Dehydrator

Abstract

To provide a dehydrator capable of adjusting a degree of pressurization and dehydration in accordance with a density of fiber pieces contained in liquid.SOLUTION: A dehydrator executes: dehydration steps (S23 to S25) of rotating a mold opening / closing motor in a first direction at a torque at which a pressing force of an upper mold to a lower mold is kept at a set pressure larger than a support pressure, from when the upper mold reaches a reference position lower than a position at which a lower outer ring and an upper outer ring come into contact with each other, and upper than a position at which the lower mold and the upper mold complete mold clamping, until a set time elapses, in a stage of clamping the upper mold to the lower mold filled with a liquid raw material; and mold opening step (S27) of rotating the mold opening / closing motor in a second direction in accordance with a fact that the set time has elapsed (S25: Yes).SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a dehydration device for pressurizing and dehydrating a liquid material. [Background technology]

[0002] In recent years, as part of environmentally friendly manufacturing, the use of plastic gears has been increasing instead of metal gears. Patent Document 1 discloses a papermaking machine that pressurizes and dehydrates a liquid containing fiber pieces to create a base material for plastic gears. Patent Document 2 discloses a vertical injection molding machine that places a lower mold on a turntable and raises and lowers an upper mold to open, close, and clamp the mold. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-77541 A [Patent Document 2] Patent Publication No. 2022-24412 Summary of the Invention [Problem to be solved by the invention]

[0004] It is possible to use the mold opening / closing and mold clamping mechanism of Patent Document 2 for pressurized dehydration of a papermaking machine. In this case, the upper mold during mold clamping always descends to the same position relative to the lower mold. However, with this configuration, if the density of the fiber pieces contained in the liquid is high, over-dehydration occurs, and if the density of the fiber pieces is low, under-dehydration occurs.

[0005] The present invention has been made to solve such problems in the prior art, and its object is to provide a dehydration device that can adjust the degree of pressurized dehydration depending on the density of the fiber pieces contained in the liquid. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention provides a dehydration device which fills a mold with a liquid raw material and dehydrates it under pressure, the dehydration device comprising: a support block; a lower mold fixed on the support block; a lower outer ring arranged to surround the lower mold and supported by the support block so as to be able to rise and fall independently of the lower mold; an upper mold which rises and falls above the lower mold, thereby opening and closing and clamping the lower mold; an upper outer ring arranged to surround the upper mold and rises and falls integrally with the upper mold; The device is equipped with a mold opening / closing motor that lifts an upper outer ring, and a control device that controls the lower outer ring cylinder and the mold opening / closing motor, and the control device performs a dehydration process in which the mold opening / closing motor rotates in the first direction with a torque that maintains the pressing force of the upper mold against the lower mold at a set pressure greater than the support pressure until a set time has elapsed after the upper mold reaches a reference position that is lower than the position where the lower outer ring and the upper outer ring contact and higher than the position where the lower mold and the upper mold complete clamping, during the process of clamping the upper mold against the lower mold filled with liquid raw material, and a mold opening process in which the mold opening / closing motor rotates in the second direction upon the elapse of the set time. Effect of the Invention

[0007] According to the present invention, a dewatering device capable of adjusting the degree of pressurized dewatering in accordance with the density of fiber pieces contained in the liquid can be obtained. [Brief description of the drawings]

[0008] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] 13 is a schematic diagram showing a drainage mechanism that drains liquid through a drainage passage. FIG. [Figure 4] FIG. 2 is a hardware block diagram of the papermaking machine. [Diagram 5]4 is an example of a screen displayed on a display input device. [Figure 6] 1 is a flow chart of a fiber filling process. [Figure 7] 1 is a flowchart of a pressurized dehydration process. [Figure 8] FIG. 13 is a schematic diagram showing a state before a second upper mold is closed relative to a lower mold. [Figure 9] 11A to 11C are schematic diagrams showing a process in which a second upper die is clamped to a lower die. [Figure 10] FIG. 4 is a diagram for explaining the positional relationship between a lower mold and a second upper mold. [Figure 11] FIG. 2 is a schematic diagram showing a state where pressurized dehydration is completed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A papermaking machine 1 according to the present invention will be described below with reference to the drawings. Note that the embodiment of the present invention described below is an example of how the present invention is embodied, and the scope of the present invention is not limited to the description of the embodiment. Therefore, the present invention can be implemented by adding various modifications to the embodiment.

[0010] [Configuration of papermaking machine 1] The configuration of a papermaking machine 1, which is an example of a dewatering device, will be described with reference to Figures 1 and 2. Figure 1 is a side view of the papermaking machine 1. Figure 2 is a plan view of the papermaking machine 1. The papermaking machine 1 is an apparatus that produces a papermaking base material 3 (molded product) by filling a mold with a slurry 2 (liquid raw material) and dewatering it under pressure.

[0011] The slurry 2 is a liquid containing fiber pieces. More specifically, the slurry 2 is a mixture of water, fiber pieces (e.g., organic fibers), additives such as a fixing agent, and resin (e.g., high-strength, high-heat-resistant phenolic resin) in a predetermined ratio. However, the content ratio of the fiber pieces in the slurry 2 is not always constant and may vary slightly.

[0012] The papermaking substrate 3 is a cylindrical member that is the base of a resin gear. More specifically, a resin gear is manufactured by forming teeth on the outer peripheral surface of the cylindrical papermaking substrate 3 manufactured by the papermaking machine 1. The resin gear is used, for example, in the drive system of an automobile. Compared to metal gears, the resin gear manufactured from the papermaking substrate 3 reduces meshing noise and teeth rattle noise and can achieve weight reduction. However, the material manufactured from the papermaking substrate 3 is not limited to gears, and the use of the gear is not limited to parts inside and around the engine of an automobile.

[0013] As shown in Figures 1 and 2, the mold of the papermaking machine 1 is composed of two lower molds 11, a first upper mold 12, and a second upper mold 13. The lower mold 11 is supported by a support block 14. An insert 15 is housed within the lower mold 11. Furthermore, the lower mold 11 is held by a lower outer ring 16, and the second upper mold 13 is held by an upper outer ring 17. However, the number of lower molds 11 may be one.

[0014] The two lower dies 11 have the same shape. The lower dies 11 have a cylindrical outer shape. The diameter of the lower dies 11 corresponds to the outer dimensions of the papermaking substrate 3. The lower dies 11 are formed with a drainage passage 11a that penetrates in the vertical direction. The lower dies 11 are fixed to a support block 14. An insert 15 is placed on the upper surface of the lower dies 11. The lower dies 11 are disposed inside a lower outer ring 16.

[0015] The support block 14 supports the lower die 11 and the lower outer ring 16. More specifically, the lower die 11 is fixed to the upper surface of the support block 14. The support block 14 also supports the lower outer ring 16 so that it can be raised and lowered. The support block 14 also has a drainage passage 14a that communicates with the drainage passage 11a of the lower die 11. The drainage passage 14a extends in the vertical direction as shown in FIG. 1, and then bends in the radial direction (horizontal direction) of the rotary table 21 as shown in FIG. 3. The drainage passage 14a is connected to drainage pumps 43a, 43b via connection parts 41a, 41b, which will be described later with reference to FIG. 3. Furthermore, the support block 14 has a ring-shaped recess 14b that is recessed downward from the upper surface.

[0016] The insert 15 is detachably placed on the upper surface of the lower mold 11. The insert 15 has a ring-shaped (cylindrical) outer shape. The outer dimensions of the insert 15 are smaller than the outer dimensions of the lower mold 11. The insert 15 is a metal part that constitutes part of the inner circumference of the papermaking substrate 3 (i.e., a resin gear).

[0017] The lower outer ring 16 has a tubular (typically cylindrical) outer shape. The lower outer ring 16 is disposed so as to surround the lower die 11. The lower outer ring 16 (more specifically, the lower outer ring holder 18 that holds the lower outer ring 16) is supported from below by a lower outer ring cylinder 64 (see Figs. 8, 9, and 11). The lower outer ring 16 is configured to be able to rise and fall independently of the lower die 11 by the extension and contraction of the lower outer ring cylinder 64.

[0018] The lower outer ring cylinder 64 is, for example, an air cylinder that expands and contracts by supplying and discharging compressed air. As shown in Figures 8, 9, and 11, the lower outer ring cylinder 64 is disposed between the support block 14 and the lower outer ring holder 18 that holds the lower outer ring 16. In other words, the lower outer ring cylinder 64 supports the lower outer ring 16 from below via the lower outer ring holder 18. Also, the lower outer ring cylinder 64 raises and lowers the lower outer ring 16 by expanding and contracting.

[0019] More specifically, the lower outer ring 16 rises to the upper limit shown in Figs. 8 and 9 by extending the lower outer ring cylinder 64 to the maximum with the rising pressure P1. The lower outer ring 16 is maintained at the upper limit by applying the rising maintaining pressure P2 to the lower outer ring cylinder 64 extended to the maximum. The lower outer ring 16 is lowered to an arbitrary position between the upper limit (Figs. 8 and 9) and the lower limit (Fig. 11(B)) by being pressed from above by the upper outer ring cylinder 65 when the support pressure P3 is set to the lower outer ring cylinder 64, as shown in Fig. 11(A). The lower outer ring 16 is lowered to the lower limit shown in Fig. 11(B) by being pressed from above by the upper outer ring cylinder 65 extended to the maximum when the support pressure P3 is set to the lower outer ring cylinder 64. For example, P3>P1>P2.

[0020] The first upper die 12 is disposed above the lower die 11 and the lower outer ring 16. The first upper die 12 has a cylindrical outer shape with an open lower surface and a closed upper surface. The inner diameter of the first upper die 12 corresponds to the inner diameter of the lower outer ring 16. Furthermore, a supply port 12a is provided on the upper surface of the first upper die 12, through which the slurry 2 is supplied from a supply device (not shown). The first upper die 12 is opened, closed, and clamped relative to the lower die 11 (more specifically, the lower outer ring 16) by transmitting the driving force of a first die opening / closing motor 62 (see FIG. 4).

[0021] The second upper die 13 is disposed above the lower die 11. The second upper die 13 has a ring-shaped outer shape. The inner diameter of the second upper die 13 corresponds to the outer diameter of the insert 15. The outer diameter of the second upper die 13 corresponds to the inner diameter of the lower outer ring 16. The second upper die 13 is fixed to the inside of the upper outer ring 17.

[0022] The upper outer ring 17 is disposed above the lower outer ring 16. The upper outer ring 17 has a tubular (typically cylindrical) outer shape with an open lower surface and a closed upper surface. The inner diameter of the upper outer ring 17 corresponds to the outer diameter of the second upper mold 13 and the inner diameter of the lower outer ring 16. The upper outer ring 17 is disposed so as to surround the second upper mold 13. The second upper mold 13 and the upper outer ring 17 are raised and lowered together by transmitting the driving force of a second mold opening / closing motor 63 (see FIG. 4 ), and are opened / closed and clamped relative to the lower mold 11 and the lower outer ring 16.

[0023] In the example of FIG. 1, one lower die 11 is supported on the support block 14, but the support block 14 may support a plurality of (e.g., four) lower dies 11 collectively. In other words, in the example of FIG. 1, one lower die 11 is arranged in the lower outer ring 16, but the lower outer ring 16 may hold a plurality of (e.g., four) lower dies 11 collectively. In addition, the number of first upper dies 12 corresponds to the number of lower dies 11 held by the lower outer ring 16. Similarly, the number of second upper dies 13 held collectively by the upper outer ring 17 corresponds to the number of lower dies 11 held by the lower outer ring 16.

[0024] 1 and 2, the papermaking machine 1 includes a frame 20, a rotary table 21 (table), a first movable die plate 22, and a second movable die plate 23. The frame 20 supports the rotary table 21, the first movable die plate 22, and the second movable die plate 23, as well as other components of the papermaking machine 1.

[0025] The rotary table 21 has a disk-shaped outer shape. The rotary table 21 is rotatably supported by the frame 20 via a rotary shaft 24 extending in the vertical direction. The rotary table 21 is formed with only the minimum number of taps (through holes). The taps provided on the rotary table 21 are closed with bolt caps.

[0026] A support block 14 is placed on the upper surface of the turntable 21. The two support blocks 14 according to this embodiment are arranged at an interval of 180° in the circumferential direction of the turntable 21 (in other words, arranged on opposite sides of the rotation shaft 24). Furthermore, the turntable 21 rotates around the rotation shaft 24 by the transmission of the driving force of a table rotation motor 61 (see FIG. 4).

[0027] More specifically, the rotating table 21 is configured to be movable (rotatable) so that the lower mold 11 placed via the support block 14 faces the first upper mold 12 or the second upper mold 13. In this embodiment, when one of the two lower molds 11 faces the first upper mold 12, the other lower mold 11 faces the second upper mold 13.

[0028] 2, 8, 9, and 11, the first movable die plate 22 is supported by the frame 20 above the rotary table 21. The first upper die 12 is fixed to the lower surface of the first movable die plate 22. The first movable die plate 22 opens, closes, and clamps the first upper die 12 relative to the lower die 11 by transmitting the driving force of a first die opening / closing motor 62 through a toggle link mechanism (not shown).

[0029] More specifically, as the first die opening / closing motor 62 rotates in the first direction, the first movable die plate 22 descends together with the first upper die 12. As a result, as shown in Fig. 1(B), the lower end of the first upper die 12 comes into contact with the upper end of the lower outer ring 16, and a cavity (internal space) is formed between the lower die 11, the first upper die 12, and the lower outer ring 16 (i.e., the die is closed). Then, when further downward pressure is applied to the first movable die plate 22, the lower die 11 (lower outer ring 16) and the first upper die 12 are clamped together.

[0030] Then, with the lower mold 11 (lower outer ring 16) and the first upper mold 12 clamped together, the slurry 2 is supplied from the supply device through the supply port 12a, so that the inside of the lower mold 11 (more specifically, the space surrounded by the upper surface of the lower mold 11, the outer peripheral surface of the insert 15, and the inner peripheral surface of the lower outer ring 16) is filled with the slurry 2. With the lower mold 11 (lower outer ring 16) and the first upper mold 12 clamped together, the drainage pump 43a is driven, so that the liquid contained in the slurry 2 filled inside the lower mold 11 is drained (primary dehydration) through the drainage passages 11a, 14a and the connection part 41a at the first connection position.

[0031] On the other hand, when the first die opening / closing motor 62 rotates in a second direction opposite to the first direction, the first movable die plate 22 rises together with the first upper die 12. As a result, the lower die 11 (lower outer ring 16) and the first upper die 12 are opened as shown in FIG.

[0032] 2, 8, 9, and 11, the second movable die plate 23 is supported by the frame 20 above the rotary table 21. The second upper die 13 and the upper outer ring 17 are fixed to the lower surface of the second movable die plate 23. The second movable die plate 23 also supports a pair of upper outer ring cylinders 65. The second movable die plate 23 opens, closes, and clamps the second upper die 13 relative to the lower die 11 by transmitting the driving force of a second die opening / closing motor 63 through a toggle link mechanism (not shown).

[0033] More specifically, the second movable die plate 23 is lowered together with the second upper die 13, the upper outer ring 17, and the upper outer ring cylinder 65 by rotating the second die opening / closing motor 63 in the first direction. As a result, the lower end of the upper outer ring 17 comes into contact with the upper end of the lower outer ring 16, and a cavity (internal space) is formed between the lower die 11, the second upper die 13, the lower outer ring 16, and the upper outer ring 17 (i.e., the die is closed). Then, when further downward pressure is applied to the second movable die plate 23, the upper outer ring 17 presses down the lower outer ring 16 against the support pressure P3 of the lower outer ring cylinder 64, as shown in FIG. 1(B). As a result, the second upper die 13 is lowered to a position where a part of the insert 15 enters the inside of the second upper die 13, and the lower die 11 (lower outer ring 16) and the second upper die 13 are clamped.

[0034] This causes the slurry 2 filled in the lower mold 11 to be pressurized and dehydrated. In addition, with the lower mold 11 and the second upper mold 13 clamped together, the drainage pump 43b is driven to drain the liquid contained in the slurry 2 filled in the lower mold 11 through the drainage passages 11a and 14a (secondary dehydration). As a result, the slurry 2 in the space surrounded by the upper surface of the lower mold 11, the lower surface of the second upper mold 13, the outer peripheral surface of the insert 15, and the inner peripheral surface of the lower outer ring 16 is compressed to become the papermaking substrate 3.

[0035] On the other hand, when the second die opening / closing motor 63 rotates in a second direction opposite to the first direction, the second movable die plate 23 rises together with the second upper die 13, the upper outer ring 17, and the upper outer ring cylinder 65. As a result, the lower die 11 and the second upper die 13 are opened as shown in FIG.

[0036] The papermaking substrate 3 in the lower mold 11 is then removed from the lower mold 11 together with the insert 15 by a robot arm (not shown). The papermaking substrate 3 removed from the lower mold 11 is then dried in an oven, and teeth are formed on the outer circumferential surface to form a resin gear. A new insert 15 is then inserted by the robot arm into the lower mold 11 from which the papermaking substrate 3 was removed.

[0037] The upper outer ring cylinder 65 is, for example, an air cylinder that expands and contracts by supplying and discharging compressed air. As shown in Figs. 8, 9, and 11, the upper outer ring cylinder 65 is extended downward from the second movable die plate 23. As shown in Fig. 11(A), the upper outer ring cylinder 65 presses the lower outer ring 16 (more specifically, the lower outer ring holder 18 that holds the lower outer ring 16) from above as the second movable die plate 23 descends. Also, as shown in Fig. 11(B), the upper outer ring cylinder 65, in a state of contacting the lower outer ring 16 (the lower outer ring holder 18) from above, extends to its maximum at a downward pressure P4, thereby lowering the lower outer ring 16 to its lower limit against the lower outer ring cylinder 64 of the support pressure P3. Note that P4>P3.

[0038] [Configuration of drainage mechanisms 40a, 40b] Fig. 3 is a schematic diagram showing drainage mechanisms 40a, 40b that drain liquid through drainage passages 11a, 14a. As shown in Fig. 3, the papermaking machine 1 is equipped with drainage mechanisms 40a, 40b. The drainage mechanisms 40a, 40b are supported by the frame 20 on the radial outside of the turntable 21. The drainage mechanisms 40a, 40b are also arranged at positions that can face the support block 14 in the horizontal direction. The drainage mechanisms 40a, 40b are also arranged at positions spaced apart (at 180° intervals) in the circumferential direction of the turntable 21.

[0039] The drainage mechanism 40a drains liquid from the support block 14 supporting the lower die 11 facing the first upper die 12. The drainage mechanism 40a includes a connection part 41a (first connection part), a drainage cylinder 42a, and a drainage pump 43a. The drainage mechanism 40b drains liquid from the support block 14 supporting the lower die 11 facing the second upper die 13. The drainage mechanism 40b includes a connection part 41b (second connection part), a drainage cylinder 42b, and a drainage pump 43b.

[0040] The connection part 41a is supported by the frame 20 so as to be movable in the radial direction of the turntable 21 between a first connection position shown in Fig. 3(B) and a first retracted position shown in Fig. 3(A). The drainage cylinder 42a is an actuator that moves the connection part 41a between the first connection position and the first retracted position. Specific examples of the actuator include an air cylinder, a hydraulic cylinder, and an electric motor. The drainage pump 43a sucks liquid from the support block 14 through the connection part 41a at the first connection position.

[0041] The first connection position is a position of the connection part 41a connected to the support block 14 supporting the lower die 11 facing the first upper die 12. A drainage passage is provided inside the connection part 41a, which connects the drainage passage 14a of the support block 14 and the drainage pump 43a when in the first connection position. The first retracted position is a position of the connection part 41a separated from the support block 14 and retracted to the outside of the turntable 21.

[0042] The connection part 41b is supported by the frame 20 so as to be movable in the radial direction of the turntable 21 between a second connection position shown in Fig. 3(B) and a second retracted position shown in Fig. 3(A). The drain cylinder 42b is an actuator that moves the connection part 41b between the second connection position and the second retracted position. Specific examples of the actuator include an air cylinder, a hydraulic cylinder, and an electric motor. The drain pump 43b sucks liquid from the support block 14 through the connection part 41b in the second connection position.

[0043] The second connection position is a position of the connection part 41b connected to the support block 14 supporting the lower die 11 facing the second upper die 13. A drainage passage is provided inside the connection part 41b, which connects the drainage passage 14a of the support block 14 and the drainage pump 43b when in the second connection position. The second retracted position is a position of the connection part 41b separated from the support block 14 and retracted to the outside of the turntable 21.

[0044] When the drain cylinders 42a, 42b are extended in a state where one of the two lower molds 11 (in other words, the two support blocks 14) faces the first upper mold 12 and the other faces the second upper mold 13, the connection part 41a moves to the first connection position and the connection part 41b moves to the second connection position. Then, the drain pumps 43a, 43b are driven to drain the liquid from the support block 14. Furthermore, when the drain cylinders 42a, 42b are contracted before the turntable 21 is rotated, the connection part 41a moves to the first retracted position and the connection part 41b moves to the second retracted position.

[0045] [Hardware configuration of papermaking machine 1] Fig. 4 is a hardware block diagram of the papermaking machine 1. Fig. 5 is an example of a screen displayed on the display input device 54. As shown in Fig. 4, the papermaking machine 1 includes a control device 50. The control device 50 controls the operation of the papermaking machine 1 as a whole.

[0046] The control device 50 includes, for example, a central processing unit (CPU) 51 which is a calculation means, a read only memory (ROM) 52 which stores various programs, and a random access memory (RAM) 53 which serves as a working area for the calculation means. The CPU 51 may read and execute the programs stored in the ROM 52 to realize each process described below.

[0047] However, the specific configuration of the control device 50 is not limited to this, and may be realized by hardware such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

[0048] A display input device 54 is connected to the control device 50. The display input device 54 is a user interface including a display (display device) that displays various information to be notified to an operator, and an input device (for example, a button, a switch, a dial, or a touch panel superimposed on the display) that accepts operations by the operator.

[0049] The display of the display input device 54 displays a mold clamping setting screen shown in Fig. 5(A). The mold clamping setting screen is a screen for receiving input of a reference position [mm], a set speed [mm / s], a set pressure [MPa], and a set time [sec]. Then, the control device 50 executes the pressurized dehydration process shown in Fig. 7 based on the reference position, set speed, set pressure, and set time inputted through the display input device 54. At least one of the reference position, set speed, set pressure, and set time is inputted, and the others may be fixed values.

[0050] The reference position is a position of the second upper die 13 below the position where the lower outer ring 16 and the upper outer ring 17 come into contact with each other and above the position where the lower die 11 and the second upper die 13 complete the clamping. The reference position is specified, for example, by the difference from the clamping completion position (the position where the lower die 11 and the second upper die 13 approach each other to the maximum, which is the 0 mm position in FIG. 10). The set speed is the maximum value of the descending speed of the second upper die 13 from the time when the second upper die 13 reaches the reference position until the time when the set time has elapsed. The set pressure is the pressing force of the second upper die 13 against the lower die 11 from the time when the second upper die 13 reaches the reference position until the time when the set time has elapsed. The set time is the time for executing the torque control of the second die opening and closing motor 63 based on the set speed and the set pressure.

[0051] Also, the display of the display input device 54 displays a cylinder pressure setting screen shown in FIG. 5(B). The cylinder pressure setting screen is a screen for receiving input of the rising pressure P1 [MPa], the rising maintaining pressure P2 [MPa], the supporting pressure P3 [MPa], and the falling pressure P4 [MPa]. The rising pressure P1, the rising maintaining pressure P2, the supporting pressure P3, and the falling pressure P4 are air pressures supplied to the lower outer ring cylinder 64 and the upper outer ring cylinder 65. Then, the control device 50 executes the pressurized dehydration process shown in FIG. 7 based on the rising pressure P1, the rising maintaining pressure P2, the supporting pressure P3, and the falling pressure P4 input through the display input device 54. At least one of the rising pressure P1, the rising maintaining pressure P2, the supporting pressure P3, and the falling pressure P4 is input, and the others may be fixed values.

[0052] The control device 50 is also connected to a table rotation motor 61, a first mold opening / closing motor 62, a second mold opening / closing motor 63, a lower outer ring cylinder 64, an upper outer ring cylinder 65, the drainage cylinders 42a, 42b, and the drainage pumps 43a, 43b. The control device 50 drives the table rotation motor 61, the first mold opening / closing motor 62, the second mold opening / closing motor 63, the lower outer ring cylinder 64, the upper outer ring cylinder 65, the drainage cylinders 42a, 42b, and the drainage pumps 43a, 43b by outputting a control signal.

[0053] [Operation of papermaking machine 1] Next, the operation of the papermaking machine 1 will be described with reference to Figures 6 to 11. The control device 50 of the papermaking machine 1 executes a fiber filling process shown in Figure 6 and a pressurized dehydration process shown in Figure 7 in parallel. As a result, one of the two lower molds 11 is filled with slurry, and the papermaking base material 3 is produced in the other. The control device 50 then executes this process repeatedly, thereby efficiently manufacturing the papermaking base material 3.

[0054] [Fiber filling processing] Fig. 6 is a flow chart of the fiber filling process. The fiber filling process is a process in which the lower die 11 is filled with the slurry 2 and the liquid is discharged (primary dehydration) from the slurry 2 by the drainage mechanism 40a. At the start of the fiber filling process, the lower die 11 and the first upper die 12 are opened, the insert 15 is inserted into the lower die 11, and the lower outer ring 16 is at the upper limit position, as shown in Fig. 1(A).

[0055] First, the control device 50 rotates the first mold opening / closing motor 62 in a first direction to close and clamp the first upper mold 12 relative to the lower mold 11 (S11). The fact that the lower mold 11 and the first upper mold 12 have been clamped can be detected by, for example, a sensor (not shown), a rotary encoder of the first mold opening / closing motor 62, or a combination of these.

[0056] Next, in response to completion of clamping of the lower mold 11 and the first upper mold 12 (S12: Yes), the control device 50 causes the supply device to supply the slurry 2 through the supply port 12a (S13). As a result, as shown in Fig. 1(B), a predetermined amount of the slurry 2 is filled into the lower mold 11 (more specifically, the space surrounded by the upper surface of the lower mold 11, the outer peripheral surface of the insert 15, and the inner peripheral surface of the lower outer ring 16).

[0057] Next, the control device 50 extends the drain cylinder 42a to move the connection part 41a to the first connection position (i.e., connects the connection part 41a to the drain passage 14a of the support block 14). In addition, the control device 50 drives the drain pump 43a to drain the liquid from the slurry 2 filled in the lower mold 11 through the drain passages 11a, 14a and the connection part 41a (S14).

[0058] Next, the control device 50 waits to execute the process of step S16 until the pressurized dehydration process executed in parallel is completed (S15: No). The control device 50 also stops the drainage pump 43a when a predetermined time has elapsed since the drainage pump 43a started to be driven. Furthermore, after stopping the drainage pump 43a and before executing the process of step S16, the control device 50 contracts the drainage cylinder 42a to move the connection part 41a to the first retracted position.

[0059] Next, in response to the completion of the pressurized dehydration process executed in parallel (S15: Yes), the control device 50 rotates the table rotation motor 61 to rotate the turntable 21 by 180° (S16). As a result, the lower mold 11 filled with the slurry 2 in the fiber filling process faces the second upper mold 13, and the lower mold 11 from which the papermaking substrate 3 has been removed in the pressurized dehydration process faces the first upper mold 12.

[0060] [Pressure dehydration treatment] Fig. 7 is a flow chart of the pressurized dehydration process. Fig. 8 is a schematic diagram showing a state before the second upper mold 13 is closed to the lower mold 11. Fig. 9 is a schematic diagram showing a process in which the second upper mold 13 is clamped to the lower mold 11. Fig. 10 is a diagram for explaining the positional relationship between the lower mold 11 and the second upper mold 13. Fig. 11 is a schematic diagram showing a state in which the pressurized dehydration is completed.

[0061] The pressurized dehydration process is a process for discharging liquid from the slurry 2 filled in the lower die 11 by clamping the second upper die 13 to the lower die 11. At the start of the pressurized dehydration process, as shown in Fig. 8(A), the lower die 11 and the second upper die 13 are opened, the lower die 11 is filled with the slurry 2, the lower outer ring 16 is at its upper limit, and the upper outer ring cylinder 65 is in a contracted state.

[0062] First, the control device 50 extends the upper outer ring cylinder 65 (S21). As a result, as shown in FIG. 8(B), the lower end of the upper outer ring cylinder 65 is disposed below the lower ends of the second upper die 13 and the upper outer ring 17. In addition, the lower end of the upper outer ring 17 is located below the second upper die 13.

[0063] Next, the control device 50 opens the upper outer ring cylinder 65 to the atmosphere, applies a support pressure P3 to the lower outer ring cylinder 64, and rotates the second mold opening / closing motor 63 in the first direction (S22). As a result, the second movable die plate 23 lowers the second upper die 13, the upper outer ring 17, and the upper outer ring cylinder 65 together, and the lower die 11 and the second upper die 13 are closed and clamped. As shown in Figs. 9(A) and 9(B), the upper outer ring cylinder 65, which has been opened to the atmosphere, contracts as it further descends after abutting against the upper surface of the lower outer ring 16. Furthermore, as shown in Fig. 9(B), before the lower die 11 and the second upper die 13 are clamped, the lower end of the upper outer ring 17 abuts against the upper end of the lower outer ring 16 to form a closed space surrounding the lower die 11 and the second upper die 13.

[0064] Then, the control device 50 continues to rotate the second mold opening / closing motor 63 in the first direction until the lower end of the second upper mold 13 reaches the reference position (S23: No). At this time, the control device 50 executes so-called "position control" in which the second mold opening / closing motor 63 is rotated based on the vertical position of the second upper mold 13. The vertical position of the second upper mold 13 can be detected by, for example, a sensor (not shown), a rotary encoder of the second mold opening / closing motor 63, or a combination of these.

[0065] Next, in response to the lower end of the second upper die 13 reaching the reference position (S23: Yes), the control device 50 rotates the second die opening / closing motor 63 in the first direction with a torque that maintains the pressing force of the second upper die 13 against the lower die 11 at a set pressure and makes the descending speed of the second upper die 13 equal to or lower than the set speed (S24). Then, the control device 50 continues the process of step S24 until a set time has elapsed since the lower end of the second upper die 13 reached the reference position (i.e., since the process of step S24 was started) (S25: No). The processes of steps S23 to S25 are an example of a dehydration process.

[0066] At this time, the control device 50 executes so-called "torque control" by increasing or decreasing the rotation torque of the second mold opening and closing motor 63 so that the pressing force and the lowering speed of the second upper mold 13 approach the set values. The pressing force of the second upper mold 13 can be detected by, for example, a pressure sensor (not shown). The lowering speed of the second upper mold 13 can be detected by, for example, a rotary encoder of the second mold opening and closing motor 63.

[0067] Here, the position of the lower end of the second upper die 13 after the set time has elapsed varies depending on the density of the fiber pieces contained in the slurry 2. More specifically, if the density of the fiber pieces contained in the slurry 2 is high, the position of the lower end of the second upper die 13 after the set time has elapsed is clamping position A above the clamping completion position (0 mm) as shown in the center of Fig. 10. On the other hand, if the density of the fiber pieces contained in the slurry 2 is low, the position of the lower end of the second upper die 13 after the set time has elapsed is clamping position B below clamping position A as shown in the right of Fig. 10. It should be noted that since it is possible to reduce the thickness when forming the papermaking base material 3 into a gear, it is sufficient that clamping position B is set above the clamping completion position (0 mm).

[0068] As a result, the slurry 2 filled in the lower mold 11 is pressurized and dehydrated with a pressing force according to the density of the fiber pieces, to become the papermaking base material 3. Then, the control device 50 extends the drainage cylinder 42b to move the connection part 41b to the second connection position (i.e., connects the connection part 41b to the drainage passage 14a of the support block 14). The control device 50 also drives the drainage pump 43b to discharge the dehydrated liquid from the slurry 2 through the drainage passages 11a, 14a and the connection part 41b.

[0069] Furthermore, in the course of the dewatering process (S23 to S25), the upper outer ring 17 presses the lower outer ring 16 downward with a set pressure higher than the support pressure P3 of the lower outer ring cylinder 64. This causes the lower outer ring cylinder 64 to contract, and the lower outer ring 16 descends into the recess 14b, as shown in Figures 9(B) and 11(A).

[0070] Next, as shown in Fig. 11(B), in response to the lapse of the set time (S25: Yes), the control device 50 extends the upper outer cylinder 65 with a lowering pressure P4, thereby lowering the lower outer cylinder 16 to the lowering limit against the lower outer cylinder 64 of the support pressure P3 (S26). The process of step S26 is an example of a lowering process. The processing process (S26) is performed between the dewatering process (S23 to S25) and the mold opening process (S27).

[0071] Furthermore, in response to the elapse of the set time (S25: Yes), the control device 50 rotates the second die opening / closing motor 63 in the second direction, thereby raising the second movable die plate 23 together with the second upper die 13, the upper outer ring 17, and the upper outer ring cylinder 65 (S27). This opens the lower die 11 and the second upper die 13. Furthermore, the control device 50 contracts the upper outer ring cylinder 65. The processing of step S27 is an example of a mold opening process.

[0072] Next, the control device 50 causes a robot arm (not shown) to remove the papermaking substrate 3 and the insert 15 from the lower mold 11 (S28). The control device 50 also causes the robot arm (not shown) to insert a new insert 15 into the lower mold 11 (S29). Furthermore, after steps S28 and S29, the lower outer ring cylinder 64 is extended with an increasing pressure P1, thereby raising the lower outer ring 16 to its upper limit (S30). The process of step S30 is an example of a raising process.

[0073] Then, in response to the lower outer ring 16 reaching its upper limit, the control device 50 sets the air pressure applied to the lower outer ring cylinder 64 to the upper maintenance pressure P2. This returns to the state of FIG. 8(A) (however, the lower die 11 is not filled with the slurry 2). Furthermore, before step S30 is completed (the turntable 21 is rotated in step S16 of FIG. 6), the control device 50 contracts the drainage cylinder 42b to move the connection part 41b to the second retracted position.

[0074] According to the above embodiment, for example, the following advantageous effects are achieved.

[0075] According to the above embodiment, in the process of clamping the second upper mold 13 to the lower mold 11 filled with the slurry 2 (S23 to S25), by performing the processing of step S24, the degree of pressurized dehydration can be appropriately adjusted according to the density of the fiber pieces contained in the slurry 2.

[0076] Furthermore, according to the above embodiment, in step S24, the speed at which second upper die 13 descends is controlled in addition to the pressing force (set pressure) of second upper die 13 against lower die 11, so that it is possible to prevent second upper die 13 from descending rapidly when the density of the fiber pieces in slurry 2 is low. However, when it is guaranteed that the density of the fiber pieces is equal to or higher than a predetermined value, control of the speed at which second upper die 13 descends may be omitted.

[0077] Furthermore, according to the above embodiment, during the dehydration process and the mold opening process, the upper outer ring cylinder 65 is extended to lower the lower outer ring 16 to its lower limit (S26). This exposes the papermaking substrate 3 on the lower mold 11, making it easy to remove the papermaking substrate 3 by the robot arm.

[0078] In addition, according to the above embodiment, after the papermaking base material 3 obtained by dehydration treatment is removed (S28 & S29), the lower outer ring 16 is raised to its upper limit, which makes it easier to remove the papermaking base material 3 and insert the insert 15, and also ensures space for filling the slurry 2 between the lower mold 11 and the lower outer ring 16.

[0079] Furthermore, according to the above embodiment, at least one of the reference position, set speed, set pressure, and set time is input through the display input device 54, so that the papermaking machine 1 can be operated appropriately in accordance with the specifications of the gear (papermaking substrate 3) to be manufactured. At least one of the rising pressure P1, the rising maintenance pressure P2, the supporting pressure P3, and the falling pressure P4 is input through the display input device 54 for the same reason. [Explanation of symbols]

[0080] Reference Signs List 1...papermaking machine, 2...slurry, 3...papermaking base material, 11...lower mold, 11a, 14a...drainage passage, 12...first upper mold, 12a...supply port, 13...second upper mold, 14...support block, 14b...recess, 15...insert, 16...lower outer ring, 17...upper outer ring, 18...lower outer ring holder, 20...frame, 21...rotary table, 22...first movable die plate, 23...second movable die Plate, 24...rotating shaft, 40a, 40b...drainage mechanism, 41a, 41b...connection portion, 42a, 42b...drainage cylinder, 43a, 43b...drainage pump, 50...control device, 51...CPU, 52...ROM, 54...display input device, 61...table rotation motor, 62...first mold opening / closing motor, 63...second mold opening / closing motor, 64...lower outer ring cylinder, 65...upper outer ring cylinder

Claims

1. In a dehydration device in which liquid raw material is filled into a mold and dehydrated under pressure, A support block; A lower mold fixed on the support block; a lower outer ring disposed so as to surround the lower die and supported by the support block so as to be movable up and down independently of the lower die; an upper mold that is raised and lowered above the lower mold to open, close, and clamp the lower mold; an upper outer ring that is disposed so as to surround the upper die and moves up and down integrally with the upper die; a lower outer ring cylinder that supports the lower outer ring from below with a predetermined support pressure; a mold opening / closing motor that rotates in a first direction to lower the upper mold and the upper outer ring and rotates in a second direction opposite to the first direction to raise the upper mold and the upper outer ring; a control device for controlling the lower outer ring cylinder and the mold opening / closing motor, The control device, in the process of clamping the upper mold to the lower mold filled with the liquid raw material, a dehydration process in which the mold opening / closing motor is rotated in the first direction with a torque that maintains the pressing force of the upper mold against the lower mold at a set pressure greater than the support pressure until a set time has elapsed since the upper mold reaches a reference position that is lower than a position where the lower outer ring and the upper outer ring come into contact with each other and higher than a position where the lower mold and the upper mold complete mold clamping; and executing a mold opening process in which the mold opening / closing motor is rotated in the second direction in response to the lapse of the set time.

2. The dewatering device described in claim 1, characterized in that, during the dewatering process, the control device rotates the mold opening / closing motor in the first direction with a torque such that the pressing force of the upper mold against the lower mold is maintained at the set pressure and the descending speed of the upper mold is equal to or lower than the set speed.

3. 3. The dehydration apparatus according to claim 2, further comprising an input device that accepts input of at least one of the reference position, the set time, the set pressure, and the set speed.

4. an upper outer ring cylinder that moves up and down together with the upper die and the upper outer ring and presses the lower outer ring from above; The dewatering device described in claim 1, wherein the control device performs a lowering process in which the upper outer ring cylinder is extended with a downward pressure during the dewatering process and the mold opening process, thereby lowering the lower outer ring to its lowering limit against the lower outer ring cylinder of the supporting pressure.

5. The dehydration device according to claim 4, wherein the control device performs an elevation process in which the lower outer ring is elevated to an elevation limit by extending the lower outer ring cylinder at an elevation pressure lower than the support pressure after the molded product obtained by dehydration in the dehydration process is removed.

6. The dewatering apparatus according to claim 5, further comprising an input device that accepts input of at least one of the support pressure, the lowering pressure, the increasing pressure, and an increasing maintaining pressure that maintains the lower outer ring at the increasing limit.

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