessed portion D in this way, the sensor portion 21 can be additionally installed in the extruder 1.

[0033] 4(a), a hole penetrating toward the hollow portion is provided on the side surface of the shaft body 130. The sensor unit 21 disposed in the recessed portion D is inserted through the hollow portion of the shaft body 130 through this hole. 4(a) is an axial cross-sectional view of the shaft 13 and the element 140, and FIG. 4(b) is a schematic perspective view of the shaft 13 with a portion of the element 140 shown in cross-section.

[0034] One or more recessed portions D are provided in the extruder 1, but preferably two or more recessed portions D are provided, and they may be arranged by folding back at the end portion of the shaft body 130. In the embodiment, two recessed portions D are provided opposite each other.

[0035] The widened portion 131 is a portion provided at one end of the shaft body 130, and has a diameter larger than that of the shaft body 130 by at least the thickness of the fitting tube 141. This allows the element 140 to be inserted deep into the shaft body 130 and to be fixed in place by abutment at a predetermined position.

[0036] The covering portion 132 is connected to the shaft body 130 via a key K on its inner circumferential surface, and rotates in cooperation with the shaft body 130. The covering portion 132 also protects the shaft body 130 inside the reduction gear unit 12. That is, the covering portion 132 abuts against a bearing on its outer circumferential surface, and is connected to the reduction gear 121 to transmit power to the shaft body 130.

[0037] Further, the widened portion 131 and the covering portion 132 are cylindrical, and the shaft body 130 is inserted therein. In the inserted portion, the inner diameters of the widened portion 131 and the covering portion 132 are smaller than the outer diameter of the shaft body 130, and the sensor portion 21 is disposed therebetween.

[0038] The shaft end 133 is provided with a diameter smaller than the concave surface of the shaft groove 134 by at least the diameter of the sensor portion 21. This prevents interference between the sensor portion 21 and the screw 14 even if the sensor portion 21 is provided on the shaft end 133.

[0039] The elements 140 are divided and provided so that multiple elements fit into the shaft body 130. This allows any element to be appropriately selected and replaced according to the properties of the fluid L. By disposing the sensor part 21 in the shaft body 130, the sensor part 21 does not move even if the element 140 is changed, so it is possible to accurately see how the measurement results change when the element 140 is changed.

[0040] The inner diameter of the fitting tube 141 is set to be larger than the diameter of at least the portion where the shaft body 130 is exposed, and the fitting tube 141 is fitted with the shaft body 130 by the fitting projection 143 .

[0041] The blades 142 are plate-like members that are continuously provided in a spiral shape on the outer circumferential surface of the fitting tube 141, and guide the fluid L to the discharge port 152 by rotating. By replacing the element 140, the distance between the blades 142, the angle of the spiral, the surface friction, and the like can be changed as desired. Note that the screw 14 may be shaped such that the blades 142 are continuously provided, or that a mixing section 146, which will be described later, is attached.

[0042] Moreover, a cap 144 is provided at the end of the shaft body 130 instead of an element having a fitting tube 141. The cap 144 has a cylindrical portion having approximately the same diameter as the inner circumference of the element 140, and this portion fits the adjacent element 140.

[0043] The cylinder body 150 is a cylindrical member, and is provided so that its inner diameter is approximately the same as or slightly larger than the diameter of the outer periphery of the blades 142, thereby increasing the efficiency of transferring the fluid L.

[0044] The hopper 151 is provided on the upstream side of the cylinder body 150, and is a funnel-shaped member that appropriately charges the fluid L material into the cylinder body 150 by gravity. The upper end of the hopper 151 is widened to make it easier to charge the material, and the lower end penetrates into the cylinder body 150. The blade 142 is located directly below the hopper 151, and the charged material is transported as is. It is preferable that the amount of material charged from the hopper 151 can be controlled by the information processing unit C.

[0045] The discharge port 152 is provided at the downstream end of the cylinder body 150, narrowing toward the end. It can also be connected to various molding devices such as a mold or a blowing device, so that the fluid L discharged from here can be molded. The discharge port 152 is provided so as to be separable from the cylinder body 150.

[0046] The heater 153 is a heating device provided on the outer circumferential surface of the cylinder body 150, and by adjusting the heating intensity of each, the fluid L inside the cylinder body 150 can be heated and the properties such as viscosity can be adjusted. It is preferable that the temperature of the heater 153 can be controlled by the information processing unit C.

[0047] The sensor unit 21 is a single optical fiber, and its longitudinal direction is at least longer than the shaft body 130. The sensor unit 21 is located in a hollow portion in the region covered by the covering portion 132, and is disposed along the axial direction on the outer circumferential surface of the shaft body 130 (recessed portion D).

[0048] In the embodiment, the sensor unit 21 is provided by folding back at the shaft end 133. More specifically, the sensor unit 21 coming out from the end of the recessed portion D on the cap side is bent at the shaft end 133 with a radius of curvature that does not inhibit total reflection of the internal light, and is inserted into a recessed portion D different from the recessed portion D from which it came out, and is also disposed on the shaft 13 here. This increases the number of measurement points on the shaft 13, and more detailed measurement data can be obtained. Note that, in order to obtain more detailed measurement data, it is preferable that the two recessed portions D are provided at symmetrical positions in a cross-sectional view. It is also preferable that the sensor unit 21 is bonded to the shaft end 133 as well.

[0049] In the embodiment, the sensor unit 21 is folded back only once at the shaft end 133, but it may be folded back again at the widened portion 131 or the covering portion 132 to further increase the amount of data to be measured. In this case, the three or more recessed portions D in which the sensor unit 21 is provided are arranged to be point-symmetrical in a cross-sectional view to facilitate analysis.

[0050] In the portion where strain is measured, the optical fiber of the sensor portion 21 is bonded to the shaft body 130 in the recessed portion D with an adhesive over the entire axial direction, so that the optical fiber expands and contracts as the shaft body 130 expands and contracts.

[0051] In the portion where the temperature is measured, the optical fiber of the sensor unit 21 is covered with a protective tube. This protective tube is bonded to the shaft body 130 along the axial direction at the recessed portion D, and holds the inserted optical fiber so that it can expand and contract due to heat.

[0052] The optical fiber of the sensor section 21 is directly bonded in the region from one end to the other end of the shaft body 130, and is inserted into a protective tube in the region from the other end to the one end, where it is folded back, so that one sensor section 21 can measure temperature and strain simultaneously.

[0053] In the embodiment, the optical fiber of the sensor unit 21 is coated to improve durability and heat resistance. This coating can be made of plastic such as polyethylene or polyimide, carbon, gold, or the like.

[0054] Here, the relationship between a specific position on the optical fiber used in the sensor unit 21 and the intensity of the specific scattered light reflected for each specific wavelength is measured in advance, and the amount of shift of that specific wavelength is measured, thereby making it possible to measure the strain and temperature at the specific position. Alternatively, FBG (Fiber Bragg Grating) corresponding to a predetermined wavelength may be written at multiple positions on the sensor unit 21, and these points may be mainly sensed. This allows the state of the shaft 13 at a specific point to be grasped more accurately. If an FBG is written at a position corresponding to the pressure gauge 2B, the state of the extruder 1 can be grasped accurately in association with the internal pressure.

[0055] The control unit 22 includes a light source 221 that sends an optical signal to the sensor unit 21 , a spectroscope 222 that branches the light from the light source 221 , and a measuring instrument 223 that measures the scattered light obtained from the sensor unit 21 .

[0056] The light source 221 is a component that emits light of a predetermined wavelength into the inside of the sensor unit 21 via the spectroscope 222, and operates according to a signal transmitted from the information processing unit C. The light source 221 is assumed to be a light emitting diode or a laser diode, and is preferably capable of emitting any wavelength.

[0057] The spectroscope 222 is a part that splits the light emitted from the light source 221 , and bends one of the split lights toward the measuring instrument 223 and the other light toward the sensor unit 21 .

[0058] The measuring instrument 223 is a component that detects and measures light, and is capable of quantitatively measuring at least the intensity for each wavelength. In the embodiment, the reference light directly split by the spectroscope 222 is compared with the measurement light scattered and returned from the sensor unit 21 to obtain measurement data. This data is appropriately transmitted to the information processing unit C.

[0059] The measuring instrument 223 mainly measures Rayleigh scattering, Brillouin scattering or Raman scattering of the measurement light, and the information processing unit C measures vibration, strain, temperature, etc. at a predetermined position of the sensor unit 21 based on this. For example, the strain and temperature of the shaft body 130 are measured by measuring the expansion and contraction of the sensor unit 21 via the amount of wavelength shift of Rayleigh scattering. The information processing unit C may be capable of calculating the bending and load of the shaft 13 based on this data.

[0060] 6, the joint unit 23 is a member that rotatably connects the optical fiber, and is connected to the middle of the sensor unit 21 via a connector. The joint unit 23 has a rotary joint 231 and a fixing jig 232 that fixes the rotary joint 231 on the control unit 22 side. A part of the connector may penetrate into the deceleration housing 120.

[0061] The rotary joint 231 is provided on the outside of the reduction housing 120, and a first portion 231a provided on the reduction unit 12 side is rotatably connected to a second portion 231b provided on the control unit 22 side. An optical fiber passes through the inside of the rotary joint 231 so that the connection of the optical fiber is not interrupted even when the rotary joint 231 rotates.

[0062] The fixing jig 232 is a jig that fixes the second portion 231b so as not to rotate. This jig is non-rotatably connected to the speed reducer 12 and the fixed base, and prevents the rotation of the shaft 13 from being transmitted to the control unit 22.

[0063] The pressure gauge 2B is provided on the upper side of the cylinder body 150, and is capable of measuring the pressure of the fluid L that passes through the side surface and flows inside. Information obtained from the pressure gauge 2B is transmitted to the information processing unit C.

[0064] The pressure gauges 2B are arranged at equal intervals on the cylinder body 150. Also, as shown in FIG. 1, the pressure gauge 2B includes a tip pressure gauge 2B' arranged close to the tip of the screw 14. The tip pressure gauge 2B' is provided penetrating the discharge port 152. This allows the pressure associated with the portion from which the resin is actually discharged or the screw 14 to be measured.

[0065] The information processing unit C is an electronic device such as a personal computer, tablet, or smartphone, and includes a processing unit C1, a storage unit C2, a communication unit C3, an input unit C4, and an output unit C5 as hardware configuration. The processing unit C1 includes one or more processors such as a CPU, and controls the entire operation processing including the control unit 22 by executing programs and other applications. The storage unit C2 is a HDD, ROM, RAM, or the like, and stores various data used in the programs. The communication unit C3 executes communication control with the drive unit 11, the hopper 151, the heater 153, the control unit 22, and the pressure measuring instrument 2B, and performs inputs required to operate the measuring device 2 including the extruder 1 and the control unit 22, and outputs related to the measurement results.

[0066] The input unit C4 is a touch panel, a mouse, a keyboard, or the like, and inputs operation requests from a user to the processing unit C1. The input unit C4 sends control signals to the processing unit C1 so as to operate at least the driving unit 11, the hopper 151, the heater 153, and the control unit 22. The output unit C5 is a display, or the like, and displays the results of the display processing performed by the processing unit C1.

[0067] A method for carrying out the present invention will be described in detail below with reference to Figs. 1 to 5. The present invention is carried out by a user who uses a measuring device 2. The method for carrying out the present invention is an example, and the method for carrying out the present invention is not limited to this, and the order of the steps may be changed.

[0068] First, the user checks whether the sensor portion 21 is properly positioned in the shaft groove 134 and corrects it if not (positioning process), and then fits multiple elements 140 in any combination into the shaft body 130. At this time, care is taken to match the sensor portion 21 with the recessed portion D. Once the element 140 has been inserted into the shaft body 130 up to near the end thereof, the cap 144 is fitted onto the element 140 at the end, covering the entire shaft body 130.

[0069] Next, the user installs various molding devices at the discharge port 152 and puts the fluid L material into the hopper 151. After that, the user sets parameters for controlling various parts using the input unit C4, operates the extruder 1 and the measuring device 2 using the processing unit C1, and starts molding. (Operation process)

[0070] When the user operates the light source 221, light passes through the sensor unit 21, and the scattered light is reflected, causing the measuring device 223 to measure the state of the shaft (measurement process). The measured information is processed by the processing unit C1 and the memory unit C2 via the communication unit C3, and is displayed on the output unit C5 in a form that is easy for the user to see. It is preferable that the display on the output unit C5 simultaneously displays the information obtained by the pressure measuring device 2B, and the current operating status of the drive unit 11, the hopper 151, and the heater 153.

[0071] As a result, the user can associate a good molded product with the information obtained by the measuring device 2. In other words, a measuring device and a measuring method can be provided that allow the user to easily obtain various information about the extruder 1 during use.

[0072] Second Embodiment Hereinafter, a measuring device 2 according to a second embodiment of the present invention will be described in detail with reference to FIG. 6. The same components as those in the first embodiment will be designated by the same reference numerals and will not be described. In this embodiment, two shafts 13 are provided, a first shaft 13A and a second shaft 13B, and a first element 14A and a second element 14B are fitted to each of the shafts 13. The measuring device 2 has the same specifications as those in the first embodiment, and therefore will not be described.

[0073] 6 is a horizontal cross-sectional view according to this embodiment. The extruder 1 includes a drive unit 11, a speed reduction unit 12, a first shaft 13A, and a second shaft 13B. The speed reduction unit 12 has a speed reduction gear 121 and an insertion part 122, the speed reduction gear 121 is connected to the first shaft 13A, and the insertion part 122 is provided so that the first shaft 13A can be inserted into it. The first shaft 13A and the second shaft 13B are provided in parallel to each other, and are connected by a constant speed gear 123 inside the speed reduction housing 120 so that they can rotate at the same speed.

[0074] A first element 14A is inserted into the first shaft 13A, and a second element 14B is inserted into the second shaft 13B, and each element 140 rotates in cooperation with the shaft 13. The blades 142 of each element 140 rotate in the same direction without overlapping with each other, thereby further improving the efficiency of pumping.

[0075] The first element 14A and the second element 14B have a kneading section 145 having a diameter larger than that of the shaft so as not to interfere with each other, in addition to the mating tube 141 having the blades 142. This allows the material of the fluid L to be pumped while being kneaded.

[0076] Here, the first shaft 13A and the first element 14A are provided with a recessed portion D, in the same manner as the shaft 13 described in the previous embodiment, in which the sensor portion 21 is disposed. On the other hand, the second shaft 13B is not provided with a sensor portion 21. This makes it possible to easily expand the sensor portion 21 without causing interference therewith.

[0077] The user operates the information processor C in the same manner as in the first embodiment to measure the first shaft 13A and search for a good molded product.

[0078] In the second embodiment, an example of two shafts is shown, but three or more shafts may be used. In this case, it is sufficient to provide the sensor unit 21 only on the shaft located in the center.

[0079] Alternatively, the sensor unit 21 may be extended from the discharge port 152 side and connected to the control unit 22 via the joint unit 23 .

[0080] Third embodiment Hereinafter, a measuring device 2 according to the third embodiment of the present invention will be described in detail with reference to Figs. 7 to 9. The same components as those in the first embodiment will be designated by the same reference numerals and will not be described. Fig. 7 shows a shaft 13 to which a screw 14 is attached, and the other components are omitted. Fig. 8 is a radial cross-sectional view of the vicinity of the tip of the shaft 13. The extruder 1 includes a drive unit 11, a speed reducer 12, a shaft 13, and a screw 14. The measurement device 2 includes an optical fiber measurement instrument 2A including a sensor unit 21, and a pressure measurement instrument 2B that penetrates into the cylinder 15 to measure the internal pressure.

[0081] The shaft 13 rotates in cooperation with the rotation of the reduction gear 121, and has a shaft body 130, an enlarged portion 131, a covering portion 132, and a shaft end portion 133. A plurality of shaft grooves 134 extend in the axial direction on the outer circumferential surface of the shaft body 130, and recesses D are provided at predetermined positions of the shaft grooves 134.

[0082] In the embodiment, four recesses D are provided, each of which has a first recess D1, a second recess D2 provided away from the first recess D1, a third recess D3 provided on the side of the second recess D2 away from the first recess D1, and a fourth recess D4 provided between the first recess D1 and the third recess D3. Among these, the first recess D1 and the third recess D3 face each other, and the second recess D2 and the fourth recess D4 face each other, and are provided on the same straight line in a cross-sectional view. A sensor unit 21, which is an optical fiber, is disposed in the recess D to measure strain and temperature.

[0083] The screw 14 is provided so as to be separable into a plurality of elements 140, and each element 140 has a fitting cylinder 141 and blades 142. In addition, a cap 144 is provided on an end of the screw 14. As shown in FIG. 7(a), the performance of pressurization and kneading can be improved by selecting elements 140 with a large diameter of the blades 142 relative to the fitting tube 141 at a position close to the base of the shaft body 130. Also, by using blades 142 with a small diameter relative to the fitting tube 141 at a position close to the end of the shaft body 130, the surface area in contact with the cylinder body 150 relative to the volume is increased, thereby improving the efficiency of melting the material. In the embodiment, elements with gradually increasing fitting tubes 141 are provided between a set of elements with a small diameter of the fitting tube 141 and a set of elements with a large diameter of the fitting tube 141, but elements 140 may be selected so that the diameter of the blades 142 gradually decreases toward the end. Furthermore, as shown in FIG. 7(b), near the tip of the shaft body 130, an element having a mixing section 146 with a larger number of protrusions per radial cross section may be provided instead of the blades 142, thereby further improving the kneading performance.

[0084] The sensor unit 21 is a single optical fiber, and its longitudinal direction is longer than at least the shaft body 130. In this embodiment, the sensor unit 21 is folded back three times, and is provided with a length at least four times the length of the shaft body 130.

[0085] The sensor unit 21 is folded back and disposed along the recessed portion D. More specifically, the sensor unit 21 is disposed from the base to the first recessed portion D1, then folded back at the end to be disposed in the second recessed portion D2, then folded back at the base to be disposed in the third recessed portion D3, and further folded back at the end to be disposed in the fourth recessed portion D4. The sensor unit 21 is provided to measure the strain of the shaft body 130 in the first recessed portion D1 and the third recessed portion D3, and to measure the temperature in the second recessed portion D2 and the fourth recessed portion D4. The sensor unit 21 can obtain information on the temperature and strain in the shaft 13. In this way, the sensor parts 21 are folded back and arranged in sequence in the adjacent recessed parts D to prevent the sensor parts 21 from crossing each other. Also, by measuring the same item at opposing positions in the rotating recessed parts D, it becomes easier to obtain average information on the shaft 13. On the other hand, the measurement target is not limited to the above, and the measurement target may be changed as appropriate. For example, the temperature may be measured at all positions, or the strain may be measured at all positions.

[0086] In the embodiment, a plurality of temperature measuring instruments (thermocouples) are further provided as the measuring device 2, and information obtained from the temperature measuring instruments is transmitted to the information processing unit C. In detail, similar to the pressure measuring instrument 2B, a temperature measuring instrument that penetrates the cylinder body 150 and directly measures the temperature inside the extruder 1, and a temperature measuring instrument that is provided between the heater 153 and measures the temperature of the outer periphery of the cylinder body 150 are provided, so that the temperature of the resin and the heating temperature of the heater 153 can be grasped and the temperature can be corrected. Note that the former temperature measuring instrument is preferably integrated into the pressure measuring instrument 2B. These measuring instruments 2 obtain information on the pressure and temperature inside the extruder and information on the temperature outside the cylinder.

[0087] A method in which the information processing unit C calculates the torque of the extruder 1 using data obtained from the measuring device 2 of the embodiment in the measurement process will be described in detail below with reference to Fig. 9. Note that the operation process in Fig. 9 is not included in the measurement process.

[0088] The information processing unit C includes, as functional means, a recording means for recording the measurement results measured by the measuring device 2, a calculation means for processing the information recorded in the recording means to calculate the torque, and a display means for displaying and processing various screens on which the user performs operation input and displaying the display processing results on the output unit C5. Here, the recording means includes at least a storage unit C2, and the calculation means includes a processing unit C1. With these means, the process related to the calculation of the torque by the software stored in the storage unit C2 is specifically realized by the information processing unit C, which is hardware.

[0089] The memory unit C2 stores various information. Specifically, information relating to temperature and strain obtained by the optical fiber measuring instrument 2A, pressure information obtained by the pressure measuring instrument 2B, temperature information obtained by the temperature measuring instrument, and information obtained by processing these are received via the communication unit C3 and stored in a database. This information is stored together with the time stamp of the measurement date and time. The memory unit C2 also stores information on the diameter and length of the shaft 13 and various coefficients that can be changed via the input unit C4.

[0090] The calculation means processes the information recorded in the recording means to calculate the torque of the shaft. Here, the torque means the torque related to the entire shaft 13 including the screw 14. The display means processes and displays the calculated torque information, and outputs the display processing result to the output unit C5 via the communication unit C3.

[0091] The following describes the processing contents of each functional means element using the information processing unit C. Fig. 8 is a flowchart showing the procedure from storing the information obtained by the measurement device 2 in the memory unit C2 to displaying it on the output unit C5.

[0092] As a pre-information recording step, information on the extruder 1 to be used (e.g., the length and width of the shaft 13) and coefficients related to the material used in the extruder (e.g., the linear expansion coefficient, Young's modulus, and transverse elastic modulus) are recorded in the memory unit C2 (means). After the pre-information recording step, an operation step is performed.

[0093] Next, as an information acquisition step, the processing unit C1 processes the information obtained from the measuring device 2 and records the temperature information and strain information inside the shaft 13, the pressure and temperature information inside the extruder, and the temperature information outside the cylinder in a recording means together with a timestamp.

[0094] Next, in the torque calculation step, the calculation means calculates the torque by using the data measured at approximately the same time. The measured data may be averaged over a plurality of times, or may be averaged over a plurality of measurement points, as necessary. For example, the average value of data obtained over 10 seconds may be used as the value of one measurement point, or the average value of data at adjacent points may be used as the value of one measurement point.

[0095] First, as a thermal strain correction step, the calculation means corrects for the elongation inside the shaft 13 due to heat, calculates the strain value of each measurement point that is not affected by heat, and stores it in the recording means. This correction is performed by applying a predetermined relational expression recorded as prior information to the internal temperature at each point of the shaft 13 recorded in the memory unit C2 to obtain a linear expansion coefficient magnification at each point, and multiplying this by the strain inside the shaft 13 measured at each point. This makes it possible to eliminate the influence of temperature fluctuations inside the extruder. Note that when measuring the temperature, information from a temperature measuring device may also be used.

[0096] Next, as an axial strain correction step, the calculation means corrects the compression inside the shaft 13 due to the axial pressure, calculates the strain value of each measurement point that is not affected by the axial pressure, and stores it in the recording means. In this correction, the pressure obtained from the tip pressure measuring device 2B' is regarded as the stress related to the axial direction of the shaft 13, the amount of compression in a predetermined area is calculated from the cross-sectional area and Young's modulus of the fitting tube 141, and this amount of compression is added to the strain at each point inside the shaft 13 obtained in the thermal strain correction step so as to cancel it out. In particular, when the cross-sectional area of ​​the shaft 13 varies depending on the position as in this embodiment, the accuracy of the obtained data can be improved by performing this correction.

[0097] Next, as an elongation calculation step, the calculation means calculates the elongation of the optical fiber based on the corrected strain at each point inside the shaft 13 and stores it in the recording means. That is, the elongation of the shaft 13 at the end on the side of the driving unit 11 is set to zero, and the strain amounts obtained at each point are added up to calculate the elongation of the optical fiber at each position in the longitudinal direction of the shaft 13.

[0098] Next, as a twist angle calculation step, the calculation means calculates the twist angle at each position in the length direction based on the stretch amount of the optical fiber at each position and stores the calculated twist angle in the recording means. In this embodiment, assuming that the optical fiber is tilted with respect to the axis by the amount of stretch of the optical fiber, the twist angle at each position is calculated as an approximation of the twist angle at that position by dividing the stretch amount of the optical fiber at each position by the distance from the side end on the driving unit 11 side.

[0099] Next, as a specific twist angle calculation step, the calculation means divides the optical fiber into unit lengths, calculates the specific twist angle at each position, and stores the calculated specific twist angle in the recording means. The specific twist angle can be calculated by taking the difference in the twist angle at both ends of the unit length. Note that, although the unit length is 0.65 mm, which is equal to the resolution of the measurement value, in the embodiment, it may be longer.

[0100] Next, the calculation means calculates the torque at each position and stores it in the recording means as a torque distribution calculation step. The torque T at each position is calculated using the transverse elastic modulus of the material, the average diameter of the shaft body 130 at the calculation position, and the torsion angle. Specifically, it is obtained by multiplying pi, the fourth power of the average diameter, the transverse elastic modulus, and the torsion angle, and dividing by 32.

[0101] Next, as an integrated torque calculation step, the calculation means integrates the torque at each position to obtain the torque of the entire shaft 13, and stores the torque in the recording means. In this way, the torque related to the entire shaft can be calculated.

[0102] Finally, in the display step, the display means displays the torque value stored in the recording means and transmits the display processing result to the output unit C5. This allows the user to check the measurement result of the torque related to the entire shaft and change the control of the extruder 1 accordingly. In the measurement step, the above-mentioned torque calculation step is repeated until the measurement is completed, so that successive changes can be measured.

[0103] Based on the obtained torque, the processing unit C1 may issue a feedback control signal to adjust the output of the driving unit 11 and the heater 153 and the opening / closing degree of the hopper 151. This makes it possible to always keep the torque constant, thereby improving the stability of production by the extruder 1 and suppressing variations in quality. In addition, it is possible to calculate the degree of kneading of the molten resin from the torque obtained as described above, and to set and design an appropriate element 140. This makes it possible to rapidly produce high-quality molded products. [Explanation of symbols]

[0104] 1. Extruder 11 Drive unit 110 Drive body 111 Drive shaft 12 Reduction section 120 Reduction housing 121 Reduction Gear 122 Insertion part 123 Constant velocity gear 13 Shaft 130 Shaft body 131 Widening section 132 Covering part 133 Shaft end 134 Shaft groove 13A First Shaft 13B Second shaft 14 Screw 140 Elements 141 Pipe tube 142 birds 143 Engraving process 144 Cap 145 Mixing section 146 Mixing Section 14A First Element 14B Second Element 15 cylinders 150 Cylinder body 151 Hopper 152 Discharge port 153 Heater 2. Measurement equipment 2A Optical Fiber Measuring Instrument 21 Sensor section 22 Control section 221 Light source 222 Spectrometer 223 Measuring Instruments 23 Joint 231 Rotary joint 232 Fixture 2B Pressure Gauge D Recess C Information Processing Section C1 Processing section C2 storage section C3 Communications Department C4 Input section C5 Output section L Fluid

Claims

1. A measuring device provided in an extruder including a rotationally driven drive unit, a shaft connected to the drive unit, and a screw rotating in cooperation with the shaft, A sensor unit including an optical fiber and a control unit that controls the sensor unit, The sensor portion is a measuring device disposed in contact with the shaft.

2. The measuring device according to claim 1 , wherein the sensor unit and the control unit are connected via a rotary joint.

3. The shaft has a shaft groove on a circumferential surface thereof that is parallel to the axial direction, The measuring device according to claim 1 , wherein the sensor portion is provided along the shaft groove.

4. The shaft groove is engaged with a mating protrusion provided on the inner circumferential surface of the screw, The measuring device according to claim 3 , wherein the sensor portion is disposed between the shaft groove and the engagement protrusion.

5. The measuring device according to claim 1 , wherein the sensor portion is disposed by folding back at an end portion of the shaft.

6. The shaft has a plurality of axes arranged in parallel, The measuring device according to claim 1 , wherein the sensor unit is provided on at least one of the shafts.

7. The sensor includes a drive unit that rotates, a shaft that is connected to the drive unit, and a screw that rotates in cooperation with the shaft while covering the shaft. The sensor includes an optical fiber, and a control unit that controls the sensor. The sensor unit measures an extruder disposed in contact with the shaft, The measurement method includes a measurement step of measuring a state of the shaft by an information processing unit that processes information obtained from the sensor unit.

8. The measurement method according to claim 7 , wherein the measuring step includes a torque calculation step in which the information processing unit calculates a torque applied to the entire shaft.

9. 9. The measurement method according to claim 8, wherein the torque calculation step includes a twist angle calculation step of calculating a twist angle from an amount of strain of the optical fiber, and a torque distribution calculation step of calculating a torque from the twist angle.

10. The sensor unit measures a temperature of the shaft, The measurement method according to claim 9 , wherein the torque calculation step includes a thermal strain correction step of correcting thermal elongation of the shaft based on the temperature obtained by the sensor portion.

11. The sensor unit has a pressure measuring device that measures an internal pressure of the extruder, The torque calculation step includes an axial strain correction step of correcting an axial strain amount of the shaft, The measurement method according to claim 9 , wherein the axial strain correcting step corrects the amount of strain based on the pressure obtained from the pressure measuring device.

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