Cylinder cleaning device and cylinder cleaning method

Abstract

A cylinder cleaning device (100) according to one embodiment comprises: a metal pipe (120) that is linearly extended in the axial direction of a cylinder (11) and is connected to a grinder (110); and a support part (130) that is disposed outside the opening end of the cylinder (11) and slidably supports the metal pipe (120). When cleaning the inner surface of the cylinder (11), the metal pipe is moved in the longitudinal direction outside the cylinder (11), and the grinder (110) driven inside the cylinder (11) is moved in the axial direction of the cylinder (11).

Description

Cylinder cleaning device and cylinder cleaning method

[0001] The present disclosure relates to a cylinder cleaning device and a cylinder cleaning method.

[0002] Resin injection molding machines and extrusion molding machines are equipped with kneaders that heat resin pellets fed into a cylinder with a heater and knead them with a screw. In such kneaders, for example, when changing the resin material, cleaning is performed to remove resin adhering to the inner surface of the cylinder. For example, Patent Document 1 discloses a cylinder cleaning device in which the rotating shaft of a grinder is elongated and inserted into the cylinder so that the cylinder can be cleaned from the outside.

[0003] Japanese Patent Application Publication No. 7-40415

[0004] The cylinder cleaning device disclosed in Patent Document 1 had a problem in that the rotating shaft of the long grinder vibrated during cleaning, making it difficult to clean the inner surface of the cylinder. Other problems and novel features will become apparent from the description of this specification and the accompanying drawings.

[0005] A cylinder cleaning device according to one embodiment includes a metal pipe extending linearly in the axial direction of a cylinder and connected to a grinder, and a support member disposed outside the open end of the cylinder for slidably supporting the metal pipe. When cleaning the inner surface of the cylinder, the metal pipe is moved longitudinally outside the cylinder, and the driven grinder inside the cylinder is moved axially along the cylinder.

[0006] In one embodiment of a cylinder cleaning method, a grinder is connected to a metal pipe that extends linearly in the longitudinal direction of the cylinder, and the metal pipe is slidably supported on a support disposed outside the open end of the cylinder. In a step of cleaning the inner surface of the cylinder, the metal pipe is moved in the longitudinal direction outside the cylinder, and the driven grinder inside the cylinder is moved in the axial direction of the cylinder.

[0007] According to the embodiment, it is possible to provide a cylinder cleaning device that suppresses vibration of the rotation shaft of the grinder during cleaning and makes it easier to clean the inner surface of the cylinder.

[0008] Fig. 1 is a schematic cross-sectional view showing the configuration of an extrusion molding device that is cleaned using the cylinder cleaning device according to the first embodiment. Fig. 2 is a schematic side view showing the configuration of the cylinder cleaning device according to the first embodiment. Fig. 3 is a schematic side view showing the configuration of the cylinder cleaning device according to the first embodiment. Fig. 4 is an enlarged view of a grinder 110 inside a cylinder 11. Fig. 5 is an enlarged view of a grinder 110 inside a cylinder 11. Fig. 6 is an enlarged view of a grinder 110 inside a cylinder 11. Fig. 7 is a schematic plan view showing the configuration of a support part 130 in a cylinder cleaning device according to a second embodiment. Fig. 8 is a schematic side view showing the configuration of a support part 130 in a cylinder cleaning device according to the second embodiment.

[0009] Specific embodiments will be described in detail below with reference to the drawings. However, the present invention is not limited to the following embodiments. For clarity of explanation, the following description and drawings have been simplified as appropriate.

[0010] (First embodiment) <Configuration of extrusion molding device> First, referring to Fig. 1, the configuration of an extrusion molding device to be cleaned using a cylinder cleaning device according to the first embodiment will be described. Fig. 1 is a schematic cross-sectional view showing the configuration of an extrusion molding device to be cleaned using a cylinder cleaning device according to the first embodiment. A resin compound in which a filler is dispersed in a resin is extruded using the extrusion molding device according to this embodiment. The shape of the resin compound extruded by the extrusion molding device according to this embodiment is, for example, a strand shape, but is not particularly limited thereto and may be, for example, a film shape.

[0011] As shown in Figure 1, the extrusion molding apparatus according to the first embodiment includes a resin raw material feeder F1, a filler feeder F2, an extruder 10, and a die 20. It should be noted that the right-handed XYZ Cartesian coordinate system shown in Figure 1 and other drawings is for the convenience of explaining the positional relationships of the components. Normally, the positive direction of the Z axis is vertically upward, and the XY plane is the horizontal plane, which is common to all drawings.

[0012] The resin raw material feeder F1 is a feeder for supplying a resin raw material, which is the main raw material of a resin compound, into the inside of the cylinder 11 of the extruder 10. The resin raw material feeder F1 shown in Fig. 1 is of a screw type and includes a feeder hopper FH1, a feeder screw FS1, and a feeder motor FM1. The resin raw material is not particularly limited, but may be, for example, resin pellets made of polypropylene, polyethylene, polyamide, polyethylene terephthalate, or the like.

[0013] The resin raw material is fed into the feeder hopper FH1 and stored therein. When the feeder screw FS1 is rotated by the feeder motor FM1, the resin raw material in the feeder hopper FH1 is supplied to the inside of the cylinder 11 via the hopper 13 of the extruder 10. For example, the amount of resin raw material supplied from the resin raw material feeder F1 to the extruder 10 can be controlled by feedback-controlling the rotation of the feeder motor FM1 while measuring the change in mass of the resin raw material in the feeder hopper FH1.

[0014] A controller (not shown) controls the amount of resin raw material fed from the resin raw material feeder F1 to the extruder 10. The resin raw material feeder F1 shown in Fig. 1 is of a screw type, but a vibrating type or other type of feeder may also be used as long as the amount of resin raw material fed can be controlled by a controller, i.e., a computer.

[0015] The filler feeder F2 is a feeder for supplying filler constituting the resin compound into the cylinder 11 of the extruder 10. The filler feeder F2 shown in Fig. 1 is of a screw type and includes a feeder hopper FH2, a feeder screw FS2, and a feeder motor FM2. The filler is not particularly limited, but examples thereof include talc, calcium carbonate powder, glass fiber, and carbon powder.

[0016] Filler is fed into the feeder hopper FH2 and stored therein. When the feeder screw FS2 is rotated by the feeder motor FM2, the filler in the feeder hopper FH2 is supplied into the cylinder 11 through the side supply port 14 of the extruder 10. For example, the amount of filler supplied from the filler feeder F2 to the extruder 10 can be controlled by measuring the change in mass of the filler in the feeder hopper FH2 and feedback-controlling the rotation of the feeder motor FM2.

[0017] A controller (not shown) controls the amount of filler fed from the filler feeder F2 to the extruder 10. The filler feeder F2 shown in Fig. 1 is of a screw type, but a vibrating or other type of feeder may also be used as long as the amount of filler fed can be controlled by a controller, i.e., a computer.

[0018] Alternatively, a side feeder may be provided between the filler feeder F2 and the side supply port 14, and the filler delivered from the filler feeder F2 may be introduced into the side supply port 14 via the side feeder. Alternatively, the filler may be supplied from the filler feeder F2 to the inside of the cylinder 11 via a hopper 13 of the extruder 10 instead of via the side supply port 14.

[0019] The extruder 10 is a screw extruder. In the extruder 10 illustrated in FIG. 1 , a screw 12 extending in the X-axis direction is housed inside a cylinder 11 extending in the X-axis direction. A hopper 13 is provided above the end of the cylinder 11 on the upstream side in the extrusion direction (negative side of the X-axis) for supplying resin raw material from a resin raw material feeder F1 into the cylinder 11. A side supply port 14 is provided on the side of the cylinder 11 downstream in the extrusion direction (positive side of the X-axis) from the hopper 13, i.e., on the die 20 side, for supplying filler from a filler feeder F2. Hereinafter, the upstream side of the cylinder 11 in the extrusion direction will be simply referred to as the "upstream side," and the downstream side of the cylinder 11 in the extrusion direction will be simply referred to as the "downstream side."

[0020] A screw motor SM is connected to the base of the screw 12 via a reducer RG. The screw motor SM is a drive source that drives the screw 12. For example, the rotation speed of the screw 12 can be controlled by controlling the rotation speed of the screw motor SM. The screw 12 may be single or multiple. For example, an extruder 10 with one screw 12 is called a single-screw extruder, and an extruder 10 with two screws 12 is called a twin-screw extruder.

[0021] The resin raw material supplied from the hopper 13 is transported from the base to the tip of the screw 12 rotated by the screw motor SM, i.e., from the upstream side to the downstream side. The resin raw material is heated inside the cylinder 11 and is sheared and melted by the rotating screw 12. Although not shown, a heater for heating the inside of the cylinder 11 is provided on the outer circumferential surface of the cylinder 11 over substantially the entire longitudinal area.

[0022] Here, the resin raw material supplied from the hopper 13 is sheared and melted mainly in the kneading zone KZ1 of the extruder 10 shown in Fig. 1. A vent V1 is provided on the upper surface of the cylinder 11 downstream of and near the kneading zone KZ1. For example, air and volatile components contained in the resin raw material are discharged through the vent V1.

[0023] A side supply port 14 for supplying filler is provided on the side surface of the cylinder 11 downstream of the vent V1. The filler supplied from the side supply port 14 is transported downstream together with the molten resin raw material. A kneading zone KZ2 of the extruder 10 is provided downstream of the side supply port 14. In the kneading zone KZ2, the molten resin raw material and the filler are kneaded together, and the filler is uniformly dispersed in the molten resin raw material.

[0024] A vent V2 is provided on the upper surface of the cylinder 11 downstream of and in the vicinity of the kneading zone KZ2. The vent V2 is depressurized, for example, by a vacuum pump (not shown). Air and volatile components contained in, for example, the resin raw material and filler are further discharged through the vent V2. Note that the vents V1 and V2 are not essential.

[0025] As shown in FIG. 1 , the die 20 is connected to the tip end (the end on the positive X-axis direction side) of the extruder 10. The resin raw material and filler kneaded in the extruder 10 are molded by the die 20 into, for example, a strand-shaped resin compound. That is, the extrusion molding apparatus according to this embodiment produces a strand-shaped resin compound. For example, by cutting this strand-shaped resin compound, pellets are obtained that can be used as a raw material for a resin molded product. The die 20 is not essential, and the resin compound may be simply extruded without being molded.

[0026] Here, for example, when changing the type of resin compound to be manufactured, the resin adhering to the inner surface of the cylinder 11 is removed using a cylinder cleaning device according to this embodiment, which will be described later. The cylinder to be cleaned using the cylinder cleaning device according to this embodiment is not limited to the cylinder of an extruder in an extrusion molding apparatus as shown in FIG. 1 , but may also be the cylinder of an injector in an injection molding apparatus. Both extruders and injectors have in common the fact that resin pellets introduced into the cylinder are heated by a heater and kneaded by a screw. Therefore, in this specification, the term kneader encompasses both extruders and injectors.

[0027] <Configuration of Cylinder Cleaning Device> Next, the configuration of the cylinder cleaning device according to the first embodiment will be described with reference to Figures 2 and 3. Figures 2 and 3 are schematic side views showing the configuration of the cylinder cleaning device according to the first embodiment. Figures 2 and 3 also show cross-sectional views of the cylinder 11 of the extruder 10 shown in Figure 1.

[0028] 2 and 3, the cylinder cleaning device 100 according to this embodiment includes a grinder 110, a metal pipe 120, a support 130, a pipe feed mechanism 140, and a stand 150. Fig. 2 shows a state in which the grinder 110 has retreated to the outside of the open end of the cylinder 11, and Fig. 3 shows a state in which the grinder 110 has advanced into the interior of the cylinder 11.

[0029] 2 and 3, the grinder 110 has a main body 111, a rotary shaft 112, and a brush 113 attached to the tip of the rotary shaft 112. The grinder 110 shown in Figures 2 and 3 is an air grinder driven by compressed air. The rotary shaft 112 and the brush 113 are rotated by compressed air introduced from a metal pipe 120 into the main body 111, which is, for example, an air motor.

[0030] 2 and 3 is a wheel wire brush having a diameter approximately equal to the inner diameter of the cylinder 11. As shown in Fig. 3, the brush 113 rotates while the grinder 110 moves inside the cylinder 11, thereby removing resin adhering to the inner surface of the cylinder 11.

[0031] 2 and 3 may be an electric grinder instead of an air grinder. In that case, an electric wire for supplying electricity to the grinder 110 is housed inside the metal pipe 120. However, in an air grinder, as shown in FIG. 3, the resin removed from the cylinder 11 can be discharged to the outside of the cylinder 11 by air exhausted from the grinder 110. Furthermore, as will be described in detail later, an end-type brush may be used as the brush 113.

[0032] 2 and 3 , the metal pipe 120 extends linearly in the axial direction (X-axis direction) of the cylinder 11, and its tip (end on the negative X-axis direction side) is connected to the grinder 110. Compressed air is supplied to the grinder 110 via the metal pipe 120. Although not shown, a hose for supplying compressed air is connected to the rear end (end on the positive X-axis direction side) of the metal pipe 120 via, for example, a joint.

[0033] In addition, the metal pipe 120 is moved in the longitudinal direction (X-axis direction) by a pipe feed mechanism 140 outside the cylinder 11, and the driven grinder 110 inside the cylinder 11 is moved in the axial direction of the cylinder 11 (X-axis direction).

[0034] The support part 130 is disposed outside the open end of the cylinder 11 and supports the metal pipe 120 so that it can slide in the X-axis direction. The support part 130 is, for example, a bearing such as a ball bearing or a slide bearing into which the metal pipe 120 is inserted. Here, because the metal pipe 120 does not rotate, the support part 130 may have a simple configuration such as a short pipe. Although not particularly limited, the support part 130 shown in FIGS. 2 and 3 is fixed to the stand 150 via a support 131.

[0035] The pipe feed mechanism 140 is disposed outside the open end of the cylinder 11 and moves the metal pipe 120 in the longitudinal direction (X-axis direction) of the cylinder 11. In the pipe feed mechanism 140 shown in Figures 2 and 3 , a pair of pinch rolls R1, R2 that sandwich the metal pipe 120 rotate, thereby moving the metal pipe 120 in the X-axis direction. Although not particularly limited, the pipe feed mechanism 140 shown in Figures 2 and 3 is fixed to a stand 150.

[0036] The pipe feed mechanism 140 may be a linear motion mechanism that grips the metal pipe 120 and slides it in the X-axis direction. Instead of using the pipe feed mechanism 140, the metal pipe 120 may be moved in the X-axis direction manually, for example. Furthermore, the pipe feed mechanism 140 may also serve as the support unit 130. In other words, the support unit 130 does not have to be provided in the cylinder cleaning device 100 shown in FIGS. 2 and 3 .

[0037] 2 and 3, the support unit 130 is fixed to the top of the base 150 via a support pillar 131, and the pipe feed mechanism 140 is also fixed thereto. Proximity sensors S1 and S2 are installed at the end of the base 150 on the cylinder 11 side (negative X-axis side) and the opposite end (positive X-axis side), respectively.

[0038] 2 and 3 is height-adjustable, and can adjust the position of the support unit 130 in the up-down direction (Z-axis direction). The support unit 150 is also movable on the floor on which it is installed. Thus, the position of the support unit 130 in the Y-axis direction and the Z-axis direction can be adjusted by the support unit 150. Specifically, the support unit 150 is provided with an alignment mechanism that aligns the central axis of the cylinder 11 with the rotation axis of the grinder 110, i.e., the metal pipe 120.

[0039] 2 and 3, the metal pipe 120 is provided with reflectors P1 and P2 corresponding to the proximity sensors S1 and S2. As shown in Fig. 2, when the grinder 110 moves backward in the positive direction of the X-axis, it automatically stops if the proximity sensor S1 detects the reflector P1. On the other hand, as shown in Fig. 3, when the grinder 110 moves forward in the negative direction of the X-axis, it automatically stops if the proximity sensor S2 detects the reflector P2.

[0040] Alternatively, the grinder 110 may be automatically switched between forward and backward movement in response to the detection of the reflectors P1 and P2 by the proximity sensors S1 and S2, and may repeatedly move back and forth within the cylinder 11. Note that a limit switch or the like may be provided instead of the proximity sensors S1 and S2.

[0041] As described above, the cylinder cleaning device 100 according to this embodiment includes the metal pipe 120, which extends linearly in the axial direction of the cylinder 11 and is connected to the grinder 110, and the support 130, which is disposed outside the open end of the cylinder 11 and slidably supports the metal pipe 120. When cleaning the inner surface of the cylinder 11, the metal pipe 120 is moved longitudinally outside the cylinder 11, and the driven grinder inside the cylinder is moved axially along the cylinder. This eliminates the need to lengthen the rotating shaft 112 of the grinder 110, suppresses vibration of the rotating shaft 112 of the grinder 110 during cleaning, and makes it easier to clean the inner surface of the cylinder 11. Furthermore, because the metal pipe 120 does not rotate, safety is also excellent.

[0042] <Modifications of Brush 113> Next, modifications of the brush 113 of the grinder 110 will be described with reference to Figures 4 to 6. Figures 4 to 6 are enlarged views of the grinder 110 inside the cylinder 11. The brush 113 shown in Figure 4 is the wheel wire brush shown in Figures 2 and 3. Therefore, the brush 113 has the same shape when it is stationary and when it is rotating.

[0043] 4, with the wheel wire brush, a gap G occurs between the inner surface of the cylinder 11 and the brush 113. Therefore, to clean the entire inner surface of the cylinder 11, for example, it is necessary to repeatedly move the brush 113 back and forth in the X-axis direction while changing the position where the inner surface of the cylinder 11 contacts the brush 113, which is time-consuming.

[0044] In contrast, in the end-type brush 113a according to the modified example shown in Figures 5 and 6, when the end-type brush 113a is stationary, as shown in Figure 5, the metal wires constituting the brush extend in the X-axis direction and do not come into contact with the inner surface of the cylinder 11. On the other hand, when the end-type brush 113a is rotating, as shown in Figure 6, the metal wires constituting the brush spread out in a direction perpendicular to the X-axis direction due to centrifugal force, and the metal wires come into contact with the inner surface of the cylinder 11. Therefore, the end-type brush can clean the entire inner surface of the cylinder 11 more efficiently than a wheel wire brush.

[0045] Second Embodiment <Configuration of Support Unit 130> Next, the configuration of a cylinder cleaning device according to a second embodiment will be described with reference to Fig. 7 and Fig. 8. Fig. 7 is a schematic plan view showing the configuration of the support unit 130 in the cylinder cleaning device according to the second embodiment. Fig. 8 is a schematic side view showing the configuration of the support unit 130 in the cylinder cleaning device according to the second embodiment. As shown in Fig. 8, the support unit 130 in the cylinder cleaning device according to the second embodiment is supported rotatably around the X-axis with respect to the base 150.

[0046] 7 and 8, the support part 130 is fixed to one end of a linear link LN. The other end of the link LN is rotatably connected via a pin PN2 to the periphery of a disk-shaped pulley PL that rotates around the X-axis. An opening is provided in the center of the width of the link LN along the longitudinal direction, and this opening of the link LN is engaged with a pin PN1 fixed to the support 131. The center of the pulley PL is fixed to the rotation shaft of the motor MT, and the pulley PL is rotated by the motor MT.

[0047] 8, when the pulley PL rotates, the other end of the link LN connected to the pin PN2 rotates around the X-axis, and the link LN slides around the pin PN1 as a fulcrum. Therefore, the support part 130 fixed to one end of the link LN also rotates around the X-axis. With this configuration, the metal pipe 120 supported by the support part 130 can be caused to move circularly around the X-axis, and the rotating brush 113 can move along the inner surface of the cylinder 11 when cleaning the inner surface of the cylinder 11.

[0048] As described above, the cylinder cleaning device 100 according to this embodiment includes a circular motion mechanism that causes the metal pipe 120 inserted inside the cylinder 11 to perform a circular motion around the X axis. Therefore, even if a gap G is formed between the inner surface of the cylinder 11 and the brush 113, as shown in Fig. 4, the rotating brush 113 can be moved along the inner circumferential surface of the cylinder 11 to clean the entire inner circumferential surface of the cylinder 11. The rest of the configuration is the same as that of the cylinder cleaning device 100 according to the first embodiment, and therefore a description thereof will be omitted.

[0049] <Other Embodiments> When the cylinder 11 is a cylinder for a twin-screw kneader, it may include a pair of grinders 110, metal pipes 120, and support parts 130. When cleaning the inner surface of the cylinder 11, the pair of metal pipes 120 are moved outside the cylinder 11 in the longitudinal direction of the cylinder 11, and the pair of grinders 110 housed inside the cylinder 11 are moved simultaneously. Here, the pair of grinders 110 may be arranged offset in the X-axis direction so that the brushes 113 of the pair of grinders 110 do not interfere with each other.

[0050] The invention made by the inventor has been specifically described above based on the embodiments, but it goes without saying that the present invention is not limited to the embodiments already described, and various modifications are possible within the scope of the gist of the invention.

[0051] This application claims priority based on Japanese Patent Application No. 2024-081569, filed May 20, 2024, the disclosure of which is incorporated herein in its entirety by reference.

[0052] REFERENCE SIGNS LIST 11 Cylinder 100 Cylinder cleaning device 110 Grinder 111 Main body 112 Rotating shaft 113 Brush 113a End-type brush 120 Metal pipe 130 Support part 131 Support 140 Pipe feed mechanism 150 Frame LN Link MT Motor P1, P2 Reflector PL Pulley PN1, PN2 Pin R1, R2 Pinch roll S1, S2 Proximity sensor

Claims

1. A cylinder cleaning device for cleaning the inner surface of a cylinder of a kneading machine, comprising: a grinder having a rotating shaft and a brush attached to the tip of the rotating shaft; a metal pipe extending linearly in the axial direction of the cylinder and connected to the grinder; and a support part disposed outside the open end of the cylinder and supporting the metal pipe in a slidable manner, wherein, when cleaning the inner surface of the cylinder, the metal pipe is moved longitudinally outside the cylinder, and the grinder, driven inside the cylinder, is moved in the axial direction of the cylinder.

2. The cylinder cleaning device according to claim 1, wherein the grinder is an air grinder, and air is supplied to the grinder through the metal pipe.

3. The cylinder cleaning device according to claim 1, wherein the grinder is an electric grinder, and the metal pipe houses an electric wire that supplies electricity to the grinder.

4. The cylinder cleaning device according to any one of claims 1 to 3, further comprising a pipe feeding mechanism that is disposed outside the open end of the cylinder and moves the metal pipe in the longitudinal direction of the cylinder.

5. The cylinder cleaning device according to claim 4, wherein the pipe feed mechanism also serves as the support portion.

6. The cylinder cleaning device according to any one of claims 1 to 3, further comprising an alignment mechanism that aligns the metal pipe inserted inside the cylinder with the central axis of the cylinder.

7. A cylinder cleaning device according to any one of claims 1 to 3, further comprising a circular motion mechanism that causes the metal pipe inserted inside the cylinder to move in a circular motion so that the rotating brush moves along the inner circumferential surface of the cylinder when cleaning the inner surface of the cylinder.

8. A cylinder cleaning device according to any one of claims 1 to 3, wherein the brush is an end-type brush.

9. The cylinder cleaning device according to any one of claims 1 to 3, wherein the kneading machine is a twin-shaft kneading machine and is provided with a pair of the grinders, the metal pipes, and the support parts, and when cleaning the inner surface of the cylinder, the pair of metal pipes are moved outside the cylinder in the longitudinal direction of the cylinder, and the pair of grinders housed inside the cylinder are moved simultaneously.

10. A cylinder cleaning method comprising: (a) a step of housing a grinder having a brush attached to the tip of the rotating shaft inside the cylinder of a kneading machine; (b) a step of driving the grinder housed inside the cylinder; and (c) a step of moving the driven grinder in the axial direction of the cylinder to clean the inner surface of the cylinder, wherein the grinder is connected to a metal pipe extending linearly in the longitudinal direction of the cylinder, and the metal pipe is slidably supported on a support part positioned outside the open end of the cylinder, and in step (c), the metal pipe is moved in the longitudinal direction outside the cylinder, and the driven grinder inside the cylinder is moved in the axial direction of the cylinder.

11. The cylinder cleaning method according to claim 10, wherein the grinder is an air grinder, and air is supplied to the grinder via the metal pipe.

12. The cylinder cleaning method according to claim 10, wherein the grinder is an electric grinder, and an electric wire for supplying electricity to the grinder is housed in the metal pipe.

Images