Screw machinery

Abstract

The extruder includes: a screw that is driven to rotate around an axis by a first motor; a barrel that has a screw hole for inserting the screw and an air outlet for discharging air in the screw hole; a filter, a portion of which faces the air outlet of the barrel; and a filter driving mechanism that displaces the filter and changes the portion of the filter facing the air outlet.

Description

Technical Field

[0001] The invention relates to a screw machine. Background Art

[0002] Japanese Patent Application Laid-Open No. 2014-223804 discloses a screw machine for feeding and processing bulk material. The screw machine comprises a housing, a shaft disposed within the housing, a screw element disposed on the outer periphery of the shaft, and a filter removably disposed at an opening in the housing to extract gas from the bulk material. Summary of the Invention

[0003] As described in Japanese Patent Application Laid-Open No. 2014-223804, in screw machines, an opening is sometimes provided in the casing to extract gas (air) from the material, and a filter is provided at the opening to prevent the material inside the casing from being discharged through the opening.

[0004] Such filters sometimes become clogged with material adhering to their surfaces. Consequently, screw machines require maintenance work such as removing the filter from the machine and replacing or cleaning it. Since this maintenance work must be performed while the screw machine is stopped, it reduces the productivity of the screw machine.

[0005] An object of the present invention is to provide a screw machine capable of improving productivity.

[0006] According to one embodiment of the present invention, a screw machine comprises: a screw, which is rotationally driven around an axis by a driving source; a barrel, which has a screw hole for inserting the screw and an exhaust port for exhausting air in the material in the screw hole; a filter, a portion of which faces the exhaust port of the barrel; and a filter driving unit, which displaces the filter and changes the portion of the filter facing the exhaust port. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a cross-sectional view showing the overall structure of an extruder according to an embodiment of the present invention.

[0008] Figure 2 This is a cross-sectional view showing an extruder according to an embodiment of the present invention, taken along Figure 1 Cross-sectional view along line II-II.

[0009] Figure 3 It is a top view of the cover of the extruder according to the embodiment of the present invention.

[0010] Figure 4It is a cross-sectional view showing an extruder according to a first modified example of the embodiment of the present invention.

[0011] Figure 5 It is a cross-sectional view showing an extruder according to a second modified example of the embodiment of the present invention.

[0012] Figure 6 It is a cross-sectional view showing a cover of an extruder according to a third modified example of the embodiment of the present invention.

[0013] Figure 7 It is a cross-sectional view showing a cover of an extruder according to a fourth modified example of the embodiment of the present invention. DETAILED DESCRIPTION

[0014] The following describes a screw machine according to an embodiment of the present invention with reference to the accompanying drawings. For ease of explanation, the scale of each component in each drawing may be appropriately modified, and the components may not be depicted precisely. Furthermore, for multiple identical components, only some of them may be designated with reference numerals, and reference numerals may be omitted for other components.

[0015] The screw machine of this embodiment is an extruder that kneads granular or powdered materials fed into the screw hole 21 of a barrel 20 while conveying them using screws 10a and 10b, and then extrudes the kneaded materials from the discharge port 23 of the barrel 20 to form the materials. Hereinafter, the screw machine of this embodiment will be described as "extruder 100."

[0016] like Figure 1 as well as Figure 2 As shown, the extruder 100 includes: a pair of screws 10a and 10b; a barrel 20 having screw holes 21 into which the pair of screws 10a and 10b are inserted; a first motor 30 serving as a drive source for rotating the pair of screws 10a and 10b within the screw holes 21; and a controller 80 for controlling the operation of the extruder 100. Thus, the extruder 100 is a so-called twin-screw kneading extruder including a pair of screws 10a and 10b.

[0017] like Figure 1 As shown, the barrel 20 is formed in a manner extending in one direction and has a pair of insertion holes 21a and 21b formed along its longitudinal direction (see FIG. Figure 2 A pair of insertion holes 21a, 21b are connected to each other, and the screw hole 21 is formed by the pair of insertion holes 21a, 21b.

[0018] At one end of the barrel 20 in the longitudinal direction, a supply port 22 for supplying material into the screw hole 21 is formed so as to open at the screw hole 21. At the other end of the barrel 20 in the longitudinal direction, a discharge port 23 for discharging a kneaded product formed from the melted and kneaded materials is formed so as to open at the screw hole 21. Figure 1 The right side of the screw hole 21 is called the "upstream" and the ejection port 23 side ( Figure 1 The left side in the middle is referred to as the “downstream” of the screw hole 21. The material supplied into the screw hole 21 through the supply port 22 is conveyed downstream by the screws 10a and 10b and ejected out of the barrel 20 through the ejection port 23.

[0019] Although not shown in the figure, the barrel 20 is provided with a heating device for heating the barrel 20 , a cooling device for cooling the barrel 20 , a vacuum device for volatilization, a temperature sensor for detecting the temperature of the barrel 20 , and the like.

[0020] like Figure 2 As shown, a pair of screws 10a, 10b have the same shape as each other and are arranged in a manner extending in parallel and are inserted into the screw hole 21 of the barrel 20 in a state of being meshed with each other. The pair of screws 10a, 10b are driven by a first motor 30 (see Figure 1 ) and rotate in the same direction around their respective central axes (axis lines). That is, the pair of screws 10a and 10b rotate synchronously with each other. Hereinafter, the pair of screws 10a and 10b will be collectively referred to as simply "screw 10" and their specific structure will be described.

[0021] like Figure 1 As shown, the screw 10 is a shaft member provided along the longitudinal direction of the barrel 20 from the base end connected to the first motor 30 toward the tip. The base end of the screw 10 is located upstream of the screw hole 21, and the tip is located downstream of the screw hole 21.

[0022] The screw 10 includes a conveying portion 11 that conveys the material in the screw hole 21 downstream, a kneading portion 13 that melts and kneads the material in the screw hole 21, and a tip portion 15 that ejects the kneaded material in the screw hole 21 from the ejection port 23. The conveying portion 11, kneading portion 13, and tip portion 15 are arranged in this order from upstream to downstream of the screw hole 21.

[0023] The conveying portion 11 has a spiral flight 11 a (screw blade) on its outer periphery. The material supplied from the supply port 22 to the screw hole 21 is conveyed toward the kneading portion 13 on the downstream side by the conveying portion 11 of the rotating screw 10 .

[0024] The kneading section 13 is composed of a plurality of kneading discs 13a arranged in the longitudinal direction (the axial direction of the screw 10). The kneading section 13 melts and kneads the transferred material.

[0025] The tip portion 15 has a spiral thread 15 a on its outer periphery. The material melted by the kneading portion 13 is extruded from the ejection port 23 through the tip portion 15 and ejected to the outside of the barrel 20 .

[0026] The first motor 30 is an electric motor and its operation is controlled by the controller 80. The rotation of the first motor 30 is transmitted to the pair of screws 10a and 10b via a speed reducer (not shown).

[0027] The controller 80 is composed of a microcomputer including a CPU (central processing unit), ROM (read-only memory), RAM (random access memory), and an I / O interface (input and output interface). The RAM stores data being processed by the CPU, the ROM stores the control program of the CPU in advance, and the I / O interface is used for input and output of information between the connected devices. The controller 80 is programmed so as to be able to execute at least the processing required to execute the control involved in this embodiment and the modified example. In addition, the controller 80 can be configured as a single device or can be configured in a manner that is divided into multiple devices and each control is processed in a distributed manner by the multiple devices.

[0028] In addition, the extruder 100 includes: a cylindrical filter 40 facing the air outlet 25 provided on the barrel 20; a filter housing 50 having a housing space 50a for housing the filter 40 and being mounted on the barrel 20; a filter driving mechanism 60 as a filter driving unit that rotates the filter 40; and a vacuum pump 70 that sucks air from the screw hole 21 from the air outlet 25 via the filter 40.

[0029] like Figure 2 As shown, the barrel 20 is provided with an opening 24 that communicates with the screw hole 21 and opens to the outside of the barrel 20 , and a cover 27 that covers the opening 24 .

[0030] The cover 27 includes a flange portion 27a that is mounted on the barrel 20 by bolts or the like (not shown), and a cover portion 27b that is inserted into the opening 24 and covers the opening 24. Figure 3 As shown, a plurality of through holes 25a are formed on the cover portion 27b and communicate with the screw hole 21. The plurality of through holes 25a constitute the air outlet 25. The plurality of through holes 25a are circular holes and are formed in the same shape as each other. Figure 3In FIG. 1 , the symbols of some through holes 25 a are omitted.

[0031] like Figure 1 As shown, the air outlet 25 (opening 24 of the barrel 20) is provided so as to open at the screw hole 21 on the upstream side of the kneading section 13 of the screw 10. That is, the air outlet 25 is provided between the kneading section 13 of the screw 10 and the supply port 22 in the axial direction of the screw 10 (the longitudinal direction of the barrel 20) and at a position opposite to the transfer section 11.

[0032] like Figure 2 As shown, the filter 40 is formed into a cylindrical shape having an internal space 40a. The filter 40 allows the passage of air and restricts (blocks) the passage of powdered materials. The filter 40 is made of a non-woven fabric, a porous material, a perforated metal, or a metal porous plate such as a metal mesh. In addition, the filter 40 can be made of a single filter component formed by a porous material, a non-woven fabric, and a metal porous plate, or it can be an assembled filter composed of a plurality of filter components with different materials and properties (such as the coarseness of the holes). The filter 40 is configured so that a portion of the cylindrical outer circumference contacts the cover portion 27b of the cover 27, or a portion of the cylindrical outer circumference is arranged along the cover portion 27b of the cover 27 with a slight gap to capture the powdered material discharged to the outside of the screw hole 21 through the air outlet 25. Therefore, a portion of the outer circumference of the filter 40 faces the air outlet 25.

[0033] like Figure 2 As shown, the filter housing 50 is formed in a box shape with one end open, and the open end is mounted on the barrel 20. The entire filter 40 is accommodated in a receiving space 50a formed in the filter housing 50. The filter housing 50 is formed with a suction port 51 that opens at the receiving space 50a.

[0034] The filter drive mechanism 60 includes a second motor 61, which is an electric motor; a rotating shaft 62 connected to the rotating shaft (not shown) of the second motor 61 and transmitting the rotation output by the rotating shaft; and a pair of mounting plates 63a and 63b mounted on the ends of the filter 40. The rotating shaft of the second motor 61 is connected to the base end (not shown) of the rotating shaft 62.

[0035] A pair of mounting plates 63a and 63b are respectively mounted on both ends of the filter 40 in a manner that blocks the internal space 40a. The pair of mounting plates 63a and 63b are disc-shaped plates each having an outer diameter substantially the same as that of the filter 40. The rotating shaft 62 is inserted through the mounting plate 63a on one side and the internal space 40a of the filter 40 in a manner that passes through the central axis of the filter 40, and its top end is connected to the mounting plate 63b on the other side. That is, the rotating shaft 62 is connected to the filter 40 via the mounting plate 63b. The rotation of the output shaft of the second motor 61 is transmitted to the rotating shaft 62, so that the filter 40 rotates around its central axis together with the rotating shaft 62. The rotating shaft 62 (the central axis of the filter 40) is perpendicular to the central axis of the screw 10 (refer to Figure 1 ), and in the direction adjacent to a pair of screws 10 (axial direction, Figure 2 They are arranged in parallel (in the left and right directions).

[0036] The vacuum pump 70 sucks air from the storage space 50a through the suction port 51 of the filter housing 50. This causes the air in the screw hole 21 to be sucked from the air outlet 25 to the vacuum pump 70 via the filter 40. Since the vacuum pump 70 can employ a known structure, detailed description and illustration are omitted.

[0037] The operations of the second motor 61 of the filter driving mechanism 60 and the vacuum pump 70 are controlled by the controller 80 .

[0038] Next, the operation of the extruder 100 will be described.

[0039] When the extruder 100 is operated, the first motor 30 is controlled by the controller 80 so that the pair of screws 10 rotate in the same direction and at the same speed.

[0040] The powdered material supplied into the screw hole 21 through the supply port 22 is conveyed downstream in the longitudinal direction by the conveying portion 11 of the screw 10. During this process, air may be mixed into the screw hole 21 along with the material. When air is mixed into the screw hole 21, a corresponding amount of material cannot be supplied into the screw hole 21. In other words, the air in the screw hole 21 hinders the supply of the material.

[0041] In contrast, the extruder 100 is provided with an air outlet 25 in the barrel 20. Therefore, air mixed with the material into the screw hole 21 is discharged to the outside of the screw hole 21 through the air outlet 25. Specifically, the air in the screw hole 21 is discharged from the air outlet 25 through the filter 40 into the storage space 50a of the filter housing 50 due to the pressure applied to the material by the conveying portion 11 of the screw 10 and the suction force of the air generated by the vacuum pump 70. The air discharged into the storage space 50a is then sucked into the vacuum pump 70 through the suction port 51. This prevents the air mixed into the screw hole 21 from obstructing the supply of material into the screw hole 21.

[0042] In addition, the filter 40 is continuously rotated at a constant speed by the second motor 61. Therefore, the portion of the outer peripheral surface of the filter 40 facing the air outlet 25 (hereinafter, this portion will also be referred to as the "filter surface") is sequentially changed as the filter 40 rotates. That is, in the extruder 100, the same portion of the filter 40 does not always face the air outlet 25, but is constructed so that different portions of the filter 40 sequentially face the air outlet 25 as new filter surfaces as the filter 40 rotates. In this way, since the filter surface facing the air outlet 25 (in other words, the material in the screw hole 21) is updated by the rotation of the filter 40, it is difficult for the pores of the filter 40 to become clogged. As a result, the maintenance work of the filter 40 caused by pore clogging can be suppressed, and the productivity achieved by the extruder 100 can be improved.

[0043] In the extruder 100, the filter 40 is provided outside the screw hole 21, and the screw hole 21 is provided outside the filter 40. The cylindrical outer peripheral surface of the filter 40 serves as a filter surface facing the air outlet 25, and the filter 40 is rotated by the second motor 61. As the filter surface of the filter 40 rotates by the second motor 61, it displaces around the rotation axis 62 within the housing space 50a and faces the air outlet 25 again.

[0044] Thus, the filter 40 is formed into a cylindrical shape and is rotated and displaced in the receiving space 50a. Figure 2 As shown, part of the air discharged from the air outlet 25 to the outside of the screw hole 21 is guided from the outside of the filter 40 to the inside (internal space 40a), passes through the filter 40 again from the inside to the outside, and is guided to the suction port 51 (refer to Figure 2(middle arrow). Thus, even if powdered material adheres to the filter surface facing the air outlet 25, the flow of air from the interior of the filter 40 to the exterior can remove the material adhering to the outer peripheral surface of the filter 40. Since the flow of air drawn into the vacuum pump 70 removes the material adhering to the filter 40, clogging of the filter 40 can be further suppressed. Consequently, the need to stop the extruder 100 for filter 40 maintenance can be avoided, and the extruder 100 can be operated continuously, thereby improving productivity.

[0045] Furthermore, in the extruder 100, the air outlet 25 of the barrel 20 is formed of a plurality of through-holes 25a. In addition to the filter 40 positioned facing the air outlet 25, the air outlet 25 itself also functions as a filter, allowing air to pass but restricting the passage of material. In other words, the cover portion 27b of the cover 27 provided for the air outlet 25 is constructed like perforated metal. This reduces the load on the filter 40 for removing foreign matter, further preventing clogging of the filter 40.

[0046] Furthermore, the mesh size of the gas outlet 25 is configured to be larger than the mesh size of the filter 40. From another perspective, the permeability of the gas outlet 25 is higher than that of the filter 40. Conversely, the pressure loss of the gas passing through the gas outlet 25 is lower than the pressure loss of the gas passing through the filter 40. Consequently, the filter 40 primarily performs the function of removing the material discharged from the screw hole 21 along with the gas.

[0047] Next, variations of this embodiment are described. The following variations are also within the scope of the present invention and can be combined with the structures of the above embodiment or with each other. In addition, in each variation, the same reference numerals are used for the same structures as the above embodiment, and the description thereof is omitted.

[0048] In the above embodiment, the filter 40 is formed in a cylindrical shape and is rotationally displaced by the second motor 61. In contrast, the filter 40 is not limited to a cylindrical shape. In addition, the filter 40 is not limited to a rotationally displaced structure.

[0049] exist Figure 4In the first variation shown, the filter 140 is formed into an endless belt with both ends connected. The filter drive mechanism 160 of the first variation includes a pair of rollers 162a and 162b around which the belt-shaped filter 140 is hung, and a third motor 161 that rotationally drives the pair of rollers 162a and 162b. The filter 140 is positioned so that a portion located between the pair of rollers 162a and 162b faces the air outlet 25 of the barrel 20. The pair of rollers 162a and 162b are rotationally driven by the third motor 161, causing the filter 140 to rotate and shift between the pair of rollers 162a and 162b. This allows the portion of the filter 140 facing the air outlet 25 to be replaced.

[0050] In addition, Figure 5 In the second modified example shown, the filter 240 is formed into a flat plate shape and is arranged so that the wide flat plate surface 240a perpendicular to the plate thickness direction faces the air outlet 25. The filter drive mechanism 260 has a function of moving the filter 240 in the direction in which the pair of screws 10 are adjacent (the direction between the central axes, Figure 5 Actuator 261 moves forward and backward in the left and right directions (in the middle and left and right directions). Actuator 261 can be a fluid pressure cylinder or a linear motion mechanism including an electric motor and a ball screw. Actuator 261 reciprocates filter 240 so that any portion of the flat surface 240a of filter 240 always faces the air outlet 25. This allows the portion of filter 240 facing the air outlet 25 to be replaced.

[0051] In this way, the filter can be formed into a belt shape and rotated as in the first variant, or it can be displaced linearly as in the second variant. That is, in the extruder 100, as long as the following structure is adopted, that is, a portion of the filter 40, 140, 240 is directed toward the air outlet 25, and the filter driving mechanism 60, 160, 260 is used to displace the filter 40, 140, 240, thereby changing the portion of the filter 40, 140, 240 facing the air outlet 25 (the filter surface), other structures can be set as any other structure. Even in the first and second variants described above, since the portion of the filter 140, 240 facing the air outlet 25 is replaced, it is possible to prevent the pores of the filter 140, 240 from clogging and suppress the need for maintenance work.

[0052] In addition, in the above embodiment, the air outlet 25 is composed of a plurality of circular through holes 25a. In contrast, the structure of the air outlet 25 is not limited to the structure in the above embodiment. Figure 6 As shown in the third modified example, the air outlet 25 may also be formed by a pair of long holes 125a and 125b formed into a substantially rectangular shape when viewed from above. Figure 7 As shown in the fourth modified example, the air outlet 25 may be formed of a single hole 225. Alternatively, the air outlet 25 may be formed of the opening 24 formed in the barrel 20 without providing the cover 27, and the filter 40 may be directly facing the opening 24. In other words, it is not essential that the air outlet 25 function as a filter.

[0053] In addition, in the above-mentioned embodiment, the second motor 61 of the filter driving mechanism 60 is controlled by the controller 80 in such a manner that the filter 40 continuously rotates in the same direction at a certain speed (always rotates during the operation of the extruder 100). In contrast, from the perspective of preventing clogging of the pores of the filter 40, it is preferred that the filter 40 rotates continuously at a certain speed, but is not limited to this. For example, the second motor 61 may also rotate the filter 40 intermittently (intermittently) in such a manner that the filter 40 repeatedly rotates and stops at predetermined time intervals. Even in this case, since the filter surface of the filter 40 facing the air outlet 25 is updated, it is possible to prevent clogging of the pores of the filter 40 and suppress the occurrence of maintenance work.

[0054] In addition, although the extruder 100 is provided with a vacuum pump 70 for sucking air from the screw hole 21 in the above embodiment, the vacuum pump 70 is not a necessary structure. In addition, the extruder 100 may also be provided with a removal unit for removing material adhering to the filter 40 from the filter 40. As the removal unit, for example, an air blower device that is provided in the internal space 40a of the filter 40 and ejects air from the inside of the filter 40 to the outside can be used. By providing the removal unit, it is possible to actively remove material adhering to the filter 40, and therefore it is particularly effective when the vacuum pump 70 is not provided.

[0055] In addition, although the central axis (rotational axis 62) of the filter 40 is arranged parallel to the adjacent direction of the pair of screws 10 in the above embodiment, the present invention is not limited to this structure. For example, the central axis of the filter 40 may be arranged parallel to the longitudinal direction of the barrel 20 (the axial direction of the screw 10).

[0056] In the above embodiment, the pair of screws 10a and 10b (see Figure 2 ) rotate in the same direction with each other. In contrast, a pair of screws 10a, 10b may rotate in opposite directions with each other.

[0057] In the above embodiment, the extruder 100 is a so-called twin-screw kneading extruder including a pair of screws 10 a and 10 b . However, the extruder 100 may be a so-called uniaxial kneading extruder including a single screw 10 .

[0058] In the above embodiment, the screw machine is an extruder 100 that kneads and extrude materials. Alternatively, the screw machine may be a material feeder (side feeder) that feeds material to the extruder 100. The screw 10 of the material feeder consists solely of a conveying portion 11, and conveys the material without kneading or melting.

[0059] Hereinafter, the effects of this embodiment will be described.

[0060] The extruder 100 comprises: a screw 10, which is driven to rotate around an axis by a first motor 30; a barrel 20, which has a screw hole 21 for inserting the screw 10 and an air outlet 25 for discharging air in the screw hole 21; a filter 40, a portion of which faces the air outlet 25 of the barrel 20; and a filter driving mechanism 60, which displaces the filter 40 and changes the portion of the filter 40 facing the air outlet 25.

[0061] In this configuration, the filter 40 is displaced by the filter drive mechanism 60, so that the filter surface of the filter 40 can be updated even during the operation of the extruder 100. This can suppress the occurrence of clogging in the filter 40. Consequently, the need for maintenance work on the filter 40 can be reduced, and the productivity achieved by the extruder 100 can be improved.

[0062] The extruder 100 also includes a vacuum pump 70 that sucks air from the screw hole 21 through the air outlet 25 via the filter 40 .

[0063] According to this structure, the air in the screw hole 21 can be efficiently discharged to the outside of the screw hole 21 .

[0064] In addition, the extruder 100 also has a filter housing 50, which has a receiving space 50a for receiving the filter 40 and is installed on the barrel 20. The vacuum pump 70 sucks the air in the screw hole 21 through the suction port 51 formed in the filter housing 50 in a manner opening at the receiving space 50a. The filter driving mechanism 60 rotates the filter 40, and a portion of the outer peripheral surface of the filter 40 facing the air outlet 25 is displaced in the receiving space 50a and faces the air outlet 25 as the filter 40 is rotated by the filter driving mechanism 60.

[0065] In this structure, a portion of the air sucked in by the vacuum pump 70 and discharged from the air outlet 25 to the outside of the screw hole 21 is guided from the outside of the filter 40 to the inside, passes through the filter 40 again from the inside to the outside, and is guided to the suction port 51. Thus, even if powdered material adheres to the filter surface facing the air outlet 25, the flow of air from the inside to the outside of the filter 40 can remove the material adhering to the outer peripheral surface of the filter 40. In this way, since the flow of air sucked into the vacuum pump 70 can remove material adhering to the filter 40, clogging of the filter 40 can be further suppressed. Therefore, it is possible to prevent the extruder 100 from being stopped for maintenance of the filter 40, and the extruder 100 can be operated continuously, thereby improving productivity.

[0066] In the extruder 100 , the gas outlet 25 is composed of a plurality of through holes 25 a , 125 a , and 125 b .

[0067] In this structure, the air outlet 25 functions as the filter 40 , so that the load on the filter 40 can be reduced and clogging of the filter 40 can be reduced.

[0068] In addition, in the extruder 100 , the filter driving mechanism 60 continuously rotates the filter 40 at a constant speed.

[0069] In this structure, the occurrence of clogging of the filter 40 can be further effectively suppressed.

[0070] In addition, in the extruder 100, the barrel 20 has: a supply port 22, which is used to feed material into the screw hole 21; an ejection port 23, which is used to eject the material in the screw hole 21 to the outside of the barrel 20, and the screw 10 has a kneading portion 13 for kneading the material in the screw hole 21 of the barrel 20. The air outlet 25 of the barrel 20 is located between the kneading portion 13 of the screw 10 and the supply port 22 of the barrel 20 in the axial direction of the screw 10, and opens at the screw hole 21.

[0071] In this structure, the air in the screw hole 21 can be discharged through the air outlet 25 at a position close to the supply port 22 . Therefore, the air mixed in the screw hole 21 can be easily discharged, and the situation in which the material supply in the screw hole 21 is hindered by the air can be reduced.

[0072] While the embodiments of the present invention have been described above, the above embodiments merely represent a part of application examples of the present invention and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0073] This application claims priority based on Japanese Patent Application No. 2020-141257 filed with the Japan Patent Office on August 24, 2020, and all the contents of that application are incorporated into this specification by reference.

Claims

1. A screw machine having: a screw that is rotationally driven about an axis by a driving source; a barrel having a screw hole for inserting the screw and an air outlet for exhausting air in the screw hole; a filter, a portion of which faces the air outlet of the barrel; a filter driving unit that displaces the filter and changes a portion of the filter facing the air outlet; a vacuum pump, which sucks air from the screw hole through the air outlet through the filter; A filter housing has a receiving space for receiving the filter and is mounted on the barrel. The vacuum pump sucks the air in the screw hole through a suction port formed in the filter housing so as to open in the accommodation space. The filter driving unit rotates the filter. The filter is formed into a cylindrical shape having an internal space, and is configured such that a portion of the air discharged from the air outlet to the outside of the screw hole is guided from the outside of the filter to the internal space, and then passes through the filter again from the internal space of the filter to the outside, and is guided to the suction port. A portion of the outer peripheral surface of the filter facing the air outlet is displaced within the accommodation space as the filter is rotated by the filter driving unit, and faces the air outlet again.

2. The screw machine according to claim 1, wherein: The air outlet is composed of a plurality of holes.

3. The screw machine according to claim 1, wherein: The filter driving unit continuously rotates the filter at a constant speed.

4. The screw machine according to claim 1, wherein: The barrel has: a supply port for feeding material into the screw hole; A spray port is used to spray the material in the screw hole out of the barrel, The screw has a kneading portion for kneading the material in the screw hole of the barrel, The gas outlet of the barrel is located between the kneading portion of the screw and the supply port of the barrel in the axial direction of the screw and opens at the screw hole.

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