Shutter mechanism and drying device

Abstract

To provide a shutter mechanism capable of sufficiently switching to a shut state, and a drying device comprising such a shutter mechanism.SOLUTION: A shutter mechanism 50 comprises: a shutter frame 51, with a first cylindrical space 50a and a second cylindrical space 50b formed therein, an inflow opening 511a formed to penetrate an inflow side plate 511 (a first outer wall), an outflow opening 512a formed to penetrate an outflow side plate 512 (a second outer wall), and a passage opening 513a formed to penetrate a partition plate 513 (a partition wall); an inflow side shutter 52 inserted / disposed in the first cylindrical space 50a and slidable between an inflow side shielding position P11 and an inflow side communication position; and an outflow side shutter 53 inserted / disposed in the second cylindrical space 50b and slidable between an outflow side shielding position P13 and an outflow side communication position.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a shutter mechanism that switches the flow of particulate matter between a blocked state and an open state, and a drying device equipped with such a shutter mechanism. [Background technology]

[0002] Conventionally, resin molding machines that perform processes such as resin injection molding are supplied with heated and dried resin pellets as a resin material for molding. These resin pellets are supplied from a drying device that performs a heat-drying process on granular materials such as resin pellets. Such a granular material drying device receives the granular materials to be dried, performs a heat-drying process, and then discharges the dried granular materials to a destination such as a resin molding machine. In many cases, a shutter mechanism that switches the flow of the granular materials between a blocked state and an open state is installed on the discharge side of the drying device (see, for example, Patent Document 1).

[0003] The shutter mechanism described in Patent Document 1 has a configuration in which an inlet opening and an outlet opening for a group of granular materials are formed coaxially through the outer wall of a cylindrical shutter frame, and a shutter is slidably inserted into the cylindrical space inside the frame. By sliding the shutter, the inlet opening and outlet opening are blocked or connected to each other, and the flow of the group of granular materials can be switched between a blocked state and an open state. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-237406 Summary of the Invention [Problem to be solved by the invention]

[0005] In the shutter mechanism of Patent Document 1, when switching the flow of granular material from an open state to a blocked state, the shutter slides while pushing aside some of the granular material flowing between the inlet and outlet openings in the sliding direction. This can cause the pushed-aside granular material to become pinched between the inner wall of the shutter frame and the shutter. If this pinching occurs, the shutter may stop before the switch to the blocked state is complete, potentially reducing the airtightness between the inlet and outlet openings in the blocked state. If this type of airtightness is reduced in a shutter mechanism installed in a drying device, dry gas, such as nitrogen gas, introduced for drying purposes may leak from the shutter mechanism, resulting in a shortage of dry gas and rendering the shutter useless for drying.

[0006] Therefore, the present invention focuses on the above-mentioned problems and aims to provide a shutter mechanism that can adequately switch to a blocking state, and a drying device equipped with such a shutter mechanism. [Means for solving the problem]

[0007] In order to solve the above problems, the shutter mechanism is a frame member in which a first cylindrical space and a second cylindrical space are formed parallel to each other, an inflow opening for a group of granular materials is formed through a first outer wall that defines the first cylindrical space, an outflow opening for the group of granular materials is formed through a second outer wall that defines the second cylindrical space and is positioned opposite the first outer wall so as to be coaxial with the inflow opening, and further, a passage opening for the group of granular materials is formed through a partition wall that separates the first cylindrical space and the second cylindrical space so as to be coaxial with the inflow opening and the outflow opening. the second cylindrical space is provided with a shutter frame; an inlet-side shutter which is a member inserted and arranged in the first cylindrical space and is slidable along the central axis of the first cylindrical space between an inlet-side shielding position which shields the inlet opening and the passing opening from each other and an inlet-side communicating position which connects the two; and an outlet-side shutter which is a member inserted and arranged in the second cylindrical space and is slidable along the central axis of the second cylindrical space between an outlet-side shielding position which shields the passing opening and the outlet opening from each other and an outlet-side communicating position which connects the two.

[0008] In addition, in order to solve the above-mentioned problems, the drying device is characterized by comprising a drying tank which is a tank that receives and stores a group of granular materials to be dried through an inlet, into which dry gas that has been subjected to a heated drying process is introduced to dry the group of granular materials inside the tank with the dry gas, and which discharges the dried group of granular materials from an outlet provided at the bottom of the tank, and the above-mentioned shutter mechanism which is connected to the outlet of the drying tank and switches the flow of the group of granular materials at the outlet between a blocked state and an open state. [Effects of the Invention]

[0009] According to the above-described shutter mechanism and drying device, switching to the shut-off state can be performed satisfactorily. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a schematic diagram illustrating a drying device including a shutter mechanism according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing the appearance of the shutter mechanism shown in FIG. 1. [Figure 3] FIG. 3 is an exploded perspective view of the shutter mechanism shown in FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view taken along line V11-V11 of the shutter mechanism shown in FIG. 2. [Figure 5] 5 is a schematic diagram showing, in a cross-sectional view equivalent to FIG. 4, how the flow of resin pellets is switched between a blocked state and an open state by the shutter mechanism shown in FIGS. 2 to 4. FIG. [Figure 6] FIG. 5 is a schematic diagram showing the clearances between the shutter frame and the inflow-side shutter and the clearances between the shutter frame and the outflow-side shutter in the shutter mechanism shown in FIGS. 2 to 4, taking the inflow-side shutter as a representative example. [Figure 7] FIG. 10 is a diagram showing, in table form, an example of a setting range of the thickness direction clearance taking into consideration thermal expansion when a stainless steel material is used. [Figure 8] FIG. 10 is a diagram showing, in table form, an example of a setting range of widthwise clearance taking into consideration thermal expansion when stainless steel material is used. [Figure 9] FIG. 10 is a table showing an example of a favorable clearance range determined from the preferable ranges in the tables of FIGS. 7 and 8, assuming use in the drying device of FIG. 1, for both the thickness direction and the width direction. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the shutter mechanism and the drying device will be described below.

[0012] FIG. 1 is a schematic diagram showing a drying device equipped with a shutter mechanism according to one embodiment.

[0013] The drying apparatus 1 of this embodiment is an apparatus that dries a group of granular materials to be dried, specifically, an apparatus that dries a group of resin pellets to be used as material in an injection molding machine A11, and supplies the dried group of resin pellets to an injection tube A111 of the injection molding machine A11 outside the apparatus.

[0014] In this drying apparatus 1, resin pellets stored in an external material tank A12 in a wet state are supplied to a first hopper mechanism 11, as indicated by arrow R11, which removes dust and other particles and then feeds the material. The first hopper mechanism 11 includes a suction hopper 111 for dust removal, a glass tube 112 for stirring the pellets, and a front-stage shutter 113 for sending the dust-removed resin pellets to a subsequent stage. The first hopper mechanism 11 also includes a charge hopper 114 for feeding the material, and a rear-stage shutter 115. The resin pellets supplied to the first hopper mechanism 11 are introduced into the suction hopper 111 and stirred inside the suction hopper 111 and the glass tube 112 by nitrogen gas injected into the first hopper mechanism 11 as indicated by arrow R14. This stirring separates the resin pellets from dust and other particles adhering to the surfaces of the pellets. The separated dust and other particles are sucked and removed together with the agitated gas from the suction hopper 111 through the filter 12 by the primary material blower 13, as shown by arrow R12. The primary material blower 13 discharges the gas from which the dust and other particles have been removed by the filter 12 to the outside. Meanwhile, the resin pellets from which the dust has been removed are sent in appropriate amounts to the charge hopper 114 through the front-stage shutter 113. Furthermore, the resin pellets are fed from the charge hopper 114 through the rear-stage shutter 115 into the drying tank 15, while being appropriately degassed by the degassing core pin 14.

[0015] The drying tank 15 is a tank that receives and stores the resin pellets to be dried through an inlet 151 connected to the rear shutter 115. In this drying tank 15, dry gas that has been subjected to a heated drying process is introduced as follows, and the resin pellets are dried inside the tank by the dry gas.

[0016] As shown by arrow R13, dry gas is introduced into the drying tank 15 while undergoing a heat drying process along the way. This dry gas is generated by nitrogen gas generated and injected into the nitrogen generator 16 and then heated and dried by the drying blower 17 and heater 18, as shown by arrow R14. The nitrogen generator 16 generates nitrogen gas using a nitrogen generator 163 from outside air drawn in through an air filter 161 and an air dryer 162, as shown by arrow R12. As shown by arrow R14, nitrogen gas is injected from the nitrogen generator 16 into various parts of the drying apparatus 1. Dry gas generated based on the nitrogen gas injected into the drying blower 17 is introduced into the drying tank 15. In the drying tank 15, the undried resin pellets introduced from the charge hopper 114 are dried by the dry gas introduced as described above. A paddle-type level gauge 152 is provided in the drying tank 15 to monitor the level of the resin pellets inside.

[0017] The drying gas used for drying in the drying tank 15 circulates as shown by arrow R13. That is, the drying gas is sucked from the drying tank 15 and returned to the drying blower 17 via a filter 19. The dry gas is then mixed with nitrogen gas injected from the nitrogen generator 16 and subjected to a heating and drying process again by the drying blower 17 and heater 18, before being introduced into the drying tank 15 and used again to dry the resin pellet groups. In this way, in this embodiment, the resin pellet groups are dried while the dry gas is circulated and nitrogen gas is injected during the circulation.

[0018] The dried resin pellets dried in the drying tank 15 are discharged together with drying gas from a discharge port 154 provided at the tank bottom 153 via a shutter mechanism 50 (described later) and sent to the material removal chute 20. As shown by arrow R15, the material removal chute 20 throws the dried resin pellets that have been sent in together with drying gas into a second hopper mechanism 21. This second hopper mechanism 21 removes dust and the like from the dried resin pellets while throwing them into an injection tube A111 of an injection molding machine A11 outside the apparatus.

[0019] The second hopper mechanism 21 includes a suction hopper 211 for final dust removal and a final shutter 212 for transporting the dust-removed resin pellets to the injection molding machine A11. The second hopper mechanism 21 also includes a gas-venting core pin 213, a charge hopper 214 for material input, a glass tube 215 for monitoring input, and a material demand sensor 216. The resin pellets from the material discharge chute 20 are introduced into the suction hopper 211 along with dry gas. While nitrogen gas is being injected and replenished from the nitrogen generator 16, the dry gas agitates the resin pellets within the suction hopper 211. This agitation separates the resin pellets from dust and other particles adhering to the pellet surfaces. The separated dust and other particles are sucked and removed together with the dry gas from the suction hopper 211 through a filter 22 by the secondary material blower 23, as shown by arrow R16. The secondary material blower 23 returns the dry gas from which dust and other particles have been removed by the filter 22 to the material discharge chute 20. In this way, the dry gas immediately before being charged into the injection molding machine A11 is circulated, being replenished with nitrogen gas along the way. Meanwhile, the resin pellets from which dust has been removed are appropriately degassed by a degassing core pin 213 and sent in appropriate amounts to a charge hopper 214 through a final shutter 212. The resin pellets are then charged into the injection tube A111 of the injection molding machine A11 through a glass tube 215. The charging into the injection tube A111 here is performed in response to a command from a material requirement sensor 216 that monitors the resin pellets inside through the peripheral wall of the glass tube 215. Then, resin molding is performed in the injection molding machine A11 using the resin pellets charged into the injection tube A111.

[0020] In the drying apparatus 1 described above, the shutter mechanism 50 is connected to the discharge port 154 of the drying tank 15 and switches the flow of resin pellets at the discharge port 154 between a blocked state and an open state. If the resin pellets become caught during switching to the blocked state and the switching to the blocked state is incomplete, the airtightness of the shutter mechanism 50 may be reduced. If such a reduction in airtightness occurs in the shutter mechanism 50, the dry gas may leak out of the shutter mechanism 50, resulting in a shortage of dry gas and rendering the shutter mechanism useless for drying. To avoid such a situation, the shutter mechanism 50 of this embodiment has the configuration described below.

[0021] 2 is an external perspective view showing the shutter mechanism shown schematically in FIG. 1, FIG. 3 is an exploded perspective view of the shutter mechanism shown in FIG. 2, and FIG. 4 is a cross-sectional view taken along line V11-V11 of the shutter mechanism shown in FIG. 2.

[0022] The shutter mechanism 50 includes a shutter frame 51, an inflow-side shutter 52, an outflow-side shutter 53, and a drive control unit 54. In the external perspective view of Fig. 2, of the inflow-side shutter 52 and the outflow-side shutter 53 housed inside the shutter frame 51, the inflow-side shutter 52 is indicated by a dotted line, and the outflow-side shutter 53 is not shown. In addition, in the exploded perspective view of Fig. 3, the drive control unit 54 is not shown. Furthermore, in the cross-sectional view of Fig. 4, the external appearances of an inflow-side drive unit 541 and an outflow-side drive unit 542 (described below) in the drive control unit 54 are shown, rather than cross-sections.

[0023] The shutter frame 51 is a frame member in which a first cylindrical space 50a and a second cylindrical space 50b are formed parallel to each other. An inflow opening 511a for the resin pellet group PR1 is formed through an inflow side plate portion 511 (described later) that forms a first outer wall that partitions the first cylindrical space 50a. An outflow opening 512a for the resin pellet group PR1 is formed through an outflow side plate portion 512 that forms a second outer wall that partitions the second cylindrical space 50b and is positioned opposite the inflow side plate portion 511. An outflow opening 512a for the resin pellet group PR1 is formed through the outflow side plate portion 512 so as to be coaxial with the inflow opening 511a. Furthermore, a partition plate portion 513 that forms a partition wall separating the first cylindrical space 50a and the second cylindrical space 50b is formed through the partition plate portion 513 so as to be coaxial with the inflow opening 511a and the outflow opening 512a.

[0024] The shutter frame 51 has a rectangular block-like appearance, and the first cylindrical space 50a and the second cylindrical space 50b are also flat rectangular cylindrical spaces. To achieve this appearance and internal space, the shutter frame 51 includes an inlet-side plate portion 511, an outlet-side plate portion 512, an intermediate block 514 having a partition plate portion 513, an end wall 515, an inlet-side drive support wall 516, and an outlet-side drive support wall 517.

[0025] In this embodiment, the shutter mechanism 50 is connected below the discharge port 154 of the drying tank 15 in FIG. 1 so that the inlet side plate portion 511 is on the upper side and the outlet side plate portion 512 is on the lower side in the vertical direction D11 along the gravity. The resin pellet group PR1 falls from the discharge port 154 into the inside of the inlet opening 511a due to its own weight and then falls from the outlet opening 512a due to its own weight and is sent to the material removal chute 20. In the material removal chute 20, the resin pellet group PR1 is pushed toward the second hopper mechanism 21 by the drying gas circulating and sent from the secondary material blower 23.

[0026] The inlet-side plate 511 of the shutter frame 51 of this shutter mechanism 50 is formed in a rectangular plate shape, and serves as a first outer wall located on the upper side in the vertical direction D11, i.e., on the inlet side of the resin pellet group PR1, with a circular inlet opening 511a formed therethrough. The outlet-side plate 512 is formed in the same rectangular plate shape as the inlet-side plate 511, and serves as a second outer wall located on the lower side in the vertical direction D11, i.e., on the outlet side of the resin pellet group PR1, with a circular outlet opening 512a formed therethrough.

[0027] The intermediate block 514 is an H-shaped plate-like portion having the same width as the inlet side plate portion 511 and the outlet side plate portion 512 and an H-shaped cross section, with the portion corresponding to the horizontal bar of the H forming the partition plate portion 513. The intermediate block 514 is sandwiched between the inlet side plate portion 511 and the outlet side plate portion 512. With this arrangement, a first cylindrical space 50a is formed between the partition plate portion 513 and the inlet side plate portion 511, and a second cylindrical space 50b is formed between the partition plate portion 513 and the outlet side plate portion 512. The partition plate portion 513 is formed in a rectangular plate shape narrower than the inlet side plate portion 511 and the outlet side plate portion 512, is positioned at an intermediate position in the up-down direction D11, and forms a partition wall separating the first cylindrical space 50a and the second cylindrical space 50b, with a passage opening 513a formed therethrough.

[0028] The end wall 515 is a rectangular plate-shaped portion that is arranged so as to close one end side of the first cylindrical space 50a and the second cylindrical space 50b in the axial direction D12 along the central axis of each space.

[0029] The inlet-side drive support wall 516 is a rectangular plate-shaped portion arranged to close the other end of the first cylindrical space 50a in the axial direction D12, and this other end supports an inlet-side drive unit 541, which will be described later. The outlet-side drive support wall 517 is a rectangular plate-shaped portion arranged to close the other end of the second cylindrical space 50b in the axial direction D12, and this other end supports an outlet-side drive unit 542, which will be described later. A support hole 516a for the inlet-side drive unit 541 is formed in the inlet-side drive support wall 516, and a support hole 517a for the outlet-side drive unit 542 is formed in the outlet-side drive support wall 517.

[0030] The inlet-side shutter 52 is a rectangular plate-shaped member inserted into the first cylindrical space 50a and slidable along the axial direction D12. The inlet-side shutter 52 slides between an inlet-side shielding position P11, which shields the inlet opening 511a from the passage opening 513a, and an inlet-side communicating position P12 (FIG. 5) which communicates the inlet opening 511a and the passage opening 513a. A connecting groove 522 is formed at the end of the inlet-side shutter 52 on the inlet-side drive support wall 516 side to connect with an inlet-side drive unit 541 (described below). The inlet-side shutter 52 has an inlet-side communicating port 521 formed therethrough. The inlet-side communicating port 521 is disengaged from the inlet opening 511a and the passage opening 513a when the inlet-side shutter 52 is positioned at the inlet-side shielding position P11, and is in communication with the inlet opening 511a and the passage opening 513a when the shutter 52 is positioned at the inlet-side communicating position P12.

[0031] The outlet-side shutter 53 is a rectangular plate-shaped member inserted into the second cylindrical space 50b and slidable along the axial direction D12. The outlet-side shutter 53 slides between an outlet-side blocking position P13, which blocks the passage opening 513a from the outlet opening 512a, and an outlet-side communicating position P14 (FIG. 5) which connects the passage opening 513a and the outlet opening 512a. A connecting groove 532 is formed at the end of the outlet-side shutter 53 on the outlet-side drive support wall 517 side to connect with an outlet-side drive unit 542 (described below). An outlet-side communicating port 531 is formed through the outlet-side shutter 53. The outlet-side communicating port 531 is disengaged from the passage opening 513a and the outlet opening 512a when the outlet-side shutter 53 is positioned at the outlet-side blocking position P13, and is in communication with the outlet opening 511a and the passage opening 513a when the outlet-side shutter 53 is positioned at the outlet-side communicating position P14.

[0032] The drive control unit 54 is a control unit that switches the flow path of the resin pellet group PR1 from the inlet opening 511a to the outlet opening 512a between a blocked state and an open state by controlling the drive of the inlet-side shutter 52 and the outlet-side shutter 53. The drive control unit 54 performs the following drive control when switching the flow path from an open state to a blocked state. That is, during this switching, the drive control unit 54 first controls the inlet-side shutter 52 to slide toward the inlet-side blocking position P11, and then controls the outlet-side shutter 53 to slide toward the outlet-side blocking position P13. The drive control unit 54 includes an inlet-side drive unit 541, an outlet-side drive unit 542, and a control unit 543.

[0033] The inlet-side drive unit 541 is a drive source that drives the inlet-side shutter 52 to slide between the inlet-side blocking position P11 and the inlet-side communicating position P12, and in this embodiment, an air cylinder is used as an example. An operating rod 541a of this air cylinder passes through the support hole 516a of the inlet-side drive support wall 516, and its tip is fitted into the connecting groove 522 of the inlet-side shutter 52, thereby connecting the inlet-side drive unit 541 to the inlet-side shutter 52.

[0034] The outlet-side drive unit 542 is a drive source that drives the outlet-side shutter 53 to slide between the outlet-side blocking position P13 and the outlet-side communicating position P14, and uses an air cylinder similar to that of the inlet-side drive unit 541. An operating rod 542a of this air cylinder passes through the support hole 517a of the outlet-side drive support wall 517, and its tip is fitted into the connecting groove 532 of the outlet-side shutter 53, thereby connecting the outlet-side drive unit 542 to the outlet-side shutter 53.

[0035] The control unit 543 controls the operation of the inlet-side drive unit 541 and the outlet-side drive unit 542. In this embodiment, the control unit 543 is a control part that controls the operation of the shutter mechanism 50 in the device control unit that controls the entire drying device 1 shown in FIG.

[0036] FIG. 5 is a schematic diagram showing, in a cross section equivalent to FIG. 4, how the flow of resin pellets is switched between a blocked state and an open state by the shutter mechanism shown in FIGS.

[0037] 5, the shutter mechanism 50 is placed in an initial state under the control of the control unit 543 in the drive control unit 54. In the initial state, the inlet-side shutter 52 is positioned at the inlet-side blocking position P11 by the inlet-side drive unit 541, and the outlet-side shutter 53 is positioned at the outlet-side blocking position P13 by the outlet-side drive unit 542. As a result, the resin pellet group PR1 from the drying tank 15 shown in FIG. 1 is retained inside the inlet opening 511a of the inlet-side plate portion 511 of the shutter frame 51.

[0038] In the next second step S12, the shutter mechanism 50 is placed in an open state under the control of the control unit 543 in the drive control unit 54. In the open state, the inlet-side shutter 52 is driven by the inlet-side drive unit 541 in the inlet-side opening direction D13 and positioned at the inlet-side communication position P12. The outlet-side shutter 53 is driven by the outlet-side drive unit 542 in the outlet-side opening direction D14 and positioned at the outlet-side communication position P14. As a result, the inlet opening 511a of the inlet-side plate portion 511 of the shutter frame 51, the inlet-side communication port 521 of the inlet-side shutter 52, and the passage opening 513a of the partition plate portion 513 are in communication with each other. Furthermore, the passage opening 513a, the outlet-side communication port 531 of the outlet-side shutter 53, and the outlet opening 512a of the outlet-side plate portion 512 are in communication with each other. By this communication, the resin pellet group PR1 from the drying tank 15 shown in FIG. 1 passes through the flow path from the inlet opening 511a to the outlet opening 512a and is sent to the material discharge chute 20.

[0039] In the next third step S13, when the amount of resin pellet group PR1 sent to the material removal chute 20 reaches an appropriate amount, the control unit 543 of the drive control unit 54 starts switching from the open state to the blocked state. In the third step S13, the inlet-side shutter 52 is first driven by the inlet-side drive unit 541 to move in the inlet-side blocking direction D15 to the inlet-side blocking position P11. At this time, some of the resin pellet group PR1 inside the inlet-side communication port 521 may become caught between the inner circumferential surface of the inlet opening 511a of the inlet-side plate 511 and the inner circumferential surface of the inlet-side communication port 521. Also, some of the resin pellet group PR1 may become caught between the inner circumferential surface of the inlet-side communication port 521 and the inner circumferential surface of the passage opening 513a of the partition plate 513. The third step S13 in FIG. 5 schematically illustrates the occurrence of this trapping of the resin pellet group PR1.

[0040] Due to this jamming, the movement of the inlet-side shutter 52 in the inlet-side blocking direction D15 stops at position P111 just before the inlet-side blocking position P11. However, because the jamming occurs near the end of the movement in the inlet-side blocking direction D15, the inlet opening 511a of the inlet-side plate portion 511 of the shutter frame 51 remains substantially blocked, and the flow of the resin pellet group PR1 also stops. As a result, the inside of the flow path from the passage opening 513a of the partition plate portion 513 to the outlet opening 512a of the outlet-side plate portion 512 becomes empty as the resin pellet group PR1 flows into the material removal chute 20 shown in FIG. 1 . Furthermore, the resin pellet group PR1 from the drying tank 15 is retained inside the inlet opening 511a of the inlet-side plate portion 511. Furthermore, most of the resin pellet group PR1 other than the jammed portion inside the inlet-side communication port 521 is confined inside the inlet-side communication port 521.

[0041] In the next fourth step S14, under the control of the control unit 543 in the drive control unit 54, after the inlet-side shutter 52 stops, the outlet-side shutter 53 is driven by the outlet-side drive unit 542 in the outlet-side blocking direction D16 to the outlet-side blocking position P13. The movement of the outlet-side shutter 53 in this fourth step S14 is performed when the inlet-side shutter 52 blocks the flow of the resin pellet group PR1 and the flow path from the passage opening 513a of the partition plate 513 to the outlet opening 512a of the outlet-side plate 512 is empty. As a result, there is nothing to obstruct the movement of the outlet-side shutter 53, and the outlet-side shutter 53 is positioned at the outlet-side blocking position P13, sealing the outlet opening 512a. This sealing prevents leakage of drying gas from the drying tank 15 shown in FIG. 1 through the shutter mechanism 50.

[0042] 1, the shutter mechanism 50 is connected to the discharge port 154 for the dried resin pellet group PR1 in the drying tank 15. As a result, parts of the shutter mechanism 50 may come into contact with the heated and dried high-temperature resin pellet group PR1, causing thermal expansion. To ensure both airtightness and smooth operation even when such thermal expansion occurs, the following clearances are set between the shutter frame 51 and each of the inlet-side shutter 52 and outlet-side shutter 53.

[0043] 2 to 4, taking the inflow-side shutter as a representative example, and showing the clearances between the shutter frame and each of the inflow-side shutter and the outflow-side shutter. In this embodiment, the peripheral structures of the inflow-side shutter 52 and the outflow-side shutter 53 are the same. Therefore, in FIG. 6, the peripheral structure of the inflow-side shutter 52 is shown as a representative example in a schematic cross section taken along the axial direction D12 in the first cylindrical space 50a.

[0044] In this embodiment, the clearance between the shutter frame 51 and the inlet-side shutter 52 is set as a thickness-direction clearance W1 and a width-direction clearance W2 of the inlet-side shutter 52. The width-direction clearance W2 is set as two times the value of the one-side clearance W21. The width-direction clearance W2 and the thickness-direction clearance W1 are set according to the materials of the shutter frame 51 and the inlet-side shutter 52, respectively, and the temperature of the dried resin pellet group PR1. This setting is performed to ensure airtightness that suppresses leakage of drying gas from the discharge port 154 of the drying tank 15 to a predetermined level, and to enable the inlet-side shutter 52 to slide even when thermal expansion occurs in each part. A similar clearance is set for the outlet-side shutter 53.

[0045] First, the shutter frame 51, the inlet-side shutter 52, and the outlet-side shutter 53 are made of stainless steel, specifically JIS standard SUS420J2. This stainless steel contains 0.26-0.40% C (carbon), 1.00% or less Si (silicon), 1.00% or less Mn (manganese), 0.040% or less P (phosphorus), 0.030% or less S (sulfur), and 12.00-14.00% Cr (chromium). Ni (nickel) may be present up to 0.60%. Furthermore, this stainless steel has the following mechanical properties: The 0.2% proof stress [MPa] is 540 or greater for quenched and tempered steel, and 225 or greater for annealed steel. The tensile strength [MPa] is 740 or greater for quenched and tempered steel, and 540 or greater for annealed steel. The elongation [%] is 12 or more for quenched and tempered, and 18 or more for annealed. The reduction of area [%] is 217 or more for quenched and tempered. The Brinell hardness [HBW] is 217 or more for quenched and tempered, and the Rockwell hardness [HRBS or HRBW] is 95 or more for quenched and tempered. The Vickers hardness [HV] is 220 or more for quenched and tempered.

[0046] Next, the clearance when the above stainless steel material is used is set as follows.

[0047] FIG. 7 is a table showing an example of the setting range of the thickness direction clearance taking into account the thermal expansion when using stainless steel material, and FIG. 8 is a table showing an example of the setting range of the width direction clearance taking into account the thermal expansion when using stainless steel material.

[0048] In both the thickness-direction clearance setting table T1 in FIG. 7 and the width-direction clearance setting table T2 in FIG. 8, the vertical columns indicate the initial clearance [mm] before thermal expansion due to a temperature rise, and the horizontal columns indicate the temperature difference [°C] before and after the temperature rise. Furthermore, in the thickness-direction clearance setting table T1, the hatched areas indicate the range T11 where slidability during sliding deteriorates and the range T12 where airtightness during shielding deteriorates. In the width-direction clearance setting table T2, the hatched areas indicate the range T21 where slidability during sliding deteriorates. Furthermore, in both the thickness-direction clearance setting table T1 and the width-direction clearance setting table T2, the areas not hatched are the preferred ranges T13 and T22 where good slidability and airtightness of the slide are maintained even when thermal expansion occurs.

[0049] FIG. 9 is a table showing an example of a suitable clearance range determined from the suitable ranges in the tables of FIGS. 7 and 8, assuming use in the drying device of FIG. 1, for both the thickness direction and the width direction.

[0050] The example in FIG. 9 shows the setting range of a favorable clearance when the temperature of the heat-dried resin pellet group PR1 is 140°C (the shutter temperature at this time is 90°C). FIG. 9(A) shows a favorable thickness-direction clearance setting table T3, and FIG. 9(B) shows a favorable width-direction clearance setting table T4. In each table, a circle indicates that favorable results are obtained for airtightness and sliding performance, and an × indicates that a decrease is observed. In the favorable thickness-direction clearance setting table T3 in FIG. 9(A), the favorable thickness-direction clearance W1 range T31 is 0.02 to 0.04 mm. In the favorable width-direction clearance setting table T4 in FIG. 9(B), the favorable width-direction clearance W2 range T41 is 0.05 to 0.08 mm. When the range T41 of the width direction clearance W2 is substituted for the range of the one-side clearance W21, it becomes 0.025 to 0.04 [mm].

[0051] According to the shutter mechanism 50 and the drying device 1 of the embodiment described above, the flow path of the resin pellet group PR1 is switched to a blocked state by a two-stage shutter, the inlet-side shutter 52 and the outlet-side shutter 53. This two-stage shutter structure allows the inlet-side shutter 52 and the outlet-side shutter 53 to slide at different timings. As a result, it is possible to first slide the inlet-side shutter 52 toward the inlet-side blocking position P11, and then slide the outlet-side shutter 53 toward the outlet-side blocking position P13. By sliding the inlet-side shutter 52 toward the inlet-side blocking position P11, the inlet opening 511a and the passage opening 513a can be blocked from each other while allowing the resin pellet group PR1 to become caught. This blocking prevents the resin pellet group PR1 from flowing out of the passage opening 513a. When the outflow-side shutter 53 is slid to the outflow-side blocking position P13 in this state, the outflow of the resin pellet group PR1 from the passage opening 513a is stopped, and thus jamming is prevented from occurring in the outflow-side shutter 53. This prevention of jamming allows the outflow-side shutter 53 to slide sufficiently to the outflow-side blocking position P13 without stopping midway. In other words, according to this embodiment, switching to the blocking state can be performed sufficiently.

[0052] In this embodiment, the inlet-side shutter 52 has an inlet-side communication port 521 formed therethrough, and the outlet-side shutter 53 has an outlet-side communication port 531 formed therethrough. With this configuration, when the inlet-side shutter 52 is slid to the inlet-side blocking position P11, the resin pellet group PR1 that was flowing in the open state moves together with the inlet-side shutter 52, with a portion of the resin pellet group PR1 remaining within the inlet-side communication port 521. This prevents the resin pellet group PR1 from getting between the outer periphery of the inlet-side shutter 52 and the inner wall surface of the first cylindrical space, thereby preventing the resin pellet group PR1 from getting caught therein. The same applies to the outlet-side shutter 53 having the outlet-side communication port 531. This, combined with the above-described operation of staggering the sliding timing of the inlet-side shutter 52 and the outlet-side shutter 53, allows for more efficient switching to the blocking state.

[0053] In this embodiment, the shutter frame 51 includes an inlet side plate 511 having an inlet opening 511a formed therethrough, an outlet side plate 512 having an outlet opening 512a formed therethrough, and a partition plate 513 having a passage opening 513a formed therethrough. The inlet side shutter 52 is a plate-like member slidably inserted between the inlet side plate 511 and the partition plate 513. The outlet side shutter 53 is a plate-like member slidably inserted between the partition plate 513 and the outlet side plate 512. With this configuration, the shutter frame 51 is a frame member having a laminated structure in which flat plate-like spaces are provided between the inlet side plate 511, the partition plate 513, and the outlet side plate 512. This laminated structure reduces the dimension in the stacking direction, thereby enabling the shutter frame 51, and therefore the shutter mechanism 50, to be made smaller.

[0054] Furthermore, in this embodiment, a drive control unit 54 is provided that switches the flow path of the resin pellet group PR1 between a blocked state and an open state by controlling the drive of the inlet-side shutter 52 and the outlet-side shutter 53. When switching the flow path from an open state to a blocked state, the drive control unit 54 first slides the inlet-side shutter 52 toward the inlet-side blocking position P11, and then slides the outlet-side shutter 53 toward the outlet-side blocking position P13. With this configuration, the drive control unit can automatically perform the preferred operation of sliding the inlet-side shutter 52 first and then sliding the outlet-side shutter 53 without manual operation by an operator.

[0055] In addition, in this embodiment, the drive control unit 54 includes an inflow-side drive unit 541 that drives the inflow-side shutter 52 to slide, an outflow-side drive unit 542 that drives the outflow-side shutter 53 to slide, and a control unit 543 that controls operation. According to this configuration, by providing the inflow-side drive unit 541 and the outflow-side drive unit 542 that drive the inflow-side shutter 52 and the outflow-side shutter 53 individually, and the control unit 543 that controls these drive units collectively, the above-mentioned preferable operation can be performed effectively and efficiently.

[0056] In this embodiment, the control unit 543 in the drive control unit 54 is a control part that controls the operation of the shutter mechanism 50 in the device control unit of the drying device 1 in which the shutter mechanism 50 is installed. With this configuration, the number of parts can be reduced, thereby reducing the device cost, compared to a configuration in which a control unit is provided separately for each shutter mechanism.

[0057] In the present embodiment, the shutter mechanism 50 in the drying apparatus 1 is connected to the discharge port 154 of the drying tank 15. The clearances between the shutter frame 51 and the inlet-side shutter 52 and the outlet-side shutter 53 are set according to the materials and the temperature of the dried resin pellet groups PR1. This setting ensures airtightness that limits leakage of drying gas from the discharge port 154 of the drying tank 15 to a predetermined level, while allowing each shutter to slide as follows. That is, the clearances are set so that each shutter can slide even when the shutter frame 51, inlet-side shutter 52, and outlet-side shutter 53 thermally expand due to contact with the resin pellet groups PR1. This configuration sufficiently prevents leakage of drying gas from the drying tank 15, and allows the inlet-side shutter 52 and outlet-side shutter 53 to slide sufficiently without being hindered by thermal expansion of each component due to the temperature of the dried resin pellet groups PR1.

[0058] The above-described embodiment merely shows a typical example of the shutter mechanism and the drying device. The shutter mechanism and the drying device are not limited to this example and can be modified in various ways.

[0059] For example, in the above-described embodiment, the shutter mechanism is exemplified as an example of a shutter mechanism, which is mounted on the drying device 1 that heats and dries the resin pellet group PR1 as a granular material group. However, the shutter mechanism is not limited to this, and the specific mounting location and the type of granular material group are not important as long as the shutter mechanism is a mechanism that switches the flow of the granular material group between a blocked state and an open state.

[0060] In the above-described embodiment, a specific configuration of an example drying device is shown in FIG. 1 , exemplifying a drying device 1 that heats and dries resin pellet groups PR1 and feeds them into the injection tube A111 of an injection molding machine A11. However, the drying device is not limited to this, and any device that heats and dries granular materials can be used, with the type of granular material to be dried and the destination of the dried granular material being set as appropriate. Furthermore, even in the case of a device that heats and dries resin pellet groups and feeds them into the injection tube of an injection molding machine, the specific configuration is not limited to the configuration shown in FIG. 1 , and any configuration can be adopted.

[0061] Furthermore, in the above-described embodiment, as an example of a shutter frame in a shutter mechanism, a shutter frame 51 having a rectangular block-like appearance and having a rectangular cylindrical first cylindrical space 50a and a second cylindrical space 50b formed therein parallel to each other is exemplified. However, the shutter frame is not limited to this, and may be, for example, a shutter frame having a cylindrical block-like appearance and having a cylindrical first cylindrical space and a second cylindrical space formed therein parallel to each other. The specific shape and the like of the shutter frame can be set as appropriate as long as it is a frame member having a first cylindrical space and a second cylindrical space formed therein parallel to each other.

[0062] In the above-described embodiment, the shutter mechanism 50 is exemplified as an example of the shutter mechanism, in which the shutter frame 51, the inflow-side shutter 52, and the outflow-side shutter 53 are made of stainless steel (SUS420J2 in the JIS standard). However, the shutter mechanism is not limited to this, and any specific material may be used.

[0063] Furthermore, in the above-described embodiment, the shutter mechanism 50 is exemplified as an example of a shutter mechanism, in which the inlet-side communication port 521 is formed through the inlet-side shutter 52 and the outlet-side communication port 531 is formed through the outlet-side shutter 53. However, the shutter mechanism is not limited to this. The shutter mechanism may be, for example, a shutter mechanism including a simple plate-like or simple rod-like inlet-side shutter and an outlet-side shutter without any openings, inserted into the first cylindrical space and the second cylindrical space. However, as described above, by forming the inlet-side communication port 521 through the inlet-side shutter 52 and the outlet-side communication port 531 through the outlet-side shutter 53, jamming between the outer periphery of each shutter and the inner wall surface of the cylindrical space is suppressed.

[0064] Furthermore, in the above-described embodiment, the shutter frame 51 including the inlet side plate portion 511, the outlet side plate portion 512, and the partition plate portion 513 is exemplified as an example of the shutter frame. However, the shutter frame is not limited to this, and any specific form is acceptable as long as it is a frame member in which the first cylindrical space and the second cylindrical space are formed parallel to each other. However, as described above, the shutter frame 51 having a layered structure of the inlet side plate portion 511, the outlet side plate portion 512, and the partition plate portion 513 allows the shutter mechanism 50 to be made smaller.

[0065] Furthermore, in the above-described embodiment, as an example of a shutter mechanism, the shutter mechanism 50 equipped with the drive control unit 54 that controls the drive of the inflow-side shutter 52 and the outflow-side shutter 53 is exemplified. However, the shutter mechanism is not limited to this, and may be, for example, a manual mechanism in which the inflow-side shutter and the outflow-side shutter are manually slid by an operator. However, as described above, by having the drive control unit 54 control the drive of the inflow-side shutter 52 and the outflow-side shutter 53, it is possible to automatically slide each shutter to an appropriate position without manual operation by an operator.

[0066] In the above-described embodiment, the drive control unit 54 including the inlet-side drive unit 541, the outlet-side drive unit 542, and the control unit 543 is exemplified as an example of a drive control unit. However, the drive control unit is not limited to this. For example, the drive control unit may include a single drive unit that collectively drives two shutters on the inlet and outlet sides, or two control units that individually control the drive of the inlet and outlet side shutters. However, as described above, the drive control unit 54 including the inlet-side drive unit 541, the outlet-side drive unit 542, and the control unit 543 can effectively and efficiently slide each shutter in a suitable manner. In this embodiment, air cylinders are used as the inlet-side drive unit 541 and the outlet-side drive unit 542. However, the inlet-side drive unit and the outlet-side drive unit are not limited to this. For example, they may be a motor-driven ball screw mechanism or a motor-driven rack and pinion mechanism, and the specific drive mode is not limited thereto.

[0067] Furthermore, in the above-described embodiment, as an example of a control unit included in the drive control unit, control unit 543 is exemplified as a control part that controls the operation of shutter mechanism 50 in the device control unit of drying device 1 in which shutter mechanism 50 is installed. However, the control unit is not limited to this, and may be an individual control unit provided exclusively for the shutter mechanism. However, as described above, by having the control part of the device control unit in which the shutter mechanism is installed control the operation of the shutter mechanism, the number of parts can be reduced and the device costs can be reduced.

[0068] In the above-described embodiment, the shutter mechanism 50 connected to the discharge port 154 of the drying tank 15 in the drying apparatus 1 is exemplified as an example of a shutter mechanism. In this shutter mechanism 50, the clearance between the shutter frame 51 and each shutter is set taking into account the requirement for airtightness and thermal expansion due to the temperature of the dried resin pellet group PR1. However, the shutter mechanism is not limited to this. For example, the shutter mechanism may be installed in a location where there is no requirement for airtightness or concern about thermal expansion, and the clearance may be set based only on the sliding properties of each shutter inside the shutter frame at room temperature. However, as described above, the shutter mechanism 50 connected to the discharge port 154 of the drying tank 15 in the drying apparatus 1 and having a clearance set taking into account airtightness and thermal expansion allows each shutter to slide sufficiently while sufficiently suppressing leakage of drying gas. [Explanation of symbols]

[0069] 1 Drying device 11 First hopper mechanism 12,19,22 filters 13 Primary material blower 14,213 Gas vent core pin 15 Drying Tank 16 Nitrogen generator 17 Drying Blower 18 Heater 20 Material removal chute 21 Second hopper mechanism 23 Secondary material blower 50 Shutter mechanism 50a First cylindrical space 50b Second cylindrical space 51 Shutter Frame 52 Inlet shutter 53 Outflow shutter 54 Drive control unit 111,211 Suction hopper 112,215 Glass tube 113 Front shutter 114,214 Charge Hopper 115 Rear shutter 151 Receiving entrance 152 Paddle type level gauge 153 Tank bottom 154 Outlet 161 Air filter 162 Air dryer 163 Nitrogen Generator 212 Final Shutter 216 Material Requirement Sensor 511 Inflow side plate (first outer wall) 511a Inflow opening 512 Outflow side plate (second outer wall) 512a Outflow opening 513 Partition board (partition wall) 513a Passage opening 514 Intermediate Block 515 End wall 516 Inlet side drive support wall 516a,517a Support hole 517 Outflow side drive support wall 521 Inflow side communication port 522,532 Connection groove 531 Outlet side communication port 541 Inlet side drive unit 541a,542a Operating rod 542 Outlet drive unit 543 Control Unit A11 injection molding machine A12 Material tank A111 Injection tube D11 Vertical direction D12 Axial direction D13 Inflow side opening direction D14 Outflow side opening direction D15 Inflow side shielding direction P11 Inflow side shielding position P12 Inflow side communication position P13 Outflow side shielding position P14 Outflow side communication position P111 Front position PR1 resin pellet group R11, R12, R13, R14, R15, R16 arrows S11 First Step S12 2nd step S13 Third Step S14 Fourth Step T1 Thickness direction clearance setting table T2 Width direction clearance setting table T3 Thickness direction good clearance setting table T4 Good clearance setting table for width direction T11, T21 Range where sliding performance decreases T12 Range where airtightness decreases when shielded T13, T22 suitable range T31 Good thickness clearance range T41 Good widthwise clearance range W1 Thickness clearance W2 Width clearance W21 One side clearance

Claims

1. a shutter frame comprising a frame member having a first cylindrical space and a second cylindrical space formed parallel to each other, wherein an inflow opening for a group of granular materials is formed through a first outer wall that defines the first cylindrical space, an outflow opening for the group of granular materials is formed through a second outer wall that defines the second cylindrical space and is positioned opposite the first outer wall so as to be coaxial with the inflow opening, and further comprising a partition wall that separates the first cylindrical space from the second cylindrical space so as to be coaxial with the inflow opening and the outflow opening; an inlet-side shutter, which is a member inserted and disposed in the first cylindrical space, and is slidable along a central axis of the first cylindrical space between an inlet-side blocking position that blocks communication between the inlet opening and the passage opening, and an inlet-side communicating position that communicates between the inlet opening and the passage opening; an outlet-side shutter, which is a member inserted and disposed in the second cylindrical space, and is slidable along a central axis of the second cylindrical space between an outlet-side blocking position that blocks communication between the passage opening and the outlet opening, and an outlet-side communicating position that communicates between the passage opening and the outlet opening; A shutter mechanism comprising:

2. an inlet-side communication port is formed through the inlet-side shutter, the inlet-side communication port being out of contact with the inlet opening and the passing opening when the inlet-side shutter is positioned at the inlet-side blocking position and communicating with the inlet opening and the passing opening when the inlet-side shutter is positioned at the inlet-side communicating position; The shutter mechanism described in claim 1, characterized in that the outlet side shutter has an outlet side communication port formed therethrough that is disengaged from the passage opening and the outlet opening when positioned at the outlet side blocking position and that communicates with the passage opening and the outlet opening when positioned at the outlet side communication position.

3. The shutter frame is an inlet side plate portion formed in a plate shape to form the first outer wall, the inlet opening being formed therethrough; an outflow side plate portion formed in a plate shape to form the second outer wall, the outflow opening being formed therethrough; a partition plate portion formed in a plate shape to form the partition wall, the partition plate portion having the passage opening formed therethrough; It is equipped with the inlet-side shutter is a plate-like member slidably inserted between the inlet-side plate portion and the partition plate portion, 2. The shutter mechanism according to claim 1, wherein the outflow-side shutter is a plate-like member slidably inserted between the partition plate portion and the outflow-side plate portion.

4. The shutter mechanism described in claim 1, further comprising a control unit that switches the flow path of the granular material group from the inlet opening to the outlet opening between a blocked state and an open state by controlling the drive of the inlet side shutter and the outlet side shutter, and that, when switching the flow path from the open state to the blocked state, first controls the inlet side shutter to slide toward the inlet side blocking position, and then controls the outlet side shutter to slide toward the outlet side blocking position.

5. The drive control unit an inlet-side drive unit that slides the inlet-side shutter between the inlet-side blocking position and the inlet-side communicating position; an outlet-side drive unit that drives the outlet-side shutter to slide between the outlet-side blocking position and the outlet-side communicating position; a control unit that controls the operation of the outflow side drive unit and the outflow side drive unit; 5. The shutter mechanism according to claim 4, wherein the shutter mechanism is a part comprising:

6. a drying tank that receives and stores a group of granular materials to be dried through a receiving port, into which a dry gas that has been subjected to a heated drying process is introduced to dry the group of granular materials inside the tank, and into which the dried group of granular materials is discharged from a discharge port provided at the bottom of the tank; a shutter mechanism according to any one of claims 1 to 5, which is connected to the discharge port of the drying tank and switches the flow of the particulate matter around the discharge port between a blocked state and an open state; A drying device comprising:

7. The drying device described in claim 6, characterized in that the clearances between the shutter frame and each of the inlet-side shutter and the outlet-side shutter are set to ensure airtightness that suppresses leakage of the drying gas from the outlet of the drying tank to a predetermined level depending on the materials of the shutter frame, the inlet-side shutter, and the outlet-side shutter and the temperature of the dried granular material, and are set so that the inlet-side shutter and the outlet-side shutter can slide even when thermal expansion occurs in the shutter frame, the inlet-side shutter, and the outlet-side shutter due to contact with the granular material.

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