Pellet manufacturing apparatus and pellet manufacturing method

Abstract

To suppress variations in the diameter of strands at a preparatory stage before manufacturing pellets.SOLUTION: A pellet manufacturing apparatus 10 comprises: an extrusion part 20; a grip part 42; a moving part 50; and a strand cutter 56. The extrusion part 20 extrudes molten resin R as a string-like strand S. The grip part 42 grips the strand S extruded from the extrusion part 20. The moving part 50 moves the grip part 42. The strand cutter 56 cuts the strand S conveyed by the move of the grip part 42.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present disclosure relates to a pellet manufacturing apparatus and a pellet manufacturing method. [Background technology]

[0002] Patent Document 1 shows a pellet manufacturing apparatus. The strand discharged from the die is solidified in a cooling tank, and then sent to a strand cutter to be cut. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-134497 A Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 does not disclose a configuration for making the tip of the strand reach the strand cutter in the preparation stage before starting pellet production. If a user manually transports the strand to the strand cutter and then starts production, the external force acting on the strand may vary depending on the skill of the user, which may cause variation in the strand diameter. For this reason, there is room for improvement in the handling of the strand in the preparation stage before starting pellet production.

[0005] The present disclosure has been made to solve such problems, and aims to suppress the occurrence of variations in strand diameter in the preparation stage before the start of pellet production. [Means for solving the problem]

[0006] In one embodiment of the pellet manufacturing apparatus, the gripping unit grips the strand extruded from the extrusion unit. The moving unit moves the gripping unit.

[0007] A pellet manufacturing method according to one embodiment includes a step of gripping the strand extruded from the extrusion section with a gripping section, and a step of moving the strand to a cutting section by moving the gripping section with a moving section. Effect of the Invention

[0008] According to the pellet manufacturing device of the present disclosure, it is possible to suppress the occurrence of variations in the diameter of the strands in the preparation stage before the start of pellet production.

[0009] According to the pellet manufacturing method of the present disclosure, it is possible to suppress the occurrence of variations in the diameter of the strands in the preparation stage before the start of pellet manufacturing. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a front view showing a pellet manufacturing apparatus according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a block diagram of the pellet manufacturing apparatus of FIG. [Diagram 3] FIG. 2 is a front view showing a state in which pellets are produced using the pellet production apparatus of FIG. [Figure 4] 2 is a plan view showing a state in which molten resin is extruded from a die of the pellet production apparatus in FIG. 1 to form strands. FIG. [Diagram 5] 2 is an enlarged front view of a conveying section of the pellet manufacturing apparatus of FIG. 1. [Figure 6] 2 is an enlarged front view of an upstream support portion of the pellet manufacturing apparatus of FIG. 1. [Figure 7] 2 is an enlarged front view of a downstream support portion of the pellet production apparatus of FIG. 1. [Figure 8] 2 is a front view showing a state in which an operation check is being performed before starting pellet production in the pellet production apparatus of FIG. 1. [Figure 9] 2 is a front view showing a state in which the pellet production apparatus of FIG. 1 has started an operation of transporting a strand before starting pellet production. FIG. [Figure 10]2 is a front view showing a state in the middle of an operation of transporting a strand before starting pellet production in the pellet production apparatus of FIG. 1.

[0023] FIG. [Figure 11] 2 is a front view showing a state in which the operation of transporting the strands in the pellet manufacturing apparatus of FIG. 1 has been completed. FIG. [Figure 12] FIG. 2 is a front view showing a pellet manufacturing apparatus according to a first modified example. [Figure 13] FIG. 11 is a cross-sectional view showing a conveying section of a pellet manufacturing device according to a second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the present embodiment will be described with reference to the drawings. Note that the same reference numerals are used to designate members having the same functions, and repeated description will be omitted.

[0012] [Configuration of pellet manufacturing device] FIG 1 shows a pellet manufacturing apparatus 10 according to the present embodiment. FIG 2 shows a block diagram of each component of the pellet manufacturing apparatus 10. As shown in FIG 1, the pellet manufacturing apparatus 10 is installed on a floor 2 of a factory. In the following, each direction will be defined and the arrangement of each component will be described on the assumption that the floor 2 is a horizontal plane. A pedestal 14, which will be described later, is provided on the floor 2. The pedestal 14 has an upper surface 14A.

[0013] As shown in Fig. 2, the pellet production apparatus 10 includes an extrusion unit 20, a control unit 30, a gripping unit 42, a moving unit 50, and a strand cutter 56. The pellet production apparatus 10 further includes an operation panel 12, an upstream cutter 16, a cooling unit 60 (Fig. 1), a water tank position detection unit 82, a water tank position changing unit 86, a support unit 110 (Fig. 1), and a measurement unit 130. The configuration other than those shown in Fig. 2 will be described later.

[0014] The start, stop and setting of the operation of the pellet manufacturing apparatus 10 are performed by a user operating the operation panel 12. The operation panel 12 is, for example, configured as a touch panel, and allows the input and display of information.

[0015] 8, in the pellet manufacturing apparatus 10, pre-extrusion of the strand S is performed as one of the preparatory steps before the start of manufacturing the pellets P (FIG. 3). The pre-extrusion of the strand S will be described later.

[0016] 9, in the pellet production apparatus 10, as one of the preparation stages before starting the production of pellets P, the strand S extruded from the extrusion unit 20 is cooled in the cooling unit 60 and is transported to the strand cutter 56 by the gripping unit 42 and the moving unit 50. Note that the transport of the strand S by the gripping unit 42 and the moving unit 50 is performed after the strand S has been provisionally extruded.

[0017] 3, when the production of pellets P is started in the pellet production apparatus 10, the strand S extruded from the extrusion section 20 is transported while being cooled in the cooling section 60, and is cut by the strand cutter 56 to form pellets P. In this way, the production of pellets P using the pellet production apparatus 10 includes two stages: a pre-production preparation stage and a production stage.

[0018] In the following description of the pellet manufacturing apparatus 10, the horizontal direction from the extrusion unit 20 toward the strand cutter 56 is referred to as the Y direction. The direction perpendicular to the Y direction and vertical is referred to as the Z direction. The direction perpendicular to both the Y direction and the Z direction is referred to as the X direction.

[0019] The Y direction is an example of a conveying direction of the strand S. The X direction is an example of a crossing direction that crosses the Y direction. The tip side of the arrow Y corresponds to the downstream side of the conveying direction of the strand S. The base end side of the arrow Y corresponds to the upstream side of the conveying direction of the strand S. The tip side of the arrow Z corresponds to the upper side in the vertical direction. The base end side of the arrow Z corresponds to the lower side in the vertical direction. The tip side of the arrow X corresponds to the front side of the pellet manufacturing apparatus 10. The base end side of the arrow X corresponds to the rear side of the pellet manufacturing apparatus 10. The specific configuration of the pellet manufacturing apparatus 10 will be described below.

[0020] <Extrusion section> As shown in FIG. 1, the extrusion section 20 includes a drive section 22, a cylinder 24, an input section 27, a die 28, and an upstream cutter 16. The drive section 22 includes, for example, a motor and a reducer. The cylinder 24 is a hollow member extending with the Y direction as its axial direction. A screw 25 is provided in the hollow section of the cylinder 24, and a heater 26 is provided on the outer surface or inside. The screw 25 is disposed with the Y direction as its axial direction, and is rotated by the drive section 22. The number of screws 25 may be either one or more.

[0021] The input section 27 is connected to the inside of the cylinder 24. In the input section 27, a resin material that is a raw material for the pellets P (FIG. 3) is input. For example, a thermoplastic resin can be used as the resin material. For example, a thermoplastic resin can be used as the thermoplastic resin, such as polyethylene, polypropylene, polyamide, polyethylene terephthalate, polyimide, polyether ether ketone, polystyrene, polyvinyl chloride, polycarbonate, polymethyl methacrylate, acrylonitrile-butadiene-styrene resin, polybutylene terephthalate resin, biodegradable resin (PLA, PBS, PBAT), etc. These resins may be used alone or as a mixture of multiple types.

[0022] The operation of the extrusion section 20 is controlled by a control section 30 (FIG. 2), which will be described later. The raw material fed into the inside of the cylinder 24 is kneaded by the rotation of the screw 25, and is melted by receiving heat from the heater 26. The melted resin material (hereinafter, referred to as molten resin R) is transferred to a die 28.

[0023] As shown in FIG. 4, the die 28 is formed with a plurality of through holes 28A spaced apart in the X direction. The molten resin R is extruded from the through holes 28A to become a string-like strand S. In other words, the extrusion unit 20 extrudes the molten resin R as a string-like strand S. Note that FIG. 4 shows three strands S (S1, S2, S3) extruded from the extrusion unit 20 as an example. As viewed from above in the Z direction, the strand S1 has a diameter W1 in the X direction, the strand S2 has a diameter W2 in the X direction, and the strand S3 has a diameter W3 in the X direction. The respective sizes of the diameters W1, W2, and W3 are measured by a measuring unit 130 (FIG. 2) described later.

[0024] <Control Unit> 2, the control unit 30 is a personal computer, and includes a CPU (Central Processing Unit) 32 and a memory 34. The CPU 32 and the memory 34 are connected to a common bus 33. The CPU 32 executes a program stored in the memory 34, thereby realizing various processes of the pellet manufacturing apparatus 10.

[0025] The control unit 30 is capable of transmitting and receiving information to and from the operation panel 12, the upstream cutter 16, the extrusion unit 20, the gripping unit 42, the moving unit 50, the strand cutter 56, the upstream shower 64, the downstream shower 66, the water tank position detection unit 82, and the water tank position changing unit 86. Furthermore, the control unit 30 is capable of transmitting and receiving information to and from the roller lifting unit 92, the temperature measurement unit 102, the temperature changing unit 104, the upstream drive unit 114, the downstream drive unit 124, and the measurement unit 130.

[0026] <Grip section> As shown in FIG. 5, the gripping portion 42 has a support frame 44, bearings 45A and 45B, a roller pair 46, and a bearing drive portion 49. The support frame 44 has a vertical wall portion 44A that stands upright in the Z direction. Two vertical wall portions 44A are provided with an interval in the X direction. Note that FIG. 5 shows one vertical wall portion 44A. The bearing 45A is fixed to the vertical wall portion 44A. The bearing 45B is provided on the vertical wall portion 44A so as to be movable upward and downward in the Z direction. The bearing 45B is located above the bearing 45A in the Z direction.

[0027] The roller pair 46 includes a lower roller 47 and an upper roller 48. The lower roller 47 is disposed with the X direction as its axial direction. Both ends of the lower roller 47 in the X direction are rotatably supported by the bearings 45A. The lower roller 47 has an outer peripheral surface 47A. The upper roller 48 is disposed with the X direction as its axial direction. Both ends of the upper roller 48 in the X direction are rotatably supported by the bearings 45B. The upper roller 48 has an outer peripheral surface 48A. The lower roller 47 and the upper roller 48 are both driven rollers that are not driven by a motor. The distance between the uppermost part of the outer peripheral surface 47A in the Z direction and the lowermost part of the outer peripheral surface 48A in the Z direction is defined as the nip distance d. The part of the roller pair 46 where the nip distance d is obtained is defined as the nip portion N.

[0028] As an example, the bearing drive unit 49 includes a cam 49A and a motor 49B that rotates the cam 49A. The cam 49A is rotatably provided on the vertical wall portion 44A. A part of the cam 49A supports the bearing 45B. The operation of the motor 49B is controlled by the control unit 30 (FIG. 2). By changing the rotation angle of the cam 49A, the bearing 45B moves upward or downward along the Z direction. In other words, by the bearing drive unit 49 driving the bearing 45B, the upper roller 48 can move upward or downward in the Z direction. And, by moving the upper roller 48 upward or downward in the Z direction, the nip interval d can be changed.

[0029] As an example, the nip interval d includes a nip interval d1 when the strand S is sandwiched between the lower roller 47 and the upper roller 48, and a nip interval d2 (>d1) when the upper roller 48 is separated from the strand S. The nip intervals d1 and d2 are preset in the control unit 30 (FIG. 2). The nip interval d1 is preset so that the pressure force in the Z direction acting on the strand S is within an allowable range when the roller pair 46 sandwiches the strand S. In other words, the nip interval d1 is preset so that the deformation of the strand S is within an allowable range. Furthermore, the nip interval d1 is preset so that a force (conveying force) that pulls the strand S downstream in the Y direction acts on the strand S when the moving unit 50 moves.

[0030] The fact that the strand S is sandwiched between the roller pair 46 is included in the fact that "the strand S is gripped by the gripping portion 42." In other words, the gripping portion 42 grips the strand S extruded from the extrusion portion 20 (FIG. 1).

[0031] <Mobile section> As shown in FIG. 5, the moving unit 50 is provided on a support frame 77 (FIG. 1) described later. The moving unit 50 is configured as an electric linear actuator, for example. The moving unit 50 includes a guide rail 52 and a carriage 54. The guide rail 52 extends in the Y direction. The carriage 54 is guided by the guide rail 52, thereby enabling it to move back and forth along the Y direction. A vertical wall portion 44A is fixed to the carriage 54. As a result, the moving unit 50 supports the gripping portion 42 so as to be movable in the Y direction. The operation of the moving unit 50 is controlled by the control unit 30 (FIG. 2).

[0032] Here, the gripping unit 42 and the moving unit 50 constitute the transport unit 40. That is, the transport unit 40 grips the strand S and transports the strand S toward a strand cutter 56 (FIG. 1) described below. The gripping unit 42 may grip the strand S before, at the same time, or after the moving unit 50 starts to move.

[0033] (Upstream cutter) 3, the upstream cutter 16 is located downstream in the Y direction with respect to the die 28 and upstream in the Y direction with respect to a camera 132 described later. The upstream cutter 16 includes a blade portion 17 that is movable in the Z direction. The blade portion 17 moves in the Z direction relative to the strand S, thereby enabling the strand S to be cut. The upstream cutter 16 cuts the strand S, for example, when the operation of the extrusion portion 20 is confirmed in the preparation stage or when the production of the pellets P is completed.

[0034] <Strand cutter> 3, the strand cutter 56 is an example of a cutting unit that cuts the strand S transported by the movement of the gripping unit 42. The strand cutter 56 has a main body 57, a strand receiving unit 58, and a rotary blade 59. The main body 57 is installed on the floor surface 2. The strand receiving unit 58 is provided on the upstream side of the main body 57 in the Y direction. The strand receiving unit 58 has an upper roller 58A and a lower roller 58B, which are an example of a pair of rotating members.

[0035] The upper roller 58A and the lower roller 58B are each provided to be rotatable with the X direction as their axial direction. The upper roller 58A and the lower roller 58B sandwich the strand S and convey the strand S while rotating. The rotary blade 59 is provided inside the main body 57 to be rotatable with the X direction as its axial direction.

[0036] The rotational movement of the upper roller 58A and the lower roller 58B and the rotational movement of the rotary blade 59 are controlled by the control unit 30 (FIG. 2). The strand cutter 56 receives the strand S conveyed by the gripping unit 42 at the strand receiving unit 58. The strand cutter 56 then cuts the strand S by the rotation of the rotary blade 59. The strand S cut by the rotary blade 59 is discharged to the outside as a plurality of pellets P.

[0037] <Cooling section> 3, the cooling section 60 is located between the extrusion section 20 and the strand cutter 56, and cools the strand S. Specifically, the cooling section 60 has an upper cooling section 62 located above the strand S in the Z direction, and a lower cooling section 72 located below the upper cooling section 62 in the Z direction.

[0038] (Upper cooling section) The upper cooling section 62 has an upstream shower 64 and a downstream shower 66. The upstream shower 64 ejects water WT, which is an example of a liquid. The upstream shower 64 ejects the water WT toward a portion of the strand S that is downstream in the Y direction from a portion photographed by a camera 132 (described later) and upstream in the Y direction from a portion gripped by the gripping section 42. In other words, the upstream shower 64 is an example of an upstream cooling section that is located between the extrusion section 20 and the gripping section 42 and cools the strand S. The strand S becomes hard by being cooled by the water WT.

[0039] The downstream shower 66 is located downstream in the Y direction with respect to the upstream shower 64 and above the strand S in the Z direction. As an example, the downstream shower 66 is provided at three locations spaced apart in the Y direction. Furthermore, the downstream shower 66 is capable of ejecting water WT (FIG. 10) toward the strand S at multiple locations in the X direction.

[0040] (Lower cooling section) The lower cooling section 72 has a water bath 74, an immersion roller 96, a water bath position detection section 82, a water bath position changing section 86, a roller lifting section 92, a temperature measurement section 102, and a temperature changing section 104 (FIG. 2).

[0041] The water tank 74 is placed on the top surface 14A via the water tank position changing part 86. The water tank 74 has a rectangular bottom wall part 75 whose dimension in the Y direction is larger than its dimension in the X direction, and a side wall part 76 standing upright upward in the Z direction from the bottom wall part 75. In other words, the water tank 74 is formed in a box shape that opens upward in the Z direction and extends in the Y direction. The water tank 74 is an example of a storage tank that stores water WT. A support frame 77 extending in the Y direction is attached to the side wall part 76. Furthermore, guide frames 93, 94, which will be described later, are attached to the side wall part 76.

[0042] The cooling water (water WT) flows from the downstream side to the upstream side in the moving direction of the strand S, and the water temperature is adjusted so that the temperature on the upstream side becomes the set temperature.

[0043] <Aquarium position detection unit> 3, the water tank position detector 82 is an example of a position detector. The water tank position detector 82 detects the position of the water tank 74 in the Y direction relative to the position of the extrusion unit 20 in the Y direction. Specifically, the water tank position detector 82 has a laser transmitter 83 and a laser receiver 84. The laser transmitter 83 is attached to the upstream end of the water tank 74 in the Y direction. The laser transmitter 83 emits laser light LT downward in the Z direction.

[0044] The laser receiver 84 is fixed to the floor surface 2 so that the surface that receives the laser light LT is located at the upper end in the Z direction. When the laser receiver 84 receives (receives) the laser light LT, it detects that the upstream end of the water tank 74 in the Y direction is located at the upstream end in the Y direction of its movable range. When the laser receiver 84 does not receive the laser light LT, it is understood that the water tank 74 is located in a position shifted downstream in the Y direction. The downstream position of the water tank 74 in the Y direction may be detected based on the amount of operation of the water tank position change unit 86, which will be described later, etc.

[0045] It should be noted that bottom wall 75 is not necessarily positioned along the horizontal plane (XY plane). For this reason, an acceleration sensor may be provided in water tank 74 as water tank position detector 82. That is, the inclination of water tank 74 with respect to the horizontal plane may be measured based on the output of the acceleration sensor, and the position of water tank 74 in the Y and Z directions may be detected. In this way, detecting the position of water tank 74 also includes detecting the angle of water tank 74.

[0046] <Aquarium position change section> As shown in Fig. 3, water tank position changer 86 is an example of a position changer. Water tank position changer 86 is provided on bottom wall 75 and placed on top surface 14A. Water tank position changer 86 changes the position of water tank 74 in the Y direction based on the detection result of the Y direction position of water tank 74 detected by water tank position detector 82. Water tank position changer 86 has, as an example, an upstream drive roller 87A, a downstream drive roller 87B, and a plurality of driven rollers 87C. The operation of water tank position changer 86 is controlled by controller 30 (Fig. 2).

[0047] When the upstream drive roller 87A is rotated, the water tub 74 is moved upstream in the Y direction. When the downstream drive roller 87B is rotated, the water tub 74 is moved downstream in the Y direction a preset distance. The multiple driven rollers 87C support the water tub 74 so that it can move in the Y direction.

[0048] <Roller lifting section> As shown in FIG. 3, the roller lifting unit 92 has guide frames 93, 94, a plurality of lifting frames 95, and a plurality of immersion rollers 96. The guide frames 93, 94 are attached to the side wall portion 76 and extend in the Z direction. The lifting frame 95 extends in the Y direction. Both ends of the lifting frame 95 in the Y direction are supported by the guide frames 93, 94. The guide frames 93, 94 and the lifting frame 95 are configured as linear actuators. That is, the lifting frame 95 can rise and fall along the Z direction.

[0049] The multiple immersion rollers 96 are an example of immersion members, and each extends with its axial direction in the X direction. The multiple immersion rollers 96 are arranged at intervals in the Y direction. Both ends of the multiple immersion rollers 96 in the X direction are rotatably supported by the multiple lifting frames 95. The multiple immersion rollers 96 are lowered in accordance with the lowering operation of the lifting frame 95, thereby coming into contact with the strand S and immersing the strand S in the water WT of the water tank 74. In this way, the multiple immersion rollers 96 are located between the extrusion section 20 and the strand cutter 56, and are configured to immerse the strand S in the water WT.

[0050] <Temperature measurement section> 3, the temperature measuring unit 102 is provided in the water tank 74. The temperature measuring unit 102 measures the temperature of the water WT contained in the water tank 74. The measured temperature data is sent to the control unit 30 (FIG. 2).

[0051] <Temperature change section> As shown in Fig. 3, the temperature change unit 104 has a tank 105, a pipe 106, a pump 107, a heater 108, and a cooler 109. Water WT is stored inside the tank 105. The pipe 106 connects the inside of the tank 105 to the inside of the water tank 74. The pump 107 pumps up the water WT in the tank 105 and sends it to the pipe 106. The heater 108 is provided so as to be able to heat the water WT in the tank 105. The cooler 109 is provided so as to be able to cool the water WT in the tank 105.

[0052] The temperature change unit 104 changes the temperature of the water WT based on the temperature T1 (FIG. 2) measured by the temperature measurement unit 102. For example, when the preset temperature range is a range between temperature T2 and temperature T3 (FIG. 2) and temperature T1 is lower than temperature T2, the temperature change unit 104 operates the heater 108 to heat the water WT. When temperature T1 is higher than temperature T3, the temperature change unit 104 operates the cooler 109 to cool the water WT. In this way, the heated or cooled water WT is supplied to the water tank 74, whereby the temperature of the water WT in the water tank 74 is changed (adjusted).

[0053] <Support part> 3, the support section 110 is located between the extrusion section 20 and the strand cutter 56, and supports the strand S. Specifically, the support section 110 has an upstream support section 112 and a downstream support section 122.

[0054] (Upstream support part) As shown in Fig. 6, the upstream support portion 112 includes an arm member 113, an upstream drive portion 114, a support roller 115, and a connecting pin 116. The arm member 113 is a plate member having a rectangular shape when viewed from the X direction. Two arm members 113 are provided spaced apart in the X direction, but Fig. 6 shows one arm member 113. One axial end of the arm member 113 is connected to the corner portion 76A by the connecting pin 116. The corner portion 76A is a portion located at the upstream end of the side wall portion 76 in the Y direction and at the upper end in the Z direction.

[0055] The upstream drive unit 114 includes a motor and a gear, and rotates the arm member 113 around the connecting pin 116. In other words, the arm member 113 is an example of a displacement member, and is provided so that its position relative to the strand S can be changed. The support roller 115 is rotatably provided at the other end of the arm member 113 in the axial direction. The support roller 115 has an outer circumferential surface 115A. The support roller 115 supports the strand S by a portion of the outer circumferential surface 115A coming into contact with the strand S. When it is not necessary to support the strand S, the arm member 113 is rotated downward in the Z direction, and the support roller 115 is retracted downward in the Z direction.

[0056] (Downstream support part) As shown in Fig. 7, the downstream support section 122 includes an arm member 123, a downstream drive section 124, a support roller 125, and a connecting pin 126. The arm member 123 is a plate member having a rectangular shape when viewed from the X direction. Two arm members 123 are provided spaced apart in the X direction, but Fig. 7 shows one arm member 123. One axial end of the arm member 123 is connected to the corner portion 76B by the connecting pin 126. The corner portion 76B is a portion located at the downstream end of the side wall portion 76 in the Y direction and at the upper end in the Z direction.

[0057] The downstream drive unit 124 includes a motor and a gear, and rotates the arm member 123 around the connecting pin 126. In other words, the arm member 123 is an example of a displacement member, and is provided so that its position relative to the strand S can be changed. The support roller 125 is rotatably provided at the other end of the arm member 123 in the axial direction. The support roller 125 has an outer circumferential surface 125A. The support roller 125 supports the strand S by a part of the outer circumferential surface 125A coming into contact with the strand S. When it is not necessary to support the strand S, the arm member 123 is rotated downward in the Z direction, and the support roller 125 is retreated downward in the Z direction.

[0058] <Measurement section> The measurement unit 130 will be described with reference to Figures 1, 2, and 4. The measurement unit 130 includes, as an example, a camera 132 and a calculation unit 134. The measurement unit 130 measures the diameter W of the strand S in the X direction. The calculation unit 134 may be incorporated in the control unit 30 (Figure 2).

[0059] The camera 132 captures an image of the strand S extruded from the die 28 from above in the Z direction. Image information acquired by the camera 132 is sent to the calculation unit 134. The calculation unit 134 has a CPU, a memory, and the like, similar to the control unit 30. The calculation unit 134 then performs binarization processing on the image information to calculate the diameter W1 of the strand S1, the diameter W2 of the strand S2, and the diameter W3 of the strand S3. Furthermore, the calculation unit 134 calculates the average values ​​of the diameters W1, W2, and W3. The calculated average value information is sent to the control unit 30.

[0060] The control unit 30 controls the moving speed of the moving unit 50 based on the diameter W of the strand S in the X direction measured by the measuring unit 130. Specifically, when the average value of the diameter W of the strand S in the X direction is smaller than a preset value, the control unit 30 controls to decrease the moving speed of the moving unit 50. Also, when the average value of the diameter W of the strand S in the X direction is larger than a preset value, the control unit 30 controls to increase the moving speed of the moving unit 50. When the average value and the preset value for the diameter W of the strand S in the X direction are approximately equal, the control unit 30 controls to maintain the moving speed of the moving unit 50.

[0061] [Function of the pellet manufacturing device] In the pellet manufacturing apparatus 10, after the start of an operation is selected on the operation panel 12 (FIG. 2), each process (step) described below is automatically performed until the stop of the operation is selected. Each process is performed by the CPU 32 reading, developing, and executing a program from the memory 34.

[0062] 8, in the pellet manufacturing apparatus 10, a provisional extrusion process of the strand S is performed as a preparation stage before the start of manufacturing. At this time, the water tank 74 is disposed close to the strand cutter 56. The gripping unit 42 is disposed at a position (start position) closest to the upstream support unit 112. In this state, the extrusion unit 20 extrudes the molten resin R as the strand S. The extruded strand S is imaged by the camera 132 and cooled by the upstream shower 64.

[0063] The control unit 30 performs image analysis (e.g., analysis based on color differences) based on the information captured by the camera 132. This determines whether or not there is a foreign object (such as dirt) in the strand S. If there is a foreign object in the strand S, the operation of the pellet manufacturing device 10 is stopped and a warning message is displayed on the operation panel 12 (FIG. 2). On the other hand, if there is no foreign object in the strand S, the extrusion of the strand S is stopped and the extruded strand S is cut by the upstream cutter 16. The cut strand S falls and is collected in a container. Then, the process proceeds to the next step.

[0064] Note that the "foreign matter" in the strand S means any matter that may affect the operation of the strand cutter 56, specifically, any solid matter such as metal powder that may wear down the strand cutter 56. Gel-like matter, unmelted matter, and the like are not included in the "foreign matter" because there is no need to stop the extrusion of the strand S.

[0065] As shown in Fig. 9, the water tank position changer 86 operates to move the water tank 74 upstream in the Y direction. When the laser receiver 84 receives the laser light LT, the water tank 74 stops moving. Next, the molten resin R is extruded from the extrusion section 20 as a string-like strand S (an example of a process of extruding the strand S). At this time, the upstream drive section 114 (Fig. 2) is driven, causing the upstream support section 112 to support the strand S.

[0066] As shown in Fig. 5, the pushed-out strand S passes between the lower roller 47 and the upper roller 48, which has been retracted upward, and advances downstream in the Y direction. Here, when the length L1 (Fig. 10) of the portion of the strand S that extends (protrudes) downstream from the gripping portion 42 reaches a preset length, the cam 49A is rotated. As a result, the position of the upper roller 48 is lowered, and the strand S becomes sandwiched between the roller pair 46 (an example of a process in which the strand S is gripped by the gripping portion 42).

[0067] The force with which the gripping portion 42 grips the strand S is kept to a minimum force that allows the strand S to move downstream in the Y direction. Therefore, even if the strand S is deformed by the operation of the gripping portion 42, the deformed portion of the strand S is limited to the portion gripped by the gripping portion 42. In other words, the portion not gripped by the gripping portion 42 is less likely to be deformed.

[0068] 10, after the strand S is gripped by the gripping unit 42, the moving unit 50 moves the gripping unit 42 toward the strand cutter 56. At this time, a plurality of downstream showers 66 spray water WT onto the strand S, thereby cooling the strand S. In this manner, the strand S moved by the moving unit 50 is moved (transported) in a harder state compared to before cooling. The gripping unit 42 that has gripped the strand S is moved to the strand cutter 56 (an example of a process in which the gripping unit 42 is moved by the moving unit 50 to transport the strand S to the strand cutter 56).

[0069] 11, the downstream drive unit 124 (FIG. 2) is driven in synchronization with the point in time when the gripping unit 42 reaches the downstream end of the guide rail 52 (FIG. 5) in the Y direction, causing the downstream support unit 122 to support the strand S. Then, the tip end (downstream end) of the strand S enters the strand receiving unit 58 as the moving unit 50 moves. In this manner, the tip end of the strand S is delivered to the strand receiving unit 58. When the tip end of the strand S reaches the strand cutter 56, the transportation of the strand S in the preparation process is completed.

[0070] As shown in Fig. 5, the upper roller 48 is moved upward in the Z direction before the multiple immersion rollers 96 (Fig. 11) start to move down. In other words, the nipped state of the strand S at the nip portion N is released. Then, the gripping portion 42 is moved by the moving portion 50 to the upstream end (start position) of the guide rail 52 in the Y direction.

[0071] As shown in FIG. 3, with the strand S having been delivered to the strand receiving section 58, a downward movement is performed by the roller lifting section 92. As a result, the strand S is immersed in the water WT of the water tank 74 by the multiple immersion rollers 96 and cooled. The operation of the multiple downstream showers 66 is stopped. Then, the manufacturing process is started. Specifically, the extrusion and movement of the strand S is resumed, and the strand S is cut by the strand cutter 56 (an example of a process in which the strand cutter 56 cuts the strand S). As a result, multiple pellets P are formed. The formed multiple pellets P are collected.

[0072] As described above, according to the pellet manufacturing apparatus 10, in the preparation stage before the production of the pellets P, the gripping unit 42 grips the strand S extruded from the extrusion unit 20. The moving unit 50 moves the gripping unit 42. As a result, the strand S is automatically transported to the strand cutter 56. When the production of the pellets P is started, the strand cutter 56 cuts the strand S to produce a plurality of pellets P. In this way, by automating the transport of the strand S to the strand cutter 56 in the preparation stage before the start of the production of the pellets P, the variation in the external force acting on the strand S is suppressed, and therefore the occurrence of variation in the diameter W of the strand S can be suppressed.

[0073] According to the pellet manufacturing apparatus 10, when there is a possibility that the tensile force acting on the strand S in the Y direction becomes larger than necessary, the roller pair 46 is driven to rotate, thereby reducing the frictional force acting on the contact surface between the roller pair 46 and the strand S. This makes it possible to prevent the tensile force acting on the strand S from becoming larger than necessary.

[0074] According to the pellet manufacturing apparatus 10, the cooling section 60 cools the strand S, which promotes hardening of the strand S. This makes it possible to suppress deformation of the strand S during transportation.

[0075] According to the pellet manufacturing apparatus 10, the cooling section 60 has an upstream shower 64. This makes it possible to harden the strand S, which has a relatively high temperature immediately after being extruded from the extrusion section 20, by cooling it with the upstream shower 64, thereby making it possible to suppress deformation of the strand S during transportation.

[0076] According to the pellet manufacturing apparatus 10, the strand S is immersed in the water WT of the water tank 74 between the extrusion section 20 and the strand cutter 56. The temperature of the immersed strand S is reduced by heat exchange with the water WT. This allows the strand S to be cooled in a shorter time than when the strand S is cooled by air.

[0077] According to the pellet manufacturing apparatus 10, the water tank position detection unit 82 detects the position of the water tank 74 relative to the position of the extrusion unit 20. Then, the water tank position change unit 86 changes the position of the water tank 74 based on the detection result of the position of the water tank 74 detected by the water tank position detection unit 82. For example, if the position of the water tank 74 is too far away from the position of the extrusion unit 20, the water tank 74 is moved closer to the extrusion unit 20. If the position of the water tank 74 is too close to the position of the extrusion unit 20, the water tank 74 is moved away from the extrusion unit 20. In this way, the distance between the extrusion unit 20 and the water tank 74 can be automatically managed.

[0078] According to the pellet manufacturing apparatus 10, the temperature change unit 104 changes the temperature of the water WT based on the temperature measured by the temperature measurement unit 102. For example, if the temperature of the water WT rises due to a change in the temperature of the environment in which the pellet manufacturing apparatus 10 is installed, the temperature of the water WT can be lowered using the cooler 109. If the temperature of the water WT drops, the temperature of the water WT can be raised using the heater 26. This makes it possible to manage the temperature of the water WT.

[0079] According to the pellet manufacturing apparatus 10, the support section 110 supports the strand S between the extrusion section 20 and the strand cutter 56. This makes it possible to suppress deformation of the strand S being conveyed toward the strand cutter 56.

[0080] According to the pellet manufacturing apparatus 10, when the positions of the arm members 113, 123 in the Y direction and the Z direction are changed relative to the strand S so that the support unit 110 can support the strand S, the support rollers 115, 125 come into contact with the strand S. Here, it is assumed that the positions of the arm members 113, 123 continue to be changed even after the support rollers 115, 125 come into contact with the strand S. In this case, the contact positions of the support rollers 115, 125 with the strand S change in the circumferential direction as they rotate. As a result, the frictional force acting on the strand S can be kept low compared to a configuration in which the support rollers 115, 125 do not rotate, and therefore the strand S can be prevented from being pulled by the support unit 110.

[0081] According to the pellet manufacturing apparatus 10, the measuring unit 130 measures the diameter W of the strand S in the X direction. The control unit 30 controls the rotation speed of the strand cutter 56 (upper roller 58A, lower roller 58B (FIG. 3)) based on the diameter W of the strand S in the X direction measured by the measuring unit 130. For example, when the diameter W of the strand S in the X direction is smaller than a preset diameter, the control unit 30 reduces the rotation speed of the upper roller 58A and the lower roller 58B. This reduces the tension acting on the strand S in the conveying direction, so that the diameter of the strand S in the X direction approaches the preset diameter.

[0082] On the other hand, if the diameter W of the strand S in the X direction is larger than the set diameter, the control unit 30 increases the rotation speed of the upper roller 58A and the lower roller 58B. This increases the tension acting in the Y direction, which is the transport direction of the strand S, and causes the diameter W of the strand S in the X direction to approach the set diameter (the diameter W becomes smaller). In this way, the diameter W of the strand S in the X direction can be made to approach the set diameter.

[0083] According to the pellet manufacturing method of the present embodiment, in a preparation stage before the production of pellets P, the gripping unit 42 grips the strand S extruded from the extrusion unit 20. The moving unit 50 moves the gripping unit 42. As a result, the strand S is automatically transported to the strand cutter 56. When production starts, the strand cutter 56 cuts the strand S to produce a plurality of pellets P. In this way, by automating the transport of the strand S to the strand cutter 56 in the preparation stage before the start of production of pellets P, variation in the external force acting on the strand S is suppressed, and therefore variation in the diameter W of the strand S can be suppressed.

[0084] According to the pellet manufacturing apparatus 10 or pellet manufacturing method of this embodiment, the transport of the strand S to the strand cutter 56 is automated in the preparation stage before the start of the production of the pellets P. This makes it possible to optimize the operating conditions and improve the quality of the pellets P, compared to a configuration in which a skilled engineer manually adjusts the operating conditions of the apparatus after observing the resin temperature and the discharge state of the strand from the strand die. By optimizing the operating conditions, it becomes possible to suppress the generation of waste in the early stages of molding the strand S. By making it possible to improve the quality of the pellets P, it becomes possible to strand a low-viscosity resin.

[0085] It is to be noted that the present disclosure is not limited to the above-described embodiment, and may be embodied in various different forms within the scope of the technical concept thereof. Below, various modified examples of the pellet manufacturing apparatus 10 of the present embodiment will be described. The same components as those of the pellet manufacturing apparatus 10 will be denoted by the same reference numerals and will not be described.

[0086] <Variation 1> FIG. 12 shows a pellet manufacturing apparatus 140. The pellet manufacturing apparatus 140 has a base 142 instead of the water tank 74 and the water tank position changing unit 86 (FIG. 1). In other words, the pellet manufacturing apparatus 140 is an apparatus in which the strand S is not immersed in the water WT. The strand S extruded from the extrusion unit 20 is cooled by the water WT of the upstream shower 64, and then moved to the strand cutter 56 by the moving unit 50 while being held by the holding unit 42. The strand S is further cooled by receiving the water WT of the downstream shower 66 while being moved by the moving unit 50. As a result, the strand S reaches the strand cutter 56 in a hardened state, so that deformation of the strand S in the preparation stage before production can be suppressed. In other words, similar to the pellet manufacturing apparatus 10 (FIG. 1), it is possible to suppress the occurrence of variations in the diameter W of the strand S in the preparation stage before the start of production of the pellets P. After the start of production, the strand S is cut by the strand cutter 56 to produce the pellets P. In this manner, a pellet manufacturing apparatus 140 without a water tank 74 may be used.

[0087] <Variation 2> 13 shows the conveying unit 150. The conveying unit 150 is provided in place of the conveying unit 40 (FIG. 1) of the pellet manufacturing apparatus 10. The conveying unit 150 has a gripping unit 152 and a moving unit 50. The gripping unit 152 includes a support block 154, a movable block 156, and a block driving unit 158. The block driving unit 158 ​​includes a motor and gears. The operation of the block driving unit 158 ​​is controlled by the control unit 30 (FIG. 2).

[0088] The support block 154 is fixed to the carriage 54. A plurality of grooves 155 are formed in the support block 154. The grooves 155 are open toward the upper side in the Z direction and extend in the Y direction. When viewed from the Y direction, the grooves 155 are formed in an inverted trapezoid shape having one bottom surface 155A and two inclined surfaces 155B.

[0089] The movable block 156 is located above the support block 154 in the Z direction. The movable block 156 can be raised and lowered in the Z direction by a block driving unit 158. A plurality of grooves 157 are formed in the movable block 156. The grooves 157 are open toward the lower side in the Z direction and extend in the Y direction. When viewed from the Y direction, the grooves 157 are formed in a trapezoid shape having one bottom surface 157A and two inclined surfaces 157B.

[0090] The strand S extruded from the extrusion unit 20 (FIG. 1) enters a plurality of grooves 155 and is supported by the support block 154. Then, as the movable block 156 descends, the strand S is sandwiched between the bottom surface 155A, the inclined surface 155B, the bottom surface 157A, and the inclined surface 157B. That is, the strand S is gripped by the gripping unit 152. The gripped strand S is moved in the Y direction by the moving unit 50. In this manner, the gripping unit 152 may have a configuration in which the strand S is gripped by a non-rotating clip-shaped member.

[0091] <Other Modifications> The pellet manufacturing apparatus 10, 140 may not have the downstream shower 66. Furthermore, when the hardened state of the strand S extruded from the extrusion section 20 is such that the strand S can be moved (conveyed), the upstream shower 64 may not be provided. The pellet manufacturing apparatus 10, 140 may have a fixed water tank 74 and may not have the water tank position detection section 82 and the water tank position change section 86. The cooling section 60 may not have the temperature measurement section 102 and the temperature change section 104. In other words, the temperature of the water WT in the water tank 74 does not need to be changed.

[0092] The pellet manufacturing apparatus 10, 140 may not be provided with the support unit 110. The support unit 110 may not have the arm members 113, 123 and the support rollers 115, 125. For example, a pad movable in the Z direction or a direction intersecting the Z direction may be provided, and the position of the pad may be changed to change the position of the strand S. The measuring unit 130 may not be provided, and the moving unit 50 may be moved at a preset speed. The cutting unit is not limited to one having a rotary blade 59 like the strand cutter 56, and may be one having a blade portion that rises and falls in the Z direction. [Explanation of symbols]

[0093] 2 floor surface, 10 pellet manufacturing device, 12 operation panel, 14 pedestal, 14A upper surface, 16 upstream cutter, 17 blade section, 20 extrusion section, 22 drive section, 24 cylinder, 25 screw, 26 heater, 27 feed section, 28 die, 28A through hole, 30 control unit, 33 bus, 34 memory, 40 conveying unit, 42 gripping unit, 44 Support frame, 44A Vertical wall portion, 45A Bearing, 45B Bearing, 46 roller pair, 47 lower roller, 47A outer peripheral surface, 48 upper roller, 48A outer peripheral surface, 49 bearing drive part, 49A cam, 49B motor, 50 moving part, 52 guide rail, 54 carriage, 56 strand cutter, 57 main body, 58 strand receiving portion, 58A upper roller, 58B lower roller, 59 rotary blade, 60 cooling section, 62 upper cooling section, 64 upstream shower, 66 downstream shower, 72 lower cooling section, 74 water tank, 75 bottom wall section, 76 side wall section, 76A corner section, 76B corner portion, 77 support frame, 82 aquarium position detection portion, 83 laser transmitter, 84 laser receiver, 86 water tank position change unit, 87A upstream drive roller, 87B downstream drive roller, 87C driven roller, 92 roller lifting unit, 93 guide frame, 94 guide frame, 95 lifting frame, 96 immersion roller, 102 temperature measuring section, 104 temperature changing section, 105 tank, 106 pipe, 107 pump, 108 heater, 109 cooler, 110 support portion, 112 upstream support portion, 113 arm member, 114 upstream drive part, 115 support roller, 115A outer circumferential surface, 116 connecting pin, 122 downstream support portion, 123 arm member, 124 downstream drive portion, 125 support roller, 125A outer peripheral surface, 126 connecting pin, 130 measuring portion, 132 camera, 134 calculation unit, 140 pellet manufacturing device, 142 base, 150 conveying portion, 152 gripping portion, 154 support block, 155 groove, 155A bottom surface, 155B inclined surface, 156 movable block, 157 groove, 157A bottom surface, 157B inclined surface, 158 block drive section, d nip interval, d1 distance, d2 distance, L1 length, LT laser light, N nip part, P pellets, R molten resin, S strands, S1 strands, S2 strands, S3 strand, T1 temperature, T2 temperature, T3 temperature, W1 diameter, W2 diameter, W3 diameter, WT water

Claims

1. an extrusion section that extrudes the molten resin material into a string-like strand; a gripping portion that grips the strand extruded from the extrusion portion; A moving unit that moves the gripping unit; a cutting unit that cuts the strand transported by the movement of the gripping unit; A pellet manufacturing apparatus comprising:

2. The gripping portion has a pair of rollers that are rotatably provided and pinch the strand.

2. The pellet manufacturing apparatus according to claim 1.

3. The extrusion section further includes a cooling section located between the extrusion section and the cutting section and configured to cool the strand.

2. The pellet manufacturing apparatus according to claim 1.

4. The cooling section has an upstream cooling section located between the extrusion section and the gripping section and configured to cool the strand.

4. The pellet manufacturing apparatus according to claim 3.

5. The cooling unit includes: A tank for containing a liquid; an immersion member located between the extrusion section and the cutting section for immersing the strand in the liquid; having 4. The pellet manufacturing apparatus according to claim 3.

6. a position detector for detecting a position of the storage tank relative to a position of the extrusion unit; a position change unit that changes the position of the storage tank based on a detection result of the position of the storage tank detected by the position detection unit; Further comprising:

6. The pellet manufacturing apparatus according to claim 5.

7. The cooling unit includes: A temperature measuring unit for measuring a temperature of the liquid; a temperature change unit that changes the temperature of the liquid based on the temperature measured by the temperature measurement unit; having 6. The pellet manufacturing apparatus according to claim 5.

8. The cutting section further includes a support section that is located between the extrusion section and the cutting section and supports the strand.

2. The pellet manufacturing apparatus according to claim 1.

9. The support portion is A displacement member that is provided so as to be able to change its position relative to the strand; A support roller rotatably provided on the displacement member and supporting the strand.

9. The pellet manufacturing apparatus according to claim 8.

10. the cutting unit has a pair of rotating members that sandwich the strand and rotate to transport the strand, A measuring unit that measures a diameter of the strand in a cross direction that crosses a conveying direction of the strand; and a control unit that controls the rotation speed of the pair of rotating members based on the diameter of the strand measured by the measuring unit. The pellet manufacturing apparatus according to any one of claims 1 to 9.

11. A method for producing pellets, comprising the steps of: (a) extruding a molten resin material from an extrusion section as a string-like strand; (b) gripping the strand extruded from the extrusion section with a gripping section; (c) conveying the strand to a cutting section by moving the gripping section with a moving section; (d) the cutting section cutting the strand.

Images